Inner | fidelity - Comparing World-Class Headphone

[Tyll Hertsens]

Here you go: http://www.innerfidelity.com/content/headphone-measurement-proceedures-frequency-response

 

[edstrelow]

Quote:

Here you go: http://www.innerfidelity.com/content/headphone-measurement-proceedures-frequency-response

Thanks, I knew there had to be something out there.
 
It looks like your set-up is doing a frequency correction for the effect of a dummy head from what would be measured with, say a microphone in an open space measuring the frequency response of a loudspeaker.
 
As I understand it any HRTF is only one of a set of measurements of the effect of the head/body/pinna/ear canal/etc on sound as the location of the sound source varies.  So there are presumably an infinite number of HTRF's for a person or dummy head because there are  an infinite number of locations around the head.  Wikipedeia provides a couple of definitions:
 
"The HRTF can also be described as the modifications to a sound from a direction in free air to the sound as it arrives at the eardrum"
 
"HRTF describes how a given sound wave input (parameterized as frequency and source location) is filtered by the diffraction and reflection properties of the head, pinna, and torso, before the sound reaches the transduction machinery of the eardrum and inner ear (see auditory system)."   and
 
"Linear systems analysis defines the transfer function as the complex ratio between the output signal spectrum and the input signal spectrum as a function of frequency."
 
http://en.wikipedia.org/wiki/Head-related_transfer_function
 
So the question arises as to just what HTRF your set-up is applying, i.e. from what direction, straight ahead, to the side or whatever?  There would be different response corrections depending on the assumed direction of the sound source. 
 
Presumably the correction for most headphones would be one based on a sound source off to the side since that is where the headphone driver  sits.  Of course this would be wrong for phones where the driver is in a  different location,eg. forward as in the Stax Sigma and AKG K1000.
 
Neverthless because you are measuring everything the same way, and all your phones have their drivers in the same locations comparisons across these phones are  valid. 
 
 

 

[arnaud]

Hi Tyll,
 
Actually, I was also curious as to your "independent of direction" correction. You said it was like an average of various speaker locations, any more info? There is nothing in the head acoustics paper (unless I read it wrong). Closest to that definition is diffuse field because this is effectively an average HRTF over the whole solid angle (all headings around / above / below the head) but you said specifically it's neither a free (0 or +/- 30 horizontal) or diffuse field equalization curve.

 

[Audio-Omega]

I guess that HD800 wasn't compared in balanced mode.  

 

[Mossback]

 
Quote:

 
So the question arises as to just what HTRF your set-up is applying, i.e. from what direction, straight ahead, to the side or whatever? There would be different response corrections depending on the assumed direction of the sound source.
 
Presumably the correction for most headphones would be one based on a sound source off to the side since that is where the headphone driver sits. Of course this would be wrong for phones where the driver is in a different location,eg. forward as in the Stax Sigma and AKG K1000.

headphones need to accomodate ears, ears don't change for headphones.
 
so where the drivers are in the headphone should not be an issue justifying a change in the process. the design of the ear mic needs to be as close as possible to the ear environment. OTOH if there are aspects of the ear adjusting to various directionality of drivers then i suppose it's a valid point as to where the drivers are. i just don't know that hearing works that way.

 

[Tyll Hertsens]

Ideally, I'd like to have the HRTF for a 30 degree off axis source to mimic speakers, as that's what were really trying to reproduce on the headphones --- what the recording engineer heard, so to speak. But ... I don't have that.  
 
I use an "independat of direction" HRTF.  It's a curve that isolates the characteristic HRTF that basically doesn't change as the sound source moves. It's fairly similar to the DF, and the largest difference is tht it removes some of the low frequency gain of the shoulders that occurs with sounds from above ... at least, that's what I've gotten from the descriptions I've read so far.
 
Sorry Arnaud, I don't have any more info.
 
 

 

[SP Wild]

Just caught up with this article now.  Wow the 009s seem to be the reigning champion of headphones.  The THD figures are the most consistent throughout the frequency response and averages the lowest of all, even matching the LCD2s in the bass and beating them every where else.  The treble shows no spike in the frequency response, a headphone that can finally perfect cymbals in a drum kit perhaps?
 
I would like to really hear these 009s, but sadly will never be able to afford them at this stage. 

 

[wink]

 
Quote:

but sadly will never be able to afford them at this stage. 

This from the forum where "Sorry about your wallet" is the catch-cry...??????
You are NOT WORTHY.     tee hee.

 

[deadlylover]

Is anyone else kind of scared as to what monster the SR-010 may be?
 
You can count on Stax trying to one up themselves, I guess we'll find out in another decade or so.
 
Hmmm the SR-009 suddenly seems cheap when it comes to only $500 per year........yes.......that's me trying to justify the purchase.

 

[n3rdling]

I'd love to see them try to make a TOTL headphone using the Sigma concept again.  Drivers aimed from the front in a better enclosure than the old Sigmas, better driver with rigid mounting, improve imaging precision and extension ala 007/009.  That's probably my ultimate dream headphone.

 

[chesebert]

Thank you, Tyll -- another phenomenal contribution to the headphone community. My understanding (not my opinion as I have not heard Wadia CDP before, just their DAC) is that the Wadia CDP can be on the warmer side of neutral. Just want to get your thoughts on that. While I recognize the several shortcomings of LCD-2 version 1, I believe those slight shortcomings were exaggerated slightly by the warmer-than-neutral tonality of Wadia player.

I do hear those same shortcomings you mentioned with the Linn Klimax/Beta22, but just slightly (should be even more slightly than your description of "slight"). One area I disagree with your review is the soundstage/imaging. I do not hear any artificial limit to the soundstage of my LCD-2 (version 1); the sound seems to extend far far beyond my reach and at times the sound appears to emanating from distance (of course, all this depending on the music).

Regardless, the real star of the show is 009, which I promised myself one as soon as we get out of this recession.

 

[n3rdling]

The LCD2 has a very limited soundstage.

 

[Loevhagen]

Limited? Maybe. Limited + very? No. 

 

[oqvist]

Quote:

Limited? Maybe. Limited + very? No. 

Definiatly limited. Possible very limited I would say. Rev1 with old pads don´t get over the very limited ranking
 

 

[Ridleyguy]

I would disagree with the 'very' limited comment.