Orthodynamic Roundup

[Kabeer]

Heh, I was the one who gave DAC the idea after my experience with the T50/NAD. In DACs case I wanted his driver to 'see' the same size hole as the driver hole. This way there isnt bass loss (well because previously it was really a bass boost

), or treble loss. Just a transparent window to the driver.

Problem with pads is not just the hole volume/diameter, but their sealing capabilty, and even the reflectiveness of their material. Its a black art.

I tried some vinyl circum pads on the NAD today, kinda Beyerdynamic DT770-sih but vinyl. I made sure they sealed by pushing down on them. But it was a rather bassy muddy mess. Now this is a large earhole volume, so one would have expected a bass reduction. But with the gaint Ross earpads with a circum hole only just small enough to fit the ear, there is much more bass control, treble, and control all around.

I put this down (at a guess) to a v.large earpad hole volume creating a cavern effect where the sound is all bouncing around inside there (hehe we might have to start damping earpads

).

Also height would make a considerable difference to the perceived treble. With more height generally giving more treble, and more perceived headstage, but starting to risk more internal reflections.

At the end of the day what I can see is, best kinda pads are the typical sealing supra ortho pads. Or a SEALING circum pad with a v.small hole diameter, just big enough for the ear. Im using big reactangular pads from an old 70's Ross dynamic.

 

[mypasswordis]

Quote:

Originally Posted by wualta /img/forum/go_quote.gif Strangely, the only company that comes to mind as one who's given the topic a lot of thought over the decades is... Koss.

Sure seems like they forgot about all of it with the ESP950. Maybe they didn't want to deal with the liquid-filled pads they had before, which definitely did not stand the test of time.

 

[cetoole]

Quote:

Originally Posted by mypasswordis /img/forum/go_quote.gif Sure seems like they forgot about all of it with the ESP950. Maybe they didn't want to deal with the liquid-filled pads they had before, which definitely did not stand the test of time.

Leaking fluid pads+600v=PARTY TIME!!!

 

[mypasswordis]

It only gets better with 1500V.

 

[BoilermakerFan]

Quote:

Originally Posted by wualta /img/forum/go_quote.gif <snip> though I'd say we need a headphone Harry F. Olson to run the experiments with different percentage enlargement/reductions in driver-to-earpad-hole diameters to really nail down the effect. Olson is famous for, among other things, his study of cabinet diffraction effects in loudspeakers. He tested just about every crazy cabinet shape you can think of, practical or not. The headphone world needs someone like him, because we know that these things have an effect, sometimes a big effect. Earpad thickness, earpad "bore" or aperture (as a ratio of driver diameter), earpad density, outer diameter, .... Yes, it's a Brave New Earpad World.

Well, my name isn't Harry, but I'll be your Huckleberry. I've had email or PM conversations with a few of the Team Ortho Clan, but I've left it out the Ortho Underground for now. It's funny it has come up now, because just this past week I've had conversations stating the lack of any individual offering niche custom earpads and I put out feelers to a few H-F'ers to see if there was interest.

I plan to do many, many experiments with modding existing pads and then making custom pads for SFIs and other cans. One experiment will be wrapping Grado GS1K bowls in leather for the Gradossandro mod simply to see if it will work to keep those $45/pr pads from disintegrating so quickly without serious detriment to the SQ. I'm also planning to try my hand at leather wrapped K240 pads and YH-3 pads. I'm planning to eventually use very thin kangaroo leather simply because it will be thin, flexible and it's amazingly tough, far better wear resistance than lambskin nearly twice the thickness. Only problem is it can only be sourced in full skins in black or natural. Even the small thin skins I would need are over $250 each, but would yield a lot of earpads! The thickest parts of teh hide would be used for headbands covers and headstraps for the K140/240 and YH/HP cans that have them.

If the initial experiments or results look good and feel comfortable but sound, eh, worse, then I'll really start looking into different foams. However, I will not use any memory foams for environmental and health reasons as they off gas far more toxic fumes then any other foams. If I can find more environmentally and health friendly, low VOCs foams than I'll definitely bring those to the top of the list.

The most difficult challenge will be bringing myself to order ESW9, O2, or other suggested leather pads with the sole intent of ripping them apart to get the pieces for patterns as I need them to start with. Anyone willing to donate sacrificial pads would be thanked and rewarded appropriately! They don't have to be virgins either. Just one clean pad if they are identical, or both if they are matched sets. Older pleather pads may also prove difficult to skin for pattern pieces as most seem to be glued and not sewn.

I also plan to try a standardized mounting scheme that used pins and locking slot sockets kind of like the K601s/701s/702s. Except mine will be in aluminum so someone could have the option for supra or circum pads of different thicknesses or diameters to manipulate the desired sound sig. once we have the test data to back up what the different pads do.

I also came up with an idea for a headband construction that I need to investigate to see if it will be possible to fabricate it with enough inherent clamping pressure that Duggeh and Kabeer have noted that is so critical to gain that little extra bass response.

I do plan to do a lot of "enclosure" experiments with turn cups for the SFI and T50 drivers, but for now the pad experiments will be done with SmeggyFI pucks to keep the designs well known ones that anyone can reference in this thread. I will also use my YH-3s, Grado 325s and RS-1s since they are so easy to swap pads and most are familiar with their memories of their sound signatures (the Grados that is). I'm also planning to use a Mogami cable for sake of comparison since anyone else can inexpensively make their own, but it will also eliminate another variable between different headphones.


Any other suggestions are greatly appreciated.

 

[BoilermakerFan]

Quote:

Originally Posted by cetoole /img/forum/go_quote.gif Leaking fluid pads+600v=PARTY TIME!!!

There are dielectric silicones on the market.

http://www.accumetricinc.com/boss/PDF/453.pdf

This one is a grease, but they make less viscous silicone fluids as well. You could in fact offer liquid pads in different sizes: A, B, C, D, DD, DDD, and Dolly Parton.

 

[ericj]

Quote:

Originally Posted by BoilermakerFan /img/forum/go_quote.gif There are dielectric silicones on the market. http://www.accumetricinc.com/boss/PDF/453.pdf This one is a grease, but they make less viscous silicone fluids as well. You could in fact offer liquid pads in different sizes: A, B, C, D, DD, DDD, and Dolly Parton.

Petroleum products are typically non-conductive. You can get away with construction methods in fuel pumps that would never ever work for water pumps.

As i understand it, the old esp pads were oil filled. The failure damaged the drivers alright but not in a spectacular fashion. A whimper rather than a bang.

I don't think that the pads on the ESP950 are holding back the performance as much as they are holding back acceptance by high-dollar customers. A higher quality vinyl or even leather would increase their production cost but not by a huge amount.

 

[wualta]

I believe the old Koss and Sharpe pads were filled with mineral oil. I have an ESP-7 here whose pads are like new. Silicone oil would do the job too and could be made so viscous it would only leak if the pad were ripped open.

Koss did become less adventuresome as the '70s drew to a close. The HV-1 used a short length of variable-density foam tube as an earpad. Felt weird, seemed to do the job, but Koss' newest serious 'phones have conventional pads, as Eric points out, and I agree that the pads are not the limitation on the ESP/950's sound. Eric, did yours come back from Koss yet?

 

[mypasswordis]

Quote:

Originally Posted by ericj /img/forum/go_quote.gif I don't think that the pads on the ESP950 are holding back the performance as much as they are holding back acceptance by high-dollar customers. A higher quality vinyl or even leather would increase their production cost but not by a huge amount.

They could have tried angling the pads in Stax fashion or at least trying to allow people to get a seal, which I admit isn't that necessary when dealing with a driver the size of the ESP950's, but it still affects sound. I couldn't get one at all because there was always a hole in the back to the bottom, where Stax Lambda pads have the protrusion and where the QP85 has its pads.

And I agree, overall the ESP950's construction feels a bit fragile to me, and the pads aren't very nice. Doesn't keep me from wanting a pair (too much).

 

[ericj]

Quote:

Originally Posted by wualta /img/forum/go_quote.gif I believe the old Koss and Sharpe pads were filled with mineral oil. I have an ESP-7 here whose pads are like new. Silicone oil would do the job too and could be made so viscous it would only leak if the pad were ripped open. Koss did become less adventuresome as the '70s drew to a close. The HV-1 used a short length of variable-density foam tube as an earpad. Felt weird, seemed to do the job, but Koss' newest serious 'phones have conventional pads, as Eric points out, and I agree that the pads are not the limitation on the ESP/950's sound. Eric, did yours come back from Koss yet?

There's also the Realistic Pro 60 (aka HV/10 with tweaks) later-version pads, which are bowl shaped foam. Got a whole pile of 'em here. I ought to try covering a pair in leather . . .


Haven't got my ESP/950 back yet. Getting anxious, but that's probably not warranted yet.

With some fancy sculpted leather pads the esp950 might pick up some more bass extension, but i really don't feel like it needs it. Might be an interesting experiment.

 

[nsx_23]

Quote:

Originally Posted by wualta /img/forum/go_quote.gif Hey, good move, and I hope you didn't pay outrageous coin for the YH-1. Let us know if you decide to damp them. Damping won't increase the width of the headstage, but it will help in separating instruments in the mix.

About $110 with shipping. A bit expensive, but they do sound lovely out of my Zero DAC.

I'm not quiet about modding these just yet because they're so mint, and I'm uber-nervous about beaking the pads and not being able to reattach them.

 

[iQEM]

Quote:

Originally Posted by mypasswordis /img/forum/go_quote.gif So I take it you definitely think your orthos are superior to the K400 now?

yes, to be honest my diyCans had leave my K400 behind...even ATH-2 more superior than K400 but still bellow my diyCans, that's why i let go the ATH-2 to my friends...just my opinion, offcourse...

Quote:

Originally Posted by BoilermakerFan /img/forum/go_quote.gif Yes, I'm serious. I want a K400/401 for my AKG collection. I have my orthos and will be starting my SFI experiments shortly, but I do plan to keep my dynamics too. Different horses for different courses. Send me a PM and tell me how much you want for them in US $...

OK, i'll think about it...do you interest to other than K400/401 to complete your AKG's collection ? like K501 or K500...

 

[wualta]

Quote:

Originally Posted by ericj /img/forum/go_quote.gif With some fancy sculpted leather pads the esp950 might pick up some more bass extension, but i really don't feel like it needs it. Might be an interesting experiment.

My feelings exactly. It's not as if there were a crying need.


Quote:

Originally Posted by nsx_23 /img/forum/go_quote.gif I'm uber-nervous about beaking the pads and not being able to reattach them.

Remember, you don't need to peel the pads off to gain access to the screw heads.

 

[DefectiveAudioComponent]

Quote:

Originally Posted by Kabeer /img/forum/go_quote.gif (hehe we might have to start damping earpads ).

I actually tried to damp the inside of the earpads, the side facing the driver, to see if it would eat less treble. But it did not work well enough. That's when I decided to try your idea with pads that don't block the driver.

 

[ericj]

Alright, I'm on day four with the ASE-50 and my impression is that while the extension is generally good on both ends (or good enough anyway - bass under 40hz and treble rolling off above 12khz, which might just be my own hearing) the only remarkable issue with it is that it has a bit of a midrange hump.

And by 'midrange hump' i mean 100hz to 5khz or so.

It's not a problem per se except for the whole fletcher-munson relative loudness thing. They sound really pretty good when turned up, not so great at a low volume.

Before i cleaned the last of the paper off as best i could (seemed to be attached with PVA glue) i had the whole outer two rings of holes in the back magnet sealed off, and the honk was astounding. So, any further tweak must not go in that direction.

I might seal up one or two holes for a tiny bit of reflex action, but no more. A superdense donut like F2D used on his T20v2 (which was what the factory had installed in cardboard form originally) is right out.

Maybe what i should do here is enhance the bass by installing a ring of medium-density felt that just covers the outer third or so of the driver?

Any thoughts?