[mudihan]

I am unsatisfied with the housing of my HP-1s. I think that it's too small for the drivers. I also want to try an open housing with those exceptional drivers. Does anyone know if there are vintage headphones, closed or open, with large housing that would accommodate HP-1s' drivers? I am especially interested in old Koss phones, since they are generally cheap but still have pads available from Koss. Thanks!

 

[Beagle]

Quote:

Originally Posted by mudihan /img/forum/go_quote.gif I am unsatisfied with the housing of my HP-1s. I think that it's too small for the drivers. I also want to try an open housing with those exceptional drivers.

The reason the drivers are "exceptional" is due to the housing they are in. If your HP-1 is in good shape, leave well enough alone. It's a classic. I've done driver swapping on YHD-1's and gotten nowhere fast.

 

[mudihan]

Quote:

Originally Posted by Beagle /img/forum/go_quote.gif The reason the drivers are "exceptional" is due to the housing they are in. If your HP-1 is in good shape, leave well enough alone. It's a classic. I've done driver swapping on YHD-1's and gotten nowhere fast.

No, I seriously doubt your claim. The stock housing is made of cheap plastic that has a relatively high resonance frequency. One may not notice it, but one can surely hear it. It contributes to distortion, which may "warm up" the sound. Dampening helps, but will not solve the problem. It's for this reason that expensive Grados use metal and wood, and expensive speakers use stone and other materials with low resonance frequency (think Wilson's Watts). The stock housing is actually the weakest link. My HP-1s do sound very good, but those drivers have much more potentials.

 

[mypasswordis]

I have had decent success with a vintage Audio Technica AT-702 and SFI ortho drivers. There are a couple more models around that range that are similar, just make sure you don't end up with an electret or you'll have to replace the cable as well. The stock earpads are just some acoustically transparent cloth with some foam inside so you may have to cut out some leather donuts to replace the foam with but that's easy to do. The housing is bigger than the YH-1's and almost completely open, but not big enough that you'd lose all the bass, and in fact are proven to work based on the fact that AT put electret drivers in the same housings for sale.

 

[mudihan]

Quote:

Originally Posted by mypasswordis /img/forum/go_quote.gif I have had decent success with a vintage Audio Technica AT-702 and SFI ortho drivers. There are a couple more models around that range that are similar, just make sure you don't end up with an electret or you'll have to replace the cable as well. The stock earpads are just some acoustically transparent cloth with some foam inside so you may have to cut out some leather donuts to replace the foam with but that's easy to do. The housing is bigger than the YH-1's and almost completely open, but not big enough that you'd lose all the bass, and in fact are proven to work based on the fact that AT put electret drivers in the same housings for sale.

Thanks. I remember reading about people diy-ing woodies for those SFI drivers. Where did they get the materials?

 

[mypasswordis]

Local places that sell hardwoods, online, etc, for the wood blanks, as well as all kinds of woodworking tools including but not limited to lathes and power drills, and various wood finishing products.

 

[aristos_achaion]

I've got a pair of open-backed woody YH1s built by smeggy and damped by ludoo (built for ludoo, originally). They're wonderful (especially with a good tube amp...my Compass just didn't have the oomph they needed), so certainly open-backed YH1s can be done. Maybe you could get some pointers from smeggy, since he's the one who did the woody in the first place.

 

[scompton]

I believe a couple of people did Grado like cups for SFIs with wooden disks bought at craft stores.

 

[Kabeer]

Quote:

Originally Posted by aristos_achaion /img/forum/go_quote.gif I've got a pair of open-backed woody YH1s built by smeggy and damped by ludoo (built for ludoo, originally). They're wonderful (especially with a good tube amp...my Compass just didn't have the oomph they needed), so certainly open-backed YH1s can be done. Maybe you could get some pointers from smeggy, since he's the one who did the woody in the first place.

Soo beautiful it could make one cry :'

OP: A rehousing could yield improvements. But purely making it bigger size wise might not be any use.
To give you some constructive advice, let me start by asking what you think of it currently. What you feel are the weak areas, and what exactly to you want to improve/achieve out of your mods?

 

[wualta]

The cautions mentioned are to the point: By changing the housing, you're changing several parameters at once, and the results may not be what you expect. That said, if you're persistent and discouragement-proof, you'll end up with something that's an improvement; I think we all agree that the original HP-1 cup is far from ideal. As long as you don't expect anything that resembles an easy fix, you'll do well.

Several ortho owners have applied blu-tack and even Dynamat damping to the cups of their headphones. That might be the first thing to try. Kabeer is correct in saying that concentrating on size alone isn't likely to give you the improvement you seek. The problems with the Orthos were caused by many factors, and it's a delicate balance-- change one thing and many other things are likely to change.

Good luck, and let us know what you find. Take pictures as you go.

 

[mudihan]

Many thanks!

The problem with the current housing is that it resonates too easily (which introduces distortion, because the housing will amplify a certain range of frequency) and is not large enough (if possible, I want to make a circumaural pair). Before I just sold my Koss ESP 9 two days ago, I listened to them again. One thing that struck me was how stable the housing felt (comfort is always secondary to me

. When the music was playing loudly, you could sense that the housing was contributing minimum distortion to the reproduction. Changing to the HP-1s, I felt that the housing sounded very BUSY. I also want to try an open version.

Wood disks? Is there a specific name for the disks (in the wood-working industry)? I tried a few searches and got many irrelevant results. It would be best if there are pre-made wooden cups that may fit the drivers. I am also interested in using housings similar to those of HD650 and A250/ESP 950 (big and open). But that's going to be very costly.

 

[Kabeer]

You want a radical change in housing structure and earpads. This will no doubt change the sound significantly.
So now you have at least partially defined what physically you disliked and wanted to achieve.
Can you express the same for the sound? Then maybe we can input some useful advice on what might be able to achieve it (but note, a lot of it might be theory)

 

[scompton]

This post http://www.head-fi.org/forums/f4/ort...ml#post5104479 has a picture of headphones made from wooden discs and circles bought at JoAnn's Fabrics. A few posts later, dBel84 posted about the materials. This is for the SFI drivers which are smaller.

Another option ludoo used was a hole saw to cut a blank out of a block of wood and a forstner bit to cut the inside of the cup.

For something premade, maybe something one of these would work. I'm not sure how you'd attach the baffle.

Unfinished Small Wooden Boxes & Wood Craft Boxes

With the bean pot, you could make something like the old Stanton Dynaphase monsters

 

[mudihan]

Quote:

Originally Posted by Kabeer /img/forum/go_quote.gif You want a radical change in housing structure and earpads. This will no doubt change the sound significantly. So now you have at least partially defined what physically you disliked and wanted to achieve. Can you express the same for the sound? Then maybe we can input some useful advice on what might be able to achieve it (but note, a lot of it might be theory)

I find the sound to be congested, and soundstage closed-in, when playing orchestral works. They sound excellent with jazz and solo/chamber classical music. I believe that one of the reasons Grados generally have limited soundstage in comparison to HD580/600/650 and A250 has much to do with the difference in housing, hence my consideration to use a larger housing with an open design for the Yamaha drivers. This is in addition to my dissatisfaction with the thin material used in HP-1. Ideally, I would want to put the Yamaha drivers in a HD600/A250/DT990-type housing made of wood or quality plastic and experiment with different dampening materials/method. What I know is that the Yamaha drivers are among the most well-made I have seen and may very well have tremendous potentials. I am fully prepared for a lengthy project, though not so well-prepared for a costly one.

I remember reading about wave cancellation and separating the front the driver completely from the back. Does anyone want to elaborate on this?

Thanks in advance!

 

[dclancy]

Quote:

Originally Posted by Kabeer /img/forum/go_quote.gif Soo beautiful it could make one cry :'

I can overlook the cheapo headband for the sake of paying homage to stock, but that screw sticking out!!! Those cups deserve better.
Nice transplant otherwise!