CHANGSTAR: Audiophile Headphone Reviews and Early 90s Style BBS

Lobby => Headphone Measurements => Topic started by: Marvey on July 03, 2012, 06:50:33 PM

Title: STAX SR007mk1 Frequency Response and CSD Waterfall Plot Measurements
Post by: Marvey on July 03, 2012, 06:50:33 PM
STAX SR007mk1 Frequency Response and CSD Waterfall Plot Measurements

(http://www.changstar.com/index.php?action=dlattach;topic=384.0;attach=1669;image)

Had some trouble getting a seal. But graph should be comparable to the mk2.5 results (http://www.changstar.com/index.php/topic,297.0.html). Keep in mind my mk2.5s are modded with the full bent springs and 90% obstruction of the vents.
Title: Re: STAX SR007mk1 Frequency Response and CSD Waterfall Plot Measurements
Post by: Elysian on July 03, 2012, 06:54:23 PM
How does that difference around 7k-8k between the MK1 and MK2.5 measurements manifest in the sound?
Title: Re: STAX SR007mk1 Frequency Response and CSD Waterfall Plot Measurements
Post by: Marvey on July 03, 2012, 06:58:54 PM
It's evident. While the extreme dip is an artifact, the mk2.5 subjectively has more amplitude in this sibilance region. There seem to be some fundamental design differences in the pads and how they affect bass which aren't accounted for in these measurements.
Title: Re: STAX SR007mk1 Frequency Response and CSD Waterfall Plot Measurements
Post by: anetode on July 03, 2012, 07:04:37 PM
Smooth but a bit dull, looks about right.
Title: Re: STAX SR007mk1 Frequency Response and CSD Waterfall Plot Measurements
Post by: rhythmdevils on July 03, 2012, 07:05:52 PM
The MK2.5 looks cleaner around 7k too.  Interesting.  Going by the CSD's, the MK2.5 looks like a nice refinement of the MK1
Title: Re: STAX SR007mk1 Frequency Response and CSD Waterfall Plot Measurements
Post by: Elysian on July 03, 2012, 07:06:41 PM
It's evident. While the extreme dip is an artifact, the mk2.5 subjectively has more amplitude in this sibilance region. There seem to be some fundamental design differences in the pads and how they affect bass which aren't accounted for in these measurements.
Thanks.  It'd be interesting to know how much the pads and the port modification contribute to the change.

I'm assuming the delta in the 7-8k range is the famous mid-bass emphasis for the MK2 and MK2.5?
Title: Re: STAX SR007mk1 Frequency Response and CSD Waterfall Plot Measurements
Post by: Marvey on July 03, 2012, 07:19:46 PM
No the bass is the result of the "ports" where the cable goes into the cup. The mk2/2.5s have an open port. This opens up the seal and creates more mid-bass at the expense of low bass.  The mk2.5s I measured have mods which sealed off most of this area.

The mk2/2.5s are said to be more forward sounding. The 7k difference could explain why.
Title: Re: STAX SR007mk1 Frequency Response and CSD Waterfall Plot Measurements
Post by: Anaxilus. on July 03, 2012, 08:55:45 PM
Smooth but a bit dull, looks about right.


x2
Title: Re: STAX SR007mk1 Frequency Response and CSD Waterfall Plot Measurements
Post by: omegakitty on July 03, 2012, 10:02:42 PM
The MK2.5 looks cleaner around 7k too.  Interesting.  Going by the CSD's, the MK2.5 looks like a nice refinement of the MK1

Not sure I would agree the 2.5 is more refined. IMO after comparing both I thought it was a step backward from the mk1 (ports sealed on 2.5), most obvious on female vocals.
Title: Re: STAX SR007mk1 Frequency Response and CSD Waterfall Plot Measurements
Post by: sachu on July 03, 2012, 10:21:31 PM
interesting.. going by the 009 plot, it almost seems the 009 has a teeny bit more of a mid bass hump..and even seems to extend lower better than the 007.

A lot smoother past 1k on the 009.

Marv, would you say you were satisfied with the seal on the O2mk1 when measuring or would it be worth having a second or third look at measuring these.
Title: Re: STAX SR007mk1 Frequency Response and CSD Waterfall Plot Measurements
Post by: rhythmdevils on July 03, 2012, 10:37:52 PM
Not sure I would agree the 2.5 is more refined. IMO after comparing both I thought it was a step backward from the mk1 (ports sealed on 2.5), most obvious on female vocals.

I've only heard them at meets and never payed attention to which version (never been in the market for one) so can't say.  I wonder what is causing the difference. 
Title: Re: STAX SR007mk1 Frequency Response and CSD Waterfall Plot Measurements
Post by: n3rdling on July 04, 2012, 12:26:10 AM
mk2/2.5 pads use real leather so that probably causes some difference.  I believe Birgir has opened up the smk2.5s and said the drivers are a little different as well.
Title: Re: STAX SR007mk1 Frequency Response and CSD Waterfall Plot Measurements
Post by: Elysian on July 04, 2012, 12:31:38 AM
Wasn't Stax saying the MK2.5 uses some driver technology related to the SR009?
Title: Re: STAX SR007mk1 Frequency Response and CSD Waterfall Plot Measurements
Post by: spritzer on July 04, 2012, 03:05:57 PM
Yes, the SZ3 (or Mk2.5) uses the same diaphragm material as the 009.  That's why my SZ2 "fix" will not work on SZ3 sets as the midrange issues do not stem from the driver-ear distance.  The rest of the drivers is pretty much the same but a Mk1 driver will not fit in a Mk2.5 shell comfortably.