optimum listening space

[peace brainerd]

I did a (ok, a cursory) search for this topic.

What are the optimum qualities of a listening space that the
speaker designer is hoping his speakers will end up in? Perhaps
there are some who would design for their present room specifically, but what of the myriad excellent available diy designs and the majority of commercial offerings?

Wood, plaster, brick walls? Round room? Four walls? Open doorways - closed? Lots of overstuffed furniture, or minimal furnishings? What height ceilings? Wooden joisted floor, types of carpet or floor covering?
Or poured basement floor? Many basements have poured floors and concrete block walls, although ceilings here are typically lower.
Are large uncurtained windows a problem? Etc, etc..

What would you ask the contractor for if you had the luxury of
planing the ultmate listening space in your new custom home (bearing in mind that it might see numerous changes of audio gear in the years ahead)?

[JinMTVT]

i do not pretend to be quite Knowledgeable on this topic,
but i have read many usefull books/article to get you started...

There are many accoustical room problems that need you attention when looking for an optimum space

I'd say that those are the most important ones :
( only to name a few )

- room modes
- bass reflection problems
- direct reflection of mid/high freqz
- bad diffusion of sound ( channeled freq dispertion )
- absorption ( or lack of )

most of the problems i know of, are related somwhere to reflections neway ..

some basic design guides to minimise the named problems

- non paralell walls and ceiling
- use of diffusion/absorption material at the right place
( quadratic residue diffusors and absorptive panels )


i hope that others will give their words in, as i am tired
and i don't have many ideas of now

hopes this help a bit

[soongsc]

There are three major issues.

1. Reflecting sound.
2. Room modes.
3. Wall, Floor, ceiling stiffness.

If you have a fully elliptical room, you preety much have the first two taken care of.

[BobEllis]

Check your library for a copy of F. Alton Everest's Master Handbook of Acoustics Although geared towards studio design, it will give you a good idea how to tackle the problem.

If you have enough money, you should consider hiring a contractor who specializes in listening rooms or HT depending on your goal. Everest's book will help you understand what they are telling you.

For a DIY effort, I'd say that you are looking for the right mix of direct sound, reflected sound and absorption. Too much absorption/not enough reflection and the room sounds dead. Too much reflection and the sound is muddied.

A non square room helps minimize room modes - no parallel surfaces.

Stiff boundaries are important if you want to isolate the sound from the rest of the house - late night Movies while young ones sleep. Otherwise, take the dissipation through walls into account when adding room treatments.

Room treatments are extremely important - the catch is getting them past the other owner of the house. If you can only get away with a couple pieces shoot for controlling the first reflection to your primary seats. I was amazed at the amount of "new" details I was able to hear in familiar recordings when I did this. Unfortunately it meant putting an absorber in front of French doors. (something to keep in mind when designing your room.)

See www.rpginc.com for some ideas of what types of treatments are available for purchase or cloning. (The Everest book includes a lot of their stuff - perhaps he once worked there) A mix of absorption and diffusion (and open reflective walls) is likely in order. A contractor has the tools to measure your room's properties (or design them in) and specify appropriate treatment with very little trial and error. DIY can take longer to reach the goal. I haven't been able to room find measurement software at a price I can justify for a hobby. If anyone has any recommendations, I'd love to hear them.

There is a thread on room treatments HERE

EDIT: Keep the flammability of treatments in mind - you might pay more for flame retardant materials, but it is worth it. Remember the night club fire in Rhode Island that spread rapidly in the acoustic foam?

[Scottmoose]

Read Linkwitz articles too.

www.linkwitzlab.com

Best
Scott

[RobWells]

The Handbook for sound engineers is also a great book.


Rob.

[BobEllis]

One more thing - that coffee table that you want to put in front of the listening couch has to go. Another one of those Eureka! moments - I pulled mine out to refinish and found another level of clarity. End tables it is.

The room seems to have almost as much impact on sound as speakers.

Edit: a link to The Master Handbook of Acoustics

[AutoAudio]

For me SAF is a huge issue and so my room has to look and be very functional to the way she wants it. I added about 10 feet of extra speaker wire for my speakers so I can pull them out to have near field listening when I want to listen criticly and they can be put back when I'm done for watching tv and what not. Also with them pulled out, I pull back the coffee table behind them so its not in the way causing reflection. There are definately still obstacles though. They aren't the exact amount of space away from the wall on both sides due to a couch and said couch probably affects the reflection differently then the one with out a couch next to it. I can only get away with so much.

Bruce

[thalis]

""What are the optimum qualities of a listening space that the
speaker designer is hoping his speakers will end up in?""


As a general ‘rule’, and without having to calculate and look into formulas, I would be happy to see a room with at least 4 meters width and 3 meters height (volume is always welcomed), thick carpet on the floor, big windows (to have some absorption in the lower frequencies) with curtains, cupboards would be nice (for the same reason, they absorb low frequencies), book-shelves as well (they act like diffusers), in general I would be very happy to not have reflecting surfaces nearby the speaker (to control the first reflection and to have a somewhat small EDT – early decay time), and to have well-balanced absorption properties in the various surfaces, so to have a somewhat uniform and rather small reverberation time (R60).

Regards
Thalis

[bremen nacht]

Originally posted by BobEllis


The room seems to have almost as much impact on sound as speakers.

Very true, and the better the speakers the more you'll feel the
need to do something about the room.

http://www.ethanwiner.com/acoustics.html