# Measuring Headphone Frequency for EQ



## AVoldMan (May 15, 2011)

I recently got a pair of Sony MDR XB500 headphones. I wanted to try and use REW to evaluate and provide EQ filter settings in Windows Media Player for use on my laptop. 

I used a block of wood for coupling to the foam surround. The block also had a 0.75" hole for mic access. I lined the mic capsule up with the front surface were the surround met the wood block. I took some frequency measurments for each side (Right and Left speaker). I averaged the two (L/R) responses and then used the REW EQ generic settings to AUTO create filters. I compared these filter settings to the actual 10 filters possible in the WMPlayer. I then adjusted MANUALLY the actual FREQ filters and GAINS to flatten the average response out. 

The end result seemed to improve the overall sound - less bassy and better balance over the whole range.

Has any one else tried this? Any tips? I noticed some dips at 3-4KHz and the 8-9KHz. Are these cavity related nulls similar to what would occur in a room with it's boundaries or just the speaker response itself?


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## Wayne A. Pflughaupt (Apr 13, 2006)

Congrats, that’s a pretty ingenious method for measuring the response of headphones! Typically it’s done using some kind of dummy head, but getting the measurement mic in place is tricky.




> I noticed some dips at 3-4KHz and the 8-9KHz. Are these cavity related nulls similar to what would occur in a room with it's boundaries or just the speaker response itself?


Probably the best way to make that determination would be to measure several sets of ‘phones to see if you get the same problem in generally the same area.

Regards, 
Wayne


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## AVoldMan (May 15, 2011)

Wayne A. Pflughaupt said:


> Typically it’s done using some kind of dummy head, but getting the measurement mic in place is tricky.
> 
> Probably the best way to make that determination would be to measure several sets of ‘phones to see if you get the same problem in generally the same area.


Yes, I agree the mic placement did make a difference. If it was placed below the top surface (foam surround plane) the response seemed to be more ragged and lower in the "highs" >10K Hz. I just decided to make the measurement consisent at the surface. My guess is ears or eardrums are probably more in a cavity than my mic location, but this was repeateable and easy to setup. I did not seal the small gap between the wood block hole and the mic. It was too difficult for a quick setup. This might affect the lows. 

Regarding the "dips" or "nulls" at 3-4 KHz and then again at 8-9K Hz, this happened with the Sony headphones and another cheaper headphone with simiilar foam surround (around the ear) design. This headphone had a totally different frequency response but similar frequency "dips". After, EQing this headphone the results were significantly better than I started.

Has anyone else tried doing this?


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## EarlK (Jan 1, 2010)

Hi AVoldMan,

I've done some EQing ( though, mostly just to play with some VST based EQ plugins / from within JRivers MediaCenter ) .

You might want to compare your results to those found at    .

They use a Neumann Binaural head ( mic ) for their measurements .










You may also want to play around with your test setup ( like sinking in the capsule ) to try to get as close a match ( to their results ) as possible . 

I really like the headroom website , since it allows for one way of making some ( online ) comparisons before going out & listening ( then buying ) / such as the following ;








]
























I certainly wouldn't get too panicked about the gnarliness of any of these curves . For instance, I have a pair of Shure SE215 ( In-Ears ) that I consider quite listenable .

























:sn:


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## Pinchgrip (May 10, 2012)

I'm a dummy.... Maybe you can use my head.


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## AVoldMan (May 15, 2011)

:rofl:


Pinchgrip said:


> I'm a dummy....


Aren't we all!


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## AVoldMan (May 15, 2011)

EarlK said:


> They use a Neumann Binaural head ( mic ) for their measurements .
> 
> You may also want to play around with your test setup ( like sinking in the capsule )


I originally had the mic more inset, but the frequency response was similar and I just wanted someway to easily and repeatedly place the mic. Flush to the wood surface was the quickest.

I was trying do create that close, sealed coupling like in Binaural head. I did not seal it completely (around the mic) so my low bass response seems lower than the charts you supplied. Overall, the frequency curve shape of my setup is similar to the charts. Both my data and the charts do infact have that same same small "dip" at 1k HZ and a larger "dip" in the 3-4K Hz area. A couple reasons I wanted to try and EQ a bit. The high frequencies (above 10K Hz) seem to be higher in my setup. Maybe the wood reflects more energy or the Binaural head absorbs more or it has the mic deeply set into the head. The main reason to try some EQing was to reduce some of the over-emphasis in the whole bass region from 40-500 Hz. That worked out well and made the phones much more balanced and easier to listen for long periods.

The website is something I'll have to add to my Favorite's list. Thanks for the info!


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## EarlK (Jan 1, 2010)

> I don't think you mentioned what mic you are using ??

> Re; all the different response graphs at the  *"HeadRoom" website.*  
> What I found most intriguing ( about the vast quantities of response graphs ) is that when using their measuring methodology , nothing measures remotely "flat" .

> I don't doubt most of these headphones sound a lot flatter than the graphs would suggest .

> Quite notable ( I thought ) , was the very large null above @ 10K . This seems to be common to just about all the measurements ( leading me to believe it may be a cancellation caused by the ear canal cavity .

> Anyways, interesting stuff .

:sn:


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## AVoldMan (May 15, 2011)

EarlK said:


> 1) I don't think you mentioned what mic you are using ??
> 
> 2) What I found most intriguing ( about the vast quantities of response graphs ) is that when using their measuring methodology , nothing measures remotely "flat" .
> 
> ...


1) EMM-6 (from Parts Express) microphone with M-Audio Fast Track External Sound Box.

2) Yes, I did some surfing on their site. Looks like everything is measured the same way => only the headphones are different. Yes, nothing really looks flat, even the highend stuff!

3) I think you might be right. At 10k Hz the wavelength is around 1.3", therefore the ear canal and headphone cativity are probably at play.

4) Yes!

It was good practice for using REW and resulted in better sound! That's what it's all about!


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