Need advice: Acoustic Panel Placement w/pics

[rickdeth]

Hey all i had my dad build me some acoustic panel frames (6) of them sized 24"X48".

Im having a little trouble figuring out where i should place them in my room. I know of the first reflection points so if anyone can suggest to me any other tips or their thoughts on where in my room i should place them that would help me out immensely.

Ill be finishing them off with some black fabric and Roxul Rockboard 60 from ats acoustics.

I added a couple pictures on where i though i should or might place them.

Thanks in advance

Rick

[jomari]

an excellent amount of articles about reflections are found in my acoustic sticky found here. you can also see these theorems applied to real life situations, in the diy thread here.

Heres an excellent article about room reflections (first reflection more importantly), and how to address them using the 'mirror trick' or flashlight method.

home theater hi fi acoustic stuff.

basics would be what you're acoustic treaments are going to do...



a quick image showing you a little more about room reflections, and how it interacts with the listening position...



Can you send us more info as to the room dimensions et al?

More details, more specifics, more specific answers will entail.

Great room by the way and welcome to the foray!

[rickdeth]

Hey Jomari thanks for the info. I read a few of the stickies ill go through them again.

The room dimensions are

13'.5" Wide at the front soundstage area
13'.5" long on the wall that the door is on (up the the closet wall where the army of darkness poster is).
17' long on the wall that has the grindhouse poster on it
10'.8" for the back wall
7'.2" ceilings

Im just looking for advice if i am on the right track on placement. Having one on the door ? Maybe 2 along the side walls and 2 on the back wall ?

Ill do some more reading on your links.

Thanks again

rick

[kareface]

The room diagram above is moronic. You'll end up over deadening the mids and highs and still coming up short on the lows. The first 2 are fine, but there isn't a great deal of celerity on how to fix the solution.

Placement is really easy, you want to start with the first reflection point to reduce reverb. Take a mirror and place it against each of the walls, adjust it along the walls until you can see the speaker that is closest to that wall from your listening position. You want to place the panel so the center is around ear height while sitting in the same position the mirror is in. You can use a thinner panel, 2" thick, spaced 2" from the wall. The second important position you want to get is behind the right and left speakers. This will improve imaging by slowing the reflections from the back wall. This panel should be placed so it's centered around majority of the drivers. This panel you want to be thicker, 4" and spaces 4" from the wall. Against the rear wall you want to use diffraction, if you dampen behind the listening position you'll end up with a dead space behind you which sounds unnatural. It's also harder for humans to pick up sounds coming from behind, and dampening the space behind should only be used when your rooms RT60 is in excess of 600ms.

[Blown 4.3]

if it were me. place 3 on the left wall as best you could(forget the door). then mirror that on the right wall.

[kareface]

I've done acoustic calibration for many rooms including dampening. Many people think you can just pop panels in where ever. You don't realize that a panel can hurt more then help, and will do so in many positions. Unless you plan to run sweeps after each placement it's not a great idea just to toss them anywhere.

[kareface]

Just for celerity I'm not calling jomari moronic, lol. You can just tell who ever came up with that diagram wanted to move some merchandise.

[rickdeth]

Originally Posted by kareface

The room diagram above is moronic. You'll end up over deadening the mids and highs and still coming up short on the lows. The first 2 are fine, but there isn't a great deal of celerity on how to fix the solution.

Placement is really easy, you want to start with the first reflection point to reduce reverb. Take a mirror and place it against each of the walls, adjust it along the walls until you can see the speaker that is closest to that wall from your listening position. You want to place the panel so the center is around ear height while sitting in the same position the mirror is in. You can use a thinner panel, 2" thick, spaced 2" from the wall. The second important position you want to get is behind the right and left speakers. This will improve imaging by slowing the reflections from the back wall. This panel should be placed so it's centered around majority of the drivers. This panel you want to be thicker, 4" and spaces 4" from the wall. Against the rear wall you want to use diffraction, if you dampen behind the listening position you'll end up with a dead space behind you which sounds unnatural. It's also harder for humans to pick up sounds coming from behind, and dampening the space behind should only be used when your rooms RT60 is in excess of 600ms.

Thank you kareface! That was kinda the answer i was looking for. I was wondering about anything placed behind the left and right speakers up front.

Im still doing my reading/research.

Thanks rick

[jomari]

Originally Posted by kareface

Just for celerity I'm not calling jomari moronic, lol. You can just tell who ever came up with that diagram wanted to move some merchandise.

nice.

anyways, no offense taken. i think ive shown a little more er, clout through a number of my postings, and ive seen kareface do the same as well. nonetheless, i can definitely take a good joke or two, and dish em out at the same time.

back to business...

Originally Posted by kareface

The room diagram above is moronic. You'll end up over deadening the mids and highs and still coming up short on the lows. The first 2 are fine, but there isn't a great deal of celerity on how to fix the solution.

ive removed the diagram mentioned earlier, pardon me, im a bit tired and just came from work. all in all, its not the most ideal, but hey, somewhat a crude example. most people can do a lot more focusing on what they want and what they need in the first place. sorry, im just tired from work.

Placement is really easy, you want to start with the first reflection point to reduce reverb. Take a mirror and place it against each of the walls, adjust it along the walls until you can see the speaker that is closest to that wall from your listening position. You want to place the panel so the center is around ear height while sitting in the same position the mirror is in. You can use a thinner panel, 2" thick, spaced 2" from the wall. The second important position you want to get is behind the right and left speakers. This will improve imaging by slowing the reflections from the back wall. This panel should be placed so it's centered around majority of the drivers. This panel you want to be thicker, 4" and spaces 4" from the wall. Against the rear wall you want to use diffraction, if you dampen behind the listening position you'll end up with a dead space behind you which sounds unnatural. It's also harder for humans to pick up sounds coming from behind, and dampening the space behind should only be used when your rooms RT60 is in excess of 600ms.

kareface pretty much hit it on the head, in regards to the 'mirror' trick or method.

ive also wanted to point this out in the article lve linked earlier, as a primer for him to get to know what we're trying to achieve, and not just 'place panels and be done with'.

its a simple science, but nothing we cant do without a little background learning.

a quick suggestion, is instead of using those two panels flanking each other at the door area, id use em at the fronts, almost quite behind the mains.

have you considered placement as well?

just a thought.

again, just got off work, im tired, and well, im sure kareface can definitely use his expertise on this one.

signing off!

[kareface]

Originally Posted by jomari

anyways, no offense taken. i think ive shown a little more er, clout through a number of my postings, and ive seen kareface do the same as well. nonetheless, i can definitely take a good joke or two, and dish em out at the same time.

Good to hear that. The only thing that really angers me is when people suggest to others that spending large sums of money on speaker cable makes any audible difference. Otherwise you'd have a hard time getting me upset, lol.

Originally Posted by jomari

two panels flanking each other at the door area

I'm not sure what you mean by flanking each other. If you could elaborate I might be able to offer an opinion.

Originally Posted by jomari

have you considered placement as well?

I assume you mean speaker placement?

I think I might of missed something or am too tired to understand what you're attempting to convey.

Originally Posted by rickdeth

Thank you kareface! That was kinda the answer i was looking for. I was wondering about anything placed behind the left and right speakers up front.

Im still doing my reading/research.

Thanks rick

I was looking at your room and a couple things popped out. You have a suspended ceiling, I assume it's not acoustic tiles? With your ceiling and your floor you'll likely have a nativity low rc60, so you shouldn't need to correct for excessive reverb. You should just consider imaging improvements. How far behind your head is the back wall? You are likely too close for diffraction to be properly effective. You could play around with placement of the last 2 panels, in the corner as sudo-bass traps or behind the main listening position would be the common suggestions. I'd consider not using them unless you still feel the room sounds too live or bass heavy after installing the first 4.

[rickdeth]

Originally Posted by kareface

I was looking at your room and a couple things popped out. You have a suspended ceiling, I assume it's not acoustic tiles? With your ceiling and your floor you'll likely have a nativity low rc60, so you shouldn't need to correct for excessive reverb. You should just consider imaging improvements. How far behind your head is the back wall? You are likely too close for diffraction to be properly effective. You could play around with placement of the last 2 panels, in the corner as sudo-bass traps or behind the main listening position would be the common suggestions. I'd consider not using them unless you still feel the room sounds too live or bass heavy after installing the first 4.

I think my chairs are around 5ish feet from the back wall. I think ill try 2 panels on the side walls. Using the hand mirror technique and use the other 2 panels ill try and place behind the front towers see how its works out.

Thanks Rick

[jomari]

Originally Posted by kareface

Good to hear that. The only thing that really angers me is when people suggest to others that spending large sums of money on speaker cable makes any audible difference. Otherwise you'd have a hard time getting me upset, lol.

This part i have to agree on, there is a certain amount of benefit recieved (your typical 16AWG speaker wire versus 28AWG, and a couple here and there), but not as a significant improvement compared to addressing the interaction of the room with the speaker. ive said it before, but matty mentioned its a slogan for another company already, 'id like to hear the sound and not the room' or what not.

what also bothers me is seeing a whole bunch of movie posters, and well, you know the drill. aesthetics, im sure they're great, but hey, to each his own right?

I'm not sure what you mean by flanking each other. If you could elaborate I might be able to offer an opinion.

i guess what im trying to say is to have panels and some bass traps in the soundstage area, as an example, something like this but bigger so to speak...



care of dls_222's gallery. (great room, both aesthetics and function)

I assume you mean speaker placement?

I think I might of missed something or am too tired to understand what you're attempting to convey.

Yup. exactly. its great to see he's put a lot of care in placement, but id like to find out if it was more of simply putting them there, or did he research on it a bit, and placed them for a reason. this is one reason why i like to include postings that have a little more technical background for them to read, instead of just instructing them to do this and that. by all means, it works for some folks, but i guess ive liked to tell them why its important.

I was looking at your room and a couple things popped out. You have a suspended ceiling, I assume it's not acoustic tiles? With your ceiling and your floor you'll likely have a nativity low rc60, so you shouldn't need to correct for excessive reverb. You should just consider imaging improvements. How far behind your head is the back wall? You are likely too close for diffraction to be properly effective. You could play around with placement of the last 2 panels, in the corner as sudo-bass traps or behind the main listening position would be the common suggestions. I'd consider not using them unless you still feel the room sounds too live or bass heavy after installing the first 4.

i kinda noticed that too. the panels above him can use an improvement, but id want to see 'how far he'd be willing to go' in respect to treating the room. some people can go with panels, bass traps, finito. some want the whole nine yards.

in respect to the panels, id look at these and hopefully can give you a better idea on what can be accomplished, this ones care of den1224's gallery...



you'd notice he has bass traps also on the corners, and how you can possibly use them as an example of what can be done aside from the panels.

Rickdeth, if we may ask, can we get more pictures in the gallery section? heck why not build a folder for the meantime, and (im not sure if you can delete them), you can disable ratings if ever. some people dont like ratings, and well, its not life threatening to me. most of the time its easier for us to 'analyze' your room, with more data. thank you kind sir!

Sorry gents, its 9am here, and i just woke up. time to fetch the coffee!

Good morning!

[kareface]

Good morning. I had the unique displeasure of being woken up by the plumber today.

Originally Posted by jomari

i guess what im trying to say is to have panels and some bass traps in the soundstage area, as an example, something like this but bigger so to speak...

You are talking about having panels behind the speakers and traps in the corners? I already mentioned placing the panels behind the right and left speakers. Maybe I should clarify that I mean the mains and not the rear speakers. As for the corner bass traps, he should be using a lower PCF insulation for anything below 150hz. If he wants to build some corner traps I can explain a decent DIY solution, but I was just planning on answering his question relating to the existing panels.

Originally Posted by jomari

Yup. exactly. its great to see he's put a lot of care in placement, but id like to find out if it was more of simply putting them there, or did he research on it a bit, and placed them for a reason. this is one reason why i like to include postings that have a little more technical background for them to read, instead of just instructing them to do this and that. by all means, it works for some folks, but i guess ive liked to tell them why its important.

Speaker placement is very important to overall acoustics. There are a lot of schools of thought on ideal ratios or distances. Some produce better results more often and some are easier to apply to most rooms. My opinion on the subject is there isn't a one answer fits all solution. With out running sweeps after each placement you only really have your ears to rely on. Even with sweeps you still have to gauge the sound stage by ear. I've written up a post on how to place your mains several times now, I can pull it up if he's interested.

Originally Posted by jomari

in respect to the panels, id look at these and hopefully can give you a better idea on what can be accomplished, this ones care of den1224's gallery...

I would respectfully disagree with his dampening scheme. He's got a really good starting point which he doesn't utilize at all. I prefer rooms with hardwood floors for acoustics. They are harder to dampen for, but the end result tends to turn out much more natural, as humans are most accustom to floor reflections over ceiling and it's easier to apply proper correction to a ceiling compared to the floor. However, if you go this route you end up with nativity higher rt60 and powerful vertical nodes that have to be corrected. He doesn't have any dampening on the ceiling, which is a terrible mistake. Depending on the height of the ceiling he'll likely have a fundamental vertical node of 40hz-60hz and it'll be pretty sizable dip. If you correct for the vertical node first, you'll end up reducing the RT60 quite dramatically reducing the need for extra panels. He also doesn't have anything placed directly behind his main speakers which are a little too close to the wall, but it's hard to tell from the image.

I agree that bass trapping is a good idea, but the effectiveness of ricks panels for bass trapping is very low. I have no idea how den designed his corner traps so I can't speak to their use. Next time I do a room calibration I'll provide some before and after sweep results with panels arranged in the 3 spaces on each side configuration to give you an example of the potential negative results. The only reason you'd consider doing that is to reduce LF standing waves but the amount of that style of panels you'd require to effectively dampen the LF range would kill your mids and highs long before that.

[jomari]

great post kareface! im glad to see we can have a decent conversation, and well, sometimes its good to see someone who acknowledges the importance of acoustic treatments, may they be addressed in different manners to get the results we'd want in the end.

then its agreed? panels behind his fronts would be beneficial, on both accounts correct? in regards to the bass traps, we can further discuss this if the OP decides to take this to another level.

with regards to dens setup, its one of the few out there who've applied this from the gecko. may it be the most impressive one, well, that can only be seen via listening to it and having measurements to show us without partiality. maybe its ideal to what he needs, and his assessments may reach his end result to his satisfaction. id have to say tho, he might benefit more if his panels behind the fronts would be larger, due to the speakers capabilities. i appreciate the diffusors tho, albeit not as much a priority to me compared to reflections. all in good faith tho, im sure he has his reasons.

i agree with the bass traps tho, its a medium room comparative to others, and maybe we can address this with a more agressive means. maybe, maybe not needed, but we cant tell unless we listen to the room. im also not sure if we can use suspended bass traps on the ceilings due to the height (7.3) of the room.

sorry to hear you were abruptly woken by a plumber. its my day off, so im trying to 'live' outside the net for at least a day.

great discussion kareface, i wish i could share the same interest with others like you.

i wonder where matty is...

[-DLS-]

Originally Posted by jomari

i guess what im trying to say is to have panels and some bass traps in the soundstage area, as an example, something like this but bigger so to speak...



care of dls_222's gallery. (great room, both aesthetics and function)

Thanks jomari!!

Hey Rick for me I'm not going for perfection having it all done taking measurements and all.. I just want to make it better so if you're like me I think the way you got it is fine. It would improve the overall sound for sure and is better than bare walls. My room is still not ideal but I'm very happy with it. . Even with the room being open to the left side you can tell a difference when entering the HT.

[rickdeth]

Originally Posted by DLS_222

Thanks jomari!!

Hey Rick for me I'm not going for perfection having it all done taking measurements and all.. I just want to make it better so if you're like me I think the way you got it is fine. It would improve the overall sound for sure and is better than bare walls. My room is still not ideal but I'm very happy with it. . Even with the room being open to the left side you can tell a difference when entering the HT.

hey DLS !! Like you said im also just trying to get better sound out of my room. I know my room isnt perfect but its what i have until we find a house where i can build my room from scratch. Im just looking for some fine tuning making my room sound better. Thanks everyone for your opinions/suggestions.

rick

[mattym]

Originally Posted by jomari

i wonder where matty is...

Hello...

ive been reading, just been a bit busy with customers projects..

the only thing I would disagree on, diffusion....lots of low profile diffusors for mid/high frequencies that will work fine at around 5foot from the listener..

when building panels at home, careful selection of materials and construction can make a simple panel into a good broadband absorber