Author Topic: Room Questions  (Read 2812 times)

LKdog

  • Guest
Room Questions
« on: July 26, 2007, 09:03:52 AM »
Bryan-

Interesting product. Congratulations.

I read your posts with interest here and other forums as I have been working on Room Tx for several months.

Quick question (I know none of this ever has a simple answer) if you don't mind.

My room is 25' long and 15' wide and then 18' wide where a staircase ends.

I have my speakers about 5' in the room and the listening position roughly 15' in the room so there is roughly 9-10' behind the listening position.

Presently have bass traps in front and rear corners which made a nice improvement in bass output and overall clarity of sound stage.

I have side reflections absorption with 2'x2' fiberglass panels.
I have two 2'X4' panels behind the me on the back wall.
I have nothing on front wall right now behind the speakers.
No diffusion anywhere.

There is an equipment rack and TV between the speakers, but they are set back a couple feet and they do not seem to hinder the sound stage. I have put panels over them and it made no difference that I could tell.

Should the larger 2'X4' panels be on the front wall behind the monitors?

I guess I was doing a LEDE thing with the front wall being live.
There is a good bit of absorption in the room from sofas in addition to the bass traps and panels.

Any thoughts are welcome. Maybe I am doing this backwards??

Thanks.

--Tony

System is:

ACI Jaguar monitors
ACI Titan subs (2)
Odyssey Mono Extremes monoblocks
Audio Mirror PP1 tube preamp
TRL SACD 900 source
 

Offline bpape

  • Audio Neurotic
  • *****
  • Posts: 1554
  • Sensible Sound Solutions
    • Owner - Sensible Sound Solutions
Room Questions
« Reply #1 on: July 26, 2007, 09:21:46 AM »
Well, if it was me, I'd be moving my seat back just a little.  If you're where you say you are, you're sitting at 40% from the back wall which normally isn't a good place.  Add in the fact that the speakers are at approx 20% and you're getting a lot of overlap.  Those are free things to try - always a good thing.

Absorbtion on the rear wall isn't a bad thing if thick enough to deal with the null that comes off that based on seating distance many times.  Moving them to behind the speakers will help smooth bass response by dealing with SBIR issues but may also open up a can of worms with the null coming back.

Normally, in an LEDE situation, you want the front more dead and the back more live and diffuse.

Bryan
I am serious... and don't call me Shirley

LKdog

  • Guest
Room Questions
« Reply #2 on: July 26, 2007, 12:16:49 PM »
Bryan-

On the "overlap" you mention.......what might be better distances?
I have the monitors in 5' as I have always been told to try and get them into the room and away from front wall.
The old rule of thirds thing would put them at 8.33' which is not feasible really.

I have an approximate listening triangle of 9' then with speakers distance between them and to the listening spot
which is about 15' back from front as noted. Actual listening distance from speakers is closer to 10'.

Can easily try some different distances and move the big panels up front.
Maybe some diffusion on the rear with a commercial product like yours, or some big hanging plants.

Thanks.

--Tony


PS- Sorry for the dumb question.....what is SBIR??  :oops:

Offline bpape

  • Audio Neurotic
  • *****
  • Posts: 1554
  • Sensible Sound Solutions
    • Owner - Sensible Sound Solutions
Room Questions
« Reply #3 on: July 26, 2007, 12:23:45 PM »
SBIR is Speaker Boundary Interface (or interference depending on who you ask) response.  This has to do with the spherical wavefront from a woofer which wraps around and comes off the wall to blend with the direct signal.  Some is in phase (peak) some is out of phase (dip).  The trick is to minimize it and/or use what's left to counter other anomolies.  Say you have a peak in response at 70Hz at your chair that is position related.  If I can move the speakers slightly to introduce a dip at 70, I'm smoothing things in the frequency domain.

Try moving your seating back maybe 6" and the speakers forward 6".

Bryan
I am serious... and don't call me Shirley

LKdog

  • Guest
Room Questions
« Reply #4 on: July 26, 2007, 01:08:46 PM »
Bryan-

Thanks for the impromptu consult.
Will experiment a bit with your ideas.

Regards-

-Tony