# Sennheiser HD 595 measurement



## Mama70 (Dec 21, 2010)

hi, 
I found this measurement(graphCompare png) for Sennheiser HD 595 in HeadRoom site. 
I read the data with GetData Graph Digitizer and adjusted the values a little bit in OpenOffice Calc. Now it's ( Sennheiser HD 595 txt) in a format that you can import the graph to REW. 

"Why?", you ask. 
I don't think a could measure the frequency response for my headphones as accurately. Now I can load this graph to REW, create right filters to correct the sound and export the FIR file for my convolver.


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## JohnM (Apr 11, 2006)

Just bear in mind that those are dummy head in-ear measurements so the shape of the dummy head's ears also have an effect on the response, and your ears are probably not the same as the dummy's ears so you won't be getting exactly the same response.


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## Mama70 (Dec 21, 2010)

Don't worry, I've been told I have a dummy head 

Well, it's a good starting point. I cannot verify the results with a mic so in the end it's going to be tweaking by the ears.


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## Mama70 (Dec 21, 2010)

I looked up also HD 800's frequency response and took that as a starting point of what 'good' sound should be. 
In the end, I decided to lower the middle frequency's because after listening to this filter the old sound (without filter) started sounding nasal. The are still some problems at the higher frequencys, a couple of spikes you can hear when playing a seep so next I have to correct those. I still can't hear any sounds after 12500Hz but that maybe the reason is my ears and I cannot change them...

As Borat would say: Great success!


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## Chester (Feb 19, 2007)

If you want to 'do this right', I would look into head related transfer functions; I am not sure what design philosophy your headphones use (there are basically 2 'camps of thought' when it comes to , diffuse field equalized, and free field equalized.) Whichever philosophy used, you can think of the philosophy as the 'house curve' (taking a term from REW) of the headphones.

head related transfer function (HRTF): when you hear a sound from a particular location (longitude/latitude, distance, from your head) in a completely absorptive environment (where you only hear the original sound and no reflections), the changes to the sound that are created by head shape, orientation to the sound, ear shape, ear canal shape, and somewhat torso interactions.
http://recherche.ircam.fr/equipes/salles/listen/system_protocol.html

diffuse field: derived by taking a 'dummy head' (microphones in the ears) and measuring the frequency response in a reverberation room: AND/OR think of it as taking the HRTFs of a human head from every possible longitude/latitude and distance and averaging the, the frequency response that results is the diffuse field response

Free-field equalized: equalized/constructed so that the headphone provides a flat frequency response at the ear canal, this may take into account typical changes introduced by the ear canal, or it may not.

Whatever response curve you prefer (I prefer diffuse-field) you can use that as a guide for equalizing the headphones. The issue is that the measured response that you are using was 1) for a different pair of headphones (every transducer is going to have a little difference in its response) and 2) measured with a dummy head and not your own head, your ears and head shape will greatly impact the frequency response, especially at higher frequencies: there will still be the 'jaggedness' at high frequencies, however the frequencies at which those resonances occur will change, so for example the dummy head had a large dip at ~12.5k: this may be occurring between 11 to 14 k when listening with your ears. What does this mean? when equalizing higher frequencies, use a wider Q and don't try to completely correct a dip in frequency response because the dip may not be where it appears to be (when using headphone responses from somewhere else).


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## titix (Sep 29, 2011)

I've tried these values on my parametric equalizer :gulp:
The sound is... incredible different

~ > -12db on 10khz-17khz range is incredible for quality headphones :blink:

What do you think about these measurements? We are far away from small "audiophile" corrects...


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## Mama70 (Dec 21, 2010)

titix said:


> I've tried these values on my parametric equalizer :gulp:
> The sound is... incredible different
> 
> ~ > -12db on 10khz-17khz range is incredible for quality headphones :blink:
> ...


What do you mean tried? What have you tried? Same kind of corrections I did? Or did you try to make completely flat freq response? 

I didn't try to make flat freq response, only -3dB corrections mostly. +10dB corrections > 12kHz but I cannot hear those frequencies, so I removed those filters. 

Chester:Haven't been tweaking so much now, I like the new sound. I know about HRTF, 'ffdshow audio' has HRTF as an option for multichannel audio for headphones. My AV amp also has some HRTF modes but haven't played with them a lot.


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## titix (Sep 29, 2011)

Yes I did major corrections (on 20hz -17khz range), for flat response.
"flat response" is not a good idea, I think it's better to take as reference the HD800 curve.


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## titix (Sep 29, 2011)

This is my corrections (green)
Based on HD600 curve. (average HD600 / HD595 for >1k average HD595 / HD800 for bass)

HD595 blue.

The sound of my HD595 is very pleasant now.


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## titix (Sep 29, 2011)

Quick equalisation with PE1 (pluggin foobar)


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## dedymann (Dec 31, 2013)

This EQ work well . Thanks DAvid


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