Ultra, I use the exact same positioning for both stock OPPOs and my Audio Zenith cans (there is a big crest with some secondary lines on the rig :-). I have to shift around some other sets like HD-800 and LCDs for example as they have tricky directivity but things like HD-600 ot K-7XX are always centered exactly as the OPPOs. I think some of the reflective properties of the materials used on the rig similar to yours play quite a few tricks with the measured sets. That is why I spent soooo much time creating mine.

I think I understand, but I doubt the materials in the rig are making the too sets (stock vs non-stock) behave so similarly. That would be quite a fluke. I guess it's not impossible though.

I'm still using my in-ear mic with my gross, ugly head as a coupler. Though any measurements from me after and including the K7XX use a smaller tri-flange tip that lets me shove the mic in there further. Generally this boosts the treble a bit prior to measurements before that. Nothing crazy different though, and same measurement method in the end. But you won't see direct comparo graphs with old/new because of this.

Just gotta type up my thoughts and compile my measurements, then I'll be ready to post (unless Alex has some sort of objection?). Taking care of the new puppy in between though, so expect it later today.

That's a great setup, with great pros and cons. One pro I can think of is perhaps better modeling of the chamber volume. One con I can think of is positional senstivity.

I think I understand, but I doubt the materials in the rig are making the too sets (stock vs non-stock) behave so similarly. That would be quite a fluke. I guess it's not impossible though.

   For what it's worth, my measurement rig shows really significant differences between all the OPPO pads; original leather, velour, pleather and alternative leather all measure quite different with the same driver and positioned exactly the same. Sorry but I seriously doubt one will be able to see serious variations in FR with the above pads while using the rig similar to yours. What do you think, could it be that it just isn't very resolving above 1.5khz and below 100hz?
   Well, maybe I am wrong but we can at least check; I have a brand new set of PM-2s along with all the aforementioned pads, also brand new. Maybe we can arrange for another measurement/listening session or something like that in the future?
   All those pads sound quite different to me personally, except maybe for pleather and alternative leather. Don't mean this to sound like my own measurement system is better but subjectively it surely corellates with what I hear quite well. Suppose yours does the same for you and that's why I was so puzzled.

   What I meant was on my rig there is up to 5db variations in FR between the pads above 1.5khz. Do you think we will see such variations on yours? I just am really puzzled about how they could possibly measure this similar on your rig. I mean the original PM-1 and Audio Zenith PMx2. Therefore a question about possible issues with resolution on such rig  with certain frequencies.
   Not trying to confuse anyone here with all the assumptions but If you want I can surely remeasure all the different pads with the same driver so you can see I am not making things up.

   What I meant was on my rig there is up to 5db variations in FR between the pads above 1.5khz. Do you think we will see such variations on yours? I just am really puzzled about how they could possibly measure this similar on your rig. I mean the original PM-1 and Audio Zenith PMx2. Therefore a question about possible issues with resolution on such rig  with certain frequencies.
   Not trying to confuse anyone here with all the assumptions but If you want I can surely remeasure all the different pads with the same driver so you can see I am not making things up.

I'm not sure what to tell you Alex. I can measure much less than 5 dB variations in frequency response above 1.5 kHz. I will re-run measurements (re-positioning and all), and zoom in. I also don't run smoothing.

It has been said before that a baffle rig should be a bit more consistent. Tyll even reported on that when he visited Philips. Scroll downs to the picture where it says "Not an industry standard, but Rowan's simple jig allows repeatable measurements quickly without worrying about critically positioning the headphones on a HATS."

http://www.innerfidelity.com/content/visit-philips-research-labs-photos

If you are experiensing that much variation maybe you should revisit your rig. Unless you are certain all variation is due to pads. But on the other hand note how Tyll's investigation and discussion with Igor ended in an agreement that these cans do not change dramatically with pads... I mean I measured things with the PM-1 and PM-2 pads in the past. They may sound a bit different, but they did not measured dramatically different as what one would expect with something like an electrostat or something like that.

Here are Tyll's measurements of the PM-1s with different pads if you want another point of view:

http://www.innerfidelity.com/content/scrumptious-oppo-digital-pm-1-planar-magnetic-headphone-measurements

I also fully agree with Anax in that replicating, or at least trying to replicate, a rig to get similar measurements might be very useful. I believe that's what some folks around here have been trying to do.

 

Welp, will be all for checking out your impressions dude... but don't leave the plots aside!