Proper Room Designs/Dimensions for Best Acoutics

I have the chance, to build from ground up, a dedicated listening room. I spoke with Dennis Foley and was very impressed with his ideas. Does anyone have any experience with him either directly or indirectly? Does anyone have any general recommendations for me as far as design or dimensions? I know about the "golden ratio" etc.
Handy - if you have any good audio stores near you, you might want to take a look at what works for them.

One audio store I frequent that appears to have a very good setup for their very expensive systems - has one room as follows

- 16ft x 30ft with a 9-10 ft ceiling
- the speakers are positioned across one 16 ft wall
- they are approximately 7-8 ft from the wall behind them
- the listening position is around 8ft from the other 16ft wall

They are using the massive Sonus Faber's.

They appear to use very little in the way of sound absorbing panels or bass traps - other than carpeted floors and pictures on the walls.

Imaging is the best I've heard

Hope that helps

I live close to Nashville and my dealer also has a great listening room. They have a couple of panels on the walls, with a trayed ceiling and some corners that are 45 degree angles, instead of 90's. I have heard Wilson speakers, with Martin Logan's sitting right beside them and am amazed how good the sound is. They have a lot of concrete also, covered with carpet etc. People with basements for sound rooms, have no idea how lucky they are-specially, if they play vinyl.
Handy - don't let yourself get hung-up on 90 degree corners - they are easily remedied
- you can probably make a very effective bass trap with sonotube and soft coverings, like carpet
- a solution I currently employ was to build two panels almost floor to ceiling height and 15" wide with soft materials and place them at approx 10 degree angle to the side walls in the corner - approximately 4"-5" from the wall behind the speaker

But the effectiveness of this also depends greatly on the speaker.

- one speaker had a rear firing 2" port and the bass resonance was really bad until I "adapted" the port to fire downwards.
- another had a front firing port, which was not so much of a problem - other than at the wall behind the listener
- my current speaker has a 2" x 9" port, so the bass is much less of a problem than most other rear firing ports and the screens take care of what issue there used to be.

I would not personally use 45 degree corners because
- they too can create even bigger problems - reflected sound
- from a resale perspective it just looks weird

Another approach is to use reflective panels e.g. two panels at slightly different angles closer to 25-30 degrees to the side walls
- that way any reflected sound gets scattered
- the rear of the panels can be covered with soft materials (carpet) to absorb sound reflected from the walls behind them.

One member with a large room reported that using carved wooden screens worked very well behind the speakers.

Unfortunately there's a ton of different ways to skin this particular cat.

I would build a rectangular room and deal with any issues as they arise
- a larger room seems to mitigate a lot of "Small Room" issues
- Materials used for floor and ceiling play a huge role in keeping echoes to a minimum
- a larger room can cause echoes, but gives you more "tuning" flexibility e.g. using reflective panels and absorbing panels
- a smaller room reduces options to absorbing panels and too many of those can lead to a dead, or flat sound.
- but speaker choice has a lot to do with the final acoustic tuning requirements and options.

I'm currently looking at deflection panels at the moment - finding one that is "pretty" on the WAF scale and easy to install is a challenge.

Hope this provided some food for thought :-)
An acoustics guy - see...

Handyman - one thing you might want to consider for your room is an acoustically damped ceiling.

Options can include...
- a simple drop ceiling with acoustic tiles - there are many options for this and you do not need a great deal of height to implement a solution.

- the $$$ultimate...

OK, so I've just finished playing - yet again...

A friends place has a 12ft ceiling, so I've been looking at possible solutions - hence the post above.

So I got to thinking about my room with an 8ft ceiling and how a "baffle curtain" might help.

I just happened to have a piece of heavy duty vinyl 2 ft x 6ft and a couple of lighting stands, so I rigged it such that the vinyl hung down from the ceiling like a banner, across the room and tried it in a couple of positions...

1. just behind the speakers...
- There was some improvements in clarity and image
- nothing really to write home about

2. just behind the listening position...
- talk about an OMG moment!
- clarity improved beyond my expectations
- image now easily exceeds the boundaries of the room on most all tracks
- projection of venue acoustics forward now easily envelopes the listener on many tracks
- it's like surround sound with only two speakers
- the improvements can easily be heard outside of the room also, just amazing.

So if you are thinking about some room treatment, start with the wall behind you and work forwards from there - but make sure it's close to the ceiling.

BTW - I also have a couple of 15" x 78"(tall) panels on the side walls behind the speakers to deal with an echo that travelled across that wall behind the speakers

If you(the O.P.) really care, obtain a copy of The Master Handbook of Acoustics by F. Alton Everest. Beginning on page 100(well, mine is a first edition from 1981) there are a series of formulas, suggestions and explanations, regarding indoor acoustics, reverberation times, avoiding resonances, modes, etc. I've found it an invaluable resource, over the years. (