[wualta]

This place (and the effort involved in stating things clearly) is actually therapeutic, so if plod we must, let us plod steadily forward. I should have a new YH-100 (commissioned by one who knows who he is) damping mod cooked up here shortly.

Here's an old method I used back in the day of the ATH-1: punch out many little dots of felt and stuff them into the holes in the magnets. Hasn't worked on recent 'phones, but I thought I'd give it a try on the YH-100, since each headphone responds a little differently, and you have to admit, it's cute. Didn't like the results, though, and I may have damaged the corrugations on the diaphragm at one point. Not to worry...

But then, we have the future of cloth, ie, microfiber (or, if you're UK, microfibre):

This is a fallout from my recent crazed interest in things microfiber, which is a contagion I caught from my friend in Atlanta, owner of a new Mazda3, who has become Mr. Microfiber. He recommended a trip to Wal-Mart to pick up a couple of products branded MicroTex. One's a famous terry blue towel, the other's a microfiber suede polishing cloth that's designed to look like chamois. Hold a disk of felt up to a lamp and you can see little dots of light poking through. Hold this stuff up to the light and you see no pinpoints of light, yet the cloth is thin. Even if it took several layers... you can see what I'm thinking. The cost at Wal-Mart is $4.36 for 3 cloths, so you can see we're talking real money here.

Oh, and don't tell my friend I'm not using the microfiber on my car.

UPDATE: Looks good, doesn't it? Nice and yellow. Well, I'll save you the trouble of reading about the results a few posts down-- the microsuede just doesn't work as a primary damping layer on the YH-100. It's too effective as an acoustic resistance; it moves the resonant frequency way up into the upper midrange, so it screeches, and there's no bass. Turns out felt is sufficient and optimum as a primary layer, and both bass and treble can be tweaked if the response isn't flat enough or extended enough at the frequency extremes when you reach the point of critical damping. However, microsuede might be the perfect secondary layer for some drivers. Also read ericj's post #132 on the next page in re his YH-2.

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[ericj]

Here's a picture of the original foam rubber in my 2nd pair of YH-2's.



This foam is in MUCH better shape than i found in my first pair of YH-2 'phones. I can actually lift the whole pad off the driver in one piece, with a knife, if I'm careful. It still crumbles to dust between my fingers.

I'm not sure which, if any other Yamaha models have this same foam.

In the 6:00 position of the metal cup you should be able to see the bottom tooth of the ball joint, which is broken off in both sides of both pairs of YH-2 'phones i own. That's some good engineerin!

 

[wualta]

Wow! That's different foam, all right. The stuff in the YH/HP-1 is always that wimpy orange foam rubber. It may be useless, but it stayed intact.

This should inspire a search for a stiff but open foam that will put even but strong pressure against the damping pad and the driver.

The ball and socket joint is, oddly, backwards: The plastic strut has the socket or cup shape on its end. The metal insert in the driver cup is the ball. Not that it matters.

In other minor Ortho news, I found that only the HP-1 used a liquid gasket material to make sure the driver was sealed airtight to its baffle. In fact, it looks as if the driver is glued to the baffle. This inspired the Yello-Tack gasket. [EDIT: This turns out to've been a false lead-- a previous owner must've seen the need for some sort of baffle seal and glued the drivers in, but no other HP-1 we've come across in this thread, including a subsequent pair of my own, has the drivers glued to the baffle.]

Have you tried feeding your modded Pro 30 some bass boost to see how it takes it?


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[ericj]

Quote:

Originally Posted by wualta /img/forum/go_quote.gif This should inspire a search for a stiff foam that will put even but strong pressure against the damping pad and the driver.

Quite so. I'm searching for such a foam on and off.

Ever consider neoprene - you know, wetsuit material? Might be too air-tight for these applications, though.

Quote:

In other minor Ortho news, I found that only the HP-1 used a liquid gasket material to make sure the driver was sealed airtight to its baffle. In fact, it looks as if the driver is glued to the baffle. This inspired the Yello-Tack gasket.

In some unrelated experiments recently I've been using Permatex Flowable Silicone for a few things. This is basically a silicone sealant with the curious feature of being capable of drawing itself into small cracks via capillary action.

It's intended use is to seal up leaks in the gaskets of old windshields. Bought it at AutoZone.

Thing is, it's not really a glue. On surfaces that are nonporous you can basically scrape it off with your fingernail once it cures.

Thus, it *could be used to seal a driver to a baffle without the risk of not being able to reverse the procedure.

Haven't tried that yet. May try it on my franken-AKGs some time this week.

Quote:

Have you tried feeding your modded Pro 30 some bass boost to see how it takes it?

Yes, it takes very well to some bass boost. Right now the only bass boostable method i have is to use the EQ on my iRiver H120. I need to implement bass boost on my M^3 amp so i can do some truly fair tests - the millett doesn't have enough gain to do a fair comparison between the YH-2 and the much more efficient Pro 30.

I still haven't unboxed the M^3 since buying my house back in april.

 

[wualta]

Permatex is an audio DIYer's friend. They make that little bottle of conductive paint which is good for fixing intermittent Heils, and now this watery RTV silicone, which looks easier to handle than yello-tack. Thanks for the tip.

Neoprene from a wetsuit would be nonporous, as far as I know, and that doesn't work-- it traps the air inside the driver, and trapped air acts like a spring, effectively increasing the tension on the diaphragm to the point that it won't produce bass. So you end up with a screecher. Good for a tweeter in a K340, but...

 

[Inkmo]

Quote:

Originally Posted by wualta /img/forum/go_quote.gif Inkmo, glad to have you back. Long time no 'mo. Hope everything's clickin'.

clickclickclickclick. Yeah. I'm super crazy busy with school now, but I can't wait till I'm done with all these dang essays so I can read this whole thread. Like I said, it's making me think about manning up and taking apart my ATH-2.

 

[wualta]

Quote:

Originally Posted by Inkmo I'm super crazy busy with school now... Like I said, it's making me think about manning up and taking apart my ATH-2.

Good to hear. Go to Big Lots and get some SuperGlue brand yello-tack, which they call Handi-Tack. Only a dollar. Then to Wal-Mart for some microfiber suede [UPDATE: Nah. Go to the fabric store instead and get the cheapest felt they sell ], maybe a #1 Phillips screwdriver. If you've bought computer stuff recently, you probably already have a chunk of grey foam that'll work as a damping-pad holder. Oh yeah, some really good scissors. When you're ready, let me know.


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[ericj]

Quote:

Originally Posted by wualta /img/forum/go_quote.gif Permatex is an audio DIYer's friend. They make that little bottle of conductive paint which is good for fixing intermittent Heils, and now this watery RTV silicone, which looks easier to handle than yello-tack. Thanks for the tip.

Driver sealing with permatex flowable silicone in my frankenphones gets two thumbs up. A little stinky and fiddly to put together, but did wonders for 'em.

I've dusted off my M^3 headphone amp and i find that the Pro 30 don't really need bass boost - they just really benefit from an amp that can feed them all the current they care to sink. The bass is tremendous - never thought I'd feel subsonics out of 32mm drivers under a Radioshack trademark.

 

[wualta]

Quote:

Originally Posted by ericj Driver sealing with permatex flowable silicone in my frankenphones gets two thumbs up. A little stinky and fiddly to put together, but did wonders for 'em.

Great! Another weapon in the Backwave Fighter's (Inkmo will be working on the surefire new comic Backwave Fighter! right after this unicorny Darkwood stuff is finished) armamentarium.

Quote:

Originally Posted by ericj ..[size=small]the Pro 30s don't really need bass boost... The bass is tremendous - never thought I'd feel subsonics out of 32mm drivers under a Radioshack trademark.[/size]

Holy dang! I'ma put that blurb on my headstone. Mind if I quote that quote in bold italics with a larger font?

This was, you see, the wholly unexpected bonus. I thought damping would help the midrange hump and the transient handling, naturally, but I never expected the apparent increase in bass quality and quantity caused by the compacting of the smeared-out bass transients.

Imagine what you could do with something the size of a Fostex T30 or T50 driver.

Try adding an outrageous amount of really low bass boost, say, 40 Hz and below, if that's possible with your setup. Maybe use your DAP as a preamp. You'll know you've got sufficient damping if the phones try to tear your ears off.

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[lcsaszar]

I disassembled my Peerless PMB-100 headphones, and sealed all the holes on the baffle around the diaphragm with masking tape. I also applied a thin layer of black felt at the whole rear surface of the headphones, just behind the covering grille. Unfortunately the bass did not increase much, only the sound character became somewhat darker.

 

[Inkmo]

Quote:

Originally Posted by wualta /img/forum/go_quote.gif Good to hear. Go to Big Lots and get some SuperGlue brand yello-tack, which they call Handi-Tack. Only a dollar. Then to Wal-Mart for some microfiber suede, maybe a #1 Phillips screwdriver. If you've bought computer stuff recently, you probably already have a chunk of grey foam that'll work as a damping-pad holder. Oh yeah, some really good scissors. When you're ready, let me know.

ooh...

Is this gonna require any soldering? What should I do about the pads that audiotechnica taped on there? maybe some grado or senn pads? You know.... the ATH-2, off the top of my head, seems like it's pretty similar size to the grados... maybe the pads might stretch over. Chris has some SR 125s. I'm sure I can get away with my experiment without breaking anything....

 

[ericj]

Quote:

Originally Posted by wualta /img/forum/go_quote.gif Holy dang! I'ma put that blurb on my headstone. Mind if I quote that quote in bold italics with a larger font? This was, you see, the wholly unexpected bonus. I thought damping would help the midrange hump and the transient handling, naturally, but I never expected the apparent increase in bass quality and quantity caused by the compacting of the smeared-out bass transients.

hehe, go ahead.

I'm not really a basshead. I mean i like it when it goes all the way down without distorting, but it's not really my gig.

But i hooked up the M^3 and started listening and noticed a significant improvement vs. driving the Pro 30 directly from the H120. And i LIKED it.

Before i knew it i had these little cans pounding out Kraftwerk tracks on my head at full volume. It was like i could feel the corners of the square waves, yaknow? It was like being an angry teenager again!

Quote:

Try adding an outrageous amount of really low bass boost, say, 40 Hz and below, if that's possible with your setup. Maybe use your DAP as a preamp. You'll know you've got sufficient damping if the phones try to tear your ears off.

I can do that. And come to think of it i do have a Carver preamp here that might be able to help the cause.

 

[facelvega]

Quote:

Originally Posted by lcsaszar /img/forum/go_quote.gif I disassembled my Peerless PMB-100 headphones, and sealed all the holes on the baffle around the diaphragm with masking tape. I also applied a thin layer of black felt at the whole rear surface of the headphones, just behind the covering grille. Unfortunately the bass did not increase much, only the sound character became somewhat darker.

No surprise there, except for the fact that you didn't hear any bass improvement. You should also be losing a lot of soundstage because of that masking tape. I recommend pulling off the tape and maybe instead putting the thin felt not over the back grille, but over the baffle holes, under the fabric you have tucked in between the cover and central panel. That's the first and easy step. It should improve bass response without making an already warm-sounding headphone go dark, as you and I both experienced with taping up those holes.

What I'm planning to do when I finally get around to it is to try to build a thick layer of felt that I can slide in behind the driver. This will be tricky, as you can see from the fact that the driver's sub-frame extends lower than the driver itself and has a broad cross-brace that will keep the felt from fitting tightly up against the back of the driver, not to having to be careful with the wire going to the driver's central contact. But I think it can be done, with maybe a little stiff foam between the felt and the grille to hold it in place.

 

[wualta]

Quote:

Originally Posted by Inkmo ooh... Is this gonna require any soldering?

No. Not unless you break something. No.

Think positive.

Quote:

Originally Posted by Inkmo What should I do about the pads that audiotechnica taped on there? maybe some grado or senn pads?

There's nothing wrong with the ATH-2's pads, but sure, why not go for the Grado feel? Don't see why not.

 

[wualta]

Quote:

Originally Posted by ericj Before i knew it i had these little cans pounding out Kraftwerk tracks on my head at full volume. It was like i could feel the corners of the square waves, yaknow? It was like being an angry teenager again!

"Feel the corners.." Heh heh heh. "Angry teenager again"... also heh heh heh.

I should point out to onlookers that this mod isn't a basshead mod, it just brings the bass up to "flat". But "flat" on an isodynamic 'phone is very extended and sometimes revelatory, and bass boost is suddenly a lotta fun.

The highs should also have come up quite a bit. Let me know about that. Don't want no dull Realistics.