What headphones are you currently rocking?
Sep 19, 2012 at 3:55 PM Post #361 of 1,757
Quote:
I tend to avoid that place.
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However I just posted roughly the same reply in the Ultrasone Club thread, here:
http://www.head-fi.org/t/569107/ultrasone-fan-club-roll-call/1125#post_8708984
I also know that there was, at some point, an Impedance Tutorial in Sound Science that I contributed not insubstantially to at one point.
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It wasn't "dead to rights" accurate, but it was a lot better than a lot of the nonsense that crops up from time to time.
Anyways, it seems that German models in general seem to fit into that trope (Sennheiser, Beyerdynamic, and to a much lesser extent, Ultrasone). The HD 598s have actually been measured, here:
http://www.innerfidelity.com/images/SennheiserHD598.pdf (posted so there's no need to guess)
Compare this to a stable headphone:
http://www.innerfidelity.com/images/AudioTechnicaATHM50B2012.pdf
Regarding the Sony cans - Sony headphones (like many other Japanese models) tend to be pretty stable*, but the MDR-F1 and MDR-MA lineup are explicitly so, because they have a Zobel network included for each driver; the goal being to flatten out the impedance. The downside (and this isn't explicitly a downside to Zobel networks) is apparently a very low nominal Z - the F1 and the MA900 are both 12ohms nominal, which presents an issue for a lot of equipment.
Basically with the HD 598 (or something like the HD 580, which I used to own) if you hook them up to a low Zsource, they can sound "thin" or "bass light" and with a high Zsource they will gain some body (at least imho - others might view it as too much bass). Personally I enjoyed the HD 580 on the 470R taps of my Yamaha more than anything else. Yes you could get the same result with a graphic or parametic EQ. But in the case of something like the M50, it really will not matter because they aren't reactive relative to Zsource. My suspicion is that a lot of people who subscribe to "all amps are different" are basing this on experience with a Sennheiser or Beyerdynamic headphone and trying out amplifiers with wildly varying Zsource figures.
* Some various Sony cans' measurements:
http://www.innerfidelity.com/images/SonyMDRSA3000.pdf
http://www.innerfidelity.com/images/SonyMDRVSA5000.pdf
http://www.innerfidelity.com/images/SonyMDRXB1000.pdf
http://www.innerfidelity.com/images/SonyMDRV6.pdf (here's an outlier)
http://www.innerfidelity.com/images/SonyMDR7509HD.pdf
http://www.innerfidelity.com/images/SonyMDRZX1000.pdf
The MDR-F1 have actually been measured before (http://www.geocities.jp/ryumatsuba/mdr-f1.html), but the reliability of that suite is somewhat suspect (there is A LOT of post-processing/smoothing going on with those measurements), and there is no impedance data. Also it's in Japanese.
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To the topic of the thread: right now I am listening to Ultrasone PRO2900s. And enjoying it.
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::EDIT
Just noticed in your signature, you list the HD 595, not the 598 - apologies. Here's the 595:
http://www.innerfidelity.com/images/SennheiserHD595.pdf (a lot of the same but not identical)

I've pretty much come to the same conclusions.  Japanese headphones's in general are pretty nonreactive.  I wonder how that happened...  Also, the Zobel network thing is pretty cool.  Perhaps an electronics build is in order for me...
 
Sep 20, 2012 at 6:08 PM Post #362 of 1,757
I've pretty much come to the same conclusions.  Japanese headphones's in general are pretty nonreactive.  I wonder how that happened...  Also, the Zobel network thing is pretty cool.  Perhaps an electronics build is in order for me...


I'm thinking the difference/history as to "why" is that the German headphone manufacturers started out targetting professional or industrial users (and all of the American companies who did that are long since defunct), while the current Japanese and American designers target consumers - where stability and ease-of-use are king. It is certainly something that can be addressed at design-time (look at the Beats Pro as a random example of a headphone that is designed to be very easily driven by anything with a headphone jack - that isn't just entropy, there were specific goals for that product (and I'm guessing that was one of them, if not the primary goal)).

Regarding building a Zobel - you need specific information about the driver you're attempting to stabilize in order to know parts values, but once you have that, be lazy (like the rest of us) and use a calculator:
http://diyaudioprojects.com/Technical/Speaker-Zobel/

Le is probably what you'll have a hard time getting, since we already know Znom. An LCR meter should give you a starting point though, but remember it's likely going to be probing at a single point (like 1khz or so) - not giving you a comprehensive image of inductance over the entire range (that plus the lack of T/S for the driver means a model is probably not plausible to construct before you go to live testing).
 
Sep 28, 2012 at 3:15 AM Post #367 of 1,757
Quote:
Ultrasone PRO2900 listening to 3Oh!3 (
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).
Ramblin,
Sounds cool! - did you build an adapter, or just re-terminate the 701s?

Built a little box that dumby loads the amp and (I think) reduces the voltage of the signal. Without the dumby load it's really just one resistor per channel. Simple enough that I could make it. 
 
These were the instructions I followed http://diyaudioprojects.com/Forum/viewtopic.php?f=9&t=2763 I have that DIY tube amp, I just have to figure out why one of it's channels cut out before I can use it for headphones. 
 
Sep 28, 2012 at 10:19 PM Post #372 of 1,757
Sep 29, 2012 at 4:39 AM Post #375 of 1,757
D2000 with a few MarkL mods and D7k cups. I never listen to these anymore. Wondering if I should sell.
 

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