[Reticuli2]

Fostex T50RP
 
Koss ESP950
 
Koss Sporta Pro
 
None of these have ever been put on a dummy head with full frequency sweeps, channel balance checking, or full range distortion tests?
 
There is a Porta Pro done on Headroom, but it's just a small portion of the frequency range tested for distortion.  Zip on the others.  Same lack of information on headphoneinfo.com, too.
 
That is kinda weird.  These are three of the most popular or wide-re-used drivers (in the case of the fostex) or headphones ever made, under maybe the V6.  We need data! 

 

[Acreo Aeneas]

Is full frequency sweeps, etc, really needed?  Knowing that the typical human hearing range is only 20 Hz to 20,000 Hz and some phones have a range of 18 Hz to 40,000 Hz, would people be able to tell that there's distortion at 35 KHz for example?
 
I ask since a lot of the reviews and buying decisions are influenced by how a set sounds to our ears, not so much whether or not it has some super frequency range.
 
Also you mention the "Sporta Pro", but then you say the "Porta Pro".  Did you mean the Porta Pros or this other model, the Sporta Pro (which I've never heard off in the Koss line up).

 

[Ishcabible]

Quote:

Fostex T50RP
 
Koss ESP950
 
Koss Sporta Pro
 
None of these have ever been put on a dummy head with full frequency sweeps, channel balance checking, or full range distortion tests?
 
There is a Porta Pro done on Headroom, but it's just a small portion of the frequency range tested for distortion.  Zip on the others.  Same lack of information on headphoneinfo.com, too.
 
That is kinda weird.  These are three of the most popular or wide-re-used drivers (in the case of the fostex) or headphones ever made, under maybe the V6.  We need data! 

I know Tyll has a pair of unmodded T50's (at least he's said so in his videos.) The full-monty job would probably be done to benefit us.

 

[scompton]

I don't know that you could call the ESP950 or Sportapro popular headphones and until about a year ago or so, no one here would touch the T50RP.   The Portapro, which I believe has the same drivers as the Sportapro, is a very popular headphone, especially in Europe where they're easy to find in brick  & mortar stores.
 
Tyll has posted tests of 2 Thunderpants on innerfidelity.com.  One measured spectacularly and another not so much. 
 
http://www.innerfidelity.com/headphone-data-sheet-downloads
 
http://www.innerfidelity.com/content/diy-orthodynamic-headphone-measurements-and-contest-page-2

Edit:  I think it's great that Tyll is measuring vintage and DIY stuff.  I sent him 3 of my vintage orthos and the same article that has the measurements of those has measurements for 2 K340s.  I know someone has sent a pair of Sextetts to be measured too.
 
Edit2:  There are 6 graphs for the Portapro on Head Room, FR, THD for a 500Hz sign wave, isolation, impedance, and 500Hz and 50Hz square wave response.
Quote:

Also you mention the "Sporta Pro", but then you say the "Porta Pro".  Did you mean the Porta Pros or this other model, the Sporta Pro (which I've never heard off in the Koss line up).

The SportaPro is the PortaPro with a different headband
 
http://www.koss.com/koss/kossweb.nsf/p?openform&pc^pt^SportaPro
 
 

 

[Reticuli2]

When did Tyll say he had a pair of T50RPs?  In the threads over there he says someone needs to send him a pair, which I've offered to do.
 
The tests that have been done on the Porta Pro are a bit limited compared to the full distortion tests done on innerfidelity and headphoneinfo.com.
 
And nothing seems to have ever been done on the ESP950.
 
Is Tyll or headphoneinfo.com accepting random submissions to get tested?

 

[Ishcabible]

I hazily recall him saying in one of his videos that he bought a pair to do his own mods with.

 

[Tyll Hertsens]

I don't have any stock T50RP and have emailed Fostex numerous times.  Argh.  I suppose at this point I'd be glad to measure a stock pair from someone else.

 

[Reticuli2]

PM me your address and I'll just buy a pair of T50RP and have them sent direct to you.  I don't know if they're backordered everywhere or not, but it's worth a try.  You could just get my address from me and send them when you're done with all the tests and listening at your convenience any time.  And you could take as much time as you want.  Cough, cough... you could even mod them with dampening and re-test them until they're golden-platinum-unobtanium perfect... and then send those to me.  Yeah, you could even do that.  Just say'n.  Heh heh.  Hell, I'd probably pay you extra for that, to hell with whatever ethics involved there are.  Anyway, let's forget I just said that for the moment and concentrate on getting you a stock one to begin with.  Give the word and the address and I'll try and get you a pair ASAP.
 
You know, Full Compass, Amazon, and B&H all seem to be out of them.  I have a local music shop that says they might be able to order them.  I think it'd be from Fostex direct.  They gave me the standard low online price + shipping as the quote.  That was last week. 

 

[Reticuli2]

[size=10pt]The stock Fostex tests are on their way from innerfidelity.com. Kind of a weird headphone, but I'm looking forward to seeing how they measured.[/size]
[size=10pt]Anyone have a Koss ESP 950 that could get tested? I do not want to have to buy one just to send them to Tyll without knowing how they perform. $500 is a lot to spend blindly on a headphone. Come on, someone man up and offer yours to the non-terminal sacrificial alter of empiricism.  I'll even pay the shipping both ways, how about that?  $20-25 is nothing to get some real data on those bad boys.[/size]
 
I did find this, in the mean time:
 
[size=x-small]http://www.google.com/custom?domains=ratsound.com&q=headphone&sa=Google+Search&sitesearch=ratsound.com&client=pub-4084542268035371&forid=1&ie=ISO-8859-1&oe=ISO-8859-1&flav=0000&sig=TTga-qg3MnG4oU_q&cof=GALT%3A%23008000%3BGL%3A1%3BDIV%3A%23336699%3BVLC%3A663399%3BAH%3Acenter%3BBGC%3AFFFFFF%3BLBGC%3A336699%3BALC%3A0000FF%3BLC%3A0000FF%3BT%3A000000%3BGFNT%3A0000FF%3BGIMP%3A0000FF%3BFORID%3A1&hl=en[/size]
 
In part 5 of this guy's mighty headphone quest there's a crude response for the 950 and it's actually showing only a little down in the deep lows with just a little midrange emphasis and quite smooth and even in its response, with gradual, smooth frequency response changes.  It gets eliminated by him only because of its open design.
 
Of closed headphones, he likes the Sennheiser HD25, Ultrasone 680, and Denon 2000.  He's mixed on the HD280, like I am, but shows that there is something wrong with the rigidity/resonance of the HD280's housing.
 

 

[Tyll Hertsens]

Thanks for pimpin' me, mate.  
 
T50RP measurements are in the can and I'm hoping to review the stock pair next week.
 
I'll try to pick up some Porta pros and sporta pros from HeadRoom.  I don't think they have any ESP950s, but I'll ask. 
 
Also got some e-stat measurement plans in the works. They should be coming along in a few months.
 
ANyway, totally open to ideas.  Feel free to post requests here and I'll keep my eye out.

 

[Armaegis]

In the meantime, here's another site with T50RP measurements ...http://www.geocities.jp/ryumatsuba/t50rp.html

 

[Reticuli2]

Wow, that japanese guy's still keeping up that website?  I haven't been on that thing I think since I had the Koss A/200 back on headwize!  Fostex, Ixos, PHX, Ex-29; he's got a lot on there.  I can barely comprehend the google translations, though.  There's a lot about fish.  A lot of his favorites also don't seem to have much to do with the measurements, though it's tough to exactly make sense of them.  He clearly has some problems with sealing or positioning on some of the closed headphones, or possibly it's an issue with amp output impedance.