Quote from: mrspeakers on Today at 12:41:28 PM

I'm not sure if what we heard at the meet was distortion or what not. But it took seconds to determine something was off with No_One411's Alpha Primes. It is uncertain if this is an isolated issue.

When I get the phones back I will give the results here, test and listening. 

How do you mean the G.R.A.S. 45CA is a "better measurement system"? Seems to me Tyll at IF is using a much more advanced system and things do not look "better" THD wise vs most TOTL dynamics. Particularly in the mids. Consider the Mad Dogs which use a similar non-modified driver:

http://www.innerfidelity.com/images/MrSpeakersMadDogA.pdf

... and the Alpha Dogs:

http://www.innerfidelity.com/images/MrSpeakersAlphaDog2014.pdf

Let's talk about repeatablity... What's going on with these two Mad Dogs? Why are these so different FR wise?:

http://www.innerfidelity.com/images/MrSpeakersMadDog2014.pdf

http://www.innerfidelity.com/images/MrSpeakersMadDogA.pdf

Quote from: mrspeakers on Today at 12:41:28 PM

    Note: our fixture is designed to deliver a precise fit to our phones so our measurements are extremely repeatable and consistent.  All our microphones are calibrated, and our A/D converters are 24/192.


Apparently best case scenario you still some QC issues though.

Mad Dog 1.0 vs Mad Dog Pro (Tyll mislabeled it).

We do not have a "QC issue," our repair rate is well below 1%. 

In no way did I mean to imply our system is "better" than Tyll's, simply that we have vetted our work on our own and on G.R.A.S. systems.  We'll be getting time on a test-head, soon, too. 

Dear Dr. Speakers,

First I'd like to thank you for your contribution to the headphone space. I really enjoyed the Mad Dog 3.something and thought it was a really good headphone at the $300 or less price for something closed and fun.

That being said, this thread really worries me.

Do you have any additional measurements? Maybe posting something in the time domain and a corresponding comment of how that translates into what people hear. I thought you learned to measure from someone on the forums years ago? Have you kept up with the latest in terms of measurement technology and theory?

Also, if you're pleating an already established driver, how do you manage the variability in distance from the traces to the magnets? Are you compensating somehow with regard to the magnetic array? How are you compensating for the fact that the motor forces on the diaphragm are no longer aligned?

Regards,
Pasta Lover

First, thanks for the promotion to "Dr." 

I didn't learn measurements from Head-fi, I had started measuring on my own and in the process I picked up  ideas from Tyll, Marv, Bluemonkeyflyer, and a few others.  I tried to share a few ideas as well. 

The motor traces are still aligned to the magnets.  The reduction in distortion as well as the extension in frequency response pretty much make it clear there's no issue with respect to the magnet array.  If there were, THD would increase. 

I'll pass on correlating time domain to what people hear, and leave that to others...  I think there's a lot on Changstar about that topic.

Cheers,

Dan

So what we have here is another case of a DIY planar that can be measured as less than optimal or even substandard by 3-4 independent rigs and confirmed by 5+ independent sets of ears prior to measuring, yet somehow again the vendor is claiming their lone rig is the standard by which all should be judged and those sets of subjective ears are hearing imaginary artifacts that happen to correlate with their independent measurements but not the vendors? Just want to make sure I have that right.

hello,

and apparently these concerns are not relevant to the vendor? 

So what we have here is another case of a DIY planar that can be measured as less than optimal or even substandard by 3-4 independent rigs and confirmed by 5+ independent sets of ears prior to measuring, yet somehow again the vendor is claiming their lone rig is the standard by which all should be judged and those sets of subjective ears are hearing imaginary artifacts that happen to correlate with their independent measurements but not the vendors? Just want to make sure I have that right.

You have reached conclusions that are polar opposite of my intent. 

I'm here to have an open conversation, and to improve our product. When I make a mistake I try to learn from it and improve, and I've been transparent about our test equipment and acceptable results because it's the right thing to do.

I have not said that what you heard is wrong, the opposite is true.  I fully accept and believe that the unit you have sounds bad.  And I accept responsibility for shipping it, though I'm not sure what the problem is or what went wrong.

I accept it measures poorly on your independent rigs.  I do wonder what these independent rigs look like and how they work, and because the quality of the rig affects results I shared some of our own experience.  Surely if you're going to publish test results you should share your test system.  Being able to reproduce results is the central tenet of science, yes? 

The simple fact that you're hearing major problems with this phone to me says there's a problem that needs to be fixed. I'd appreciate seeing some of the test fixtures and how they work because it will help me, and others on the forum, understand the results better, and maybe reproduce them.