More Stax Measurements: SR-009; SR-007; SR-507; SR-404 Ltd; SR-404; and SR-003

By Tyll Hertsens • Posted: Oct 11, 2011

I'm making ready to head off to RMAF, but I certainly didn't want to shirk my duties measuring Stax headphones, and getting them back to their rightful owners.

Unfortunately, I just did a quick listen on each and didn't have time for listening tests, so other than a couple of notes here and there, I'll let the measurements speak for themselves.

We'll start with the round ear-piece; the rectangular ear-piece Stax will be on the next page.

Stax SR-009 New Out of Box (# SZ9-1278)
This is a brand new headphone of the second batch of SR-009 (shipped about mid-Sept '11), fresh out of the box. Compared with the first pair of SR-009s, which had some break-in time, the measurements are near identical with the exception of the THD+noise. It will be interesting to see if anything happens after they're used some, though it's just as likely an error in measurement. I'll be re-measuring these after RMAF.

Click on graphs image to download .pdf for closer inspection.

Stax SR-009 (# SZ9-1207)
This is the first SR-009 I used during the high-end comparison. Wow! They sounded great. Look hard, there's some magic in these measurements.

Click on graphs image to download .pdf for closer inspection.

Stax SR-007 (# SZ1-1023)
These are a late model Mk 1.

Click on graphs image to download .pdf for closer inspection.

Stax SR-007 (#SZ3-1576)
These are a Mk 2.5 version.

Click on graphs image to download .pdf for closer inspection.

More measurements of rectangular Stax next page ...

Comments

Fascinating!

Submitted by Jazz Casual on October 12, 2011 - 5:29am.

Thanks again Tyll. Am I right in thinking that the SR-404 holds its own against the pricier SR-507, and that the SR-404 LE looks like the pick of the Lambda bunch?

Qualia

Submitted by Shufny on October 12, 2011 - 8:35am.

Do you plan on remeasuring the Qualia 010? I would be really intrested since your previous one seems like it had a bad seal. I assume this is the reason it's not among the data sheets.

Great stuff

Submitted by Stefraki on October 13, 2011 - 2:48pm.

Have been looking forward to seeing some Lambda measurements. Pretty much what I expected from the ones of those I've heard. I can see why I like the 507s the most - it's that extra little bump in the deep bass between 20 and 40 hz that counters the Lambda treble emphasis so well.

RMAF Baby!

Submitted by The Monkey on October 13, 2011 - 9:17pm.

RMAF Baby!

Stax impulse response

Submitted by jeffreyfranz on November 17, 2011 - 6:13pm.

Great contribution to our understanding of this family of phones. Thanks, Tyll.

I do have one question: Why is the SR-507 the only one with a positive-phase impulse response, while all the others are inverted (even the 009)?

Thanks.

That remains a mystery at the

Submitted by Tyll Hertsens on November 17, 2011 - 7:34pm.

That remains a mystery at the moment. From what I can gather it's most likely something in the test set-up. Not sure where it's coming from, but next time I get the gear in, I'll peck my way through it.