The Perfect Listening Room.

If you had the opportunity to design and build your own listening room, how would you design it? What dimensions and materials would you choose for the floor, walls and ceiling? Is there a 'best' way of doing it?

 

There is no easy answer really. For the perfect listening room (or as close as you can get) you really need to build it then take real life measurements and tweak it from there; theory only gets you in the ball park.

Non-parallel walls are a nice idea, like a tapered trapagon. But the most important thing is to have evenly climbing modal distribution. A rectangle room 15.4' x 12.8' x 10' does pretty well and is a nice usable size.

I would probably use an upstairs room and fill the gap beneath the floorboards with absorption that would help the upper bass area a lot of rooms seem to be a bit poor in. I'd also use a thick hair-felt underlay and a wall to wall carpet. That should for fill most of the absorption needs of the room in one hit and all you would only need to use a few diffusers on first reflection points. Diaphragmatic bass traps in the rooms corners.

I generally find a dead space directly behind the listener woks well, so I guess it would be a dead back, live front room design.

That should give you some ideas anyway.

 

interesting room dimensions there tenson.. how do you arrive at them?

i ask as im about to move my kit into a room that is roughly 3.5x4.5x2.5m which almost bang on the dimensions you mention above.

How would you acheive a dead space directly behind a listener, as factoring speaker positioning into a room like that means that the listening position would have to be all but against the back wall.

 

There is a nice house up for sale in Hastingsabout 5 minsaway from me. Paul Messenger told me about it.

Have a look

It has a dedicated Music/Hifi room designed by Jim Rogers. Paul mesenmger did a write up on the house in hifi choice years ago. But it has just come up for sale.

 

Hi,

It is based on a method set out by Oscar Juan Bonello that the low frequency range of a room be split in to 1/3rd octave bands and that as you progress up in frequency each 1/3rd octave band must have more or at least equal number of modes as the last. I think identical room modes in each band are not allowed either. There are probably some applications that will calculate good proportions from that method or you can do it yourself using a normal room mode calculator.

I think the room you describe will be pretty good. Having the listening position near the back wall is fine, just use an absorptive panel behind the listeners head. I happen to sell such panels, and they are rather good I could send you a leaflet if you are interested. The point behind the listener IMO is the most important to treat if you sit near the wall. If that’s all you treat in the room it is worth it, and worth doing well.

 

Why? I thought the best floors acoustically were concrete, which usually means ground or basement level.

Wasn't there someone else who came up with a set of dimensions for building a space? There was a name for it, I think.

But if you have so much space that you don't need to be up against the back wall, would that not be better?

That house near Hastings looks really fab. The only thing is the music room might be difficult to keep warm in winter.

 

...for teeny weeny speakers...

 

I think that what we need is a real summer of good weather and move the speakers outside - would need a big garden and forgiving neighbours, but no standing waves, no corners etc and my ESL 63s would sound brilliant half way down the garden. I could even experiment with absolute phase differences!!

 

the problem with that is that speakers actually rely on room boundary reinforcement.... in a completely open space you would almost be dealing with anechoic conditions, in such a situation it would make the system sound very dull and flat.

Whats needed is a good compromise between the two.

 

I have heard that said too, but in my experience that isn't the case. Concrete won't resonant which is good, but it will reflect very strongly and set up standing waves, so its a compromise. If you had lots of damping material under floorboards then even if they did resonate they would stop very quickly and it would help reduce modal issues. The room would not sound too dead as the floor would still reflect specular frequencies.

Yes, there are many.

Some distance between you and the back wall would be good but more than 4'-6' doesn't really seem worth it to me. You would still need to treat the boundaries and it would need more surface area covered since the walls would be bigger. IMO super large rooms don't really offer much advantage over a certain point, especially now we have DSP to help control troublesome room modes.

 

ive never actually liked having space behind me (at least not much) in a listening situation. I tend to find that when theres more than a few feet behind me it sucks away bass and i tend to find the systems sound bass light. A hell of a lot of dealers have their rooms set up like this and generally to me it sounds very poor.

I usualy have maybe 1-2ft behind me and this seems to suffice.

 

Just stick some carpet or a rug over the concrete. That will sort out the reflections.

 

Yes I agree. If you sit too far from the back wall you are more likely to be in a null at some frequency.

I don't see why a room around 15' x 13' wouldn't be large enough as a listening room. If you don't have an over-sized room you don't need oversized speakers! ...unless they are making up for the size of something else?

 

Okay, you do that then!

 

I'd agree with that. Standard joists floors tend to be fairly effective absorbers at the upper bass frequencies.

I'm running some large speakers in a medium sized upstairs room and the bottom end sounds much better than it should really. I also have one stud plasterboard wall and that also helps low-freq. modal issues.

My downstairs rooms with concrete floors and block walls sound pretty dire in the bass..

 

Useful absorption (to reduce reflection) will only occur at frequencies where wavelength is roughly equal to or less than the thickness of the carpet. 8kHz has a wavelength of about 40mm in air.


And you need to nail a rabbits foot (with blue LED) to the wall to quantum order the air molecules in your room.

 

I agree that listening to music outside has a lot going for it other than you need a lot of volume to recreate realistic listening levels, which would, inter alia, seem to rule out the ESL 63s.

 

dead listening end and live speaker end is better IME, having played around with both. However, this was with my system and may not be for everybody.

From my experiments, the rear reflections are the biggest effect. So I use home-made diffusors behind the speakers which work very well

(although I've since moved the speakers onto wall mounts due to the enormously destructive effects of a toddler called Anna)

 

sorry, there isen't any,
nando.

 

Went to a dance event last night in a spectacular church, which was hired out. It was like being in a mini-Westminster Abbey. The ceiling was probably about 60 feet at its highest point with wonderful arches around the sides. Acoustically, it was a revelation. Music was from a single pair of JBL 15-inch EON actives, reduced to looking like computer speakers. They were hardly the last word in finesse but they sounded so clean and enjoyable and really made me realise what a difference a room can make.

Now where were those details for that house in Hastings?