Just listened to some Fostex T50RPs today... WOW! - Page 270

All this time!

Thanks man!

 

Applying Dynamat (or FatMat) to the ear side of the baffle for mechanical dampening:

 

I sent some Dynamat to a fellow head-fi'er along with some application suggestions. I thought I'd cut/paste that message, here, for everyone's consideration.  Armaegis and I have been discussing ways to use Dynamat and similar materials to improve mechanical dampening. Armaegis' suggestions and hypotheses are indicated by * *.  

 

 

Measure sections needed to surround the driver on the ear side of the baffle right up to the outer rim's 4 attachment screw heads. Use an X-acto knife chisel blade to score the Dynamat aluminum backing, bend along the scored seam, and use scissors to cut through the goo.  Use this same approach for cutting curved sections so the pieces fit flush with the baffle outer rim.  Measure and cut a notch from the Dynamat section that goes over the top right area of the baffle to expose the pressure equalization vent so it can breathe.

 

Apply a bead of hot glue to the positive and negative wires at the driver solder points to prevent pulling the wires loose while modding.  **Sand with a Dremel** or use an X-acto chisel blade (be careful) to cleanly remove the dust cover and all the adhesive from the baffle surrounding the driver.  Dynamat won't work if you apply it to the felt. If you have already removed the dust covers over the drivers, **apply some masking tape to temporarily cover the drivers before sanding/chiseling. This will prevent debris from falling into the guts of the drivers. Dust/debris will cause problems with the sound reproduction and is almost impossible to remove, once in there.** 

 

Leave the Dynamat aluminum layer in place because it is an essential component - the constrained layer.  Dynamat won't work its mechanical magic if you remove the constraining layer.

 

After applying Dynamat to the ear side of the baffle, use a battery as a roller to compress the Dynamat to the baffle and bond the 4 separate pieces along their seams.  This essentially transforms 4 separate pieces to function as one piece and may improve its dampening effectiveness. You can apply adhesive-backed thin craft felt over the Dynamat to prevent the goo from attaching to the ear pads.  Another option that will seal the goo and  **may provide improved mechanical dampening effectiveness is to cut pieces of aluminum tape (the kind used for sealing heating/air conditioning duct work)**  and apply 1 or 2 layers on top of the Dynamat aluminum backing. You can then apply Paxmate (Silverstone or AcoustiPack Lite) over the aluminum tape (or felt) if you want to raise/angle the ear pads.

 

I'm going to add a second layer of aluminum tape over the first layer to see if this results in better mechanical dampening. I'll then apply a second layer of Dynamat over the first to see if mechanical dampening is further improved.

 

Related:  I used a small flathead screwdriver to separate the Dynamat from the cups of a previous mod.  It takes a lot of pressure to remove and caution to prevent ripping away the wires and terminal connections.  Once sections of Dynamat are separated from the plastic cups, you can pull it out with your fingers.  It's a messy job but I got it all out without damaging anything.

Got a stupid question but got to ask the pro here. When you say Plasticine does the kid Play-Doh stuff work's for this? I saw a lot of colored plasticine in these pictures that look like Doh. And does is matters if it got a Green apple sent?  (Just kidding )

Guys we're in deep here, Fostex is releasing new models...

Plasticine is modeling clay. I bought some from Michaels..i think crayola modeling clay. I'm not sure what play-doh is made of but any arts and crafts store should have some kind of modeling clay. It was cheaper than plasticine and online so I got that instead and easier since it was local.

 

Play-dough will dry out, then weigh less, become brittle, and may foul-up your drivers.

Go to Amazon or local art supply store and buy modeling clay that never dries out. Get the most dense, but malleable, clay you can find. Newplast available from Amazon-UK is more dense and heavier than the clay I've found in the States. That said, I've had excellent results using Claytoon modeling clay and Super Mass Loading by using 4 to 5 times the usual amount.

Edited by bluemonkeyflyer - 10/19/11 at 6:33am

I think that Play-Doh is made of Flour so that cannot be good. I stop at the Art&Crafts store tonight. I've also ordered some Paxmate and that stuff not cheap ($30 with shipping). I might have to much and might be able to share if people need some. 
 

 

Here's a tip on applying Dynamat. Ideally, you want as much contact between the Dynamat goo and the baffle as possible. Because the goo is, well, gooey, it's easy to introduce bubbles between the two surfaces. So use BMF's recommendation to use a battery as a roller as you start to apply the Dynamat, to work out bubbles.

 

I've had good luck positioning the dynamat with the backing in place. Then I peel back a section of the backing and roller the Dynamat down. Then I pull back more backing and roller. Repeat until done. 

 

 

Good call.  I forgot to mention the importance of rolling out any bubbles.  
 

 

When you say "Pell back a section of the backing" you do not mean the metal sheet?
 

 

No, not the metal foil. It's important to keep that in place. Like a band-aid, the adhesive side of Dynamat has a paper backing that needs to be removed before application.

That's what I tough. Thank you for the clarification.
 

 

Edited by Twinster - 10/19/11 at 9:03am

LFF, BMF, mrspeakers, etc...

 

How do your T50's sound to your neighbors? (The person sitting next to you).

 

I've read through this topic but being as there are over 4000 posts, I am sure this has been mentioned and just skim passed by me. I am waiting for my pair of FA-011 to arrive in the mail, but need a pair of phones that I can listen to on the train. I am debating ordering the T50's (I DO plan on modding the heck out of them), but I am worried that they are going to blow the people sitting next to me on the train up.

 

Thoughts?

They don't leak out much sound, but I wouldn't recommend them to be used in a train, because they don't isolate as much as a Beyerdynamic DT770 Pro does.

 

bluemonkeyflyer,

 

Thanks first off for all of the work! I just installed most of your BMF#5 on one of my pairs that already had dynamat original and paxmate in the cups. I had removed the original white felt on the drivers, so I used 2 layers of 3M Transpore and the large reflex dot. The sound of this pair of headphones is very good. I have not added the cotton balls or gauze to build up the pads yet, but will do that as well as trying Shure 840 pads on it (using the stock pads right now). I may also try a layer of Dynamat Original covered by Paxmate on the ear side, or I may add one or 2 small pieces of Transpore to bump the high end just a touch. Not sure yet on which way I will go.

 

On another subject, do you or anyone else have any thoughts on Dynamat Original versus Extreme? I have Original (1.7mm thick, no foil or goo).