Dealing with a large TV between speakers


Thought I'd post this since it's a glaring problem (somewhat literally, very figuratively). I've got a 50" rear projection LCD TV between my speakers that has to be there for many reasons (HT/living room/etc). Soundstaging on the x and y planes seems OK, perhaps a little narrow, but forget about the Z plane. All the action seems to take place horizontally between speakers, with vocals perhaps a bit projected forward.

I've done the Master Set method on my speakers. They are ~3ft from the rear wall and about 7.5' apart (measured from drivers) . The TV is about 20" out from the rear wall and 4.5' wide. There is roughly 18" between the speakers and the sides of the TV.

For a better visual, I've created a drawing here that I've used for submission to various acoustic panel websites.

As you can see, speakers and TV are along the long wall, and I only have about 12' total between that wall and the wall behind me. I can't move the speakers out too much more, and based on Master Set and the rule of thirds, they seem to be where they should and they do sound good there (no bass bloat, clear imaging, etc). There is roughly 2' of space between the rear wall and my head.

What I've done so far for treatment are the acoustic and diffusion panels you see in the picture, and I've wrapped thick round foam pipe insulation (the tubes you can buy at Home Depot) vertically along the sides of the TV, which seems to help. I've also experimented with hanging a diffusion panel or light foam panels over the front of the TV to cover the front. However, I'm not noticing much of a difference with the front of the TV treated or not, surprisingly (I assumed that there would be more glare and smearing with such a large, untreated, reflective surface between the speakers and directly in front of me).

Outside of throwing a blanket over the TV (which I tried, didn't really work) do you see any way to accomplish more depth to the soundstage? Questions and comments welcome, but keep in mind, I can't move the TV.
tholt
I'm not sure I properly ended this thread, but perhaps it's moot now anyway. As stated, I did get a flat panel plasma and it's replaced the large original TV. The plasma is hung on the wall behind the speakers. Much improvement all around -- soundstage depth both real and psychological (not seeing a huge obstruction between the speakers helps quite a bit in the perception of depth) better clarity of sound, elimination of certain frequency glare that I attribute to sound waves bouncing off the sides and front of the TV, etc.

Thanks all who contributed to this thread.
From a 36 XBR to a 40" LCD to a 100" projection screen. Each step improved the depth of soundstage. Now I wonder if I should have a curtain to draw over the screen when I'm listening to music, because the screen is a large reflective area.

db
With the absence of the TV, the soundstage was hovering in space between and behind the speakers, and thus seemed to be more holographic and go deeper...Also, the removal of the TV alleviated some frequency glare in the midrange.

This was my experience exactly.

And being a true and crazy audiophile, yesterday I went down to Best Buy and bought a flat panel plasma to hang on the wall. This despite my current TV working perfectly fine.

Yes, that was crazy. And it is exactly what I would have done. :)
04-24-10: Rrog
Tholt, I wonder if two 2x4 panels are sufficient behind your head. Two more might be better.

I've wondered the same thing. Will likely add 2 more panels in the near future.
Tholt, I wonder if two 2x4 panels are sufficient behind your head. Two more might be better.

So, you have addressed the leather couch. It's surprising how many audiophiles use a leather couch or chair without realizing how reflective it is and what it does to the sound.
Thank you all for responses thus far. I apologize for the belated reply. Homework to help with, High School Open House one night and open curiosity as a reader instead of being the OP are the reasons. The other night I tried moving the TV out of the way. At first, the difference was subtle (ie not immediate nor night/day) but over the space of a few hours as I listened intently there was an apparent improvement in the illusion of depth. I think this was aided significantly by there being no visual barrier directly in front of me. With the absence of the TV, the soundstage was hovering in space between and behind the speakers, and thus seemed to be more holographic and go deeper. Another interesting observation: the soundstage seemed to end at the furthest visual barrier. In this case, it was now the wall. But at any rate, there was more dimensionality. Also, the removal of the TV alleviated some frequency glare in the midrange. So the TV is contributing not just to a perceived flatness in stage but also negatively to the sonic reproduction.

And being a true and crazy audiophile, yesterday I went down to Best Buy and bought a flat panel plasma to hang on the wall. This despite my current TV working perfectly fine. But what would an audiophile be if not obsessed with that last percentage of realism, no matter what the cost or logic? I now will happily list my current TV on craigslist for a little more then 1/10 what I paid for it a few years ago.

to address some specific comments:

@ Niturner920 and Peter_s re: DIY diffusion panels. Feel free to PM me and I will explain how I made the panels. Cost and labor are both fairly negligible.

@ Bryoncunningham and others re: material on the wall behind my head. Currently there are two 2x4x2" fiberglass absorption panels on the wall behind my head. I tried the DIY diffusion panels there but they didn't seem to improve anything. Regarding the vaulted ceiling - it's true that it is pointed the 'wrong way', ie ideally in my room things would be turned 180º so that the ceiling would be going up toward me like an amphitheater. Unfortunately, that layout doesn't work for other reasons in my room. I've thought about hanging panels from the ceiling at reflection points above my head but am not crazy about poking holes in my ceiling just yet, mostly because I'm not sure I have the paint color to touch up the holes if I want to repair them.

@ Tpreaves/Rrog re: entry way. Good observation. I will try putting an absorptive panel in there and listen for an improvement. I realized in the back of my head that having that large hole behind my speaker was a liability, but never thought to treat it. Also regarding the leather couch, there is a large sheepskin blanket/rug draped over the length of the top to address the purpose of reflection from the leather.
I like the long wall for many reasons. First of all midbass energy is much better on the long wall. Some speaker manufacturers recommend the long wall as the preferred setup for their speakers.

The long wall also offers a wide soundstage that is very addicting. The short wall may give you more depth, but not very likely with a TV or equipment rack between the speakers.
Rrog - You're right, my panels (Johns Manville 817) are fiberglass. I don't know why I considered fiberglass a synthetic material (looks?).
Newbee - Thanks, I will try diffusive as well (or combination).

I have no choice but to have it on long wall. One side of this long wall is a staircase (upstairs and downstairs) that I plan to open one day.
Kijanki, The material in a good commercial room treatment product such as ASC is fiber glass that comes from natural raw materials and according to every Acoustician I have talked with, synthetic materials do not have a flat absorbtion rate.

I find it intersting that you heard no difference at all. If the wall behind your listening position is not treated it could very well be the reason you did not hear the difference when you covered the TV.

Once you finish your room treatment project you will be amazed at how good your system sounds.
Kijanki, I think what you need to cover that TV is not sound deadening materials, but diffusive materials. That is what works for me.

I've never liked long wall placement sound, period, but like you if I had to live with it and I had your issues, I would get a wall mounted panel TV and makes some diffusive faced panels to place in front of it. You seem to be handy and it would be easy to do.

Just a thought.
Rrog - Blankets were not synthetic (wool) and very thick (multiple layers). Being synthetic has nothing to do with it since sound absorbing panels I bought are purely synthetic and have flat absorption characteristic from 20kHz down to 100Hz.

I was just expecting some difference but there was none. It is possible that reflections from back wall are masking effect of TV and I will be able to hear difference when I fix it.

Kijanki, First of all having something there is not the same as having nothing there.

Also, professional sound absorbing products are made of specific materials to evenly absorb a broad range of frequencies. This is not the case with blankets made with synthetic materials which will only have an affect on some frequencies and not others.
Rrog - why do you think this experiment means nothing? Main problem with TV, in my opinion, is that it might create secondary reflection from it's shiny sound reflective screen. If that would be the case then covering TV with sound absorbing material should change something.

You stated that TV is still there. Yes it is, but we're talking of acoustic presence of it that can be reduced. It's like saying that in studio sound absorbing material on the walls does nothing because walls are still there.
"I agree with Shadorne that reflections from the wall (especially back wall) and not TV create problem. I tried to cover TV with multiple blankets and it doesn't change imaging (pretty good)."

Your experiment means nothing. The TV is still there whether you covered it or not.
Tholt - I have exactly same situation, same TV and similar stand plus exactly same Hyperion speakers. Speakers are on the long wall and sofa is on opposite wall. I agree with Shadorne that reflections from the wall (especially back wall) and not TV create problem. I tried to cover TV with multiple blankets and it doesn't change imaging (pretty good). I bought high density 2" thick sound absorbing panels effective equally down to 100Hz and plan to finish them and hang (twelve 2'x 4'). I was once in the room with all walls made of such panels and effect is amazing. My own voice sound cleaner and other people voices come from exact points. I have also very tall cathedral ceiling (starting at 12') and too much reverberation. Windows curtains (or similar covers for the walls) don't help much because if I can hear sound standing behind them with almost no loss, then sound will bounce back from the window (or wall) thru the curtain.
Less toe-in. Maybe a bit closer together. Try swapping diffusion panels position with absorption panels. Maybe some corner foam or soffit traps at ceiling/wall on front and back walls.
If this is about a two channel system I'm in. I don't do HT.

Tpreaves is correct regarding the entry behind the right speaker. This can act like a mini echo chamber and really mess with your sound. Clap your hands while standing in the entry and listen for unwanted echo. If echo exists you may want to treat the entry to eliminate the echo.

From your drawing you are set up correctly and I prefer the long wall, but you may want to either spread the speakers farther apart, pull the speakers farther into the room or a little of both.

If you want to know how the TV is affecting the sound you can temporarily remove it.

When making adjustments or treating your entry, be sure to do only one thing at a time. Don't do anything else until you realize how a single change affected the sound.

One thing I don't hear mentioned is the leather couch. Your leather couch is a large reflective surface right in the listening position. It is my experience that leather couches are not good for the sound. Try covering your couch with a blanket and see if you hear the difference. Leather couches affect the sound in a similar way to having a non-treated wall behind your head. I'm surprised nobody has mentioned this before.

I would be interested in knowing what products you are using on the wall behind the speakers and the wall behind the listening position. A good rule to follow is "live end dead end". In other words, if you are treating the wall behind the listening position don't treat the wall behind the speakers.

Only make one change at a time.
I get great soundstaging with my speakers on the long wall and my listing position near the rear wall. Almost as good as shortwall placement in my room but with much better bass response. My room is well treated though.

I think the comments about removing the TV are good. You need to figure out what each piece of room set up contributes to the sound. It is possible that with the TV completely removed doesn't make that much of a difference.

Do you have the speaker cable length to try the speakers way out into the room? Just to see if you can get any depth. There are some set up that just don't do depth well.

It takes a long time and effort to get a handle on room acoustics.

Seriously, you should write up some plans for those diffusors I would love to build a set. Really non recording studio look.
Before doing anything you need to get the center channel's drivers in the same plane as the side speakers drivers. The way it is now creates all kinds of problems when the center is active.
Since you cannot move your setup to a short wall, here are two more things to consider:

1. Maybe you would have better luck with diffusion behind the listening position, rather than absorption, as indicated in your overhead plan. I have a friend who listens close to the rear wall, and the addition of diffusion behind his listening position improved his soundstage significantly. Since you already have diffusors in the room, you can easily experiment with them on the rear wall.

2. I just noticed that you have a vaulted ceiling. I once had a listening room with a vaulted ceiling, and it resulted in lots of undesirable effects, some of them unpredictable. I was able to minimize these effects by hanging absorptive baffles like these. Whether it would improve your soundstage, I cannot say, but it should improve things generally.
Tholt - take your TV out temporarily and see if it is indeed the problem. Thus we can stop speculation on that!

Are you sure the absorbers are good behind your speakers? In my room, I preferred diffusors, but I was using Quads then. I would say, never assume that treatments are for the best - play with them some.

That said - I like your diffusors too. I build my own Skyline diffusors out of balsa wood. Can you share more about them, parts, construction, etc?

Thanks, Peter

PS - I have friends with a similar layout to yours. They are using GMA Europas and getting very good soundstage along the long wall with heads near the rear wall on a sofa. It must be possible.
@ Learsfool - there are curtains over the glass door and window. Not very thick, but there nonetheless.
Appreciate the responses thus far. Unfortunately due to room layout, it's totally unpractical for me to place speakers against either of the short walls. I would love to try it someday, but would have to put them back anyway, so maybe better left untried for fear of it actually sounding better.

Tonight I tried moving the speakers into the room as far as practical and fine tuning them in that position, ended up being 6 more inches further from the rear wall. The 3D has improved slightly, but not significantly. I think Bryoncunningham is right -- for me it's going to be a matter of inches. And yes, she has said that.

@Nikturner920 - yes diffusion panels are DIY. The diffusion squares come 12 to a box, very cheap, and fit together like puzzle pieces. Though more professional and costly diffusion panels likely have better results.

I may try removing the TV to see if the soundstage improves. If so, I know that a mounted flatscreen TV could be a viable solution.
Looking at your drawing, I would definitely agree with Shadorne that the TV is not the main issue. In fact, I would say that the sliding glass door behind the left speaker, and the entryway behind the right speaker probably have even more to do with the loss in your soundstage depth than the TV in-between the speakers does. But the main thing is that they should ideally be on one of the short walls.

My brother has a similar situation to yours, and also has a large TV between his speakers. He experimented with removing the TV (and also covering it as you did) and found it made no significant difference to the overall soundstage, so he put it back. He unfortunately cannot place his speakers on the short wall. If you can, this is by far the best solution. If not, I would also consider curtaining the screen door somehow, and if there is not a door on that entryway, considering putting something there as well.

I myself have a large plasma TV between my speakers (as well as my audio rack, for that matter), but they are on a short wall and the speakers are also horns, so their shape minimizes the effects of the room anyway by directing the sound much more where I want it to go, even though the set-up is very far from a theoretical ideal. I also have plenty of diffusion throughout the room, which is also much larger, so I have plenty of space behind the listening spot. The effect of the TV is therefore very minor in my set-up. I have a huge soundstage however you want to measure it - width, depth or height. I am sure it could be improved by better placement, but that is not possible with the other furniture in the room. I hope someday to have a dedicated room, but that is years off yet.
I agree with Shadorne that the principal problem lies in your system's orientation along the long wall. I assumed, looking and your photos and overhead plan, that moving the system to the short wall was not an option. If that is an option, then that will be your best solution by far.

However, if you must keep your system on the long wall, then I respectfully disagree with Shadorne that your television is not a factor in your efforts to get the best sound possible with that configuration. I too have a large TV screen between my speakers. When I sit down to listen, I place a large piece of acoustic foam (12" in depth) in front of the TV screen. This minimizes undesirable comb filtering effects by reducing first order reflections from the TV. The result, IME, is an audible improvement in image focus and soundstage depth.
You also sit with your head near a wall - this is well known to collapse the soundstage and make if feel claustrophobic or constrained.

It has nothing to do with your TV.
Your problem is not the TV - you are sitting along the short axis of the room. Have you ever seen a concert hall designed this way? No. And for good reason, the acoustic are not good in the orientation you have chosen
...speakers and TV are along the long wall, and I only have about 12' total between that wall and the wall behind me.

As you seem well aware, this is the heart of the problem. As I see it, you must play a game of inches. The solution, suggested by several posters, of moving your speakers farther into the room, and thus closer to you, is a natural one, and worth experimenting with. I have a fear about that solution, however, which is that, by getting your (I believe) 3 way speakers closer to you than (the current) 9 feet, you may have problems with driver integration, i.e., coherence. To me, that is a more important consideration than soundstage depth.

In light of that, I agree with Mark's suggestion of getting a flat panel TV and wall mounting it. If I interpreted your measurements correctly, that would place the surface of the TV at least ten inches further back from the drivers of the speakers than it is currently. I know that's not a huge amount, but like I said, this is a game of inches.

The other thing I would consider experimenting with, if you haven't already, is moving your speakers a little farther apart, so that you are a bit closer to an equilateral triangle. I don't think that will improve soundstage depth per se, but it should enlarge the soundstage on the x axis, and possibly enlarge the image sizes slightly, which might compensate, psychologically, for the lack of soundstage depth.

Good luck!

Have you considered selling the TV and getting one of the new ultra thin displays and wall mounting it? You have some nice gear there - the cost will probably be relatively low.

Mark
Love those diffusion panels, are they DIY?

I have to agree about moving the speaker back from the front wall. In my experience, treating the front wall between the speakers helps with imaging and clarity there is a minimum distance the speakers need to be out in to the room to get depth.

I have my speakers on the long wall but am out about 60".
In playing with speaker placement and moving the speakers back towards the wall there is a point where the sound stage just snaps flat and I lose all depth. Obviously this point will depend on your speakers and your room.

Buy some furniture sliders and put them under your speaker spikes and try sliding your speakers forwards and back until you get a handle on all the trade offs with speaker position in your room. All the set up methods are really just guide lines to get started, you have to to the final tuning by ear.
Probably not the response you want, but I can see a way to improve your depth of image etc. Put them on the short wall. The only problem would be the left speaker would probably have to be in a location that would interfere with entering the room. I have a room of similar size and my width/height fill is the rear wall +, and the depth is beyond it. BUT I don't have an entry way where yours is. My speakers are 66 inches from the back wall and only two feet from the side walls. the speakers are 9 1/2 feet apart and my listening chair is 11 feet back.

If you can accommodate that physical set up and are interested, post and I will expand upon how and why it works (for me).
Tholt,I'm by no means an expert so don't take this comment as the gospel.I don't think the thirds rule works in all situations.I think the only way to deepen the soundstage is to get some more room behind the speakers.The farther away from the wall you get,the less breakup in the sound.This seems to be the consensus on everything I've read on the subject.I realize you only have so much room to play with.Maybe experiment with the toe-in some.I also noticed you have a opening behind the right side.My setup does too and it's a feat to get really great sound when one side is being funneled away thru an opening.Good luck.
Here are some room pics of the setup -
image 1
image 2

this is with my homemade diffusion panel over the TV