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 8 responses by tholt

Here are some room pics of the setup -
image 1
image 2

this is with my homemade diffusion panel over the TV
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.
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.
@ Learsfool - there are curtains over the glass door and window. Not very thick, but there nonetheless.
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 180ยบ 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'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.