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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

Showing 7 responses by rrog

rrog
1,958 posts
 
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.
rrog
1,958 posts
 
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.
rrog
1,958 posts
 

Tholt, Good idea. Are you placing them vertical or horizontal?
rrog
1,958 posts
 
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.
rrog
1,958 posts
 
"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.
rrog
1,958 posts
 

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
1,958 posts
 
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.
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