Axiom Home Page Forums General Discussion Home Theater Dealing with boomy bass. . .

With the long weekend, I decided to not be so lazy and finally deal with some room issues that had been bugging me--namely the ugly monster of boomy bass. My first order of business was to finish putting up some acoustic treatments. I already had the corner traps in place and added some wall seams and an extra ceiling pad along the front and back wall--the latter for more coverage. An added benefit of the rear wall seams is to help hide the QS8 wires. Here's some pics:


Rear wall. Before there was only one pad, now there is two for more coverage.


Front wall. Lotsa bare space. Picture hanging is still in progress.


Rear left. Acoustic treatment/cable management. It ain't pretty, but it works.


Rear right. More of the same.

Another issue was bare wall space. As you can see, the front wall is still in progress. I haven't decided what I want to hang yet. Also, I still need to get another picture, so it can wait a bit.


I found an unexpected assistant to help me hang! Need to be careful where I put my fingers

After a whole day of listening, things still weren't quite right. Bass was still bloated and not as defined as I knew it could get. Also, separation in the soundstage wasn't there. Everything was a bit jumbled. Well, my first thought was that if I wanted more separation I should just push the speakers farther apart. You know, it actually worked. Despite some obvious concerns--my left speaker just an inch away from the bookshelf, and the right one directly in line of the doorknob--I think this is where they will stay. Took care of the doorknob fear with one of those little hinge stopper things. Also, another concern is now my speakers are behind the TV stand. So far, imaging seems to be holding up. I can try moving the whole unit back, but I like having the space available for cable access.


Movement evidence.


More up-close movement evidence. This is the right speaker.


Bird's eye view. Better idea of speakers in relation to TV stand.


Ugh. Next project will be cable management. Having this crawl space is awesome, though. I'm constantly adding, subtracting, changing, moving, etc. and I can easily get to everything without having to do some interesting circus contortions.

I am continually amazed by the effects of speaker placement and room acoustics. Sometimes small moves can have big dividends. What threw me for a loop is that I tried moving my speakers farther out into the room and away from the walls, but the boominess just got worse. Pushing them farther back into the corner and closer to the wall seemed to tame the overhang. Weird. My biggest regret is that I didn't bust out the SPL meter and take before and after measurements as proof of sound changes. Oh well. To my ears everything sounds better. In the end, that's really what matters.

When I get motivated again I'll move the speakers to the original positions and measure just to see what the differences are. Until then, I've got some music to listen to!

Sean,

You would have definitely been one of my heroes if you had before and after room response plots. I'm not opposed to dressing my room up but I am still very dubious about the benefits.

BTW, what kind of spider is that?

Looks like a black widow. Ouch!

Bingo!

I like your TV stand a lot. *creepy sidelong gaze*

I know, I'm sorry. It was one of those things where I started in on the project (putting everything up) on a whim and didn't stop till I was done. If I stopped, the whole thing would've died. It was that kinda lazy weekend.

Tell you what, Mojo. In the interest of measurable tweaks, I'll make an effort to do before and after SPL readings. That's all I'm set up for, no frequency sweeps or computer generated charts. It's just gonna be me, pencil and paper, and an SPL meter. I'm taking the week off between Christmas and New Year. That'll be a good time for this. Unless I get really bored in the interim.

I don't have any fancy equipment either. I have test tones that Randy recommended and I play them from 16Hz to 300Hz in 1 Hz increments and record the SPL. Then I plot SPL vs. frequency in Excel. Now that I have a laptop, maybe I should look into getting some software though.

Make sure you don't change your configuration between measurements. I look forward to seeing what you come up with.

Thanks! It's a Sanus/Salamander mixture. Came upon an interesting idea while trying to incorporate a center channel in my new set-up.

It definitely works.

Will do, Tex. Definitely no changes. It'll be interesting reaching for the corners with the speakers in the way. Perhaps it's time to get a small ladder and not rely on my dinky plastic fold-up Ikea chair for support.

I was thinking that you would place your SPL meter at your sweet spot and take measurements that way. You would keep the position constant and just vary the frequency.

If you get really bored, you can vary the position also . I am mainly interested in how much difference it made right at your sweet spot.

Good work, Sean. Yes, on the question of boominess and positioning it isn't necessarily being too close to the walls, but rather that the center of the woofer cone shouldn't be an equal distance from the side wall, front wall and floor, if possible.

Is this boominess from your speakers or the sub? I know my sub gets quite the boost to become boomy when in the corner like yours. Maybe try moving the sub around or better yet do the dreaded sub crawl, when you are off to try to find a better position for it.

Jason, the boominess comes from the speakers. Really noticeable with two-channel listening, during which I don't run the sub. I like the boom during movies! (insert sheepish grin)


And, JohnK, my speakers play pretty low (less than 30Hz) and I erroneously thought that putting them too close to the wall would accentuate that. Sometimes, it's okay to be wrong!

Hi St.Pat guy,

Like others here, I like your stand and I also was curious about that big spider. Looks a bit like the big dock spiders I used to get on my floating dock up in Georgian Bay (Lake Huron).

What are your main speakers, by the way? Big enclosures, so it doesn't surprise me that you might have issues with boominess depending on placement. And yes, it is amazing what audible changes are invoked by slight readjusments in speaker location. Sometimes when it comes to low bass, I throw up my hands and say, "The room is EVERYTHING!"

Regards,

::Runs away crying::

LOL @ MSJ!

Sean, those pictures are great. +1 on the ingenious center channel accommodation.

I used the Room EQ Wizard (REW) software available at Home Theater Shack. It makes uber groovy graphs if you have the right sound card and an SPL meter. You can also use it in conjunction with a Behringer FD unit, but I think it would work stand-alone just for analysis. Very quick and elegant once you get it going.

I'm going to have to try that software out once I'm able.

Thanks, Alan. Not a dock spider, just your typical black widow. Don't usually find these gals inside.



Odyssey Audio Loreleis. From the same guy that Sirquack and Haoleb got their amps from.




And heavy, too! The room I had these in previously was smaller, but I didn't have that much bass issues. In that room, which was square, I ran them diagonally trying to avoid bad reflections. Yes, the room can make or break things. It's amazing how bad a good speaker can sound if not set up properly.

Thanks, Tom! After I moved and rearranged my system, I was determined to make things work with what I had. I didn't want to spend money on a new stand. Such a simple solution, but it took me a week to think of it! Hey, I never said I was smart.

I am frustrated with software because nothing seems to be available for Macs. Maybe there is now, but I gave up looking a long time ago.

Mark, I wish there was something we could suggest that would help. Maybe you could talk your wife into some major redecorations?

Easy for the single guy to say. . .

Dude(?):
She's cool...we just don't have the space. I need 100 grand to build the big sunroom-with-a-fireplace-type room that I want....

Here you go Mark:



Now get to it.

You guys need to give up - it's clear to me that Mark simply doesn't WANT to solve his square room problem.

I'm thinking wall to wall bookshelves on one wall, packed with books. In addition to taking one of the room dimensions down by a foot, it would fool visitors into thinking Mark's an intellectual.

It's perfect!

Although, I don't think it would fool visitors that long.

LMAO.....

>>I am frustrated with software because nothing seems to be available for Macs. Maybe there is now, but I gave up looking a long time ago.

Boot camp (for the "Wintelmacs") ?

One of the PC emulator programs which work pretty well on 68xxx and PPC Macs ?

Boot camp don't count as software for a Mac... yeesh...

Maybe Ken means until the first time you opened your mouth?

That's what I was assuming!

>>Boot camp don't count as software for a Mac... yeesh...

You handled that well. I was expecting far worse

I've had some experience...

I'm not saying the Boot Camp isn't a valid alternative (although he'd have to buy a Windows license, technically), but it simply cannot be called software for a Mac if you have to use Windows to run it.

So, Boot Camp really isn't going to help me then? I'm not trying to be funny, I really don't know. That's why I bought a Mac--so I don't have to think so much.

Boot Camp will help you if you're willing to buy Leopard and a copy of Windows.

I'm gonna say no, then. *shrugs*

You're in luck! Instead of continuing to fly blindly, I googled Room EQ Wizard and it's actually available as a Java program, which will run just fine on your Mac. Go to this page on the Home Theater Shack (you'll need to be registered) and download the wizardjarv4.00.zip version. Then just unzip and double-click the RoomEQ_Wizard_obf.jar file.

>>So, Boot Camp really isn't going to help me then?

Boot Camp allows you to run Windows on your Mac, assuming it is a relatively recent one with an Intel processor. Running Windows allows you to access all the same software as any other PC.

Boot Camp may be "pure evil" in the eyes of long-time Mac owners, but it seems to have allowed Apple to attract a whole new group of users who always loved their design but were either afraid to move away from PCs or needed to use some specific program they couldn't get on the Mac.

I was sort of joking but only in the sense that there is probably a less drastic solution.

Oh, not pure evil by any means. Just not particularly convenient.

That said, I'd love to have a Mac with Boot Camp on it.

Very cool! Thanks for the link, Peter.

Of course this has to be the night my internet connection is going wonky. On top of that, it seems Axiom's server is having issues, too. I may have to wait until I can activate my account tomorrow. Had to use my work email.

More waiting. . .

I can't wait to try this out!

Spend some time at the HT Shack forums. I think the program only works with a few, specific audio cards. I got the external SoundBastard one, and it works just fine.

Yeah, I was able to download it, but am having problems with the soundcard thing. Shoot, it looks like I'm gonna have to actually read the instructions. . .

I'm hoping I can get this program to work!

I downloaded it too, hopefully I will get some spare time to see how it works.

The test tones were seriously wonky when I tried it. Looks like the excitement was premature.

That's not good news. I've got to pick up some cables before I try this out.

Sean,

Any progress on placing your meter in the sweet spot and running frequency response measurements before/after?

You'd be doing a great service to many of us.

Not yet. The thought of taking all those doodads down and putting them back up makes me realize how lazy I am.

Don't give up hope. I'll try to get the task tomorrow.

Yes, I know. But think of all of the "Sean" effigies that board members will bow down to in honor of your research .

Alright. Tomorrow for sure. I thought about it while making a drink for myself. I should have been thinking about what movie I'm about to watch. . .

Oh, the decisions. . .

Okay, Tex, I feel terribly guilty for not getting this done. The day after my above post was a day one of my housemates decided to have a study group. All day.

It's still on my list of things to do. I came across some info, though, that makes me think about this. The type of acoustic treatment I have is for something called modal ringing, which is something akin to echo--the old "clap your hands and listen" trick. Taming the ringing is not something one can measure with an SPL meter.

Things that make you go hmmmm. . .

So you are telling me that you need a new housemate ?

Ringing is typically a higher frequency phenomenon. So if this treatment is intended to rectify ringing, you would have to use test tones above 300Hz. Whatever effects are evident in the time domain are also evident in the frequency domain. So you should still be able to measure the improvement by placing a meter at your listening position and recording the SPL for various test tones with and without the treatment.

Of course if you have better things to do, I understand .

Sure. . .lay on the guilt trip why dontcha?

I downloaded and then burned to a CD some test tones from the RealTraps website, but the tones only go up to 300Hz. I'll have to look around to see if there are any available higher frequency downloads.

I have been using this and it works quite well.

Cool. Thanks Jason.

Man, this is gonna take a while to download. . .

Pretty slick. Be careful with playing the DC offset tracks...unless you like to cook speakers.