Stupid Room Tricks

Posted by: bridgman

Stupid Room Tricks - 07/19/14 10:04 PM

OK, so I ripped out some furniture in the living room and made room so I could move my 2-channel system out there and get some decent sound. Much better than the dining room with the low ceiling but still not great. Sound is decent, but imaging is iffy, bass is a bit boomy despite having the M40s almost 3 feet out from the wall, and whenever the music gets busy I get that "too many people talking" feeling where everything blurs together.

First step is noticing that speaker distance from side wall is the same as from back wall, and that the arms of the sofa between the speakers might be interfering with the midrange sounds from the speakers. That's what you get when you have an obsessive need for everything to be aligned & centered -- it's all scrunched in around the window.

Realize there's empty space off to the right if I move the rifle rack (I don't normally keep a rifle rack in my living room but I dumped it there after the last hunting trip and haven't gotten around to taking it down to the basement) so I move the right speaker over about 4 feet and left speaker over a foot or so. That leaves a bit more space between the speakers so the couch arms don't interfere, and lets me sit in the right hand seat of the listening sofa so *its* arms aren't interfering with the sound so much.



Bass is smoother, soundstage seems a bit better, but room is still too live. I already have a half dozen cushions from the couches & chair covering first reflection point on the left window and blocking some of the glass in the window on the rear wall, so I don't think it's just that. Start giving the ceiling the ol' hairy eyeball. The sloping-up part in front of me doesn't seem like the problem (angles don't work out) but the sloping-down part behind me seems like it could be acting like a VERY reflective back wall (it's that flattened stucco) in addition to the real back wall & window.

Next step is holding one of the cushions from the couch behind my head to block reflections from the back wall. Makes a bit of a difference but not much. Then I raise the cushion and angle it a bit so it blocks reflections from the lower half of the cathedral ceiling. All of a sudden things sound a lot better.

Not looking forward to prototyping something on the ceiling (peak is 20 feet up, and there's an inch or two of foil-backed foam insulation over the 2x12 rafters so even finding a rafter is going to be the opposite of fun. OK, so maybe I can build some kind of frame to hold a couple of cushions in the right place so I can do some proper listening without my arms bent back over my head.

Seems like too much work, but I go down to check the scrap lumber situation anyways. First thing I see is the roll-up mattress I take camping... hmmm.



It's "powerful ugly" but definitely improves the imaging. Now have a decent soundstage that doesn't fall apart if I move my head a few inches. Still gets too "busy" sometimes though, probably needs some more absorption. Owens Corning fiberglass doesn't seem real easy to find, but Roxul Safe n Sound seems like a decent substitute.

Pick up a pack of 24x48 batts, put a couple on the front wall behind the M40s and "eureka"... there was a dramatic difference even listening to the radio with only the batt on the right installed. Finally a decent listening area for the first time in ~20 years. Yay.



Yes I will make it all look nicer tomorrow. Anyone know a good source for cheap/suitable fabric around here ?

I figure 2 panels on the front wall, 2 panels replacing the mattress, 1 or 2 panels on the back wall, and 2 panels at the first reflection points of the HT upstairs and that will pretty much use up the pack of 8 batts. I can cut the last batt into 4 wedges and make a tiny bass trap for the front left corner of the room, but I'm thinking about just dumping a couple of cheap bales of fiberglass insulation there instead, at least until I figure out what the room needs. Seems like unopened bales of insulation should make good bass traps, anyone tried it ?
Posted by: Gr8_White_North

Re: Stupid Room Tricks - 07/19/14 10:16 PM

Our local Walmart stocks some decent looking material worth a look if you have one near by . Pick up some lumber and get the staple gun fired up . Nick can probly add to this as he made some for his theater. You definitely have a room that is working against you.
Posted by: bridgman

Re: Stupid Room Tricks - 07/19/14 10:24 PM

Originally Posted By: Socketman
You definitely have a room that is working against you.

Yeah, I had to plan the house in a real hurry and didn't think about acoustics. The builder asked about stepping down the foundation for a home theater and I laughed at him -- "who would want a theater at home ?".

Even worse, I had an idea in the back of my head about putting up a separate building with a dedicated listening room in the imaginary future (you know the one where we have more money ?) and letting the Rives Audio folks go nuts with the design, but in hindsight I probably should have made a nice rectangular house with more walls, more golden rectangles, and fewer windows.
Posted by: nickbuol

Re: Stupid Room Tricks - 07/19/14 10:59 PM

Hey, glad that you are getting things figured out acoustically.

My panels that I made were using custom printed fabric so that they were the standard "solid colored rectangle." A number of people over at AVS use this in a 24" x 36" panel that simulates a movie poster, but I opted for some custom artwork to span my panels.

The company is called Spoonflower.com and the two best products are Performance Knit (my personal favorite for acoustical purposes and great print quality) and Silky Faille for slightly crisper images, but a little sacrifice in acoustical performance (only noticeable with measuring equipment and software). The SF is a stiffer material that is a tad bit easier to get nice and square, but if you need to stretch it at all you are kind of out of luck because stretching it actually makes some noticeable distortions. The PK is more stretchy which makes it a little harder to get square, but easily fixed to make it right. That only matters if you have something, like those move poster images, that need to be square. With artwork it looks cool to have the whole image wrap around the sides like a painter's canvas.

If you want just a plain color for cheap locally (Spoonflower is really cheap for what you get, but obviously more than a plain color), you can use a basic solid muslin fabric (a bit too "industrial" for me), or really any fabric that you can literally blow through... Try putting the fabric up to your mouth and think, "If I was a hostage, and they put this over my mouth, would I be able to breathe, or would I pass out." smile If you can breathe through it, then you are pretty good for being passable for covering an absorption panel.

Just make a frame out of whatever wood material you want, take the fabric, lay it down, and warp the frame around to the back and staple it. Look for YouTube videos on canvas stretching for some good techniques.

Then put your insulation material inside.

Keep this in mind...

2" of material with a 2" air gap behind it performs almost as well as 4" of the same material but obviously the 2" is cheaper and the air is free. smile

I went with 2" of OC703 with a 1.5" air gap because I wanted to use readily available lumber and a 1x4 is .75" x 3.5". Works great.

Oh, and yes the Roxul Safe 'n Sound is a VERY common material to use for this application. You did good there!
Posted by: bridgman

Re: Stupid Room Tricks - 07/19/14 11:28 PM

Thanks Nick. I hadn't thought about making the frame deep enough to include the air gap -- that's a great idea and takes care of the inevitable "gee why are your pictures sticking out from the wall ?" questions. Thanks !

I was eyeing another Roxul product at HD called ComfortBoard, probably more like OC 705 I guess ? 1.5" thick and definitely denser / more rigid than the Safe 'n Sound.

The room is feeling just a tiny bit too dead, although I'll let it "break in" for a while before I decide laugh

Guess after all these years I'll finally have to find out what muslin is. And go in a fabric store. Yikes.

EDIT - OK, so Wikipedia says :

1. Not to be confused with Muslim (knew that)

2. A cotton fabric of plain weave (didn't know that)
Posted by: bridgman

Re: Stupid Room Tricks - 07/20/14 11:13 PM

OK, took the "ugly" down a bit but still need to work on the "straight"...



The fabric isn't all that transparent (you can breathe through it easily but you know it's there) but I figure the room was a bit too dead anyways. The nice fabric store people looked at me really strangely when I asked for a sample to blow through.

Next time I'll ask for a sample then ask where the washrooms are wink

The panels are currently about 3/4" off the wall, but I'll pick up a couple of post base brackets from HD tomorrow and move them out a few inches.
Posted by: bridgman

Re: Stupid Room Tricks - 07/21/14 08:06 PM

You need a big trap if you want to catch big bass :



I tried putting double thickness (2 x 3.5") Safe 'n Sound across the main corners but didn't hear much difference. Walked around looking for where the bass was without the traps (just checked the immediate area, not down the street or anything) and for some reason it seemed to be mostly in one corner behind the left speaker.

So I figured if all the bass was there I might as well put all the SnS there too (a 24" x 48" x 24" pile) and *that* made a difference. Significantly less bass "boom" on certain low notes and generally better low-end sound all round. Call it half way between "before" and "ideal" which seems surprisingly good for a single treatment, even a big-ass one.

The M40's are really starting to live up to their potential (graph below is from a 2001 SoundStage review). Very impressive, especially considering they use them same drivers as M3's but with a larger enclosure and different tuning.

Posted by: bridgman

Re: Stupid Room Tricks - 07/21/14 09:11 PM

Originally Posted By: bridgman
... especially considering they use them same drivers as M3's ...

For clarity, my use of "them" in this sentence was a typo, not an attempt to sound folksy.

Originally Posted By: bridgman
Walked around looking for where the bass was without the traps (just checked the immediate area, not down the street or anything)

I learned to do this when Dennis ("Tharkun" ?) was trying to figure out why a pair of EP600's didn't seem to be producing much bass in his listening area. It turned out that a lot of the missing bass was ending up in a small room at the other end of the house, being used as an office and server room.

My first thought was that moving the EP600's into the server room might improve bass in the listening area, but I don't believe that theory was ever tested.
Posted by: Gr8_White_North

Re: Stupid Room Tricks - 07/21/14 10:24 PM

Bass waves are super long and they do some crazy things. The waves come back on themselves and can cancel each other. I am just beginning to study all this on the internet and using software to analyze the room so I know ( hopefully ) what is happening to better address the situation. I am using an antimode in my bedroom and it works darn good. Since you are using towers without subs your only option is bass traps. Keep us posted as you progress.

Richard
Posted by: nickbuol

Re: Stupid Room Tricks - 07/22/14 12:59 PM

Bass traps in corners should be at least 4" thick and "straddle" the corner to give a good air gap, or be something that completely fills the corner from floor to ceiling.

I went for the latter, because mine are hidden, but a nice framed floor to ceiling piece like the wall ones would look cleaner, but still feel a bit "odd" in a non-dedicated space.
Posted by: bridgman

Re: Stupid Room Tricks - 07/22/14 01:28 PM

I guess I meet the "at least 4" thick" criteria for sure laugh

It's not in the picture, but there's also a 4" thick panel mounted vertically on the left edge of the wall, with a 4" air gap behind it so essentially all of the non-glass area in the corner is covered by trap. Adding the panel seemed to help a bit but it's hard to be sure without test equipment -- seemed to help anyways.

Initial tests had 8" thick SnS straddling the corners, but results were not as good as stacking everything in one corner. I think that was because most of the corners didn't actually have much bass signal due to the funky floorplan... so traps put there were semi-wasted.

Since all of my wall-wall corners are at least 50% glass I figure the straddling model doesn't work so well because bass is not reflected back from the glass. That doesn't explain the difference between the front left corner and the rest though.

Internet research (there's an oxymoron for you) suggests that the peak of the cathedral ceiling would be a good place to trap but I'm not going up there to check -- guess I need a microphone on a stick so I can go bass hunting without having to get my head 20 feet up.

Until I find more bass somewhere though, I guess the big pile stays.
Posted by: bridgman

Re: Stupid Room Tricks - 07/23/14 01:53 PM

Moved the M40s upstairs to the HT area and brought the M60s downstairs for music. Definite improvement -- apart from the obvious "slightly more forward" sound of the M60s their ability to play louder made a big difference.

The M40s could play jazz or chamber music as loudly as anyone would want but weren't really comfortable at the levels you need for rock & orchestra.

Upstairs, of course, different story. The M60s were already running as Small with low frequencies going to an EP500 and an SVS PC-Plus 20-39 plugged for 16 Hz and center channel handled by a VP180, so the M40s didn't have to work nearly as hard in the HT system as they did playing full range music.

The Boston Cherry finish doesn't fit in with the upstairs decor any better than it did with the downstairs decor, but at least it's usually dark up there.

I guess some kind of v4 High Power in Knotty Pine needs to be somewhere in my future.
Posted by: brwsaw

Re: Stupid Room Tricks - 07/23/14 03:01 PM

The HP's are so subtly different in all the right ways.
Posted by: bridgman

Re: Stupid Room Tricks - 08/11/14 09:57 PM

OK, so I finally found my bass - but I have no idea why it builds up where it does or what to do about it. I had already discovered the first part of the bass buildup and put a trap there (3 sheets of Roxul ComfortBoard vertically across the wall corner), but when I found a longer playing bass track and went further into the bedroom I found even more bass.

Rough floor plan below. The area to the left (above speakers & listening position) is open to a cathedral ceiling, while the center section is under a loft (beams & 2x6 T&G) and the right section is ground-floor only with conventional trusses above. The primary bass buildup is a few feet to the right of where the loft starts.



Only clue so far is that the cathedral ceiling is in sort of a cross shape above the area with bass buildup -- will try to figure out how to photograph or draw that.

EDIT -- here's a pic with details of the loft. Listening position in the following pic is for the HT area, not the stereo system in the living room on ground floor. Also the piano did not "go there" in the end, it didn't really fit up the stairs so it's still on the ground floor.



I guess the bass is building up under the peak where the wall and ceiling raise up. But why there rather than under the peak WHERE I PUT THE COUCH AND THE LISTENING POSITION ?

Stupid bass...

At least I may have found something worse than a square room cry
Posted by: bridgman

Re: Stupid Room Tricks - 08/12/14 01:20 AM

OK, the bass build-up is definitely right under the peak of the ceiling where it joins the wall. When time next permits I'll put a bass-heavy track on again and go up in the loft to see if there's a build-up of bass there as well, or up in the peak.

If so, then I guess that's where the next bass traps go. I can't add any more downstairs because there's no free space in the high-bass areas, but it would be really convenient if I could put them upstairs where the piano was supposed to go (but closer to the wall).

I'm seriously thinking about revisiting the room layout -- maybe start by putting an M60 in the current listening position then doing a sub crawl to see where the bass ends up and hopefully find a potential speaker position.

I'm already envisioning some kind of bizarre outcome where the ideal speaker position is 11 feet off the ground in the living room and the ideal listening position is 4 feet up a tree out in the yard frown
Posted by: Ken.C

Re: Stupid Room Tricks - 08/12/14 06:50 AM

Wish I had some answers for you, John, but I feel for you. I'm pretty sure I've got a bass null on my couch again.
Posted by: bridgman

Re: Stupid Room Tricks - 08/12/14 10:11 AM

I really wish we had moved Dennis's EP-600's into the computer room and confirmed that the bass then showed up in the living room. Otherwise this all seems like voodoo.

EDIT - deleted most of the post, need to stop futzing with the system and enjoy it for a while.

"Bass null on the couch" seems to be one of those things that happens every time you have a reasonable furniture layout. The solution seems to be dedicating everything to the needs of your audio system. Not unlike owning a cat, I guess.
Posted by: chesseroo

Re: Stupid Room Tricks - 08/12/14 11:46 AM

Originally Posted By: bridgman

EDIT - deleted most of the post, need to stop futzing with the system and enjoy it for a while.


Are you kidding?
This is the best post i've seen in a long while.
Keep going!
Would be interesting to see frequency response graphs before and after all your changes, if you were to go that far with software and a good mic.

I'm guessing with all the photos that you got onto high speed internet at some point.
Posted by: bridgman

Re: Stupid Room Tricks - 08/12/14 12:15 PM

OK, maybe I'll keep going then. Every addict needs an enabler.

Originally Posted By: chesseroo
Would be interesting to see frequency response graphs before and after all your changes, if you were to go that far with software and a good mic.

Yeah, I figure that needs to be the next step. A lot of what I'm hearing & and tweaking only shows up in reverb time measurements and waterfall charts.

IIRC my Radio Shack SPL meter had a suitable mic and an output jack for the computer, but it's been working its way around my friends' HT systems and nobody seems to know where it is at the moment. It's probably in a toolbox somewhere under a flywheel puller and a pile of hammers.

Originally Posted By: chesseroo
I'm guessing with all the photos that you got onto high speed internet at some point.

Good catch. A couple of years back I held my nose and signed up for cellular modem service from Bell, using an integrated modem/router so I could plug in my Linux systems. The data limits are worse than what I was moving over dial-up (past 10GB a month you basically give them your entire paycheck) and the service goes out randomly & frequently, but on average it's better than dial-up.

We had a big country music festival across the road recently (Boots & Hearts), and my internet service was down for ~4 days as 30,000 people were loaded onto our local cell tower, which normally handles ~10 square miles and ~50 people.
Posted by: chesseroo

Re: Stupid Room Tricks - 08/13/14 11:54 AM

Originally Posted By: bridgman
OK, maybe I'll keep going then. Every addict needs an enabler.

Well i'm always good for stirring the pot!
wink

Some day i'll graph my room as well. I have the sound meter, but no mic although i might be able to borrow a good one from a friend.
Then i just need a laptop...or, if anyone has tried, could this be run from a Nexus pad?
Posted by: bridgman

Re: Stupid Room Tricks - 08/13/14 12:54 PM

Any chance your sound meter has an output jack somewhere ?

At least one of the room analysis packages (REW I think) is written in Java, but I think it expects the Oracle runtime - don't know if that would be a problem on the Nexus.

If the Java RT recognizes the mic & audio input logic on the Nexus then that should be enough to make the software happy, although there might be a teeny calibration issue.

Laptop & external mic seems like the no-pain solution.
Posted by: chesseroo

Re: Stupid Room Tricks - 08/14/14 12:28 AM

Originally Posted By: bridgman
Any chance your sound meter has an output jack somewhere ?

Mine is that common Radio Shack meter, which i can no longer get in Canada in part because Radio Shack no longer exists.
I actually haven't used the meter in years now. Since setting up the HT, i haven't needed it for anything else.
Posted by: bridgman

Re: Stupid Room Tricks - 08/14/14 12:56 AM

I thought the RS meter had a line out jack, but I can't find mine so all I have to offer is vague memories and internet gossip... but both of those say "go look, it might have a jack".
Posted by: CV

Re: Stupid Room Tricks - 08/14/14 01:18 AM

Yeah, my RS meter has an RCA connection that says "Output."
Posted by: bridgman

Re: Stupid Room Tricks - 08/14/14 01:41 AM

So vague memories, internet gossip and CV *all* say you should go look for an output jack laugh
Posted by: exlabdriver

Re: Stupid Room Tricks - 08/14/14 02:29 AM

The old analogue RS Meter (33-2050) that I just won from ebay has a RCA Out connector on the side...

TAM
Posted by: bridgman

Re: Stupid Room Tricks - 08/14/14 07:17 PM

Hah. I have a new metric for telling if the room allows adequate imaging... if you can tell how far the piano is away from the microphone by triangulating the side-to-side movement of the piano sound as the pianist plays runs of notes up and down the keyboard.

My room currently only allows that with a couch cushion held over my head to block the first reflection point on the angled ceiling, but on the way home I picked up a cheap duvet and hardware to build a 1x2 frame.

The nice lady at the Walmart checkout looked at the duvet and asked if I was getting ready for winter. Apparently I managed to reinforce her emerging theory that males really were a different species.
Posted by: medic8r

Re: Stupid Room Tricks - 08/15/14 11:05 AM

New Metric?! Wow! When did that come out?! I missed it!

Wait, you're not talking about this, are you?



Dang.
Posted by: bridgman

Re: Stupid Room Tricks - 08/15/14 11:51 AM

Well, they are a "local band" (based in Toronto).
Posted by: bridgman

Re: Stupid Room Tricks - 08/17/14 07:09 PM

Originally Posted By: bridgman
When time next permits I'll put a bass-heavy track on again and go up in the loft to see if there's a build-up of bass there as well, or up in the peak. If so, then I guess that's where the next bass traps go.

Nope, all the bass seems to be on the ground floor where hall, bathroom, bedroom and bedroom closet all meet. Nothing significant up in the loft, not even in the peak. Bass seems to increase a bit as I get closer to the floor in the loft but that is consistent with having max bass one story down.

I realized today that the bass buildup is not just under the peak in the loft ceiling but also midway along the length of the open area in the house, which I sort of expected to be a null rather than a peak. Auggh.

Getting tempted to haul everything outside where there are no walls, no room reinforcement, no peaks and no nulls, at least until winter comes or mice build nests in the M60s. No way I have time to start from scratch with a new layout. For now I'll just stand in the bedroom when I want bass.

I'm almost ready to consider port plugs, but not quite that desperate yet laugh

EDIT - Chesseroo, did you find the RS meter and if so did it have a jack ?
Posted by: bridgman

Re: Stupid Room Tricks - 08/17/14 08:06 PM

Originally Posted By: bridgman
7:09pm - No way I have time to start from scratch with a new layout.

8:06pm - The new layout seems to be working OK whistle

I basically rotated everything 90 degrees, so the speakers were along the end wall instead of a side wall. Didn't make much difference in where the bass buildup happened, but I figured if the bass was "over there" then moving the listening position in that direction couldn't hurt either. The change also fits with the general advice that you should orient the speaker-to-listener axis along the ridge of a cathedral ceiling, not across it, which I had rejected earlier because each of the placements I could imagine resulted in a dysfunctional furniture layout.

Downside is that I now have a totally dysfunctional furniture layout, where you have to sort of slide between sofas to get to the listening area, but I figure I can fix that some other day. At least the sound seems to be a bit better. Makes for better sound in the loft too, which is where the office will hopefully end up.

As a bonus, I no longer have to hang a duvet up near the ceiling to block a first reflection point, so I'm going to take another shot at declaring this exercise finished other than improving turntable isolation. The turntable is now pretty close to the left speaker, and there were already audible "bumps" when I walked around near the turntable. No skipping, not even close (knock on wood) but not silent either.
Posted by: Murph

Re: Stupid Room Tricks - 08/18/14 08:29 AM

2 things....

1.
B-Man. I think it's intervention time. We are all here for you today because we love you and have been concerned about this obsession since a Duvet fell on our heads as you tried to hang the subwoofer over the 23rd newly decided sweetspot, like some sort of deathtrap from the movie Saw.

OK I'm not serious about #1 but I am about #2.

2. Metric? I still have a strong hatred for them since Emily Hanes made everyone wait for 90 minutes only to decide she was refusing to play in the ever so slight mist that was left over after the three opening acts all played through actual rain.
Posted by: bridgman

Re: Stupid Room Tricks - 08/18/14 01:46 PM

Thanks Murph, but don't worry I can quit any time.

I mean just this morning I was walking to the CD player and heard an edgy sound I didn't like. Turned out that since I was standing up the Roxul panel covering the first reflection point on the window was too low to be effective.

I didn't buy more ComfortBoard, or move the existing panel, or even steal an extra panel from one of the bass traps -- no I confirmed the sound was still good in the listening position, and went back to work.

It is kinda weird hearing all the frequencies in the same room though, it's actually a bit distracting.
Posted by: MarkSJohnson

Re: Stupid Room Tricks - 08/18/14 01:57 PM

Originally Posted By: bridgman
Thanks Murph, but don't worry I can quit any time.

I mean just this morning I was walking to the CD player and heard an edgy sound I didn't like. Turned out that since I was standing up the Roxul panel covering the first reflection point on the window was too low to be effective.

I didn't buy more ComfortBoard, or move the existing panel, or even steal an extra panel from one of the bass traps -- no I confirmed the sound was still good in the listening position, and went back to work.

It is kinda weird hearing all the frequencies in the same room though, it's actually a bit distracting.

Whew.
I was waiting for you to say that you broke out the window! smile
Posted by: exlabdriver

Re: Stupid Room Tricks - 08/18/14 06:25 PM

Thankfully I have aged hearing or perhaps I'm just not that observant...

TAM
Posted by: Gr8_White_North

Re: Stupid Room Tricks - 08/18/14 06:47 PM

Originally Posted By: exlabdriver
Thankfully I have aged hearing or perhaps I'm just not that observant...

TAM


I have become less critical with age.
Posted by: bridgman

Re: Stupid Room Tricks - 08/18/14 08:32 PM

I was wondering about the same thing yesterday -- whether the huge differences in sound quality I see from changing speaker placement or room treatment were typical, or (and you guys said it much more nicely) I was just wierd.

I went 5 years or more with a relatively crappy sounding system (the room, not the equipment), but I ended up not listening to music much either during that time. Not sure which was cause and which was effect -- the music just didn't sound very good, and started to bug my ears after a few minutes.

I may be more sensitive to first reflection signal than most, since even now I notice immediately if there's a bad reflection even if it takes me five minutes to figure out the bounces ie where the reflection is coming from.

The interesting thing is that some albums I had written off as "poor recordings, listen in the car only" now sound much better. As an example, the B.B. Gabor CD (local guy from the 80s) sounded like crap on both the HT system and the stereo system downstairs, but with all the treatments in place it now has that "raw" sound you associate with direct-to-disk recordings but nothing fatiguing at all.

The bass problems are at least partially my own fault -- I'm drawn to interesting architecture so tend to end up in challenging rooms. That said, the level of mid-bass clarity you can achieve through luck or treatment is incredible -- the M60s are finally starting to remind me of the $50K systems in $100K rooms I listened to during my misspent youth (forget drugs, my parents worried about me mugging old ladies to feed my audio habit).

Getting into specifics :

1. Mark - breaking the window out didn't occur to me but that's a great idea, will remember it for next time smile

2. It's possible I was starting further back (ie with poorer sound) than most people, since AFAICS most of you do think about first reflections when setting up your systems in the first place (eg putting speakers on the long wall so you can ignore most of them) and aren't above making little tweaks (wall hangings, carpet, strategically located pillow/chair) where needed.

3. After some more listening I realized that the bass build-up in the bedroom *was* substantially reduced after all -- there was still a lot of bass there but almost as much bass out in the living room, so it turns out that moving one speaker had a huge effect on how the room was energized.

4. Decided there was actually too much bass with the new layout so experimented with speaker distance from the wall. First pulled them out ~5 inches and that seemed to reduce the bass too much, so pushed them back in a couple of inches and now it seems just right.

There's still a freaky amount of bass relative to what I've been hearing for the last 5+ years but the response seems pretty even, at least as far as I can judge by listening to bass notes walking up and down the scale.

My impression has been that when people buy Axioms and end up listening to all their recordings again it's because of the much-improved midrange clarity, but now I'm in the weird situation of wanting to go through every recording again and listen to all the bass lines I haven't heard before.
Posted by: bridgman

Re: Stupid Room Tricks - 08/19/14 03:58 AM

Originally Posted By: bridgman
I didn't buy more ComfortBoard, or move the existing panel, or even steal an extra panel from one of the bass traps -- no I confirmed the sound was still good in the listening position, and went back to work.

It is kinda weird hearing all the frequencies in the same room though, it's actually a bit distracting.

When I got home from work tonight the first thing I did was move a panel from what seemed to be a no-longer-needed spot so I could sit on the couch or stand behind it and have first reflection points covered in both cases. Removing the panel from its previous location did seem to have a minor effect on the sound but since I can't even characterize it as better or worse I'm going to ignore it.

After pulling the M60s a couple of inches further from the wall (which slightly reduced bass levels and got rid of the distracting aspect) I think the bass is as close to "just right" as I'm going to get on this round of tweaking. It is a "freaky level of bass" relative to what I had been hearing before but it sounds pretty accurate and boom-free -- I just have the same ability to "see deeply into the music" in the low notes that I previously only had with higher frequency sounds.
Posted by: bridgman

Re: Stupid Room Tricks - 08/19/14 05:18 AM

The depressing thing is that all this tweaking has done is "get the room out of the way" so the speakers can work as designed. Probably would have been easier to haul everything out in a field and listen there.
Posted by: MarkSJohnson

Re: Stupid Room Tricks - 08/19/14 05:50 AM

Make sure you hang your sub from a pole!
Posted by: Murph

Re: Stupid Room Tricks - 08/19/14 07:26 AM

Great! Now I'm going to have the Blues Brothers in my head all day.

I'm a pole man, DAda da, da DADA da da
Posted by: bridgman

Re: Stupid Room Tricks - 08/23/14 12:21 PM

Hmm... OK, so I moved the M60s from HT area down to the living room and worked over the living room acoustics to make a decent listening area for music. M40s moved from the music system back up to the HT area. I just paralleled M2s on top to make M42s, which sound pretty good even for music. That just led to a serious D'oh!! moment though...

My original reason for setting up a separate music system (some years back) was that my AV receiver didn't have a phono input and I didn't know about standalone phono preamps at the time.

Now that I know about phono preamps, and since I'm planning to move the office up to the loft (HT area), I guess a better plan might have been to fix up the acoustics in the HT area, pick up a phono preamp and run everything through the AVR instead.

Of course the HT area has its own acoustic challenges -- it's basically an attic arrangement where the ceiling angles at 45 degrees all the way to the floor, so there's a huge honkin' mode because the distance from floor to ceiling to opposite ceiling to floor is constant no matter where you start, and it has all the usual "speakers on the short wall" challenges too.

Not looking forward to starting the acoustics exercise again but it would be nice to have a useable-for-something-other-than-audio living room again too.

Improving the HT acoustics would also improve sound for movies, and having a 200WPC amp driving the mains couldn't hurt for those "crank it to 11, the helicopter's about to hit the building" moments. I also plan to get off my butt one day and flash the AVR firmware to properly support 7.1 and then use the M2s as rear surrounds, so I guess it all fits. Pity.



(this was a quick pic to show the new VP180, it's tidier now)
Posted by: MarkSJohnson

Re: Stupid Room Tricks - 08/23/14 12:25 PM

John, if you're going through all these exercises in acoustics, doesn't it just make sense to get the M100s now, so you don't have to re-do everything? grin
Posted by: bridgman

Re: Stupid Room Tricks - 08/23/14 12:41 PM

La la la la !!!!

(but yes it does)

Louder this time, with just a hint of desperation...

La la la la !!!!
Posted by: brwsaw

Re: Stupid Room Tricks - 08/23/14 03:34 PM

The Vault is perfect for adding acoustic clouds, lots of room above and around them.

Do you have acoustic treatments in this room? Sorry if I missed it...
Posted by: bridgman

Re: Stupid Room Tricks - 08/23/14 05:29 PM

No treatments in the HT area, although if pressed I might claim the rug in the picture is there as an acoustic treatment. I have a rough idea where the first reflection points are but need to measure carefully to find studs and haven't done that, so nothing mounted yet. The ceiling is framed with 2x12 joists covered by a few inches of rigid foam to get R40, but the foam + distance seems to confuse the stud finder.

Lots of treatments down in the living room, to the point where my friends now call it "the ugly room".
Posted by: bridgman

Re: Stupid Room Tricks - 08/23/14 11:30 PM

Originally Posted By: brwsaw
The Vault is perfect for adding acoustic clouds, lots of room above and around them.

I do have a vault (technically a gun room, I guess) in the basement but it has a low-ish ceiling and I was struggling to figure out where the cloud would go.

After some sleep my brain finally remembered that "The Vault" is "the pointy thing at the top of the room" smile

That's a great point -- I thought about adding treatments there for the living room but since it's ~20 feet up from the living room floor I wasn't really enthusiastic about it. Up in the loft the vault is only 10 feet off the floor which makes it an ideal area for treatment.
Posted by: bridgman

Re: Stupid Room Tricks - 08/28/14 01:15 PM

OK, no more changes for a while. I've been missing the M60's from the HT system (the M42's just didn't sound the same, even with levels re-tweaked) and I was even eyeing a used pair of Revel F12's as a way to let me move the M60's back upstairs, free up the M2's for use as rear surrounds, and stop agonizing about spending $3-4K on new speakers for the music system.

Out of curiosity I moved the M40's back downstairs last night. With the bigger amp and improved room acoustics they now sound *really* good, and AFAICS they actually go a bit deeper than the M60's (although not as loud and a bit recessed in the midrange). Bass drum sounds deeper, I finally figured out what is so catchy about Kylie Minogue's "Can't get you out of my head" (there's a really deep bass pulse off-the-beat from the rest of the rhythm), and I can *finally* hear the really low notes in "On the run" from DSOTM crawling around under the floor.

My subs should have been able to reproduce those low notes from DSOTM but I guess the room & placement were never up to snuff. I think this is the first time I have ever heard "On the run" sound right on a system at home -- that's been a "megabuck demo room" experience only until now.
Posted by: Gr8_White_North

Re: Stupid Room Tricks - 08/28/14 03:52 PM

The girls are gonna think you bin working out what with all the speaker moving. smile
Posted by: bridgman

Re: Stupid Room Tricks - 08/30/14 04:13 PM

Originally Posted By: Socketman
The girls are gonna think you bin working out what with all the speaker moving. smile

That's the plan. Carrying the M40s and M60s up and down the stairs every couple of days has to help a bit. If I was more motivated I guess I would rig a pulley arrangement so that the weight of the speakers I'm bringing down from the HT area offsets the weight of the speakers I'm carrying back up.

Rather than tilting the speakers back ~5 degrees (1x2 under the front feet) I tried raising them ~10 inches instead. I was surprised how much the midrange seemed to improve (presumably from being a bit less off-axis ?) and the soundstage seemed to increase in size vertically (which I don't understand at all).

On the downside I think the really deep bass I was enjoying was impacted a bit for the worse -- I can still hear the really low notes in On The Run but I don't seem to be able to hear them moving as much as I did with the speakers on. Could be placement nuance or different levels (wishing I had taken a picture of the volume control setting) but I experimented with both and didn't get the same results as before.

On the other hand the midrange improvements mean I'm now hearing phasing effects on a few songs (Heart's Mistral Wind and a Tangerine Dream song whose name I don't remember) which I previously only noticed on the M60s. Better midrange at the cost of cool deep bass, that's a choice I would rather not have to make. Ignoring the very deep bass, however, the M40s are now sounding closer to the M60s in the midrange than they ever have before, enough to make me wonder if the M40s would have been loved more if they had been a few inches taller.

As usual no expense was spared and only the finest materials were used when constructing the speaker stands. I might replace them with something solid after a bit more testing:

Posted by: brwsaw

Re: Stupid Room Tricks - 08/31/14 12:25 AM

Bean bag chair?
You would be able to lower the speaker back down to the floor and, in theory, get the best of both worlds.
Posted by: bridgman

Re: Stupid Room Tricks - 08/31/14 01:46 AM

Originally Posted By: brwsaw
Bean bag chair?

Hah, that's a great idea. I clicked on a Sumo beanbag chair ad once and now the ads are coming up all the time... had a nagging thought that I needed to get one but couldn't figure out why. Now that you mention it we always used to prefer beanbag chairs for music listening but I never made the connection with listening height before.
Posted by: CV

Re: Stupid Room Tricks - 08/31/14 02:14 AM

I had a Sumo Omni several years back and liked it, though I never got enough use out of it. It was never in the main room. I eventually got rid of it after deciding I wouldn't have space for it in the future layout. If you can accommodate one, I say go for it.
Posted by: brwsaw

Re: Stupid Room Tricks - 08/31/14 03:22 AM

I wonder...
I can't raise my ceiling height for Atmos but I could replace some or all of the seating.
I wonder which fabrics and or fillers have the best acoustic properties (do no harm).
Posted by: bridgman

Re: Stupid Room Tricks - 08/31/14 04:05 PM

Nickbuol gave me some good advice about fabrics on the first page of this thread :

Quote:
... you can use a basic solid muslin fabric (a bit too "industrial" for me), or really any fabric that you can literally blow through... Try putting the fabric up to your mouth and think, "If I was a hostage, and they put this over my mouth, would I be able to breathe, or would I pass out." If you can breathe through it, then you are pretty good for being passable for covering an absorption panel.

After doing a bit more listening/testing it occurred to me that the deep bass notes sounded just a bit like someone thumping on the bottom of a big Rubbermaid tote ... so maybe I'll try some solid speaker stands before I replace all the furniture with beanbags.
Posted by: bridgman

Re: Stupid Room Tricks - 09/01/14 02:29 PM

Hmm. At first glance the more solid stands didn't improve things, although I may just have lost some artificial bass reinforcement from the tote bottom resonating. Coupling to the floor seems a bit better, ie the bass can be "felt" more readily, but there still seems to be a loss of very deep bass relative to having the speakers on the floor.

I guess next steps are (a) moving the speakers closer to the front wall to see if that helps to make up for moving the woofers/ports away from the floor, (b) raising them a smaller amount, trading off better midrange/imaging for better deep bass, (c) beanbags or sitting on the floor.

Option (d) - taller speakers -- looks a bit better every day laugh
Posted by: bridgman

Re: Stupid Room Tricks - 09/01/14 02:30 PM

Whoops, double post. As long as I'm here, I tried the second option from the above list (raising the speakers, but not so much) and that seemed to help quite a bit, ie the improvement in bass was noticeable and any loss in higher frequencies was not.

I don't know how much of the improvement came from making the stand effectively more solid vs getting the drivers & ports closer to the floor, but guessing the reduced height made relatively more difference. Anyways, the M40s are about 6" off the ground now and are sounding good enough to leave alone for a while.
Posted by: bridgman

Re: Stupid Room Tricks - 09/02/14 08:25 PM

OK, that was interesting and a little bit disturbing...

After getting comfortable with the M40's for music I hauled the M60s back upstairs to the HT area and now it sounds right again. That freed up the M2s and got me thinking about how they would sound down in the music system. Fortunately they're a lot easier to carry than M60s.

Put the M2's upside-down on top of the M40's and moved the speaker cables across to the M2s. Wow. I never did a direct A/B between M40's and M60's but I guess now I know what the results would have been. Vocals on the M2's are a lot clearer than on the M40's, to the point that it was a tough call between the excellent full-range response of the M40's and the crisp midrange of the M2's. If I had to listen to just one I probably would have leaned slightly towards the M2's over the M40's (!!!), at least for the (not very bass-dependent) tracks I was listening to.

So what to do ? Duh, wire 'em up in parallel and listen to some music. The result was a tough call. From a distance the combination works really well, pretty close to the M60's, but sitting in front of the speakers there was something mucked up with the imaging (basically it wasn't there). I checked for obvious out-of-phase stupids and didn't find any, but I never have 100% confidence in a one-time check.

The M60's are staying upstairs, so I either need to throw another pair of full-range speakers into the mix or at least go back to 2005 and pair up a subwoofer with the M2's. As Yoda says, meditate on this I will.
Posted by: exlabdriver

Re: Stupid Room Tricks - 09/02/14 09:36 PM

Just pair your M2s with an EP400 or two (like I have) & you can have sonic nirvana - crisp mid & upper end & oh so deep & powerful lower end...

TAM
Posted by: bridgman

Re: Stupid Room Tricks - 09/03/14 11:24 AM

Good point -- like bi-amped, LF-optimized Bryston Mini-T's. Nice !!

I took the stands out from under the M40's, aligned the baffles of the M2's and M40's more carefully and toed them out a bit further - one or more of those seem to have improved the imaging.



At first glance the M2's seem to have wider midrange dispersion than the M40's so they don't need to be toed in quite as much as the M40's did on their own. I could try angling the M2's out a bit further than the M40's but that's a bit too Bose Cube for my liking.

Or I could turn the M2's around and mock up an LFRxxx system. The possibilities are endless laugh
Posted by: CV

Re: Stupid Room Tricks - 09/04/14 01:02 AM

I just wanted to say that I appreciate you sharing your experimenting with us all. Great thread.
Posted by: bridgman

Re: Stupid Room Tricks - 09/04/14 01:15 AM

So after a brief "LFR" experiment (turning the M40's to face the wall -- doesn't work so well without a DSP) I moved the M2's back upstairs and put the M40's back on higher (~10.5") stands, toed in about 2/3 of the way towards the listener.

If I want really deep bass I can always bring one of the subs downstairs.
Posted by: chesseroo

Re: Stupid Room Tricks - 09/04/14 12:02 PM

I'm going to need some spreadsheets and ppt presentation from you to pull all this together, you do realize that no?
Posted by: bridgman

Re: Stupid Room Tricks - 09/04/14 12:16 PM

No worries -- I'll try to follow the usual corporate model of "if I don't know what I'm doing yet, dump everything I know into a long rambling powerpoint deck and hope people will think I'm making progress".

There's still some uneven bass response but so far I've only found one song that really shows it off -- Genesis' "Can-Utility and the Coastliners" from Foxtrot. Hopefully my RS sound level meter will surface from my brother-in-law's basement and give me a no-cost mic that I can use for some redneck room analysis.

Did you get a chance to look at your RS SPL meter and if so did it have an output jack ?
Posted by: chesseroo

Re: Stupid Room Tricks - 09/04/14 12:54 PM

Originally Posted By: bridgman

Did you get a chance to look at your RS SPL meter and if so did it have an output jack ?

I did check and yes it does have a RCA output jack.
Not exactly sure what i could feed that into.
Posted by: bridgman

Re: Stupid Room Tricks - 09/04/14 02:47 PM

AFAIK it's a line-level output, which would go into the blue line input minijack on a typical sound card (pink is microphone input). At that point all you need is something like Room EQ Wizard (the "REW" everyone talks about) and you're ready to start making undecipherable graphs.

I found an online manual link which seems to match what I remember about my meter:

http://www.ko4bb.com/Manuals/08%29_Misc_...r_with_Mods.pdf
Posted by: bridgman

Re: Stupid Room Tricks - 09/14/14 12:00 PM

Originally Posted By: bridgman
There's still some uneven bass response but so far I've only found one song that really shows it off -- Genesis' "Can-Utility and the Coastliners" from Foxtrot.

OK, I found more tracks that showed the uneven bass response frown

Experimented some more with speaker stand height and found that (a) I could lower the speakers a fair amount without noticeable change in frequency response as long as I toed the speakers in more to compensate, (b) with a 3.5" stand** (2 thicknesses of 2x6) the LF response was very even, to the point that some tracks which I had thought to have uneven bass on the recording (start of Pink Floyd's Meddle, for example) now showed even response.

This height seems to be right on the edge for FR and imaging (any lower is definitely a problem) but going any higher seems to start making the bass response uneven. The speakers are now toed in enough to almost point directly at me, so the visible side of the speaker appears to be less than a half-inch wide.

I did a bit of reading about floor bounce and AFAICS that seems to be essentially a first reflection thing but at low frequencies, ie the difference in path between direct and reflected LF results in some cancellations. The difference in path length seems to affect higher frequencies than the ones where I'm seeing changes, so guessing this has something to do with port and/or woofer height from the floor/wall/ceiling (although a few inches shouldn't make a big difference there either, so it's not clear what is happening).

** I guess if the stand is low enough I'm supposed to call it a plinth, wonder where the transition point is ?
Posted by: bridgman

Re: Stupid Room Tricks - 09/14/14 01:51 PM

Apart from the obvious conclusion that room and placement can make a huge difference in your listening enjoyment, I'm starting to believe that interaction with the room (ignoring how good the room is) explains another mystery that's always bothered me.

I have often seen a significant difference between reviewer comments about bass response and what the frequency response charts from an anechoic chamber show, even when reviewer and listening room are the same. It's not at all unusual for a speaker with smooth response down to ~40 Hz to be described as having weaker bass than a speaker which starts to roll off at ~70 Hz and is ~10dB down at 40 Hz (eg Soundstage reviews of PSB Image T45 vs Revel F12, where the T45 bass extension goes quite a bit deeper on the charts but the F12 is described as having deeper bass).

http://www.soundstage.com/revequip/psb_image_t45.htm
http://www.soundstage.com/revequip/revel_concerta_f12.htm

It's almost as if the reviewer only hears the bass from the drivers and not from the port(s), which doesn't seem to make sense unless ports and drivers are sufficiently far apart that they interact differently with the room... although there's the obvious argument that having drivers & ports separated is good because it can reduce the impact of room reinforcement by dividing the bass energy across multiple points each with a slightly different room response.

I don't remember worrying about all this stuff when I was building speakers... but back then we had just learned that restaurants were feeding "french fry smell" into the air and suspected that end audio stores might be using some kind of mild hallucinogenic in the HVAC system to make their systems sound so different from ours.
Posted by: bridgman

Re: Stupid Room Tricks - 09/17/14 10:26 PM

OK, that was interesting. Now that the room is finally beaten into shape I figured the next step would be to roll some different speakers through it. I figured that Magneplanar 1.6 or 1.7 would be the next step (I really liked the Quad ELS's I had during my mis-spent youth) but I ran across a pair of B-stock Ascend Sierra-1 speakers and ordered them. One of the reasons for trying Sierra's was that the most virulent Axiom haters (the ones who spit when they post) usually said nice things about Ascend speakers, so I figured I should own a pair of Ascends as well as my Axiom farm.

So... after disappearing from DHL's computers for a couple of days they finally showed up at my place. Executive summary is that I really like them, and they sound surprisingly different from my M40's, but the difference is a mix of "better" and "less better".

The M60s, and to a lesser extent the M40s, have an awesome clarity that's hard to explain without listening to them. You can pick apart different instruments, and there's almost a "clinical" aspect to the sound. Example is No Doubt's "Hella Good" -- with electric bass and bass synth both happening in the intro, normally it's hard to tell them apart but with the Axioms it's totally obvious that there are two different instruments at different positions in the soundstage. I haven't found the CD yet (I have a 200 CD changer and have to write down numbers for each CD) but you get the idea. The Sierra 1s don't have that level of detail, although the NRT (Neodymium Ring Tweeter or something like that) option apparently gives you that.

Anyways, I think the M40s play deep bass more clearly than the Sierra's, but the Sierras do something in the mid-bass that is more open than anything I've heard on M40s or M60s (both ti vintage). The newer Axioms have different crossovers and different frequency response, so I think I need to sync up with current sound rather than 10 year old sound.

Current thinking is that I want to combine Axiom M60ti sound from maybe 1 KHz up, Sierra sound from a couple of hundred Hz to 1 KHz, and something I haven't owned for years from 30 Hz up to a couple of hundred Hz. Looking at the different curves between regular and HP speakers there's a good chance that the HP woofers & associated cabinet/crossover changes do just that.

Seems like I need to carve out time for a trip to Dwight.

Anyways, between M40s, M60s and Sierra-1s I'm really enjoying my record collection smile

Major things to investigate so far :

1. Grand piano sounds more realistic on the Sierra's, which is a surprise -- I expected the Sierras to be different around the crossover freq but not so much at other frequencies

2. My primary test recording for ~30 years has been the first track off Triumvirat's "Old Lives Die Hard". Still not sure why -- it's a pretty bland recording -- but there's a mix of bass drum and bass guitar that seems to be a pretty good leading indicator for how I'll like the sound of the speaker.

Best playback so far was the old PSB "acoustic feedback" servo speaker using a Philips DeForest 8" woofer with a servo coil, followed by my old 3-way KEF DIY speakers. The Sierra's sounded better than the M40s but will try them against the M60s on the weekend.

The difficult thing about comparing these speakers is that the Sierras are M3 class in terms of ability to play loudly, but M40/M50 class in terms of bass response. Anyways, they're interesting.
Posted by: MarkSJohnson

Re: Stupid Room Tricks - 09/18/14 06:16 AM

John, there's nothing meaningful I can add to your thread but wanted to let you know that I enjoy reading about your journey.
Posted by: chesseroo

Re: Stupid Room Tricks - 09/19/14 08:20 PM

Originally Posted By: MarkSJohnson
John, there's nothing meaningful I can add to your thread but wanted to let you know that I enjoy reading about your journey.

I have to agree.
I can't say much about John's journey here, but reading this inner monologue like posting is quite fascinating.
It's like reading everything that goes through a tweaker's head that usually doesn't come out of the mouth.
Posted by: AAAA

Re: Stupid Room Tricks - 09/20/14 03:58 PM

Gotta agree with Mark and Chess. This is a great thread for someone else searching for logic in the endless variables when it comes to system response, speaker character and room treatment. Good read and thorough explanations.

Thumbs up!
Posted by: bridgman

Re: Stupid Room Tricks - 09/20/14 05:46 PM

Thanks, hope it helps someone, or at least serves as a warning to others. I've pretty much hit the limit of what I know how to do, unfortunately -- last thing was moving that stupid rockwool panel against the window from left to right trying to get some kind of balance to the imaging... otherwise it sounds a bit too dead on one side and live on the other. Or I could be imagining things... I figure I'm about ready to start investing in crystals and $300 power cords wink

The right solution would probably be putting fiberglass on the fireplace behind me instead of the window in front of me, but that would look too ugly even for me. Think it's time to focus on making the place look better -- I guess getting some Varathane on the speaker stands would be a good start.

Posted by: bridgman

Re: Stupid Room Tricks - 09/20/14 11:47 PM

... and yes, since that photo was taken I *did* move the electronics a few inches to the left so they would line up with the coffee table and the rockwool panel against the window.

http://www.roadkilltshirts.com/I-HAVE-CD...INK-P13513.aspx
Posted by: brwsaw

Re: Stupid Room Tricks - 09/21/14 01:25 AM

Maybe a mirror behind the LH speaker?
Posted by: AAAA

Re: Stupid Room Tricks - 09/21/14 08:40 PM

Question for you. When you added the roxul centered behind the speakers, it centered the phantom image better for you I understand, an overall improvement in image specificity. Did it have any effect on the depth of the soundstage? Ie did it make the soundstage extend back less in your opinion?
Posted by: bridgman

Re: Stupid Room Tricks - 09/21/14 11:32 PM

Hmm, good question. I'll experiment a bit and post back.

It didn't center the phantom image as much as center the "cloud of spaciousness" if you'll forgive the lame expression.

Bit of background. The listening area is now on one side of the living room, under one side of a 45 degree cathedral ceiling (so sound going straight up would bounce off to the left). I have walls & windows to the right and a big open space to the left, so I decided to leave the wall-mounted absorbers / bass traps (originally added for a different room orientation) in place, in the hope of balancing "absorbent on the right" with "open on the left".

I had to add a panel leaning against the RH window to treat the FRP, and the combination made the room seem fairly well balanced left-to-right.

The panel against the window on the front wall was originally placed at the left side of the window to treat what seemed like a bit of slap echo off the fireplace (actually a big-ass masonry heater) about 5 feet to my back-left when seated. The panel seemed to help with the echo (could be placebo effect 'cause I don't have time for any credible testing at the moment) but over the next few days I noticed that the room seemed a bit "unbalanced" again.
All Canadian orders ship from our local Markham Ontario warehouse for the fastest possible shipping time throughout Canada. Most orders are shipped through FedEx with our freight partners delivering our largest Ported Box subwoofers.
I tried moving the panel over to the right of the window and that was too much, so after a brief binary search I ended up with the current position. It's probably obvious that I don't know the proper terminology for whatever I was adjusting, but I'm talking about whatever your brain uses to recognize by sound that there's a wall off to your right, for example. I guess it's basically the sum of reflected sounds from all around -- too much with the wrong delays and it mucks up imaging, too little and the room sounds dead, just right and everything sounds spacious & natural.

Whatever the name is, I unbalanced it a bit by adding that panel (in the hope of addressing slap echo that seemed to be hurting imaging a bit) and moving the panel to the right a bit at least centered the impact without losing too much of the benefit. The next obvious test would be with/without the panel in its current position to see if it is still helping, but I used up all my playtime for the weekend already.

EDIT - the fact that I could unbalance the sound by adding a panel on the front wall suggests that there's more energy reflecting off the front wall than I had expected. I don't really have a back wall in the usual sense -- the living room, dining room and kitchen are all part of one big area -- so I didn't expect much energy from the drivers to reach the front wall since there was not much for it to bounce off (other than the kitchen cupboards and the back wall of the loft, both 40 or 50 feet away).

Wonder if anyone makes quadratic residue diffuser window blinds ?
Posted by: bridgman

Re: Stupid Room Tricks - 09/21/14 11:36 PM

Originally Posted By: brwsaw
Maybe a mirror behind the LH speaker?

Interesting idea. I think I have a big mirror somewhere in the basement, will give it a try. I had been thinking that there probably wasn't much difference in reflectivity between drywall and glass at higher frequencies, but that was nothing more than an unverified "simplifying assumption".
Posted by: bridgman

Re: Stupid Room Tricks - 09/22/14 12:28 AM

This pic shows the room layout a bit better. This is taken from the extreme left of the masonry heater, using the chimney to stabilize the camera.



You can see all the sound-absorbing stuff on the right wall -- 4" Safe'nSound in the wall-mounted panels, 2" rigid ComfortBoard leaning against the window. I believe the panel on the front wall was just fine tuning the balance, not establishing it, but that said I don't remember if I actually tested with the panel centered between the speakers.
Posted by: bridgman

Re: Stupid Room Tricks - 09/22/14 11:59 AM

Bah. There's an old saying along the lines of "experience is what protects us from doing stupid things... and doing stupid things is how we gain experience".

I put a coat of varathane on the stands last night but it didn't warm up the colour the way I was expecting. Apparently (based on research done *after* applying the finish) oil-based poly finishes dry with an amber hue but water-based finishes dry clear... and all the other pine in the room has an oil-based finish.

Did I mention "Bah !!" ?
Posted by: bridgman

Re: Stupid Room Tricks - 09/22/14 05:12 PM

The worst part is that I had a can of (oil-based) "Professional" Varathane in my hand at the store, but that got me thinking about consumer marketing people who put the word "Professional" on cheap junk (since any problems customers encounter with the cheap stuff can be blamed on them not having the specialized knowledge to use it correctly) so I put the "Professional" can back on the shelf and bought the regular (water-based) stuff instead.

<insert sound of head banging on amber-hued pine>
Posted by: bridgman

Re: Stupid Room Tricks - 09/22/14 07:07 PM

Originally Posted By: Serenity_Now
When you added the roxul centered behind the speakers, it centered the phantom image better for you I understand, an overall improvement in image specificity. Did it have any effect on the depth of the soundstage? Ie did it make the soundstage extend back less in your opinion?

OK, that was interesting. The panel only had an easy-to-notice effect on instruments with prominent highs, so I tested with the first track from "Metheny Mehldau", guitar and piano. Guessing the percussive nature of the instruments helped as well.

Removing the panel made everything seem more intense & detailed, but also seemed to shift the soundstage a couple of feet further away from me, as if the instruments were level with the window pane rather than with the speakers. I didn't like the effect, so I put the panel back and after some side-to-side experimentation ended up with it in the same spot as before. Oddly enough when I centered the panel between the speakers it seemed to make the room too "dead". I was walking around shaking my head at how much of a difference one panel could make.

On a positive note, I'm finally happy enough with the room (if not with the colour of the speaker stands) that I'm going to stop tinkering for a while and listen to music instead shocked
Posted by: chesseroo

Re: Stupid Room Tricks - 09/22/14 08:12 PM

The only part i didn't understand was this:

Originally Posted By: bridgman

All Canadian orders ship from our local Markham Ontario warehouse for the fastest possible shipping time throughout Canada. Most orders are shipped through FedEx with our freight partners delivering our largest Ported Box subwoofers.
Posted by: chesseroo

Re: Stupid Room Tricks - 09/22/14 08:15 PM

Originally Posted By: bridgman

I put a coat of varathane on the stands last night but it didn't warm up the colour the way I was expecting. Apparently (based on research done *after* applying the finish) oil-based poly finishes dry with an amber hue but water-based finishes dry clear... and all the other pine in the room has an oil-based finish.

Did I mention "Bah !!" ?

I've used both but unfortunately my experience only extends to "outdoor" poly (both oil and water based). Both left that amber hue (which i didn't want) on cedar. I understand that this comes from the UV protectant however the marketing on the side of the water based poly specifically stated it wouldn't change the wood colour.
Ummm, ya.
Sell me another ice cube i guess.
Posted by: bridgman

Re: Stupid Room Tricks - 09/22/14 09:24 PM

Originally Posted By: chesseroo
I've used both but unfortunately my experience only extends to "outdoor" poly (both oil and water based). Both left that amber hue (which i didn't want) on cedar. I understand that this comes from the UV protectant however the marketing on the side of the water based poly specifically stated it wouldn't change the wood colour.

Guess I should have bought whatever you bought. Turns out mine was outdoor anyways -- Varathane Diamond Coat Outdoor Satin.

Originally Posted By: chesseroo
The only part i didn't understand was this:

Originally Posted By: bridgman

All Canadian orders ship from our local Markham Ontario warehouse for the fastest possible shipping time throughout Canada. Most orders are shipped through FedEx with our freight partners delivering our largest Ported Box subwoofers.

Huh, wonder what was supposed to be there ? I noticed a forum thread on CanuckAudioMart talking about SVS shipping directly to Canada, and nobody seemed to get that they had probably just partnered with ElectronicsForLess / SonicBoomAudio (their previous dealer) and were handling ordering/billing through the SVS site now and having SBA handle fulfillment. I think the text was quoted from the SVS site -- no idea why I selected it though...

One of life's little mysteries.
Posted by: bridgman

Re: Stupid Room Tricks - 09/23/14 02:53 PM



OK, think I figured it out last night. There's a bit too much absorption on the right wall, and I was compensating for it by having the front wall absorption offset to the left. Problem is that the results varied depending on the amount of high frequency content, since AFAICS only the high frequencies reflect off the window behind the speakers.

Guess the next step would be to try removing the panel to the immediate right of the listening position (partially cut off in the pic above) then moving the panel on the front wall a bit to the right.
Posted by: bridgman

Re: Stupid Room Tricks - 09/23/14 06:26 PM

Removing the panel on the right was too much. I tried a few combinations, including having two rigid panels in various positions against the "front wall" window, and ended up with something simple -- moving both panels (arrow and X) about 6" to the right. That seemed to balance the reflected sound a bit more consistently. All of the other options seemed significantly worse.

Putting two panels on the front wall rather than one made a big difference -- basically all the instruments in the middle of the soundscape stayed there but seemed really quiet. The instruments were still loud, but the impression of the instrument in a specific spot was much reduced. Not good. Maybe that's why the general recommendation is absorption on the back wall and diffusion on the front.

The interesting thing was that having an alternating mix of reflection and absorption really made a difference -- too much absorption in one place made for a really dead sound. In one sense this is a seriously black art, but the general guidelines from acoustic treatment vendor sites and forums seem to work really well.

AFAICS the complexity comes from the fact that the system is off to one side rather than being centered in the room. In my previous system setups (all centered in the room) getting the acoustics right has been much less work... but that was in another century.
Posted by: CV

Re: Stupid Room Tricks - 09/24/14 01:10 AM

Out of curiosity, what are your test tracks that you've been using for all of this trial and error?
Posted by: brwsaw

Re: Stupid Room Tricks - 09/24/14 02:09 AM


Have you considered removing the coffee table, at least temporarily?
Posted by: bridgman

Re: Stupid Room Tricks - 09/24/14 04:57 AM

Originally Posted By: CV
Out of curiosity, what are your test tracks that you've been using for all of this trial and error?

Pretty much every CD in the carousel (maybe 150 disks) -- room testing seems to need a wider range of tracks than speaker testing, at least if you're learning as you go like I am. I'm not using LPs much because the CDP's remote control and ability to replay sections over and over is really useful.

When I was trying to get the bass smoothed out I was using the first part of "Echoes" from Meddle and "On The Run" from DSOTM along with "Can-Utility and the Coastliners" from Foxtrot, but when I was playing with reflected higher notes I started with Metheny/Mehldau then settled on isolated vocal tracks, eg the opening bars of "Dancing with the Moonlit Night" from SEBTP. There's a bit of an edge on Peter Gabriel's vocals at the start of the song and that seems to hit all the right frequencies for adjusting reflections from the front wall window.

The pattern is basically "get it right, listen to a bunch of tracks, realize it's not right yet, tweak using the track that identified the problem, repeat ad nauseum" interspersed with periods of "forget about all that stuff and just enjoy the music".

One odd/neat thing is that I'm starting to get an overwhelming "yeah, that's what it's supposed to sound like" feeling as the room & speaker placement gets into "good enough" territory. It's been ~25 years since I've been able to sit back and just be aware of the music, not the system that provides it.

Originally Posted By: brwsaw
Have you considered removing the coffee table, at least temporarily?

Thanks for the reminder. I had tried removing the coffee table a couple of months back and it didn't make a lot of difference at the time (although it was covered with so much junk I guess it was pretty stealthy) but when I moved it over to the right hand wall tonight there was a small but noticeable difference.

I ended up moving the coffee table out of the listening area completely. I'm not sure it improved the imaging but it somehow made the sense of "ambience" seem less disturbed. On the downside, in a sense all that did is expose the next problem -- the overstuffed arms on the couch in the listening position.

Guess replacing the seating is next on the hit list, although the room is getting good enough that the position of my own arms is starting to make a noticeable difference smile
Posted by: J. B.

Re: Stupid Room Tricks - 09/24/14 08:08 AM

Bridgman, you said: "that's why the general recommendation is absorption on the back wall and diffusion on the front."

i was surprised at reading this; i always did the diffusion on the back wall and the absorption on the front one.
in fact, i use both absorption AND diffusion on the front wall, but only diffusion on the back wall.

sitting at the MLP, balance between direct and reflected sound is very good, but if i move my head forward, then the sound balance is more towards direct sound and less reflected sound.
when i move back some 1-2 ft. then it's as if i was sitting in the middle of the concert hall, instead of the front, with good amounts of reflected sound.
the effect is very similar to what happens when you move from a front seat to one in the middle of the concert hall.

hope this helps. :-)
Posted by: CatBrat

Re: Stupid Room Tricks - 09/24/14 09:51 AM

You really need some curtains there. That would solve a lot of problems, I'd think. I use blackout curtains with a sheer on the room side so it won't be so plain, but it's for a small theater setup, so may not work for you, but they do seem to be sound absorbent.
Posted by: J. B.

Re: Stupid Room Tricks - 09/24/14 12:10 PM

I'm too lazy to read the whole thread, but what about doing it like this:
first, do the front wall for well balanced sound, using mirrors to indicate where and how much absorbers/diffusers you will have to install. In my room, i treated the whole front wall.
second, you should need to have much stronger absorption/diffusion on the right side, where your windows are, to compensate for the relative lack of reflections on the left side. for this you use mirrors again, and you install a wider surface of treatment than needed.
third, use bookshelves or whatever to diffuse reflections from the back and backside.

in all of this, the main listening position should be well considered; too far back and the acoustics will be too reverberant,
and too far forward will diminish the reverberant sound field and give you too much direct sound.
one must choose the best compromise in placement.

i tend to like better hearing the original acoustic ambiance than too much room reflections which tend to subdue the natural ambiance and sound more artificial.
if a room does not have enough absorbers/diffusers, high level sounds will be overbearing and distorted and it will be impossible to listen to music (and movies) at reference level.
i have realized in the long run that any music or movie that is not listened to at reference level will seem distorted compared to the right (live) level where the sound will be wholly natural and much more detailed than at any other volume, even by .5 dB more or less.

when one is near the optimum sound level, small changes are heard as changes in tonality of the instruments, while large changes sound like adjustments in volume.
Posted by: bridgman

Re: Stupid Room Tricks - 09/24/14 08:07 PM

Originally Posted By: J. B.
Bridgman, you said: "that's why the general recommendation is absorption on the back wall and diffusion on the front."

i was surprised at reading this; i always did the diffusion on the back wall and the absorption on the front one.
in fact, i use both absorption AND diffusion on the front wall, but only diffusion on the back wall.

Whoops, you're right. I have definitely seen recommendations for dead back wall and live front wall, but I did have at least one of the "standard practices" (Live End / Dead End) backwards. Apparently the idea with LE/DE is to have the speakers in the dead end so the first room effects you hear are recorded reflections from the studio, and only later do you hear reflections from the listening room.

Good catch, thanks.

Right now I don't have much of a back wall (the living room, dining room, kitchen and loft are all basically one big area if you ignore the floor between the loft and the kitchen/dining area) and my front wall is a big window, so I'm kinda hoping I won't need a lot of treatments on either, other than curtains over the window on the front wall.
Posted by: AAAA

Re: Stupid Room Tricks - 09/25/14 02:50 PM

Thanks for the feedback on the soundstage depth question. It seems you are taking more of a studio/HT approach to your treatment situation. Be careful with thinking purely LE/DE. Seems like you are being pretty experimental and staging your process. No doubt you will get exactly what you want in the end.

Generally, a deep front to back soundstage is desired for 2ch setups. The speakers tend to "dissapear" more I find. I have also found that absorbtion directly behind the listening position pushed vocals back to the speaker plane from forward as well. This might help you if you prefer all elements on the speaker plane only. smile

I have found slatted blinds do a good job of breaking up glass reflections if curtains arent your thing. You can play with the tilt. A somewhat "variable" high frequency diffuser. Definitely better than glass in any case. smile
Posted by: bridgman

Re: Stupid Room Tricks - 09/25/14 05:02 PM

Originally Posted By: Serenity_Now
Thanks for the feedback on the soundstage depth question. It seems you are taking more of a studio/HT approach to your treatment situation. Be careful with thinking purely LE/DE. Seems like you are being pretty experimental and staging your process. No doubt you will get exactly what you want in the end.

I didn't actually plan to do anything with treatments other than covering the first reflection points, getting some absorption on the right to help compensate for the off-center positioning, and getting some bass trapping in place.

Originally Posted By: Serenity_Now
Generally, a deep front to back soundstage is desired for 2ch setups. The speakers tend to "dissapear" more I find. I have also found that absorbtion directly behind the listening position pushed vocals back to the speaker plane from forward as well.

Agree on wanting the deep soundstage. Makes sense that would help the speakers to disappear, hadn't thought about "why it happens" before.

Interesting point about absorption behind the listener compressing the soundstage. I have often put a small amount of absorption on the back wall since without it I had no imaging at all, but sounds like it's easy to go too far with it as well.

At the moment I don't have any front or back wall treatments other than that one panel in the front window that I added because of a harsh/bright sound off to the left. I don't really have a back wall, just lots of open space.

Originally Posted By: Serenity_Now
I have found slatted blinds do a good job of breaking up glass reflections if curtains arent your thing. You can play with the tilt. A somewhat "variable" high frequency diffuser. Definitely better than glass in any case. smile

Slatted blinds sound like a good thing to try next. I definitely don't like curtains and am getting the impression that too much absorption on the front wall is not good anyways. What I really need is the old broken set of slatted blinds I threw away a lot of years back, where the cords had rotted out and each blind was at a different angle smile
Posted by: brwsaw

Re: Stupid Room Tricks - 09/25/14 05:51 PM

Have you turned the set up with its back to the open space?
I gave advice to spin a room 180 degrees once, and after a few days followed my own advice to see what it would do in my own room. It made a nice difference, note worthy for sure.
I'd add when tweaking my current 7.1 set up I'll often turn my back to the mains, lean against the back of the love seat and am always surprised at how similar the sound reflecting of the back wall can be to the direct sound (7.1 again). I thought I'd mention this just in case you might have a reservation to trying because you listen in/from the larger space behind as well. You might solve all the issues in one fail swoop...or not.
Just a thought.
Posted by: bridgman

Re: Stupid Room Tricks - 09/25/14 06:46 PM

The original setup had the speakers against what is now the right wall. That didn't work for a couple of reasons -- evil first reflection off the back part of the cathedral ceiling, and really weird bass response (see page 1 for details).

The current setup has the back to the open space - dining room then kitchen directly behind (separated from living room by masonry heater), with loft above and behind.
Posted by: brwsaw

Re: Stupid Room Tricks - 09/26/14 02:52 PM

If the last picture is the most current it would be the opposite of my last post. The front wall (currently behind the speakers) would become the back wall, behind your seat.
I can't say it would be worth the effort but I can confirm the idea has worked.
Its all good, just trying to offer an alternative pount of view.
Posted by: bridgman

Re: Stupid Room Tricks - 09/26/14 06:39 PM

Ahh, when you said "with its back to the open space" I was thinking "my back" not "the back of the speakers". Nope, haven't tried that but will think about it, thanks !!

First problem would be finding a way to get into the listening area, but I might be able to put the electronics against what is now the right wall so that the space between the speakers can be used as a walk-way (and a trip-over-the-speaker-wires-way).
Posted by: bridgman

Re: Stupid Room Tricks - 12/20/14 04:37 AM

Whoa, that was a surprise. After reading the "how long did you spend setting up your speakers" thread (or whatever it was called) I figured I would try my M2s for a change. Powered off the amp, put M2s inverted on top of the Sierra-1's, hooked 'em up and started playing music.

Now that the room is set up decently, the M2s actually sound close enough to full range that I can enjoy them on most music. That never happened before -- M3s sounded great but M2s sounded too thin without a subwoofer. Now that the room & placement are good, the M2s sound really good without a subwoofer too.

Dang. I need to get some M3's. Or M100's in Cherry Real Wood.
Posted by: brwsaw

Re: Stupid Room Tricks - 12/20/14 05:53 AM

What changes did you make since your last post?
Posted by: bridgman

Re: Stupid Room Tricks - 12/20/14 12:41 PM

I vacuumed smile
Posted by: brwsaw

Re: Stupid Room Tricks - 12/20/14 01:21 PM

Lol
Posted by: fredk

Re: Stupid Room Tricks - 12/20/14 04:34 PM

Originally Posted By: bridgman
I vacuumed smile

Annual cleaning? I just did mine yesterday. 2014 was a good year for dust bunnies.
Posted by: AAAA

Re: Stupid Room Tricks - 12/20/14 08:14 PM

Dust bunnies in corners are natures bass traps.... For mice HT. grin