Tuning a room for reducing its modes

[djanogil]

I was reading an article about that,
and it said that since it's impossible to treat your room's modes completely (even into world class studios with unlimited budget), it's a common thing to compensate for the peaks and nulls using a parametric equaliser.

How many of you are doing that, Is it a good solution?

[jwl]

There has been a lot of debate about this.

In general, I'm of the opinion that EQing a room to sound good is misguided at best, and is certainly not the first or best approach to making a room sound good. You should treat the room first, then small doses of EQ can work well as "icing on the cake."

But you certainly aren't going to solve room mode problems with an EQ. First of all, even if you know the exact frequency of the room modes, do you boost or cut? By how much? Because different spots in the room will respond differently to the room modes: some areas will give a very narrow and tall boost, other spots will give a very narrow and very deep cut. This is the physics of standing waves and comb filtering, it's HUGELY variable throughout the room. So even if it's theoretically possible to get one spot sounding great, you are very likely making things MUCH worse everywhere else in the room.

This is without regard to other problems with EQing a room (possibly blowing speakers, pushing amps harder, adding distortion, adding phase smearing, etc).

I did read where John Storyk used an EQ treatment for a very small control room he designed, but only because he was unable to use acoustic treatments in the room for whatever reason. So even people who like room EQ recognize that room treatment is a better solution in general.

[djanogil]

Originally Posted by jwl

There has been a lot of debate about this.

In general, I'm of the opinion that EQing a room to sound good is misguided at best, and is certainly not the first or best approach to making a room sound good. You should treat the room first, then small doses of EQ can work well as "icing on the cake."

So even people who like room EQ recognize that room treatment is a better solution in general.

Yes that makes sense, I also read another topic on that very same subject.

I hope I'll be able to treat my room properly, for at the moment the differences in response at the sweet spot are alarming;

If I move my head back or forward in a 50 cm range (about 20 inches), I don't hear the same thing at all in the bass region, that's quite disturbing and makes me wonder what I should rely on..

I'm in the process of treating the room, I have buit 6 4" panels on top of my existing 8
2" ones, they're not fixed yet, just free standing for experimentation,
but I have a sloped ceiling plus a lot of windows so it is difficult to mount the panels in the necessary spots..

[jwl]

Don't be too alarmed, the response differences you describe are to be expected in a small room. Bass trapping is the answer. Depending on the size of your room, 6 panels should begin to help, but more will probably be better.

[Ethan Winer]

Originally Posted by djanogil

Is it a good solution?

jwl already gave you the right answer - No, it's not a good solution. I've researched this and written about it extensively:

RealTraps - Audyssey Room EQ
RealTraps - EQ versus Bass Traps

However, I'm not opposed to using one or possibly two bands of cut-only EQ below 40 or 50 Hz where conventional bass traps are not so effective. Even then EQ should be used in moderation. For example, if you have a 6 dB peak at 35 Hz at the listening position, I'd cut no more than 3 or 4 dB. Otherwise you risk making a dip somewhere else in the room.

--Ethan

[LittleJohn]

My crystal ball --- which is certainly been known to have been wrong in the past, tells me that the home theater market will run to the equalizer approach since it sounds easy. ( just add another gadget and all is good )
The home theater marketing crowd will be sensitive to the guys selling TVs and stereos, and not want the construction issues to impede those sales conversations. Room treatment just sounds like piled on expense to folks in a hurry who want to watch "fast and furious" at 130 db.
Those are the people consuming the products. Fine for them.

For those of us creating the products, the same crystal ball tells me that folks selling traps for a living will still be around for a while. I cant see music production leaning too heavilly on the eq versus using room treatments.

I am no expert, but I have read both Gervais and Everest, ( chapter 15 from Everest is very interesting ) and I did not see anything that suggests an EQ can put back or insert something that is not there to begin with ( i.e. the "valleys or the dips )
My personal experience with just doing FOH for bands in large clubs is that doesnt work very well. You can emphasize the missing frequency but it sounds a little hokey ( cause it aint really there to start with )

-- again, potentially faulty crystal ball, and only read he books last month.
Just my $0.02

[jayfrigo]

The quickie points - don't try to fix a time domain problem in the frequency domain. EQ won't stop the ringing decay of problem modes. As you push up the EQ to fill in certain holes, you are actually exciting those problem modes even more, putting more energy into the room at the problem frequency, increasing the intensity of the standing wave, perhaps increasing ringing, and making the rest of the room more uneven. The EQ "solution" only works if you put your head in a vise grip at that one location. It usually makes all the rest of the room even worse. Those are the usual suspects for this subject. Treat room issues acoustically. EQ has its place, but making up for room deficiencies is not the best use of it.

[djanogil]

No no, I'll not do it, I have nearly completed my bass traps and I' ve just remixed a song getting excellent result, so I'm on the right track hopefully..

Thanks for the science

[xmostynx]

listen to ethan. i did and i built something like 30 bass traps/ broadband absorbers.

treat the ceiling. and BAMO

my mixes blow people away- including myself.

[djanogil]

Originally Posted by xmostynx

listen to ethan. i did and i built something like 30 bass traps/ broadband absorbers.

treat the ceiling. and BAMO

my mixes blow people away- including myself.

Yeaaaah

[Ethan Winer]

Originally Posted by LittleJohn

My crystal ball --- which is certainly been known to have been wrong in the past, tells me that the home theater market will run to the equalizer approach since it sounds easy.

This has already happened, which is the whole point of the two articles I linked above. Not only because EQ is cheap and easy, but because it passes muster with the missus versus a dozen or more big bass traps. But it's not only audiophiles who fall prey to the myth of EQ as room treatment. Witness the new ARC plug-in from IK Multimedia, and all the new near-field monitors that claim their built-in DSP room "correction" will make the speakers sound perfect in any room. As if!

--Ethan

[duvalle]

Anyone else got the ARC?
Please let us know how it's doing ...

i have the feeling that most of the haters are ether selling foam and bass traps
or just troll about a product they never heard ...
(if you mind to follow some of the links to other threads you will find out
that some people seem to be everywhere and allways say the same. go figger ...)

since arc is considered software and can't be returned to the store
it's hard to test it. so it would be cool to hear more voices of people
who actually own the arc system.

rounding up some infos i found:

Reviews:
audioMIDI.com : ProTools Corner By Brian White
Title: Review: IK Multimedia ARC (list $699)
Article Preview - IK Multimedia ARC
[Show #95] Simple Drum Miking & ARC From IK Multimedia - watch the video, vlog, or video podcast on mefeedia
(German) Test ARC System: Professional Audio Magazin

Reports from users:
Forum Cakewalk: IK Multimedia ARC
Forum Digidesign: DUC: Has Anyone Tried The IK Multimedia ARC System?

Audyssey / ARC threads:
"Official" Audyssey thread. - AVS Forum
IK Multimedia's ARC plugin... - The Womb
KVR: ARC- I just find it hard to believe- fix your room?
Studio-Central Community :: View topic - Treatments.. We don't need no Treatments
(German) Forum - Newbie Kaufberatung - ARC von IK Multimedia - homerecording.de

by the way - here are some videos:

Sonic State - News (Video Item) AESNYC07: ARC Room Correction Plug from IK, Compensates for the room, sounds pretty hot
YouTube - IK Multimedia ARC Advanced Room Correction
YouTube - ARC System Microphone Set-up
YouTube - More about ARC System Plug-In
YouTube - ARC System Overview

...

[jwl]

Duvalle, you are right to be somewhat suspicious of those of us selling bass traps. :-) Good for you for thinking critically.

Regardless of what I do or do not sell, however, my knowledge of room acoustics and physics tells me that room EQ cannot work completely as a room treatment for the reasons outlined previously in this thread. I'm open to being proven wrong, but I just can't see how a single EQ curve applied to the monitor output can fix all the problems in all parts of the room.

As I and others have said previously, EQ can be effective in small doses for specific problems. Not much more than that.