View Full Version : what do you think is the best acoustic treatment

25-01-2008, 04:37
Greetings all

Thought i would throw this one into the mix

with the advent of dsp room correction, having a couple of velodyne dd15 delivered soon, and also reading thru reviews of the latest dsp room correction devices, any opinions on which will be the winner

seems like a digital correction is a lot cleaner install, than all those non wife approved bulky room traps

any opinions?



25-01-2008, 09:57
For my money (and this is free), I'd say the finest acoustic treatment is experimentation. Listen, jiggle, listen, move furniture, listen, close the curtains, listen, have a ciggy, listen, fiddle etc etc.

I've found some really great positioning techniques this way. Of course it helps that my listening room doesn't have parallel walls (house built 1850) but just by moving furniture the room can really be deadened.

Having said that I've never tried a DSP but I would consider that to be adding components into the chain and therefore (potentially) degrading the sound by means of straying further from the original signal.

On the other hand, with AV it practically invites itself. :)

29-01-2008, 20:47
I have spent a long time looking into the benefits of room correction and acoutic treatment and currently own a Tact 2.2x. I find many of these room correction devices take away the magic of music and much prefer to perform the final tweeking in the cross-over and in the listening room where room measurements are taken and either the amount of internal wadding adjusted or the tweeter level adjusted to suit the room. I appreciate hardly any-one has this facility how-ever it's the only real way of identifying some problems, especially with dry rooms.

Ashley James
02-02-2008, 14:52
Over the years different companies have expended vast amounts of money on research into room equalisation. All of it showed that you can't correct a room problem by altering the amplitude response of the source, in this case your hi fi.

When you listen to a sound emanating from anything in a room, the first thing you hear is the direct sound travelling straight to you. Its SPL drops by 6dB each time you double the distance from it.

Next you hear early reflections, which comprise of sounds bouncing off reflective surfaces and arriving a little later than the first arrival.

And finally you heat the reverberent energy as the sound reflects backwards and forwards around the room. RT time defines how long it takes to drop by 60dB. As long as there is sound exciting it, the level stays the same everywhere.

Despite the fact that the direct sound may be less loud than the reverberent energy because of the distance you are from it, you still hear it first and make your critical judgement from it. Therefore if you alter it, things won't sound right. It's blindingly obvious when you think about it, but that hasn't stopped experts from wasting a fortune.

There are Acousticians around who measure rooms and recommend treatment if there is a problem. Typically, if the RT time of high frequencies is longer than all the others, you're system will sound bright, and so on. This can be measured and fixed.

Most of us probably will have reasonable rooms without realising that we've filled them with furniture so that they are pleasant to relax and talk in and that it helps the hi fi as well.

Bass isn't usually a problem either because not all the walls are necessarily solid and there are doors and windows.

And we tend to buy small speakers that probably won't excite room resonances.

Years ago when I was at ATC, we sold a pair of SCM200's to the BBC which were mounted about half way between the floor and the ceiling and the same distance from the back wall; the result was a total absence of Bass. Measuring them showed a huge boost at 35Hz and nothing at 70Hz and if any equalisation was applied 35 Hz got Louder and 70Hz quieter and altering it digitally wouldn't have made a scrap of difference. Putting the speakers in the wall cured the problem along with suitable traps. Most of you won't have 4 x 12" bass drivers with 700 wpc so needn't worry.

I hope this helps.

Filterlab's advice is the best.

03-02-2008, 08:35
I tried EQ, TAG TMREQ and Krell processor simpler equalizer...

It appears to sound better in the begining, but it "kills" the music, I always ended up switching it off...

Adequate speakers, well positioned, some care with furniture and wall covering, and bass management with a reasonable subwoofer, will be enough for very good results...

The Grand Wazoo
25-05-2011, 07:01
From The Grave

25-05-2011, 13:43
TubeTraps, as I've recommended elsewhere. A natural room treatment setup is going to beat any digital room correction system, however good it is. I want my analogue signals to remain analogue!


They really work. I use four TubeTraps, three PicturePanels and a SubTrap in my room.

25-05-2011, 13:59
Believe filterlabs advice. Forget room treatment stuff, move furniture and speakers around and don't forget to look at where you sit. Make sure both speakers are the same distance from you and you are exactly inbetween them !
I've got a lot of time for this bloke's take on things http://www.getbettersound.com/speakout.html

25-05-2011, 14:16
Forget room treatment stuff

It's fine for that to be your opinion, but you have directly contradicted a posting and recommendation I made just above. I have and use room treatment - what brand and types do you have experience of?

Ammonite Acoustics
25-05-2011, 14:58
As a qualified acoustician, I can comment here. In the first instance, moving the listening position and furnishings around, sensible use of natural diffusers like bookcases etc, adjusting the listening position etc are all free and will tell you if you really have a residual problem that requires investment in physical room treatments or in DSP. It may be that bass traps etc are the answer, but to be effective, bass traps in particular must be quite large (the laws of physics dictate this) - something that does not necessarily sit well in smaller British rooms. It is very common for audiophiles to get hung up on room modes and their effects, but if the listening position corresponds to a maximum amplitude part of a standing wave, simply moving to one side will usually be rather more effective than trying to absorb enough (bass energy) to balance the overall sound properly.

Unlike Martin, I would not be dismissive of digital room correction techniques, which can be spectacularly successful if not asked to work too hard; however by the same token when used lazily, eg without addressing the fundamental basics of room acoustics, musical satisfaction can be severely damaged.

26-05-2011, 03:58
The prefect solution (headphones).

Food for thought, One of the best rooms sonically speaking was a largish den with a very old cork floor,wood walnut paneling from the floor to your shoulders and lath and plaster walls nearly full of these.

Mounted heads 2 feet apart on every wall.
And 2 book cases of law books.

26-05-2011, 21:30
That sounds like a room from a Scooby Doo episode Jeff! Well, it would freak me out, and I'm not even Shaggy! ;)

Rare Bird
26-05-2011, 23:06
The prefect solution (headphones).


28-05-2011, 08:58
The prefect solution (headphones).


Or as I call it, throwing the baby out with the bathwater...

29-05-2011, 23:16
Or as I call it, throwing the baby out with the bathwater...

A good headphone set up can be very magical.
My point is there is no perfect room treatment (one size fits all) for every room.
Creativity is far better served with a lot of time spent trying different things.

Remember good headphones are speakers that come with there own listening room.

purite audio
30-05-2011, 10:58
Actually there are active room correction boxes available that will do everything, literally everything, frequency response ,group delay, first reflections, impulse times etc, check out the Trinnov website.

30-05-2011, 11:13
I'm surprised that passive room treatment is dismissed by some users in favour of complex digital room treatment. Passive works very well and need not be expensive - there are solutions other than TubeTraps available at much lower prices. Plus, of course, your own selection of furnishings.

I have some experience of treating two rooms that have held my hi-fi system. If anyone wants to discuss it further, let me know.

purite audio
30-05-2011, 14:35
Can passive room treatment , replace bass lost in a suck out, or correct phase or group delay?

30-05-2011, 14:53
Can passive room treatment , replace bass lost in a suck out, or correct phase or group delay?

It depends on what is causing it. A suckout - no, but it could even out the bass response so that a nearby reinforcement in frequency is reduced. Group delay - possibly if it's caused by reflections from side walls. Phase? More likely to be speaker crossover anomalies.

purite audio
30-05-2011, 16:53
It depends on what is causing it. A suckout - no, but it could even out the bass response so that a nearby reinforcement in frequency is reduced. Group delay - possibly if it's caused by reflections from side walls. Phase? More likely to be speaker crossover anomalies.

Foam can absorb some frequencies it has to be extremely thick to absorb lowish frequencies, some diffusion absorbs ion will help with first reflections and the impulse time of your room.

30-05-2011, 19:09
I bought a SubTrap originally to match my REL Studio II subwoofer. It worked wonders. When I sold the REL on, because my current Ushers don't need a subwoofer, I kept the SubTrap in the room and it still has a good effect on keeping 'one-note' resonances and bass peaks at bay.

I wouldn't recommend buying a SubTrap for this kind of use, as it's too expensive. But it is very effective at deep bass absorption.

The TubeTraps are a combination of diffraction and absorption. You can 'dial-in' their effect by rotating them.