CHANGSTAR: Audiophile Headphone Reviews and Early 90s Style BBS

Lobby => Headphone Measurements => Topic started by: Marvey on May 16, 2012, 07:21:37 PM

Title: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: Marvey on May 16, 2012, 07:21:37 PM
STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots

(http://www.changstar.com/index.php?action=dlattach;topic=297.0;attach=1619;image)
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: gurubhai on May 16, 2012, 07:30:25 PM
Wow!
Why do people call these dark?
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: Marvey on May 16, 2012, 07:34:34 PM
The mk2.5s are a little bit more forward than the mk1s. The mk2s are definitely not dark sounding. Maybe slightly laid back or even too forward for those would prefer the mk1. These mk2s were modded with a partial 80% block of the vents and a full spring mod.
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: Anaxilus. on May 16, 2012, 09:40:26 PM
Interesting behavior from 10khz-20khz.  That a result of any particular mods?
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: Marvey on May 16, 2012, 10:06:00 PM
Nope - they are just shiney up there! These have a ton of air. This could be a characteristic of the mk2.5. Jude mentioned when he heard them that he actually heard treble - which he said wasn't the case with other 007s that he had heard in the past. Could be the amp though. Or could be the mods.
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: rhythmdevils on May 16, 2012, 10:54:38 PM
The 10khz-20hz region seems unique among the phones you've measured.  Even FR, fast but rough decay.  I wonder what causes the jaggedness and how it manages to be so clean despite. 
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: maverickronin on May 17, 2012, 12:03:04 AM
Quote from: rhythmdevils on May 16, 2012, 10:54:38 PM
The 10khz-20hz region seems unique among the phones you've measured.  Even FR, fast but rough decay.  I wonder what causes the jaggedness and how it manages to be so clean despite.

I find that really interesting too.  The 009 CSD was similar too.  The ESP950 didn't have those tiny little ridges though.
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: Maxvla on May 17, 2012, 12:40:48 AM
Looks like a Grado.
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: rhythmdevils on May 17, 2012, 12:51:27 AM
Quote from: maverickronin on May 17, 2012, 12:03:04 AM
I find that really interesting too.  The 009 CSD was similar too.  The ESP950 didn't have those tiny little ridges though.

It looks to me like a well controlled problem of some sort.  Something Stax saw in the driver's response and worked to minimize to the point of irrelevance. 
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: Marvey on May 17, 2012, 12:54:56 AM
I've seen those tiny micro-ridges in ribbon transducers too. Let me run the ESP950 with the same visualization later to see how that looks. I do know the ESP950 has less tension on the diaphragm.
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: Currawong on May 21, 2012, 12:14:40 AM
What amp was this with, out of interest?

I don't think that the 10-20k brightness is going to affect much. Most of what we call "bright" is the result of what is between 4-10k.
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: Marvey on May 21, 2012, 12:19:08 AM
T2. The mk2.5 does seem to have more treble energy than the mk1, but yeah that entire 10k+ region is "air". Very nice effect.
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: RexAeterna on May 21, 2012, 12:52:36 AM
whatever you did the right channel and the headphone looks awesome(measuring wise. i bet though it sounds good as it measures).


Quote from: Currawong on May 21, 2012, 12:14:40 AM
I don't think that the 10-20k brightness is going to affect much. Most of what we call "bright" is the result of what is between 4-10k.

interesting seeing someone saying that cause usually with most stuff involving past 10khz not very bothersome to me either but, i tend to find lot of electrostatics more comfortable and less fatiguing compared to lot of headphones cause of less treble energy build-up since most electrostatics are completely free-air/open(that's why i hate closed phones as well besides the weird pressure they give even when playing nothing is bothersome for some odd reason) 
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: Armaegis on May 02, 2015, 07:13:33 PM
So what's the verdict on a 007mk2? What's a good used price? I have a potential trade offer, but I've never heard anything above the (lambda?) models and don't have an amp, though thinking I might try to get a WEE so I don't need a separate amp.
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: shipsupt on May 03, 2015, 04:55:56 AM
They are better than they get credit for because they always get compared to the MK I.  Yes, the MK I is better in many ways, but in small ways.  The MK II certainly holds its own, and can be modded to get pretty close to the MK I sound.

The 007 is probably the most amp dependent of the Stax line up.  With stats we don't talk much about needing power, but the 007 's crave it and are rewarded with a strong amp with lots of control.  The 717 starts to get them sounding right, but the aftermarket stuff lights them up.  007 from something like the BHSE is stunning.  The EC Electra drives them with ease.

There are a lot of guys who run stuff like the Wee who report great results, and you should probably check in with them, but if there was one Stax I'd be wary of running like that it would be the 007.

It's been a long time since I was in the market so I can't help much with current prices.

Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: Armaegis on June 01, 2015, 06:50:44 PM
So I made that trade I mentioned a month ago and got a 007mk2 and Woo WEE... but I've got reduced output and severe distortion/buzzing in the left channel. Is this a fried driver?

I have no other stax headphone or amp to experiment with.
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: Tachikoma on June 01, 2015, 11:45:00 PM
Hard to say, could be a fried transformer. Is the buzzing there with no music signal?
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: n3rdling on June 02, 2015, 03:20:46 AM
Are you able to do simple soldering?  You can wire one of the Stax jacks with swapped L/R pins to determine if the problem is the transformer or HP.
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: Armaegis on June 02, 2015, 04:57:49 AM
Quote from: Tachikoma on June 01, 2015, 11:45:00 PM
Hard to say, could be a fried transformer. Is the buzzing there with no music signal?
The buzzing gets worse as I increase volume. Tapping/shaking the headphone sometimes makes it better or worse.

No buzzing without music.

What does a fried transformer sound like?

Quote from: n3rdling on June 02, 2015, 03:20:46 AM
Are you able to do simple soldering?  You can wire one of the Stax jacks with swapped L/R pins to determine if the problem is the transformer or HP.

I am capable... but this was a trade with a dealer and I don't want to go down that route if I can just get a refund or new headphone.
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: Armaegis on June 03, 2015, 10:00:57 PM
Hmm definitely the 007 and not the WEE.

I was going to try swapping channels on the WEE but the wires are so short in there I don't think I could actually swap without rewiring which is more that I want to bother with. So I just pulled the plug out a little bit and tapped speaker outputs directly to the pins. Right side is fine, left side is diminished and buzzy. Guess I'll be taking this up with the seller.
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: n3rdling on June 04, 2015, 04:02:23 AM
Sorry to hear :(
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: Armaegis on June 04, 2015, 06:42:31 AM
It sucks. I contacted the seller and he says it was working when he sent it out, so he's going to pursue damages/insurance from canadapost and if that pans out probably send me a new one.

I opened up the 007 and I can see a discoloration on the left driver. I didn't take it fully apart, but looking through the stators it's like a dark splotch. Almost burnt? Has anyone heard of this before?
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: Armaegis on June 04, 2015, 06:50:56 AM
some pics...
(click to show/hide)
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: DefQon on June 04, 2015, 06:53:18 AM
Doesn't sound good, probably a fried  or half damaged driver. I killed a pair of Lambda Nova's with a punctured dust cover I did not know, some moisture got in and left a scorch mark on the stator where moisture went in when I powered the amp on.

It could be just a dirty spot on the dust cover? Buzzing noise usually either from a faulty cable, bridged short somewhere or faulty transformers from the energizer IME.
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: n3rdling on June 04, 2015, 07:58:28 AM
I can't tell from your pictures...is that blotch on the outside of one of the stators, on a dustcover, or on the diaphragm itself?
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: Armaegis on June 04, 2015, 04:15:15 PM
It does not appear to be on the stators. I think it's on the diaphragm.
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: n3rdling on June 04, 2015, 10:02:59 PM
It looks like it may have arced the insulation then.  Can you watch it closely while playing music?  Look for any very small sparks.
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: Armaegis on June 05, 2015, 03:41:44 AM
Hmm no sparks as far as I can tell...
Title: Re: STAX SR-007 mk2.5 Frequency Response and CSD Waterfall Plots
Post by: Armaegis on August 21, 2015, 05:25:44 AM
So another two months have passed, we've been fighting with the post office for the insurance claim over my damaged 007. This has been a ridiculous journey... at first the adjuster went on vacation and didn't pass the file on to anyone, then they just stalled for a few weeks, then I finally got a call to talk about the damage, I sent it to the claims office on their own shipping label and they LOST the package, then they eventually found it but then misplaced it again, and then the guy closed the claim because the bloody file hadn't been touched in so long and didn't notify any of us. So finally after much screaming and threatening, the claim has finally been settled... but now the dealer is on vacation.  facepalm

Ugh, I kinda just want to give up on stax at this point. But I've already got the WEE, and I *should* be getting a brand new 007. Maybe I shouldn't bother and just sell it when it finally arrives. Or do something stupid and try trading more stuff to the dealer to upgrade to the 009...