"First reflection"...what it means, why it's important, how to find it

That's very true. What I am wondering is how do you examine the spectral content of the reflection? Without that information aren't we guessing at for instance, how deep or thick our absorber needs to be?
It really isn't important. All (typical) absorbers absorb in the high frequencies, with lower frequencies being absorbed as thickness increases. So as long as you have enough thickness to catch all the directional frequencies (down to 500 to 1000 Hz) you're good to go. The point of the first reflection absorbers isn't to achieve spectral balance. It's to clarify directionality by removing signals that may confuse your ears about the origin of the source.
 
I just wondered since some speakers are quite directional.

And you guess right that my ceiling fans are not a couple of inches away from the ceiling but since this is not my primary listening room I would rather work on the speakers interactions with the room and leave the aesthetics of the room as is. I would not have ceiling fans in my dedicated listening room anyway.

Thanks guys.
 
If you want speakers that have less interaction with the room then you need to move away from monopole designs. Line source dipoles have less side wall, ceiling, and floor interaction by virtue of their figure of eight dispersion pattern.
 
Currently in the living room, my first significant reflection is now the rear wall and its fairly diffuse. Although its not my primary listening room, it might as well be all it can be but it's really her room.

I was just wondering what you were measuring and how.

Thanks again.
 
Currently in the living room, my first significant reflection is now the rear wall and its fairly diffuse. Although its not my primary listening room, it might as well be all it can be but it's really her room.

I was just wondering what you were measuring and how.

Thanks again.

I'm just measuring fundamental room response and bass decay times...been using a Dayton OmniMic.
 
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ok ... question:

I have an odd room - I'll try to describe:

Wall behind the gear (front wall?) is pretty standard along with the "stage left" wall that has a large window (with blinds).

The oddball part is "stage right" and the back wall (behind the listener)... they are half-walls, approx 3.5 feet tall. Above that height is a gaping cut-out sort of empty window that looks down into the lower level. I hope that makes sense --- in other words - I have basically a room with only 2 walls, so to speak.

So rather than reflection problems - it's more like infinite space problems... I realize "infinite" is overstating, but clearly a lot of the sound is just leaving the room and bouncing around other parts of the house downstairs.

I'm assuming putting some sort of curtain over the gaping holes will help - yes?

I feel like this is the priority issue that needs to be addressed first, before fiddling with "first reflections".

Am I correct in assuming this?

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Is the problem the sound for people downstairs or are you just worried about the sound when you're in this room/loft place? If the latter, the left wall is your problem.
 
Is the problem the sound for people downstairs or are you just worried about the sound when you're in this room/loft place? If the latter, the left wall is your problem.

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Not concerned with the folks downstairs one bit ... as I pay all their bills and feed their lazy arses... :D

Yes, my concern is a hollow un-contained sound... which is more evident when listening two channel. 5.1 sounds quite good - but I'm thinking it could also be greatly improved
afcvo6.jpg


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Ah, that's a tough space. Sounds like you're saying you're getting an echo-y sound? I was not expecting that since I've had sort of similar spaces where the levels coming back were extremely low and it basically just acted like a room with tons of absorption on the missing walls, sounded great (except for no bass gain). Anyway, yeah that shouldn't be too hard to fix with panels or curtains or something, but that right speaker being in the corner.. (this looks like a mirror-image of what you described?) that's unfortunate.
 
Flipping the Room Layout ?

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Not concerned with the folks downstairs one bit ... as I pay all their bills and feed their lazy arses... :D

Yes, my concern is a hollow un-contained sound... which is more evident when listening two channel. 5.1 sounds quite good - but I'm thinking it could also be greatly improved
afcvo6.jpg


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You may have already tried this, but what about "flipping" the room layout ? Right now, your "L" speaker has an open space behind it, and your "R" is in a corner. If you rotate the layout 180 degrees, your front channel speakers would have symmetrical acoustic environments.

Of course, the trade-off is that your rear channel speakers wouldn't lose a symmetrical environment, and your Feng Shui might be off, because you'd be facing away from the entry to the space when watching/listening, but if those are acceptable "prices-to-pay," then.....

As an aside, the February 2012 issue of Stereophile Magazine featured Acoustic Geometry's "Curve" System. They're not inexpensive, but they appear to be somewhat mobile solutions. You may be able to put these in place when you need them for critical listening, then tuck them away when not needed
 
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Sorry - here's some pics to avoid confusion - Flipping the entire thing did occur to me but that would put the TV and everything sort of jutting up over the half-wall... which would be seen from downstairs. Although if curtains are used ... hmmmm. All of this of course needs to be run by the wife.

Any way like I said the 5.1 sounds pretty good - it's the 2.0 that seems to get lost...of course, it's probably more room than those little bookshelf speakers can fill... that's another project.

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Re: Pix

WOW !!!

OK....NOW I see what it's such a challenge !
Thanks for posting the pix, and I apologize about prematurely posting an overly simplistic solution.

Short of sheetrock - after seeing the pix, the only thing I can come up with is turning it 90 degrees. Personally, I've always tried to follow the basic "Reflecting End/Absorbing End" theory - where the wall behind the Front Left/Right Speakers is "absorbing" and the wall behind the listener is "Reflecting." The theory is that by the time the longest wavelengths "bounce back" to hit the wall behind the speakers to be absorbed, they've "deadened" out. As you already know - in it's current layout, you really don't have that "Reflecting Wall" behind you

It's still tricky, because as you mentioned in another thread - it's not really a "sealed speaker enclosure" that you're sitting in the middle of.

Good Luck, and hopefully there's been something in here that can inspire a new solution!
 
That really doesn't look bad to me as far as the openings... I'm still just bothered by the right wall. I wonder if it's the placement that's really messing things up by giving you too much early ceiling reflection.

Try putting the bookshelf speakers upright and aiming them at the base of the couch. If that proves physically impossible, or even if it doesn't, try them upside down on top of the 5.1 speakers.
 
WOW !!!

OK....NOW I see what it's such a challenge !
Thanks for posting the pix, and I apologize about prematurely posting an overly simplistic solution.

Short of sheetrock

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Actually - sheetrock is what the wife has wanted to do for a while ...I''m fortunate that she appreciates good sound as much as I, but walling up that hole (or both) just seems a bit drastic... I'm considering it though.

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That really doesn't look bad to me as far as the openings... I'm still just bothered by the right wall. I wonder if it's the placement that's really messing things up by giving you too much early ceiling reflection.

Try putting the bookshelf speakers upright and aiming them at the base of the couch. If that proves physically impossible, or even if it doesn't, try them upside down on top of the 5.1 speakers.

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Ok... will experiment with that... just a note - the bookshelf speakers up top are actually angled down directly at "head height" center of the couch... may not be apparent in the photo.

I appreciate the input!

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...as you mentioned in another thread - it's not really a "sealed speaker enclosure" that you're sitting in the middle of.

Yes - and in a round about way that thread lead me to this one ... and got me to thinking about my ongoing frustration with this room.

On the other hand... "First World Problems" - right?

Also - didn't mean to hi-jack this thread... :D

Thanks again
 
The strategy I think you should employ here is no different than the fundamental information in the OP. What you need to get under control are reflections and the echoes they create. You are getting a reflection off the wall to your left that's very different than the reflection off the wall to your right. This is no doubt creating and unbalanced acoustic response. Additionally, the main boundary layer to your left (the stairwell's far wall) is not only reflecting content back into the room, but into the stairwell itself as well....which is likely creating a rogue acoustic response all it's own and I can't help but think this is migrating into the primary room's response. So my advice to you is to first eliminate the reflections from both of those boundary layers. I'd probably locate one absorption panel at first reflection on the right side wall and three panels on the stairwell wall to your left in an attempt to drastically reduce the rogue information coming from the stairwell.

As far as the opening behind you.....well, first I think you should treat the side walls as suggested, see what that does and report back with your findings.

- Michael
 
Any way like I said the 5.1 sounds pretty good - it's the 2.0 that seems to get lost...of course, it's probably more room than those little bookshelf speakers can fill... that's another project.

Have you tried moving the bookshelf speakers down to ear level with vertical placement? Oh, never mind. Dumptruck already covered that.

Cheers,

Otto
 
Thanks Tom, all helpful info!

I only wish I had the room or free walls to put treatment on. One of these days I am going to get a dedicated listening room.
 
Thanks Tom, all helpful info!

I only wish I had the room or free walls to put treatment on. One of these days I am going to get a dedicated listening room.

Your rather lush looking decor is probably doing you more favors than you think, Ken. But yeah, I'd say you're overdue for a dedicated listening space.

- Michael
 
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