# Listening room question



## needspeed52 (Aug 2, 2008)

Hello all,
I have a question which I'm just now addressing, my setup is in a 14' X 26' X 8' room, I'm using a little more than half of the 26' length and setup is on the short 14' wall, it's a 5.1 system, using half of the length of the room means that I don't have a rear wall, I do but it's 10 to 12' away. My question is how detrimental is this to sound quality not having that rear or back wall? Thanks for the time.
Jeff


----------



## charles_b (May 10, 2010)

Well, regarding sound quality I would like to make the following comments:

1. The effect of having "no back wall" will be influenced by the acoustic interior of the room behind you. Is it totally empty? Or are other peaces of furniture there, a carpet and so on? This will be the most important issue in order to understand sound quality.

2. Using a 5.1 there usually is the option to control delay time to the rear speakers. You may want or have to adjust these parameters as a part of the sound travels to the back of your room. Maybe you can even turn around the rear speakers and use the "trunk" as a big sound volume.

3. Overall I would not worry about the sound. I´d rather wonder if I would like to sit in a room having no "back" behind me. There may be special emotional effects if you watch horror movies with strangle scenes and there is a dark hole behind you...


----------



## needspeed52 (Aug 2, 2008)

charles_b said:


> Well, regarding sound quality I would like to make the following comments:
> 
> 1. The effect of having "no back wall" will be influenced by the acoustic interior of the room behind you. Is it totally empty? Or are other peaces of furniture there, a carpet and so on? This will be the most important issue in order to understand sound quality.
> 
> ...


Hey Charles, thanks for chiming in, the space behind me is an office area with desk and computer, carpeting, furniture and an open side wall leading into another area. I have things dialed in fairly well now but I just thought about it today not having a close back wall and wanted to get some thoughts on this. I thought about adding rear surrounds but can't justify doing it. I put this question out because I do a lot of two channel listening and wanted to know how much of an effect, if any not having a back wall would make. Thanks for the reply.
Jeff


----------



## lsiberian (Mar 24, 2009)

needspeed52 said:


> Hello all,
> I have a question which I'm just now addressing, my setup is in a 14' X 26' X 8' room, I'm using a little more than half of the 26' length and setup is on the short 14' wall, it's a 5.1 system, using half of the length of the room means that I don't have a rear wall, I do but it's 10 to 12' away. My question is how detrimental is this to sound quality not having that rear or back wall? Thanks for the time.
> Jeff


Size is always helpful in a dream world we'd live in a mammoth room. This is because for every meter sound travels it loses 3 db in magnitude. So 4 extra meters means a -12 reduction in magnitude at reflection and by the time it comes back you will have nearly -20 db which means your rear wall distortion is greatly reduced. of course larger rooms are harder to pressurize with subs, but they also have better overall acoustics on bass.


----------



## needspeed52 (Aug 2, 2008)

lsiberian said:


> Size is always helpful in a dream world we'd live in a mammoth room. This is because for every meter sound travels it loses 3 db in magnitude. So 4 extra meters means a -12 reduction in magnitude at reflection and by the time it comes back you will have nearly -20 db which means your rear wall distortion is greatly reduced. of course larger rooms are harder to pressurize with subs, but they also have better overall acoustics on bass.


Thanks ISIB for the very informative reply. When I'm working on the computer at the far end of my room and listening to music, the sound quality is very good, kind of not just background sound, does that make sense what I just said? Speaking of subs, I would really like to try a build, my skill level is not up to doing that though. I truly believe that a DIY sub can compete with some of the big commercial brands for a lot less money, the problem is if I have someone build it for me there goes the cost factor in DIY. Any thoughts on direction to pursue with this endeavor, someone who could do this? Thanks my friend.
Jeff


----------

