which speaker do you choose to EQ?

A few questions...

First, what aspect of the direct signal requires equalization? Is there a deficiency in the direct speaker response?

As this would be a characteristic of the speaker itself, why would you propose EQing 'one' speaker and not another? (e.g. left versus right, for example.) As any issue existing in one would similarly exist in the other.

(I will also suggest without further information that utilizing asymmetrically placed panels on only one wall unbalancing the left right symmetry and thus creating a differing/asymmetrical indirect specular behavior between the left and right side walls may very well be Much the Cause of the problem!)

If you are trying to resolve speaker-room interaction issues, EQ is not the proper tool, as EQ cannot resolve specular issues resulting from the combination/interaction (properly termed "superposition") of direct and indirect signals.

Options are available, but from what little we now know, I doubt EQ is the solution, and it certainly would not be my first choice in any event.

The first step would be to precisely identify the nature of the 'problem'. The second step would be to move from the perceptual identification of a problem to an identification and quantification the actual physical behavior contributing to the issue.

Tools such as RoomEQWizard combined with a calibrated Dayton EMM6 mic and an ART Dual USB Preamp (available from B&HPhoto for ~$69) would allow you to ascertain all of the behavior of your system and more...

So, I apologize if I don''t have a 'direct' answer to your question, but I might suggest that you will be happier and more successful in your endeavor if a few more questions allowing more comprehensive and targeted solutions were first answered...

The main use of EQ is in very low frequencies and there, you need very narrow filters. It is unlikely that your receiver has that kind of high resolution filter (its automatic calibration however usually does). And if it did, it would have needed to come on a per channel basis which as you say, is not the case. Therefore, what is there is not a tool for fixing acoustic problems but rather, changing the sound to your taste.

Have you tried the auto eq? How about subs? They often come with their own EQ and/or software to optimize them.

Baloney. EQ's main use isn't in very low frequencies.


Why do you ask? Because you sell those things?

True but its most effective use is.

If effectiveness is judged on the amount of audibility, it would be the mid-range audioband where our hearing is most sensitive to.

Simplistic. No need for that if your speakers are good and set up correctly in your room. Low frequency modes are unavoidable and EQ is the most efficient way to deal with them as physical treatments are unavoidably massive. Of course, if you are using EQ as a tone control, YMMV.

Just a small comment in regards to the "physical treatments are unavoidably massive".

That is actually not true. May I suggest that one NOT ignore a very significant segment of the market, name that of tuned resonant absorbers. They (e.g RPG Modex modules, VPR panels, etc.) are typically much smaller, are ideally suited for boundary placement, and are more more efficient than either porous absorption of EQ in addressing modal behavior.

But many ignore them as they are not trivial to tune.

It really speaks volumes that this segment of the market seems to remain totally unaware of such treatments which are the norm in the professional world.

The real use of a EQ in home stereo/music listening is to flatten out or bring down those frequencies that are too bright, and bring up those frequencies that are too low, regardless of the speaker type, a room will always make each brand sound differently.

The only catch is, that along with using the EQ, and depending on the distance from the speakers and placement, you would also need some type of delay, so that you can further make the music sound better in the room, without having to install traps and baffles.

A lot of people use EQ's for tone control, or to kill those frequencies they do not wanting passing through a sub woofer, which is not the real reason why Equalizers, specifically Parametric EQ's were made for.

No need for that if your room design is good and speakers are set up correctly within.
We can use the word "if" in broad ways, can't we?

I cannot vouch for any one else but I am not only aware of such, I have reviewed one and have some others on order. The reason you see little of it discussed in these forums as this is that they are "not trivial to tune" and can be expensive to purchase. They also require more knowledge to select and implement than do the broad-band passive bass panels.

For these reasons, as well as the ubiquitous WAF, many (most?) are forced to rely on bass EQ as an alternative.

Certainly. However, "if your speakers are good and set up correctly in your room" does not apply to you, you are off to a bad start and no good will come of it.

Not really compared to "high-end" disc players, amps and cables.


Based on what I've observed over the years, audiophools (some post on this forum) consider EQ as another signal tainting circuit in chain so it's a taboo in their view. They rely on swapping out power cords, speaker / interconnect cables, DAC, cable lifters, wooden shelves for their CD players, ...etc.

EQ'ing a single speaker may be necessary. One example would be poor quality control of the speaker by the manufacturer (not going to get into the weeds regarding physics of voice coils, crossovers, and such). Suffice it to say, I have encountered this problem in the past. Only way to deal with it is through EQ'ing a single speakers response.

One thing to keep in mind is that most receivers use a graphic EQ and not the more useful parametric EQ.

I agree with you.

This 'mixed metaphor' is confusing as heck!

What ARE you trying to do?
First you lead by saying you do not like how the unit Auto-EQs the sub, and then you immediately launch into how the EQ does not allow you to individually select left/right/front/rear speakers!

This is two separate issues confused into one!

EQ is legitimate for addressing modal peaks and is limited to the sub.

EQ is legitimate for EQing the DIRECT source signal of the main speakers, but it is NOT appropriate for trying to compensate for speaker-room issues which must be addressed with treatment.


So, please first determine what is the problem: the sub or the main speaker response.

Then, if it it has to do with the specular frequencies and the main speakers, if the problem is comb filtering and other response anomalies caused by the destructive interaction of non-minimum phase direct and indirect signals, use the proper tool which is NOT EQ, but analysis and room treatment.

This 'mixed metaphor' is confusing as heck!

What ARE you trying to do?
First you lead by saying you do not like how the unit Auto-EQs the sub, and then you immediately launch into how the EQ does not allow you to individually select left/right/front/rear speakers!

This is two separate issues confused into one!

EQ is legitimate for addressing modal peaks and is limited to the sub.

EQ is legitimate for EQing the DIRECT source signal of the main speakers;

BUT:
EQ is NOT appropriate for trying to compensate problems resulting from comb filtering and other response anomalies caused by the destructive interaction of non-minimum phase direct and indirect signals, use the proper tool which is NOT EQ, but analysis and room treatment.


So, please first determine what is the problem: the sub or the main speaker response.

Then, if the problem has to do with the specular frequencies and the main speakers, and if the problem is a result of speaker-room boundary issues causing comb filtering and other response anomalies, use the proper tool which is NOT EQ, but analysis and room treatment.

Your understanding of the use of EQ to correct for speaker-room interaction response anomalies above the modal region where specular behavior dominates is incorrect.

Thus the question of "which speaker do I choose" is not a valid approach to solve the problem.

Except in very limited cases where a minimum phase condition exists amidst a complex characteristic non-minimum phase soundfield, EQ is not appropriate nor effective for affecting correction of specular speaker-room interaction issues above ~200-300 Hz.

What all this means is that EQ affects only the direct signal of the speaker. It will NOT correct for modifications to the sound you hear that results from the interaction of the direct signal with high gain indirect reflections at the listening position. EQ is the wrong tool for this.

For any given speaker(s), such issues are properly addressed via analysis and the subsequent surgical application of room treatment addressing high gain reflections.

Thus, instead of EQ, the solution to the problem is (in part) to perform analysis* of the specular region at the listening position, and to identify anomalous high gain reflections and to treat them appropriately with either absorption or diffusion, so as to mitigate the cause of the response anomaly.


As far as EQ, here is a short list that mentions limitations of EQ as a solution from Toole's The Acoustical Design of Home Theaters:

"...there is no doubt that equalization has acquired a bad reputation over the years...

There are four principal reasons :

1. The popular measuring instruments, 1/3-octave real-time analyzers, do not have enough resolution to describe the problems accurately.

2. The popular equalizers, 1/3-octave “graphic” equalizers, do not have enough resolution to address the problem resonances specifically, without doing a lot of “collateral” damage.

3. Attempting to fill deep frequency response dips caused by acoustic cancellations or nulls is an absolutely futile effort, because no matter how much sound energy one pumps into a room the cancellation persists. All that happens is that amplifiers clip, and woofers distort, or worse, destruct. The only solution to this kind of problem is to relocate the loudspeaker or the listener, whichever is sitting in the null.

4. Equalization is attempted at too high a frequency. Low-frequency room resonances behave like minimum- phase phenomena, and addressing them specifically with parametric filters is a true solution. Above a few hundred Hz, the situation is very different, because we are using steady-state measurements to examine a complicated combination of direct and reflected sounds – time domain phenomena. The measurements may show “comb filtering” that is alarming to the eyes, but the ears hear only the natural sounds of a room – not necessarily a problem at all. If the reflections are perceived to be too energetic, the solution is not equalization, but rather the addition of some strategically placed sound absorbing or diffusing devices. As stated earlier, if there are obvious sound quality problems at middle and high frequencies, the only true solution is a properly designed, room friendly, loudspeaker."


*A freeware program such as RoomEQWizard and a mic pre-amp such as an ART Dual USB Pre-amp (~$69 at B&HPhoto), an calibrated Dayton/Superlux EMM6 microphone (Parts Express or Cross Spectrum for a calibrated version) and a laptop computer are a sufficient entry level package capable of doing this.

Yes.
It is not the proper tool for the job.

While the point is valid taken in a vacuum, the real world intrudes. The room's greatest audible effects usually relate to low frequencies. Speakers generally vary more in terms of how they respond in the low frequencies.

If you take the approach: "Well, I'll get the bass right and then listen to determine what else there is to worry about", you just might be doing yourself a big favor.

What speakers are you using? Where is your sub positioned? How many samples did you take with the audyssey software?

........and have you read this: http://www.avsforum.com/avs-vb/showt...5#post14456895

Yes, and I still disagree with how people are using and depending on Audyssey to do something that has been done manually for years.

Nope. Only a rare few have been able to do this manually. The vast majority were totally unaware, had not even tried to setup/EQ properly and lacked the tools even if they were aware and tried.

Even if you abjure Audyssey, you should acknowledge that it has (along with siimilar apps) finally raised a wider awareness of acoustical issues with home systems.

I'm will Kal on this one, with a bullet.

I've manually eqed a number of large and small systems over the years. There's no way that the average audiophile is going to manually master this technology for a surround system.

By most accounts facilities like Audessey are improving the average level of sound quality in typical audiophile/videophile media rooms.

Yes, a well-educated, well-experienced professional or dedicated amateur might do better.

But that ain't the real world for most people, by a long shot!

Yes, they said the same thing about tone controls 40 years ago.
But hey, one has to admit that automated tone controls are quite an advancement....



With all due respect, and before everyone becomes too teary-eyed to continue reading at the amazing advancements, that reality to which you refer is also one where most cannot find Chicago on a map and where those who favor a survey determined reality can rest easy in the knowledge that more people believe in ghosts than believe we landed on the moon.


It would be amazing what the average person could do if they spent but 1/10 the time an effort wasted edumacating themselves reading marketing brochures and actually read a good book on acoustics.

But pardon me, as I need to run as the Audio Adviser has a new amazing deal on a $250 cable conditioner and I need to check out the Brodule - guaranteed to resolve the finest nuances sure to solve whatever ails me - except ignorance.

I just wish I had had the foresight to invest in the AudioAdviser's water insulated and light insulated cables they featured back in the mid 1980s! Then I would not have the problems I have today!

IF you want to stay within the limits of your measuring tools (SPL meter & CD with test tones) and adjustment (fixed-band graphic equalizer), then you might want to attempt improving consistency across your front soundstage by trying to get the three front speakers to sound more similar to each other than they currently do. Your wording is a little confusing, so can you clarify: can each of the 3 front speakers be EQ'd individually or are the L/R speakers EQ'd as a pair?