How far can EQ really go towards truly equalizing headphones?

[Nevod]

The stereo convolver plugin for fb2k
http://www.hydrogenaudio.org/forums/index.php?showtopic=90662
 
Instruction:
Go to one of these sites to listen to various examples of recorded HRTFs. 
http://recherche.ircam.fr/equipes/salles/listen/context.html   
http://earlab.bu.edu/databases/collections/cipic/Default.aspx
 
I have personally used IRCAM's site. Find a subject whose record circles around your head in a flat plane, not going up/down, not changing distance, or at least most close to that. Download a zip with records of his HRIR's.
Go to compensated folder.
File name format is as follows:

 IRC_<subject_ID>_<status>_R<radius>_T<azimuth>_P<elevation>

R is the same for all IIRC, azimuth is the left-right angle (030 is 30 degrees to the right, 330 is 30 degrees to the left), elevation is vertical angle.

You probably won't need any elevation, and use a file that represents left speaker for the left channel (I use T330), and right speaker for right channel (T030).

The slider below is just gain, it's set by default to -6dB so there would surely be no clipping. Probably better leave it as is and increase volume with other controls to compensate.

 

 

[ultrabike]

Thanks! I'll give it a try!

 

[Nevod]

Now I do need help from gurus of EQ
 
On the IRCAM's site's downloads page, there's a system's impulse responce file presented. I have imported it into REW to make an filter to correct out the responce. I've successfully exported filter responce and applied it into fb2k using convolver plugin (made an error, should have applied it after stereo convolver, not before, but that only has implications with clipping, not tonal balance).
 
However, REW only allows filter autogeneration for frequencies below 10 kHz. As a result, I've got a +35 dB @ 20kHz  from 0dB at 10kHz. Tried to listen and obviously, got ultra shrill sound. Have applied three consequent xnor's graphic EQs with 20 kHz set to -12 dB each, it had balanced the sound and I've heard some pretty insane bass. But I think it's not the best way to do so.
 
So, what other free software can be used to generate compensating filters from a sample IR? DRC-FIR seems to do so, but is a bit complicated for the first time, so perhaps there's something easier to use. If not, well, I'd have to learn DRC.

 

[bigshot]

Above 10kHz is it simple to EQ by ear. There isn't a lot of music up there anyway. Try listening to a lot of really good recordings with cymbals and triangles and see what you can do with a spit in the wind tweak. It will probably be fine. I use Fiedler's Gaeite Parisienne for this sort of tweak.

 

[Nevod]

I probably have already balanced it well enough just by eye - it was a simple slope to compensate, but it irks me to use 4 plugins instead of one. Seems to tax CPU a bit, my computer is old.

 

[MrMateoHead]

I'll bite. After 14 pages, has anyone said that, despite a perfect flat EQ response on 2 utterly different speakers, there is still a chance that
 
A) The SPL possible by one will not be possible by the other
B) This is because of mechanical limits like X-max and relative efficiency
 
My experience with EQ says that it is relatively hard to make a bad speaker sound great, and easy to make a good speaker sound terrible. Even when you can, limits to power handling and other factors prevent perfection anyway. Theoretically, I would expect 2 speakers of exact frequency response sound the same.

 

[bigshot]

Yes, some speakers can go louder than others. But balancing the response will improve *any* speaker's performance. It's about getting the most out of the speakers you've got.
 
Also, correcting spikes in the bass can let you turn the volume up a bit, so they won't be so quiet.

 

[ultrabike]

Quote:

I'll bite. After 14 pages, has anyone said that, despite a perfect flat EQ response on 2 utterly different speakers, there is still a chance that
 
A) The SPL possible by one will not be possible by the other
B) This is because of mechanical limits like X-max and relative efficiency
 
My experience with EQ says that it is relatively hard to make a bad speaker sound great, and easy to make a good speaker sound terrible. Even when you can, limits to power handling and other factors prevent perfection anyway. Theoretically, I would expect 2 speakers of exact frequency response sound the same.

We sort of did, even with headphones: http://www.head-fi.org/t/612665/how-far-can-eq-really-go-towards-truly-equalizing-headphones/90#post_8460432

 

[mikeaj]

Theoretically, I would expect 2 speakers of exact frequency response sound the same.

They should sound similar, not necessarily the same. The speakers will still have different nonlinearities even aside from the different limitations nearing the excursion limit. e.g. what if THD in midrange for one speaker is still higher than the other?

Also, if you balance the FR at one point out in space, any (slightly) off-axis response may be a bit or a lot different for the two—even in free space or an anechoic chamber—much less a more typical room.