Home Theater feng shui Zen masters needed inside! :D

[nibhaz]

Sweet, keep us updated!

 

[KASR]

...On one hand having the opening might be nice since there is less asymmetrical reinforcing boundary there, but OTOH it seems like a pretty reflective and resonant space through that keyhole....

This was one of my concerns as well - would hanging a wall treatment/acoustic panel on the wall through the keyhole be a good idea? I don't want any acoustic funkiness going on in the hallway.

For the moment, without hooking up speakers, I would clap, shout, sing, bang POTS and PANS in all of the potential spaces. Listen for ringing, resonances, etc.

Would I make the racket in the areas where the speakers would be placed or somewhere else? If it's where the speakers would go, I did this test when the room was empty and I did notice alot of echoes from all positions where the front three speakers would be placed. I can't help but think that this will be a concern.

 

[jostenmeat]

This was one of my concerns as well - would hanging a wall treatment/acoustic panel on the wall through the keyhole be a good idea? I don't want any acoustic funkiness going on in the hallway.

While it may be a good idea, it's unfortunate to cover up that unique entry, may cost a lot, and thus it's hard to know what the ROI would be.

Would I make the racket in the areas where the speakers would be placed or somewhere else? If it's where the speakers would go, I did this test when the room was empty and I did notice alot of echoes from all positions where the front three speakers would be placed. I can't help but think that this will be a concern.

Both; everywhere. How does the "racket" sound in the fireplace room? Same?

You are going to want to treat the area quite a bit, especially if you have a lot of echo issues. Go nuts.

Well... you will notice the greatest difference, I would think, at higher volumes. If listening is only ever moderate, room issues do not come into play as nastily, or at least this is my experience. The issues are there, but they're just not as prominent, if only for reasons that are obvious to some.

 

[Woogie526]

I like

The newest iteration. Still sort of limited for seating though. :/

But the addition of the poker table will make a nice man's room.

I like the keyhole opening, I worked in construction for a long time, and that was a first for me.

 

[KASR]

While it may be a good idea, it's unfortunate to cover up that unique entry, may cost a lot, and thus it's hard to know what the ROI would be.

Well, what about putting an acoustic panel on the hallway wall that is through the keyhole? It seems that if the sound is passing through there, it could/would bounce off that hallway wall. Would it?

 

[KASR]

So my Polk Audio Monitor 50's came in! The cable company is gonna be at the house this morning to wire up the wall where the dvr is going - that means tonight, it's on like the Kong!!! Gonna wire everything up I'll get pics up ASAP.

I put the 50's next to the speakers they are replacing....I can tell a slight difference in them.

 

[jostenmeat]

Well, what about putting an acoustic panel on the hallway wall that is through the keyhole? It seems that if the sound is passing through there, it could/would bounce off that hallway wall. Would it?

A single acoustic panel is not going to do much. In fact, you might not be able to tell any difference at all. Especially in what looks like a highly reflective/resonant space. Sorry.

As someone I respect said recently, "There is treated, and then there is treated".

Those who seem to be very serious about the impact of treatments and their positioning seem to get around the order of 50 panels. Just to put this in perspective. I've got 9 in the HT, and could probably use double that, but I'm fine for now. My ceiling is still completely bare, and for many months did I have small pieces of scotch tape all over it to mark future upgrades. I've since removed them.

 

[nibhaz]

So my Polk Audio Monitor 50's came in! The cable company is gonna be at the house this morning to wire up the wall where the dvr is going - that means tonight, it's on like the Kong!!! Gonna wire everything up I'll get pics up ASAP.

I put the 50's next to the speakers they are replacing....I can tell a slight difference in them.

Well, I should hope that there was a difference

 

[nibhaz]

A single acoustic panel is not going to do much. In fact, you might not be able to tell any difference at all. Especially in what looks like a highly reflective/resonant space. Sorry.

I'll have to second the opinion that a single panel will not do you much good. From the picture I would say that 3 thick panels would be needed to get any real control in there.

I can’t tell by the picture what the distance from that wall is to your planned seating position is but a large poly diffuser my have some value in your particular situation. Here is a primer for various treatment options which includes polys. This is a more in depth poly discussion.

Another possible approach would be to build custom space couplers similar to these from Auralex. It would be a pain, but if you built them to fit in the odd spaces of the “keyhole” entrance this would give a temporary solution that you could remove later.

 

[KASR]

Ok, so I'm trying to figure the best place to start in concerns to wall treatments and acoustic panels - am I correct in thinking that the below illustration kinda shows where sound is possibly bouncing in the room? (green arrows is the sound, red zones are the reflected sound/echoes - the keyhole entry opens up into the hallway and in my theory sends the sound bouncing in that space)

So to begin bringing the reflected sound under alittle control (as a starting point) would this be a logical choice for the room's configuration? (green arrows is the sound, red is the acoustic panels):

Again, thanks for the input!

 

[nibhaz]

I think you’re on the right track, but perhaps looking at the directionality of your speakers a little two simplistically.

Your diagrams would be mostly correct if you were only dealing with high frequency information. The radiation pattern of your speakers is frequency dependent. Generally speaking at high frequencies most speakers are vey directional. This is why you are always being told to have your tweeters at ear level, and generally toed-in towards the listening position. As you go lower in frequency the radiation pattern “spreads”, until you get into the lowest octaves where your speakers begin to radiate in an omni-directional pattern. This is why you can place subwoofers in multiple positions in a room without losing the stereo image.

This is why treating a room in is more complex than most assume, which jostenmeat has already alluded to.

 

[jostenmeat]

nibhaz has both scientifically and eloquently explained what I would try to impart here.

While you are thinking of absorbing the red line on the right, I personally suspect that you would actually have a heavier balance on the left, because there is more wall there. Yeah, we often use the billiards bank shot in understanding where to treat first reflections, but like nibhaz alludes to, any boundary is a reinforcing thing.

With this latest iteration, I suspect that the front left speaker is the area that you should address first. Both behind it for bass trapping, and directly left/front of it as well (for I predict the left speaker will sound louder, maybe muddier too, because of the asymmetrical boundary there, which is also very close).

As I've already advised you, I'd see if I could scrounge up some stereo receiver somewhere, and hook up a pair of speakers.

Again, how does the racket sound in the fireplace room?

Your very best first move is choosing the better room. I say this from experience!

 

[KASR]

Thanks for the input guys - I really value it. Unfortunately, the fireplace room is out of the picture, so I'm stuck with making the "L" shaped room work.

I understand the radiation effect of the sound as it approaches the lower levels - but as a good starting point (cuz we all can't buy acoustic panels till our hearts content) I'm looking for the best starting point. So with the bass trapping on the left side (I'm assuming you mean the area behind the speaker?) what can I do to treat that area?

 

[jostenmeat]

Thanks for the input guys - I really value it. Unfortunately, the fireplace room is out of the picture, so I'm stuck with making the "L" shaped room work.

OK, so that's now clarified.

So with the bass trapping on the left side (I'm assuming you mean the area behind the speaker?) what can I do to treat that area?

Yes. Healthy amount of broadband absorption. A very thick panel vertically arrayed, corner mounted. Or some "superchunk" tritrap kind of thing. Or the panel + small tritraps above and below. You can just add over time. Also, use your ears too. When you get some panels, put em in different places to see.

My recommendation for absorption just next to and in front of the left speaker is so that the reflected energy there does not make it sound heavier on the left, as well as "contaminating" the audio with strongly reflected information. See, your right speaker has no sidewall near it, at least not anywhere as close as the left speaker. This is just my instinct though.

 

[KASR]

OK, so now that I've done some more research about where to look for "early reflection" in a 5.1 setup in a rectangular room - I've come up with this rough diagram....hopefully, it's closer to what I would need - everyone please chime in! I've got "???" where I'm unclear on what needs to go in that area.

 

[jostenmeat]

The left sidewall is on the other side of they keyhole entry, right? If so, it's not there I was thinking of absorbing, but at the more immediate sidewall.

The closer that you, or any speaker, is to any boundary, the more likely that area will benefit first in treating.

Ok, let's pretend we are only talking about low freq's, just for discussion. In fact, let's take it further, and just pretend that the speakers are omnipolar. If that was the case, do you see why I would recommend treating the front left area first?

How many feet will you sit from the rear wall?

At this point, we've really posted a LOT on this matter. While I've never yet treated a ceiling, I am definitely under the very strong impression that your sidewalls and corner trapping are by far the most important things to immediately address.

I'd do the ceiling last.

I would consider DIY to further your dollar. For a compromise, there is DIY made easier like Ready Acoustics. If you are looking for pre-made stuff, it could* be worth waiting to save, as companies like GIK and Real Traps start offering bulk discounts at roughly double digit panels or so, IIRC. Then there are the classifieds, but as you can imagine they don't last a day. Since we don't worry about "failing electronics", we pull the trigger pretty quickly. I bought near 300lbs off Audiogon myself. (crazy guy going Rives 3).

 

[KASR]

OK, I see what you are saying - so if we were talking about a clock - you are saying at about between 10 and 11 o'clock on the immediate wall before the opening of the keyhole entry would definitely benefit...right?

I've been reading alot outside of this site and I'm getting alot of no-sloped ceiling or low ceilings are the first place for reflection and should be treated before side and back wall. I'm guessing it's starting to sound like a matter of preference now.

So as far as the right side goes, that spills into the poker table area - is there enough space leading into that area that doesn't make sound reflection a problem and thus no treatments are needed?

And I'm DEFINITELY doing a DIY panel for this stuff....it just makes more sense in the long run and I can customize the sizes.

 

[jostenmeat]

OK, I see what you are saying - so if we were talking about a clock - you are saying at about between 10 and 11 o'clock on the immediate wall before the opening of the keyhole entry would definitely benefit...right?

That's the idea. Put a beefy one there. By absorbing the early reflection there, the desired effect would be to make it "seem" more like a symmetrical room. Even if it WAS symmetrical, the close proximity would call for them anyways, most likely.

LIKE I KEEP SAYING, the closer You or your Speaker is . . .

SPL decreases exponentially with distance. The distance between left sidewall and speaker is very close, and thus the reflected energy will be very great.

I've been reading alot outside of this site and I'm getting alot of no-sloped ceiling or low ceilings are the first place for reflection and should be treated before side and back wall. I'm guessing it's starting to sound like a matter of preference now.

I'm not really one to argue, but if the ceiling is further away than the left side wall is . . .

And I'm DEFINITELY doing a DIY panel for this stuff....it just makes more sense in the long run and I can customize the sizes.

DIY should be pretty affordable. Make it all at the same time. Go overkill. Think overkill.

 

[KASR]

DIY should be pretty affordable. Make it all at the same time. Go overkill. Think overkill.

LOL! dammit, my wife is gonna kill me!!!

 

[jostenmeat]

LOL! dammit, my wife is gonna kill me!!!

You have my sincere empathy.

Would you put me in your will if just for the acoustic panels?