[xnor]

Did a quick test:
 

 

 
Second plot shows the same headphones' CSD, but with a simple parametric EQ (one filter with a cut at 4300 Hz) applied to the signal used for the impulse response measurement.

 

[arnaud]

XNOR: simply well done!!
 
It also made me think I say something completely stupid just before . No way the ridge is going to split into two, the eq. filter and headphone resonance would have to be coupled (like a mass-spring added on top of another mass-spring to damp its resonance, but creating another one in the process...).

 

[TMRaven]

I want to see what happens to the waterfall plots if something like the iTunes EQ is applied.

 

[xnor]

Won't install iTunes again, but I wouldn't use that EQ anyway:
 

 
results in
 

 
And it's too imprecise to do anything but rough changes in overall balance.

 

[purrin]

That's really scary. What's up with the steps on the Fb2k EQ? LOL, I would have to try hard to write a DSP routine like that. Why is Winamp so far off?

 

[xnor]

Quote:

That's really scary. What's up with the steps on the Fb2k EQ? LOL, I would have to try hard to write a DSP routing like that. Why is Winamp so far off?

 
Yes. I guess the fb2k dev bought into the points on the SuperEQ library page, doesn't really care about it, didn't find a better implementation or doesn't know how bad it is. That's why I wrote a 31-band graphic EQ plugin that produces a smooth, minimum phase response.
 
I haven't looked at the implementation but I assume it's about as simple as it can get: ifft a frequency spectrum that corresponds to the EQ's sliders, voila, there you have a crappy linear phase, stair-step FIR filter.
 
I don't know why Winamp is so far off. I tried to configure the EQ as accurately as possible according to what the GUI says.
 
Anyway, this is getting off-topic so I'll stop here.
 
edit: btw, I don't remember if it was the iTunes or Winamp or Sansa Clip EQ, but at least one of those produces different results if applied on an impulse compared to a sweep or noise... in one word: broken.

 

[kingpage]

Is there any readily available software for CSD plots? Trial or freeware.

 

[purrin]

PureBits: http://www.purebits.com/
ARTA: http://www.artalabs.hr/index.htm
Praxis: http://www.libinst.com/index.htm
SoundCheck: http://www.listeninc.com/us/products/data_acq.html
CLIO: http://www.audiomatica.com/clio/home1.htm
REW: http://www.hometheatershack.com/roomeq/ (works for best for rooms)
WinMLS: http://www.winmls.com/
 
Oh never mind...
 
ARTA or Praxis may have a trial. No sure.

 

[kingpage]

Which one are you using for yours?

 

[purrin]

I wrote my own program to process the impulse response and visualize the waterfall plots. But I do the data acquisition via CLIO.

 

[LFF]

Quote:

 
Yes. I guess the fb2k dev bought into the points on the SuperEQ library page, doesn't really care about it, didn't find a better implementation or doesn't know how bad it is. That's why I wrote a 31-band graphic EQ plugin that produces a smooth, minimum phase response.
 
I haven't looked at the implementation but I assume it's about as simple as it can get: ifft a frequency spectrum that corresponds to the EQ's sliders, voila, there you have a crappy linear phase, stair-step FIR filter.
 
I don't know why Winamp is so far off. I tried to configure the EQ as accurately as possible according to what the GUI says.
 
Anyway, this is getting off-topic so I'll stop here.
 
edit: btw, I don't remember if it was the iTunes or Winamp or Sansa Clip EQ, but at least one of those produces different results if applied on an impulse compared to a sweep or noise... in one word: broken.

 
I use that and recommend it to people all the time. Never noticed it was you who wrote it.
 
Thanks!

 

[Anaxilus]

Quote:

 
I use that and recommend it to people all the time. Never noticed it was you who wrote it.
 
Thanks!

 
And people wonder why some of us are scared to death of using EQ.  I've always had horrible sonic experiences in the past w/ most EQ programs with every tweak yielding some other negative effect I couldn't compensate for, in the end things just became a mess.  Seeing this and hearing LFFs work though has restored my faith in giving EQ another go.  Fortunately my primary rig is getting close enough via hardware synergy that any EQ will be kept to a minimum.

 

[LFF]

Quote:

 
And people wonder why some of us are scared to death of using EQ.  I've always had horrible sonic experiences in the past w/ most EQ programs with every tweak yielding some other negative effect I couldn't compensate for, in the end things just became a mess.  Seeing this and hearing LFFs work though has restored my faith in giving EQ another go.  Fortunately my primary rig is getting close enough via hardware synergy that any EQ will be kept to a minimum.

That my friend...is the key!

 

[slwiser]

I get confused reading back into this thread...specifically which EQ software program is the one that is recommended above that produced the better CSD profile?

 

[ultrabike]

Quote:

I get confused reading back into this thread...specifically which EQ software program is the one that is recommended above that produced the better CSD profile?

 
Probably this one:
http://www.foobar2000.org/components/view/foo_dsp_xgeq