[wualta]

T50RP

Removing all damping from the T50RP driver and letting it operate in its vented cup (with the little hole sealed) theoretically gives us the most bass this driver is ever going to give us, and it's adequate at best. After hearing good iso bass from the Pro 30 (the standard for this comparison, using the Panasonic SA-XR10's digital amps), the T50RP lops off the bottom two octaves [EDIT:and it was a true lop, the result, it later turned out, not of too much diaphragm tension as I had originally thought, but of earpads that let bass leak out and bass backwave leak in] . In this state, the T50 suggests bass very nicely, and if it wasn't for the big hump in the upper midrange, it'd be acceptable. Damping out the upper mid hump with a layer of felt gives a peaky sort of treble and moves bass cutoff an octave or so higher, which removes all suggestion of bass. Fooey. [EDIT: Not to worry-- the improved earpads that came along sometime during 2007 changed the prospects of this headphone so completely as to remake it, but since it's just an earpad mod, we continue to call it T50RP.]


T20v2

The T20v2 from Tyre has these big poofy comfy cushions that make it grinningly comfortable. Bass is okay, but there's some of that midrange rise (= honk), and there's no high treble-- just the opposite of what Tyre likes, the AKG sound exemplified by the K240 Sextett (or the surprisingly similar K501).

Since there's some bass to work with here, a reflex disc and a thin damping pad might just tame the midhonk, goose (heh) the treble and save most if not all of the bass. Will it ever be a HF darling? Probably not, but with some EQ you'd have the tight bass and treble sparkle of a good iso. [but see link below] Trouble is, even though they're not expensive even when new, the rugged contruction makes them heavy and bulky, and they are expensive compared to the bang for the buck you get from the Pro 30. The T20v2 shows that, alone among the early makers of isodynamics, Fostex really did know what they were doing. It's just that with the exception of the T50 (and with reservations the T30), what they were doing was stuff that HFers wouldn't get too excited about. Not surprising, since pro sound is almost never purist/audiophile sound, often by emphatic intent.

I hope to be able to change that for the better.

To sum up, the stock T20v2 sound is very like what I heard from the T20v1, only louder, because the magnets have been improved. There's a bit more [good] bass with the T20v2. Damping the T20v1 with a felt disc and a reflex disc gives good mids and a crisp treble, but the bass is gone. [UPDATE: This was due to a peculiarity of the T20 and T40 drivers: because of the driver clamp, the driver and any felt damper disc you use sit in a shallow recess-- the same-size reflex disc thus effectively sealed off the rear of the driver, and that's guaranteed to kill the bass on anything. See the later experiments, which were much more successful.]

 

[AudioCats]

wualta, does the T40 sound similar to the T20? MK1 models of course.

Now if somebody drill four holes next to that T50RP square driver and mount four V-moda (in series, plus a coil as low-pass filter)......Never mind, that many v-moda's will cost too much money

 

[AudioCats]

Wualta, that Monsoon planar thing was the wrong kind of information to show me....

If I get out-bidded again this time, I am gonna go get a set of them Monsoon MH-500 PC speaker system, take out the planar drivers and roll my own ortho headphones! Them big Monsoon squares will kick YH-1's ***.......

Like a Monsoon Float you know....






Thanks for the info

 

[wualta]

Quote:

Originally Posted by AudioCats Wualta, that Monsoon planar thing was the wrong kind of information to show me....

[Ian McKellen evil laugh] They're a lot of fun. You can actually do a Float/K1000 sort of thing by placing them on a carpeted floor on either side of your feet, aiming straight up at your left and right ears. Amazing. No worries about bass, either, with the bandpass-type woofer module. But don't get the MH-500/502-- get the MM-702 (not the 700) if you can find one. The panels go all the way down to 200 Hz without a crossover. They're a little midrangey, so a good soundcard/EQ unit is desirable, but they're smooth-midrangey, so it's easy to flatten them out.

Quote:

Originally Posted by AudioCats I am gonna go get a set of them Monsoons, take the planar drivers and roll my own ortho headphones! Them big Monsoon square will kick YH-1's arse!

The question is, is the tension set such that they won't produce bass even at close range no matter what you do, or isn't it? I've never tried driving the panels full range to see, and I've never been tempted to, because the woofer module with the 702 is so good. The one supplied with the 700 is so mediocre that it's not even in the running.

Highly recommended if you ever had doubts about isodynamic treble, and I know some of you do. I just wish Sonigistix had built EQ into the panels' amps-- it would've been so easy. Come to think of it, powered headphones with EQ wouldn't be a bad idea either, since some of you are making the tiniest dang amps I've ever seen.

Quote:

Originally Posted by AudioCats Like a Monsoon Float you know....

With french vanilla ice cream-- delicious! I'mna have one now.

 

[AudioCats]

if it is in a float form, there will be plenty of rooms for the KSC35 drivers...



"..... placing them on a carpeted floor on either side of your feet, aiming straight up at your left and right ears..."
--- now am I supposed to be standing while listening? sitting down? or squating with my hands resting on the carpet (kind of like a dog sitting)?

lets hope I won't have to build my own float, it seems to be a lot of work, and to get good bass I will have to sit on the sub, very uncomfortable....

 

[wualta]

Quote:

Originally Posted by AudioCats if it is in a float form, there will be plenty of rooms for the KSC35 drivers...

But once the KSCs are away from your ears, their fabled bass will disappear.

Hey, that rhymes. Sounds like a curse or something.


Quote:

Originally Posted by AudioCats now am I supposed to be standing while listening? sitting down? or squatting with my hands resting on the carpet (kind of like a dog sitting)?

When I did the experiment I was standing, but it doesn't matter. You could even set this up near or even in a chair, if you're clever with upholstery. Having a helper to aim the panels would be a help if you want to make this a permanent installation.


Quote:

Originally Posted by AudioCats lets hope I won't have to build my own float, it seems to be a lot of work, and to get good bass I will have to sit on the sub, very uncomfortable....

Just upholster the sub. Or: stick it in a hassock. Or: don't worry about it-- merely put it somewhere in the room such that the bass is good where you are, just like any other sub.

Oh, and to answer your earlier question about the T20 and T40: yes, they do sound similar, since they use what appears to be the same driver in enclosures that are almost identical. [UPDATE: This guess turned out to be wildly wrong. They may have sounded similar stock, but damping procedures for the T20 and T40 couldn't be more different, and the results are very different also. See below for the T40 and post #371 for the T20.]

.

 

[wualta]

"Nailed"-- yeh rite. Put it this way: Here's a simple, easy mod for the T40v1 which doesn't kill all the bass and gives great highs.

The T40v1 has an odd earcup-within-the-earcup, a section of a hollow rubber cylinder forming a ring about 6mm high that surrounds the baffle hole within its inside diameter (35mm) and covers the rest of the earcup space, extending under the earpads. Its function appears to be that of a funnel or duct, leading the sound from the diaphragm directly to the ear, as if they didn't trust the airtightness of the baffle or the strength of the bass. The ear lightly rests on this ring, so it's covered with a thin layer of opencell foam. I removed the rings (upper-mid cavity resonance) and will try the T40v1 both with and without. UPDATE: Without sounds much better.


Inside the driver cup, my guess that an additional chunk of opencell foam would both press the damping film against the driver properly and add just a bit more damping turns out to be more or less correct. I used the pink eggcrate stuff I used earlier in the ATH-2, with the "eggs" facing the back of the driver. The idea is simply to apply max pressure to the damping film, so the "eggs" aren't really necessary-- they just happen to be the right size so I don't have to cut out a precisely-sized little cylinder of foam:

The T40v1 now has flat, tight bass (kinda AKGish) and high highs that at first sound excessive but which are so clean and smooth that so far I've just been enjoying it. Very flat, extended on the top end like you wouldn't believe. As for the bass, well, this is not for bassheads, though what's there is satisfying. And I can always turn the treble down a click on the receiver, or just crank in some bass boost and have blam 'n' zing all I want. So, not my favorite 'phone but far better than the blah iso I first thought I'd be condemned to. It's got pizzazz. Civilized pizzazz.

And hey-- don't forget to give your moms their cards and gifts; your moms won't be around forever, y'know.

 

[ericj]

How dense would you say your eggcrate is? Looks medium-low from here.

Those rubber things in the earcups, they just peel off?

 

[wualta]

Quote:

Originally Posted by ericj How dense would you say your eggcrate is? Looks medium-low from here.

You're right, it's not very dense stuff, but it's not bunny-fluffy either. It's also not totally open-cell. Like I said, if you're a normal PC geek person, you'll have gotten some of this stuff in mailers used to ship video cards, graphics accelerators, muvvaboards, etc.

Quote:

Originally Posted by ericj Those rubber things in the earcups, they just peel off?

Yes. Unfortunately they're not held on by doublesided tape; they're actually glued, so removing them is slightly destructive. The rings are made of dense foam rubber. Here are some pix. First, the rings:

Next, one of the rings installed upside down so you can get a sense of its intended function:

Finally, the baffle with the ring removed, driver clearly visible. You can also see where the glue has held onto bits of the ring:

Note that the earpads will hold the rings on; there's no real need to reglue them, should you want to do such a thing, and you don't.


The T20v2's baffle looks identical, but the 20's earpads are wide and flat, leaving only enough room in the center for the driver to peek through. It's technically supra-aural instead of circumaural. Experiments pending.

.

 

[ericj]

Quote:

Originally Posted by wualta /img/forum/go_quote.gif The T20v2's baffle looks identical, but the 20's earpads are wide and flat, leaving only enough room in the center for the driver to peek through. It's technically supra-aural instead of circumaural. .

Like the T50 earpads, then?

As much as i like the way they sound, the maiors are a little uncomfortable and fiddly. I bet k271 velours will fit on them, and other fosters. I should have ordered a pair with my akg parts. worst case scenario i could put them on my k340.

 

[AudioCats]

wow, you guys should see how much that T40 went for...... people are crazy.......

 

[ericj]

Seriously. Inkmo got *two of 'em, NOS, for less than that.

 

[wualta]

Quote:

Originally Posted by ericj Like the T50 earpads, then?

Kinda. The T20v1 and the T50 both have conical earcups/earpads [EDIT: Nope, just the T20v1.] that kind of tent over the outer ear without touching the skull. Well, without resting entirely on the skull.
 
Quote:

Originally Posted by ericj As much as i like the way they sound, the maiors are a little uncomfortable and fiddly.

They're unavoidably heavy (think of how dense the plastic has to be to keep those magnets in place-- hey, I never thought of it before, but it's the only iso with a nonremovable driver! [EDIT: Weird thing to say, and totally wrong--- it's the T20v1 and v2 andT40v1 drivers that are integral with their baffles and thus nonremovable (not without surgery, that is), but the T50's driver is in a nicely removable pod) is that the trouble? Or is it the earpads?

"Fiddly"? Could it be a function of the simplified headband?
 

 

[ericj]

Quote:

Originally Posted by wualta /img/forum/go_quote.gif Kinda. The T20v1 and the T50 both have conical earcups/earpads that kind of tent over the outer ear without touching the skull

The pads on my maiors are as flat as the pads on my Pro 30. But not as soft.

Quote:

They're unavoidably heavy (think of how dense the plastic has to be to keep those magnets in place-- hey, I never thought of it before, but it's the only iso with a nonremovable driver!) is that the trouble? Or is it the earpads? "Fiddly"? Could it be a function of the simplified headband?

It's a combination of the earpads, the fact that i wear glasses, and the way that the earcups can swivle almost a whole 360.

I end up fiddling with them for 10 minutes to get them to sit on my head so that I've got the same position and pressure on both sides.

I can't decide if that means i shold lubricate the joint where the headband meets the struts.

 

[wualta]

Quote:

Originally Posted by ericj The pads on my maiors are as flat as the pads on my Pro 30. But not as soft.

[digs out the T50]Yep, you're right, they're flat. Their effect is like the flat pads on the T20v2, overlaying and smothering the outer ear, which is subjectively like the T20v1. That may explain why I thought of the T50's that way.

T20v1 is the only Fostex with conical cups. Kind of like a padded Nón lá.

Not soft? Mine are softer than any of my Pro 30s, though the Pro 30 pads do harden with exposure to human skin (plasticizers leaching out? Polymerizing skin oils leaching in?).


Quote:

Originally Posted by ericj It's a combination of the earpads, the fact that i wear glasses, and the way that the earcups can swivel almost a whole 360. I end up fiddling with them for 10 minutes... I can't decide if that means i should lubricate the joint where the headband meets the struts.

Aaah, you should just sell 'em to me.

Seriously, I think if you lubed the joints, they'd be so floppy you'd never be able to pick them up, much less get them settled firmly on your head. They need quick-releases, like on a bike.

By the way, I wear glasses too.

.