Orthodynamic Roundup

[nick n]

got any pictures of the shell?  you liking the sound?  congratulations on the transplant!!

 

[kalbee]

Well the shell is the HP-2 shell that I had lying around after using it's driver.
Sound is not bad, I feel like the lower-midrange is a little bit higher, making the vocals and overall sound a bit warmer but stuffier... but not a bad sounding phone per say!
 
I saw you mention using neoprene as a spacer, and thought I'd try with whatever I had in hand... the cork sheet I had worked plenty, even with the short screws of the Yamaha's. Thanks for the spacer idea nick!
 
As for the driver issue I have, it's not as bad now because the baffle clamps the drivers pretty hard against the back of the cup, where the hinge is elevated. Whenever I occasionally lose the right channel, I just press against it and it's back!

 

[vid]

Well, the Unipolars seem to work fine out of the SU-300, no overheating or nothing; no issues came up in about 30 minutes of playing. Maybe the SU-300 simply prefers taking in regular headphones through its frontal section rather than the bottom.

 

[wualta]

The Unipolars WORK? Boy, that sure is a slap in the face to anyone who warns people against buying electret headphones. Do they sound Sennheiserisch?

 

[nick n]

Quote:

The Unipolars WORK? Boy, that sure is a slap in the face to anyone who warns people against buying electret headphones.

shhhh.

you forgot you read this post, you forgot you read uhhhh what .

 

[vid]

Don't worry, they do have some channel imbalance in the bass. Nothing a few ortho modding methods couldn't mitigate, at least for now.
 
The sound overall is definitely something to EQ - without it, they're dominated by a bright and unnatural-sounding treble. That non-EQd response is relatively neutral between 80 and 2500 Hz or so, but the problems are beyond that: some extra brightness at 3 kHz, about 10 dB sucked out between 5 and 7 kHz, about 5 dB extra at 7-11 kHz, and the bass only extends down to about 80 Hz before slowly fading off (though it's still within 5 dB of 1 kHz at 60 Hz). The upper mids and treble aren't too hard to fix with EQ and the phones seem to take it ok-ish.
 
With that sort of corrective upper-end EQ, the treble is listenable, the mids are natural if a bit withdrawn - and some bass exists, in neither a negative nor positive way. Soundstage is ok, though I've not given them enough time to say too much past that. There's some amount of detail, but not massively - I think about the same as what the HP-50S does, which isn't bad. The overall sound is somewhat responsive but at the same time somewhat laid back.

 

[MaciekN]

Hello guys,
 
Does anyone still have some spare SFI drivers? PM would be welcome as I haven't seen any e-bay since May...
 
Cheers,
Maciek

 

[wualta]

Quote:

shhhh.

you forgot you read this post, you forgot you read uhhhh what .

Oo, right. Yeah. Electrets, they straightup without merit, man.
 
 
Quote:

Don't worry, they do have some channel imbalance in the bass. Nothing a few ortho modding methods couldn't mitigate, at least for now.
 
The sound overall is definitely something to EQ - without it, they're dominated by a bright and unnatural-sounding treble. 

Glad to hear they have some promise. Still, you were brave to buy them, since they're the poster child for electret failure. The bass-only channel imbalance is probably a blown earpad or some other leak. If the mids and highs are okay, chances are the electrets are okay. Keep us posted. Any idea of when these were made?

 

[vid]

Quote:

Any idea of when these were made?

 
This specific pair, you mean? No. For some reason I have the year 1977 in my head for the Unipolar 2000. There's that review from Gramophone magazine on Google that's dated 1978, so late '70s is likely.
 
Our MDR30 owns (or used to own?) two pairs of Unipolar and went as far as this to find a replacement driver - I'm surprised he hasn't said anything about the sound.

 

[wualta]

1977 should be in the safe zone for commercial electret products. Like I said, keep us up to date on these. As farz I know, they were never sold in the US.

 

[vid]

Quote:

1977 should be in the safe zone for commercial electret products. Like I said, keep us up to date on these. As farz I know, they were never sold in the US.

 
What kind of updating did you have in mind?

 

[GREQ]

.

 

[wualta]

Wow, it's sho nuff an ortho. Looks like an SFI/Audio-Technica driver. How's the sensitivity compared to a modern dynamic? Bass?

 

[nick n]

whoa!!!!!!!!!!!!!!!!!!!!!
 
I know of a couple other names these go under also... not saying until I secure a pair. Absolutely excellent find!

 

[vid]

Quote:

 
I know of a couple other names these go under also... not saying until I secure a pair. Absolutely excellent find!

 
Greq's already done securing a pair. I repeat, a pair has been secured. Feel free to splurge infos.