[Folex]

I downloaded TrueRTA just to play around with. I know it gives very broad info but its seems like a good program to play around until I know what I'm doing.
 
Will this yield accurate results ?
 

 
 

 

[SilverEars]

Tyll would know better than any of us as he conducted numerous measurements.  You should read up on Tyll's measurement methods.  
 
http://www.innerfidelity.com/headphone-measurement-procedures
 
Looking at the image I see the mic at a location that probably wouldn't pick up the headphone output accuratly, and would pick up environmental sounds also although I don't know how much of an affect environment sound has on the open back he measures.(he uses a chamber)  One thing for sure, for openbacks, it will pick up ambiant noise through the opening depending on the ambient noise level.  
 
Since you want to reveal the FR of how it's heard, you want to simulate the apparatus as closely to the human ear and how it's warn as much as possible.  Looking at your setup, it doesn't seem to get that close.  I believe these measurements can change drastically from the way the cups are sealed on the apparatus.  
 
The resolution on the software looks almost like the HD800 graphs given out.  

 

 

[Folex]

  Tyll would know better than any of us as he conducted numerous measurements.  You should read up on Tyll's measurement methods.  
 
http://www.innerfidelity.com/headphone-measurement-procedures
 
Looking at the image I see the mic at a location that probably wouldn't pick up the headphone output accuratly, and would pick up environmental sounds also although I don't know how much of an affect environment sound has on the open back he measures.(he uses a chamber)  One thing for sure, for openbacks, it will pick up ambiant noise through the opening depending on the ambient noise level.  
 
Since you want to reveal the FR of how it's heard, you want to simulate the apparatus as closely to the human ear and how it's warn as much as possible.  Looking at your setup, it doesn't seem to get that close.  I believe these measurements can change drastically from the way the cups are sealed on the apparatus.  
 
The resolution on the software looks almost like the HD800 graphs given out.  

 

 
Thank you for the input. I was gonna mention that too. With the headphones directly on the microphone the drop after 100hz is pretty noticeable. When I pulled the headphones away from the microphone you could see everything under 100hz evening out more. 
 

 
So far the link you sent me is a good reading. My goal is to try and determine if there is any drastic spikes. My friend and I are getting into modding headphones, part of that is driver transplants and I want to try and get tangible numbers so that I can visually see what we've created and where possible areas of sibilance are. 

 

[SilverEars]

Is there a way to raise the resolution of the output?  If you want to detect more drastic variations, you want something of higher resolution like Tyll's graphs. 

 

[Head Injury]

   
Thank you for the input. I was gonna mention that too. With the headphones directly on the microphone the drop after 100hz is pretty noticeable. When I pulled the headphones away from the microphone you could see everything under 100hz evening out more. 
 
So far the link you sent me is a good reading. My goal is to try and determine if there is any drastic spikes. My friend and I are getting into modding headphones, part of that is driver transplants and I want to try and get tangible numbers so that I can visually see what we've created and where possible areas of sibilance are. 

You'll need a software capable of higher resolution to find peaks with any accuracy. It looks like TrueRTA is averaging the results for each octave (each doubling of frequency is one octave, so 100 to 200 Hz or 10 to 20 kHz).
 
See what options you have under that RTA Resolution pull-down menu on the right hand side, see if there are any smaller options. You'd want 1/3 octave smoothing at worst (this is what Headroom uses IIRC). The smaller the better when looking for something isolated like sibilance, but also the more susceptible to external noise, placement, and other factors it will be. So test several times and average the results (looks like there's an option for that too!)

 

[Folex]

The trueRTA is free and if you pay money you can get down to 1/24th octave. I'm just playing around until I get an idea that how I'm testing is somewhat proper. When that has been established I'll worry about getting a more precice program.  Even with it not precise you can see a drastic difference under 100hz from being on mic to pulled away. 

 

[SilverEars]

I really like Tyll's setup.  It seems that he tweaked it closely to how an average listener would hear.  I especially like the setup for iem measurements. Not sure if others are using an ear dummy for iems measurements.

 

[Folex]

So averages were on. I was wondering why it seemed  laggy. This is with the microphone in front of my rokit 8's. I picked Skream 0800 because its constant. My camera does a horrible job picking up bass =/
 
 

 

[Head Injury]

  The trueRTA is free and if you pay money you can get down to 1/24th octave. I'm just playing around until I get an idea that how I'm testing is somewhat proper. When that has been established I'll worry about getting a more precice program.  Even with it not precise you can see a drastic difference under 100hz from being on mic to pulled away. 

Ah, just watched your video. The change in the bass actually looks like it's caused by you bumping the microphone while you pull the headphones away. Notice how it goes up as soon as you grab them, before you actually pull them apart, and how much the microphone is moving around. It's unlikely the headphones alone are generating that much energy between 10 and 20 Hz.
 
You might want to try building a simple DIY dummy head to put the headphones on, to simulate a seal around the ear. You could probably make a decent one out of a cardboard box, just cut ear-sized holes in the side and put the microphone inside.
 
This program looks like it's pretty fun to play around with. I might download it myself.
 
One other thing to try: Increase the dB bottom setting for headphone measurements, to something like -100 dB. You don't need to know what's down -140 dB, you'll never hear it. -140 is more for testing amps and DACs.
 
One more more thing: Take a measurement without any audio playing, to see what the ambient noise in the room is at. You want this as low as possible for accurate measurements. You'll also want to know about how much volume the room is contributing at any given frequency so you can better interpret your results.

 

[Folex]

yeah I am def going to have my cousin build me a custom wood box for this. I already have a great idea for how to build it. 

 

[Kaffeemann]

We look forward to your headphone measurement site 

 

[esldude]

I think your methodology has a number of deficiencies.  But it might give an idea about general trends.  Headphone measurement is fraught with difficulty for many reasons.  You might read up on dummy head couplers and such.
 
http://libinst.com/SynRTA.htm
 
This is a free bit of software that will give you up 48th octave resolution.  Written for real time EQ changes using speakers and a mic.  But would work fine for your purposes too. 

 

[SilverEars]

  I think your methodology has a number of deficiencies.  But it might give an idea about general trends.  Headphone measurement is fraught with difficulty for many reasons.  You might read up on dummy head couplers and such.
 
http://libinst.com/SynRTA.htm
 
This is a free bit of software that will give you up 48th octave resolution.  Written for real time EQ changes using speakers and a mic.  But would work fine for your purposes too. 

Do you have links to them?  

 

[Folex]

This is a big reason why I want to get into testing sound. Deep within this headphone breathes ad2000 drivers. Curious what the graph looks like with all the mods. 
 

 

 

[esldude]

  Do you have links to them?  

Well not right off hand.  A google search will turn up some articles.   These will give an idea of what is involved.
 
http://www.innerfidelity.com/content/headphone-measurement-proceedures-frequency-response
 
http://www.innerfidelity.com/content/expert-tests-innerfidelitys-headphone-measurement-repeatability-and-reproducibility-page-2
 
My main point is that many methods will give erroneous results.  For instance stick a phone on a box with an opening large enough for the OP's pictured mike and the box will have its own resonance and null points that will corrupt the process. 
 
Now I haven't got a good homebrew method worked out myself.  Every approach seems to have a big confounding factor.  But I am not trying to discourage the OP or others.  Even the method in the OP's initial post can help you learn something comparing phones.  I think one of the better approaches I have seen is someone who got very small condenser mics they could put inside the ear canal (have to be careful).  Then wear the phones and make measurements.  Even then there is some individual response shaping between ear opening and ear drum, but at least this makes comparing response at the ear possible between phones.