[purrin]

Set 6:

Fostex T50RP Anaxilus modified, Koss DJ100 (by request)
 

Fostex T50RP light mods

These are not modified off the same set measured above, so it would not necessarily be a good idea to compare these with those. I believe the stock Fostex measured above went to LFF for mods. I will get those in later for another measurement. I need to make another visualization tool better see the decay at specific frequencies. Finally, maybe Anaxilus can chime in on exactly what he did.
 

• Felt removed from front of driver
• K271 paddeds added
• Foam from vent removed

 
 
 

Blue - L channel - minor tweaks
Purple -  R channel - minor tweaks

Green - L channel stock

Red - R channel stock

 

Koss DJ100

When I put them on my head to first hear them, I really didn't want to measure these. By special request...

 

[Head Injury]

Haha, the DJ100 looks awesome 

 
EDIT: Now that you fixed it, it doesn't look so bad.
 
At first glance the HD800 looks to be the best so far. I wonder if that's why some people describe them as dry, analytical, etc? They're used to artificially sustained notes.
 
You gotta get your hands on a LCD-2, see how truthful that old low-res graph is. I've never seen it described as analytical, so maybe there's extra energy in the mid-range like the HP1000.

 

[purrin]

The HD800 can be dry sounding probably more because of its slight midrange dip with a sudden revenge of the treble. From the plots, the treble's hot, but it settles quickly. There's a broad ridge at 5kHz that settles fairly early too. All this is consistent with how I hear the HD800s.
 
The ESP950 measures good too. It doesn't seem to be as clean as the HD800 below 2k. A lot of that is probably due to enclosure resonance (cheap plastic) and reflections. I've noted very open phones tend to measure cleaner below 2k. But from 2k upward, the ESP950 settles very quickly. There are minor ridges throughout the treble, but they mostly in blue color that I don't think are really noticeable. The ESP950's frequency response - the back most plot at T=0, is awesome, and tonally, it sounds that way too.
 
As for LCD2s, I'm very curious myself. I can't seem to find anyone I actually know in person who still owns them. Anaxilus has a lead and is working on that for me right now - maybe in a week or so.

 

[electropop]

Maybe a rev1 vs. rev2 to shut people up at last 

 
And very interesting to read. Thank you again for the time and enthusiasm. 

 

[Anaxilus]

To chime in I've been waiting to do a full transplant and never got around to actually tuning the stock phones as I figured it to be a waste of time if I was pulling the drivers anyway.  The T50rp's had the felt removed from the front of the driver, K271 pads added and the foam from the vent in the cups removed.  It's not a finished phone at all.  Nothing has been added for damping or acoustic tuning but only removed from the stock the phones.  Pads changed as they provide better seal and comfort.  I was curious to see the effect on the treble region and cup resonances versus stock as those are the two most common mods apart from formulating various damping schemes.
 
 

 

[Reticuli2]

[size=10pt]Thanks for the ESP950 waterfall. Wow. At less than half the price of an HD800, it's got possibly a superior response, even if its low-end decay and resonances are inferior. And that's with the stock amp, right? One problem with the Koss has always been the build quality, which while partially compensated for by the peerless warranty policy, is still aggravating in its cheapness. If Koss built them slightly better, they'd probably improve sonically AND not have to be replaced so often.[/size]
 
[size=10pt]I wonder what some of the good full-on Thunderpants would measure as with this technique. It's hard to believe most of those issues on the Fostex will be alleviated and I'm not sure Tyll's single frequency impulse response give enough information to verify that. The square waves and distortion figures looked good on the Smeggy ones, though. If a waterfall could verify Tylls results, that would go far at providing motivation towards getting the most out of them.[/size]
 
[size=10pt]The HD800's analytical character could be as simple as it having slighting more high frequency energy over neutral, especially over an even, smooth trend. I get a similar impression with Biamp DJ mixers over Allen & Heath and Ranes. A small 1-2dB even trend in favor of the highs over neutral (in the case of mixers, neutral is 0dB flat) is enough to do that. In the case of headphones, since it's the last in the chain you're going to get differing opinions as to whether it's analytical or "just right".  But you aren't going to hear anyone call it dark.[/size]
 
[size=10pt]Anyone got the other big boy, the T1, to send to him? [/size]

 

[tdockweiler]

Thanks for the DJ100 measurements

 

[Reticuli2]

That HP1000 looks like a halfway between the ESP and the HD800.

 

[purrin]

Quote:

[size=10pt]Thanks for the ESP950 waterfall. Wow. At less than half the price of an HD800, it's got possibly a superior response, even if its low-end decay and resonances are inferior. And that's with the stock amp, right? [/size]

Those ESP950 measurements are from the POS stock amp. I'm listening to the ESP950s right now with an adapter to an SRM323 and it sounds very very nice. The relatively poor low-end <2k decay is IMO the result of the cheap enclosure. I will soon post ESP950 CSD and FR out of the SRM323. Not much of a difference.
 
Quote:

I wonder what some of the good full-on Thunderpants would measure as with this technique. It's hard to believe most of those issues on the Fostex will be alleviated and I'm not sure Tyll's single frequency impulse response give enough information to verify that. 

 
Arnaud (and I, to a much lesser extent) is working with Tyll to see how much of his existing data is usable. Believe if or not, all we need is the impulse response (it actually has characteristics of white noise). Tyll may change his data capture methodology going forward and Arnaud will probably do the data crunching. I actually have some graphs from Tyll's data, but I don't want to post it because they are not comparable with mine and could lead to confusion.
 
Quote:

Originally Posted by Reticuli2 /img/forum/go_quote.gif
 
The HD800's analytical character could be as simple as it having slighting more high frequency energy over neutral, especially over an even, smooth trend. I get a similar impression with Biamp DJ mixers over Allen & Heath and Ranes. A small 1-2dB even trend in favor of the highs over neutral (in the case of mixers, neutral is 0dB flat) is enough to do that. In the case of headphones, since it's the last in the chain you're going to get differing opinions as to whether it's analytical or "just right".  But you aren't going to hear anyone call it dark.

 
Exactly. IMO, it's more of an FR issue (despite Senn's insistent claims of "neutral"), although I feel the 5k broad ridge contributes to some "hardness". I would kill to have an HD800 with the FR of the ESP950, which is more or less a slightly downward tilted line from the bass to the treble - it doesn't get better than that. Still what Sennheiser did with the HD800 driver is quite an amazing achievement.

 

[purrin]

Set 7

ESP950 comparison from different amps: Koss vs SRM323.
I took multiple measurements rotating the cycle to ensure repeatable results.
 

1. Not much difference at all, especially on the R channel.
2. Overall, maybe a slightly more even decay and less spurious HF spikes from the SRM323.
3. Notably more extended bass on L channel from SRM323 (see the partially obscured line in the back at 100Hz)

 
NOTE: Freq and time scale on these differ from most others.
 

from Koss Energizer

 
 

from STAX SRM-323

 
 
Impulse Response Click Here

 

[Anaxilus]

Nice work!  Explains why I never felt a need to pick up a 323 after hearing it in Venice.  I know I've raised a few eyebrows around here when I made some snarkey comments about the 323 before.   I really wish we had a KGSSHV to hook up to.  >.<

 

[purrin]

What! Despite the measurements, they do sound better out of the 323 compared to the stock Koss box, but maybe it's just not enough for you.

 

[purrin]

Set 8

Fostex T50RP mods. Here are some real mods by LFF. You'll have ask LFF exactly what he did. The headphones did feel heavier and they had some heavy duty pads on them. He tuned these by ear and was horribly afraid they would measure badly. I should have stuck a DJ100 graph to freak him out.
 

Stock (of actual headphone before mods)

 
 

After LFF Mods

 
 
These modded T50s sound great. Bass sounded most excellent with great low-end extension, no midbass hump (passed my piano test), and tons of slam. The stock T50RP can sound hollow and tizzy. The mods result in a much smoother and tighter sound. As for the measurements, the decay is faster and much more uniform with is a lot less random spiky stuff.
 
I'll be throwing out some more related graphs in a bit... some will be interesting.


Continued Here.

 

[tdockweiler]

Sorry, I feel like a complete idiot trying to decipher these graphs. So, I take it the DJ100 measured very poorly..oh well..
I did expect a lot of spikes near the upper mids and my ears hear this too. I kind of like it though. Certainly it's no studio monitor

 
 

 

[purrin]

T50RP Impulse Response

Red is the modded version. Impulse response is less compressed with a little more overshoot, but eventually settles more quickly.