Axiom Home Page Forums General Discussion Technical Questions Learning about room acoustics

Hey All,

In anticipation of our move to a new house , I’ve started taking a deep dive into room acoustics.

I wish I had a better understanding of the features of this forum asi would’ve bookmarked a specific thread. I can’t recall whom,Trev maybe? But started a good thread as deep dive into room setup. Complete with pics and diagrams and a big ruler or something? Can someone point me in the direction of that thread? (And I will follow it then !)

Anyway, I’ve come across this guy :
https://www.acousticfields.com/

That’s his website but he’s got a ton of videos on YouTube. Seems like good stuff in terms of the info shared but I’m not convinced of his products or pedagogy to a point. A lot of what he says makes sense. Does anyone have experience with his videos or products?

Thanks everybody. I’ve been busy lately ,so only been able to kinda read all the current posts and threads but no time to really comment. Nice to see all the familiar names around!

Stay away from the black arts. I figure, if there is a problem, identify it. Then go about dealing with it.

I have a friend with a very expensive system. He has over-treated his audio room (2 channel) so it is just dead. Not good.

I don't like Audyssey room correction for HT. Haven't heard Dirac or any of the others.

I agree with disgruntled hard wood. Identify the problem then deal with it. Although using REW or Audyssey isn't all that bad, as they can sometimes help show you problems you didn't naturally recognize. They are just a guide not gospel! Your ears always have the final judgement!

I like that , “ the dark arts “. Nice. Yes I agree with you 2x6. I don’t use room correction but only bc I’ve never owned an avr that has it. Some would call me “ old school “ but it’s more like “ tight budget “ for now.

Well here’s a link to one of this dudes videos.... his products aside is the information he is teaching accurate? My gut says he’s close as it seems logical but even in my very untrained way I noticed some questions..... like the angle the sound bounces off the wall to make it back to the listener..... what creates that angle?

Anyway without getting overly complex here I think what I’ve learned is there are some really good things you can do at a basic level to improve sound.

https://youtu.be/d7rOtBvz8OU

Dennis Foley is not well regarded by acousticians. He does NOT practice what I would call proven and trusted methods.... Try Nyall Mellor or Anthony Grimani.

If you have a room of known dimensions post them here with windows and doors as well. Sketch is great. I routinely plan rooms with software renders for installs. It is not a “black art”. It is not magic at all.

The pile of University Textbooks here indicate it is entirely empiracal and methodical if you follow proven principles. Please DO NOT confuse what 2x6 or Reblux or anyone else says about your room as facts. Measurements are facts.

A real person in real life will need to measure your room in person if you are going to treat it. You can do it. I can walk you through it. 2x6’s pal likely reduced his RT60 below 0.2s. Bad news.

Anyone who has heard a properly treated room would not deny its overwhelming importance.

Here is one we just did. Built to spec. Probably one of the best rooms in the province after tuning...

I can ask him if I can post pics. Anyways, post a dimensioned sketch and we can go from there.

Judging by that diagram my surrounds are definitely too far forward. With my odd shaped room should I treat my front locations as if the room were squared off? I have watched several videos on measuring speaker location but everything is always based on rectangular shaped rooms.

Kodiak, like Trevor says, there are others who know it and can explain it better than Dennis.

The angles are formed between the listener, the wall, floor, ceiling and the speaker. As you move your MLP closer to the speakers, there is less wall, floor and ceiling in front of you to reflect and you hear more of the speakers. The opposite happens as you move further away. There's a region where the direct energy from the speakers is the same as the reflected energy from the reflecting surfaces.

As you move closer, you may feel as if you are on stage or in the first few rows of the performance. As you move further away, you may perceive that the performance is "out there". I prefer the latter. As I turn it up, I get more envelopment that makes me feel that I am there with them but not right beside or in front of them.

There is no right or wrong distance with well-designed speakers. It's a matter of preference. Of course when you are dealing with multi-channel, you better understand which way you prefer before setting the equipment up.

Notice I said there is no right or wrong with well-designed speakers. A well-designed speaker is one that has a well-behaved family of curves like Toole has said. This makes the speaker sound tonally similar whether you choose to sit closer or further. The only difference is in the nature of the spatial imaging as I described above. This is certainly the case with all properly placed v4 that I've heard.

But no one ever listens to scientists....since since they listen to a youtube guy named Dennis, maybe they'll listen to a guy named Trevor.
Well said Trevor!

Just thinking about this a bit further, once the new AVR is obtained, hopefully sometime this crazy year, we plan on switching around the Axioms likely to newer versions but because we are adding more surrounds as replacing the sub and centre as well (the finishes just have to match or it would bother me to no end). As such, i've been thinking more about where to move my back surrounds which currently sit a bit to the sides. The new back surrounds would also have a location different from the existing. Our room is odd in dimensions with an angle on a side, angle on a back wall from ceiling downward, a header dropdown on the far wall ceiling. I should send you some diagrams or images and see what you think for placement compared to what i had setup many years ago.
Personally i think one far wall is going to need a bit of treatment. Yet to do the room measurements...

Hey Guys, thanks for all the responses. Much appreciated. This is turning into quite the interesting hobby. I starting thinking about getting new amplifiers ( my NAD post from a few weeks ago..) but bailed on that. I realized i was just guessing and band aiding in anticipation of new a larger space. In addition to that , introducing new amps would change my " reference point for sound " so im better off to just move in with my very modest system and get comfy and go from there with upgrades and comparisions so I can judge how each change impacts the quality and the space.

I've heard so many times about how important the room is. So i figure i'll start there, hence my deepish dive into room acoustics and treatment. I had a feeling that Dennis was a bit un conventional, some of the products seem too good to be true. I'll check out the guys you suggested Trev. But some of his videos certainly got me thinking and looking into how acoustics work in room, the research and learning will continue, along with all of your guys' wonderful insights. ( Thanks Mojo for the knowledge there as well.)

I will post some photos and a spec sheet of the 2 spaces I have to work with.

Dedicated 2 channel space: This one space is our " great room ", it's not massive but its pretty big. 12 foot ceilings in main living room then drops down to 9 feet for kitchen and dining. 7400 cubed feet. Its open to upstair well and foyer too. This space will need to be aesthetic so i will have to be clever and discrete with any treatments. We have purchased heavy curtains to go over all the glass and windows. We went with the full 12 foot curtains in the living room and full 9 foot height in dining room. Theres 2 large skinny windows that flank to center position, those will also have cutains at full height.

Theatre Space or dedicated listening space for anything really: This space is fully below grade concrete basement. The concrete is insulated with 2 inch rigid insulation all the way around. Floor is concrete too. It is the same footprint as the great room / kitchen / dining. ( It's directly below the great room....) so same square feet but 7 foot ceilings. I'll have freedom down there to do absolutley whatever i want, the only drawback is the 7 foot ceilings and perhaps the concrete, im not sure if that s good or bad. Maybe both? But its a big space to work with and i'm hoping i can make something special down there. I can keep it wide open or make it smaller too, whatever goes.

I'll see if i can figure out how to post some pics and diagrams to share. I'm very stoked to share this with you guys as I know you get the excitement of all things audio.

Here's a photo of the room spec. This is a test to see if my photo link works too.....hopefully.

[img]http://https://www.flickr.com/photos/80455676@N06/50970298293/in/dateposted-public/[/img]

trying again....

I have no clue how to post a photo up. Shouldn't be so complicated.....I thought it was just put the link in and it should work.

You need to direct link to a file. Like .jpg or .png

Anyway, looks like you are at the exciting time of your build. Ramboard on floor so hardwood? Kitchen millwork going in. Getting close.

I will take a proper look later on the computer. We have 2 builds like yours on the go right now. -Living backing onto kitchen. Each with Axiom in wall surround setups. One Atmos.

Too late to cancel heavy curtains? Honeycomb blinds may be better. In archers windows too. Then you can hang a light tapestry on other wall for balance. Doesn’t have to be padded out panels. If heavy curtains, going to need acoustically similar on opposing surface. Trickier to hide heavy treatments to suit.

Having heavy absorption on one side and not other is not ideal.

Sounds like the basement is clean slate, so aim high there. Fully treat if you want. Start ground up with drawings.

Will get you speaker locations tomorrow. Going to be on the computer for taxes anyhow.

Canes are you referring to the alcove on the front right in your room?

Hey Trev, thanks for having a look. Yeah its a pretty exciting time. Those photos are from about a month ago. We move in a couple weeks.
Yes, hard wood floors thru out on the main floor, carpet upstairs. We're planning some large throw carpets / rugs for the living room too and a wood stove along the blank wall.
The curtains are already here and are what my wife really wants in the house. She is not into having blinds anymore, they are a pain to clean. It could be possible to have a set of cutains for the other wall simply to mirror the acoustics of the other side......just leave em tied back as an aesthetic thing and then pull em closed when going for symmetry for listening. Not sure how that would look to be honest! ha! We'll see....maybe a freestanding setup when i want it and just store it elsewhere when not in use.
We're doing a walk thru this week, i'll get some current photos of what it all looks like. I'll work on how to post a pic properly, ( eye roll, embarrassing...)

Another question for everybody, do I manage the acoustics of the room first with my current gear or do I do my upgrade of system first then manage the acoustics with that system in the room? Or maybe it's a little bit of both, basic damping of the room with normal room things ( furniture , curtains rugs etc...) see how that goes. Then go from there with the current gear.

I gotta admit, when i saw that room I wanted the house even more because of its size and shape and acoustic potential! And the freedom the basement provides too was very enticing. Can't wait!

PS. Yes, the basement is a total clean slate and i'll have total freedom down there to do as I please. So the acoustic managment down there will only be limited by free time and budget. I want to do that space correctly from the start. I'm in no rush to hurry into a build down there. I want to do it right. I was thinking a 5.2 system down there eventually with a good 2.2 channel capable L/R as part of it.

Yeah, im rambling but im just stoked! And I know you guys get it. The only other person I know that could actually get the excitment level is my brother but he's 3 hours away.

Dont buy anything before you try what you have first. Wait till its furnished and go from there.

Agreed! I’m just spinning ideas right now.

The curtains are going in for sure. That’s non negotiable and so is at least one large throw rug in living room. That’s also non negotiable. She’s open minded and into symmetry and balanced look of things so that works in my favour in the living room for sure.

When you say archer windows do you mean the 2 long / tall windows flanking the center position?

Any idea how the transition in ceiling height from 12 feet to 9 feet will effect things?

The ceiling transition won't create audible effects unless you're flying high.

Curtains bad...which is why my neighbors have a free show.

With 3 kids I should be flying high.... it’d be easier!!!

Ok well that’s good news on the ceiling height being a non issue.

Curtains bad? Really? I trust you guys for sure but I thought curtains would be better than glass. I had it in my brain that curtains would be a good thing. Dam. I was stoked when the wife said curtains all the way. I was like
“ awesome that works for my audio needs. “ So blinds would be better then eh?

Mojo I have noticed in your photos that there’s no curtains in your bay window. Is that the mankini observatory. ?
Ha!

wait, did someone say my name! thats my favorite. Thanks Trevor, but, what did i say? If it was wrong i'm sure I was drinking that night...wait... my wife says I drink every night... damn! I'm sure I was wrong now, but wait, what facts are you referring too?

The ATMOS and Auro-3d specs can be applied to non rectangular rooms and setups which only take up part of a room. DTS claims it can use what ever you have ... not sure how their rendering engine figures it out but most agree that if you setup to the ATMOS spec your going to be ok. I’m currently working on reconfiguring what speakers I’m prewiring for ... so I’m in the middle of trying to combine the ATMOS and Auro specs and figuring out what compromises I want to make to best support all three (and guess at what may come in the future).

BTW, the specs are a bit funky as each specifies how to layout the speakers in different ways and then you need to read the whole document to figure out the exceptions. They also have slightly different labeling and sometime you need to burn some brain matter to figure out exactly what a number means ...

Have fun

Lol. Not trying to get you worked up. Wasnt a personal attack on you guys.

I'm not upset, actually excited you mentioned my name, like a dog wagging it's tail... is that weird? lol

Rebulx, Rebulx, Rebulx,Rebulx, Rebulx

Sorry.

I couldn’t help myself.

Rebulx.

I’m chuckling now.

And no it’s not weird...... it’s dopamine. It’s what drives Facebook. We’re just chemically driven “ sacks of mostly water “. ( See what I did there trekkies?).

Rebulx.

I see what you did there with 1.5” x 5.5” dimensional lumbers name. Clever.

But...but...wood doesn't have any feelings.

I'm literally panting right now! lol When I catch my breath i'll start responding to other threads.

I don't know why but i'm going to grab a snack now, I think I need a treat. ;-)

Scoobie doobie doo!

I've found this series of videos to be really insightful/helpful

https://youtube.com/playlist?list=PLvfTZmvZzNmD4WzBNKhNpBKtyJcxJ4Ajl

Yes!! Those are good. I’ve watched about half of those so far. Very helpful. Cheers!

Grimani is good. Thanks for the links.

He was a great guest on home theater geeks. Not much has changed since then and the older vids are more detailed than these newer ones so far. I like how there was a new vid on diffusion itself, albeit with not much for specific info other than where to put them. But all the same welcome info.

He is definitely dialing it down for a livestream. He is very technical and I could tell at times he was a little impatient with off topic questions or superchat interruptions. No idea why the guy with the beard is there....

Anyway great content for intro stuff. Thanks!

Grimani is one of the best, very willing to help the average guy! One of the biggest shocks i've learned in this hobby is just how much room acoustics play in how amazing a speaker can sound!

btw, the guy with the beard is cool, he owns a HD2020 in Tampa and does home installs. I've spoken to him a few times. He's just trying to grow his business. Knowledgeable and friendly.

Right on! Hope he does well in the new era of “normal”. Seems very promising for home entertainment in general as people are investing more into being at home with family.

Yup, that's true!

It'll be good for Axiom!

They did another series on bass management. It's a little more technical than the room acoustic series. They have them in a separate playlist:

https://www.youtube.com/watch?v=FlyGM5GDcBo&list=PLvfTZmvZzNmB4rSRRpfIqRp5rF5WREwK4

Thanks! I’ll look for those. Appreciate it.