Just listened to some Fostex T50RPs today... WOW! - Page 192

Hey, before you try to use fiberglass, don't. You're not supposed to touch this stuff anymore than you have to with bare hands. Breathing it causes cancer. Do NOT use fiberglass aka home insulation anywhere other than in your walls. It will make for a very unpleasant experience and (quickly) causes major health issues.

Do not put this stuff anywhere near close to your head. Leave it securely in your walls.

Quote:

Originally Posted by Hennyo 

Hey, before you try to use fiberglass, don't. You're not supposed to touch this stuff anymore than you have to with bare hands. Breathing it causes cancer. Do NOT use fiberglass aka home insulation anywhere other than in your walls. It will make for a very unpleasant experience and (quickly) causes major health issues.

 

Do not put this stuff anywhere near close to your head. Leave it securely in your walls.

Hennyo,

Thanks for the advisory warning.  I did not know that.

I guess I should cancel my asbestos order, huh?  

How are the mods coming along for you?

Quote:

Originally Posted by bluemonkeyflyer 

 

Hennyo,

 

Thanks for the advisory warning.  I did not know that.

 

I guess I should cancel my asbestos order, huh?  

 

How are the mods coming along for you?

 

 

Actually been dealing with my family right now.. Something came up and my parents we're lazy and completely unprepared for it, so I'm currently saving their butts.

You might have missed joelpearce's final "Omega" mods, posted in the other thread. He combines some interesting mods that may be of interest here. Some things he included: A new type of sound absorber (mentioned below), Dynamat on both the baffle and in the cups, and the use of one square of Micropore medical tape as a reflex dot on the driver. 

Quote:

Originally Posted by Hennyo 

Hey, before you try to use fiberglass, don't. You're not supposed to touch this stuff anymore than you have to with bare hands. Breathing it causes cancer. Do NOT use fiberglass aka home insulation anywhere other than in your walls. It will make for a very unpleasant experience and (quickly) causes major health issues.

 

Do not put this stuff anywhere near close to your head. Leave it securely in your walls.

Joel went with another form of home insulation: Roxul (at least that's what we call it in Canada. I think it's called Rock Wool in the US.) It's a mineral wool with very good sound absorption properties. I looked at the MSDS sheet and it appears to be relatively inert and benign. He used this in addition to Paxmate. 

Quote:

Originally Posted by arnaud 

This is not well known but melamine foam (sold nowadays as sponge http://en.wikipedia.org/wiki/Melamine_foam ) has excellent sound absorption capabilities. It's actually used in launch vehicles since it's very lightweight yet effective ( http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA476215 ). I used it for modding HD800's ( http://www.head-fi.org/t/464042/want-more-bass-from-your-hd-800-easy-mod/15#post_6299244 ). It's available in every supermarket in Japan, maybe elsewhere too?

 

 

Melamine foam is available as Mr Clean Magic Erasers in North America. You can get them at any hardware or grocery store. Melamine foam is super easy to work with. I used a bread knife to cut it and it does not shred or crumble easily. (BTW, Joel did not use Melamine foam in his mod. I'm just replying to arnaud's comment about its availability in Japan.) 

Quote:

Originally Posted by bluemonkeyflyer 

 

I happen to like the bass quantity/quality of my current T50RP mods but my wife wants a set with less bass quantity, thus the search for a fix.  I think one possibility is to use standard mods of plasticine in the baffles and Paxmate or Silverstone in the cups, leave the denser white felt on the back of the drivers, and try with/without a reflex dot - OR standard mods but remove the white felt and apply more than one layer of Organdi.  It make sense to try leaving the white felt intact, first.

I have modified one pair for my parents without hammering bass, but with very detailed extension and presence when the track needs it. You need to put plasticine in the back of the cups, remove the stock felt of the vents and put a layer of 1 mm thick craft felt over the plasticine, leaving the vents covered. 

In the driver, leave the white felt, add the plastic bumper reflex dot and the plasticine around the driver.

You can try it, as it's totally reversible and doesn't take too much time to do it. With this combination, is the most detailed and balanced headphone that I've listened to.

While I have a hard time believing that using a bit of fiberglass insulation in a closed headphone would cause serious health damage, the rock wool is a bit less horrible to deal with.  It's still itchy as all get out, but the stuff is not supposed to have the same kind of health hazards related to it.

I doubt any of it is going to sneak through the felt, the driver, and the dust shield to get at my ears, though.

Thanks, guys, for the suggestions about toning down the bass.  

JP:  I think you are right on the money when you posted in the Fostex Mods Link page your hypotheses about the stock white felt:  Maintaining a balanced freq range, serving as a big reflex dot to provide treble, and controlling the movement of the driver diaphragm to prevent bass bloating (paraphrased).

My last 2 mods (my version based on mrspeakers Rastapants and my BMF configuration) involved removing the stock white felt.  My first series of mods kept the white felt intact.  The last 2 mods have SIGNIFICANTLY more bass quantity than my first mods while the bass quality is consistently very good across all 3 mods.  I had to add a reflex dot to my second and third mods, I believe, because removing the white felt diminished the treble end of the frequency spectrum.  I had to add felt to my second mod and Organdi to my third mod to contain (minimally) the bass slam.

If this is really what's happening, the take home message appears to be this: leave the white felt alone unless you absolutely love bass slam and can add mod components to bring back the treble response and better balance the SQ by removing bass bloat bleed-over into the mids.

Ok, thanks for the reply!!!

Quote:

Originally Posted by bluemonkeyflyer 

Fostex cups are 3.75" x 4.25" ovals.  LCD2 cups are 4.25" round.  Mine are original and glued in place.  

 

Yes, I've looked at this one and a few others, thanks.  I looked at some by JVC and Sony, Nady, Samson Tech, Audio-Technica, AKG, and Sennheiser and they were either too expensive, closed-back, cheaply made, or too small.  I supposed you could use a closed back like  Frankenphone's RX900 or RX700, but I was hoping to find one already open with a finished look.  I'll keep looking.

I just fixed my last big issue with these, which was headband comfort. After 40 minutes or so it would kill the top of my head, no matter what I did. I found a nice soft leather "spare" belt and was able to glue it to the headband last night. Sadly I was forced to use super glue (hot glue wouldn't hold and I was out of Gorilla Glue) which made some white marks on it, but after a few minutes with some sandpaper, things were all good. It doesn't look too bad and is a ton more comfortable now. I might have some smaller tweaks in store, but I am pretty happy with where these are for now.

Melamine based plastic wares are banned over here :P

Quote:

Originally Posted by sharkz 

I just fixed my last big issue with these, which was headband comfort. After 40 minutes or so it would kill the top of my head, no matter what I did. I found a nice soft leather "spare" belt and was able to glue it to the headband last night. Sadly I was forced to use super glue (hot glue wouldn't hold and I was out of Gorilla Glue) which made some white marks on it, but after a few minutes with some sandpaper, things were all good. It doesn't look too bad and is a ton more comfortable now. I might have some smaller tweaks in store, but I am pretty happy with where these are for now.

Good for you, sharkz.  Would you mind summarizing your mods and how they sound?

I'm actually surprised people find the stock headphone so uncomfortable. Is is just me because I don't have an issue with them where I would think about modding the headband to make it more comfortable. I'm sure if I really wanted I could get the HD580/HD6x0 padding they have on their headband and attach it but I don't find the need for it.

This is a cross-post from the Fostex Mods Link page.  I'm posting, here, because this forum may have larger readership and I'd like to hear from anyone with experience/opinions on this topic.

Cross-Post:

Quote:

Originally Posted by joelpearce 

Given how itchy it is, I didn't try to blow through it or anything.  It's pretty lightweight, though, so I suspect it breathes quite a bit.

 

Whether it's the additional material or the pressure against the driver, this is the best treble I've had with these mods by a long shot.  Once that material on the back of the driver is removed, it's really hard to get a good level of treble that extends all the way up.  This version is great, though, nice and sharp but not harsh at all.  It's hard to quantify the difference here, but it's definitely the best.  They are a bit more forward, and it emphasizes the speed that orthos are capable of delivering.  The soundstage seems a bit more coherent as well, probably because I've finally gotten rid of that midbass hump  It's pretty big, too, which I think might be a perceived larger cup volume with the rock wool. 

 

Some people might find this setup a bit too bass-heavy, but it doesn't impact the rest of the sound range, similar to what I've experienced with the Thunderpants so far.  This is some of the best headphone bass I've heard, though.  The bass has speed and impact, and you can hear where it is coming from in the sound mix. 

 

Too bad it's hard to get the Roxul in small quantities... I had some around from my renovations this summer.

 

So, I wonder if by removing the white felt we have to replace it with something that will serve a similar purpose and that either:

1) allows less air flow/driver excursion and results in more treble-less bass  ---> do this if you like hotter cans

2) allows more air flow/driver excursion and results in less treble-more bass ---> do this if you are a bass head

3) allows about the same air flow/driver excursion and results in no significant change in the frequency response ---> then you should leave it alone and avoid re-inventing the wheel

BMF