Just listened to some Fostex T50RPs today... WOW!

[mmayer167]

I like your simple cup solutions above bmf.
Quote:

 
That's my conclusion after adding more than 1 layer of Paxmate and more than medium mass loading the baffles. 
 
Doesn't adding anything over the back of the white driver felt further dampen the sound?
 

Im not sure what you meant by that last part? the 2mm white creatology floppy felt im using doesnt touch the driver... it sits in the back of the cup. Im using this felt since it looks and feels like a consistant density teased cotton ball. here is a picture of the inside of my cups without the felt square... the picture is of a previous mod that i didnt like so ignore the square of facial sponge material. that sponge material made it sound stuffy. and the highs were gone. yes, i know thats alot of clay on the baffle. I have stock felt front and back of driver with no reflex dot.
 

 
M

 

[Arleus]

Quote:

 
 
Actually, the other three holes around the driver are not open at all. Initially, I thought they were open and covered by the dust cover on the ear side of the baffle. That is not the case as I discovered a couple of days ago (see previous post). I drilled them out with a 1/16" bit. I'm playing with various numbers of these fully open vs covered with electrical tape for fully closed vs covered with thin felt for partially open.
 
I hope this is helpful.
 
 

Whoops - I skimmed over the last couple of pages and obviously missed that bit. I'm going to play around with some things a bit more over the next few days, such as paxmate on the cup side of the baffle, etc etc. Will report back if I make any breakthroughs (I think most of this stuff has been tried by this point, mind you). 

 

[bluemonkeyflyer]

Oh, O.K. I misunderstood. I thought you put the 2 mm stiffened craft felt directly against the back of the drivers, over the stock white felt.
 
I will have to try your idea.  Thanks!
 
BTW, as I mentioned a few days ago, last night I tore out the Paxmate in my BMF 6v3.2. I installed a layer of AcoustiPack Lite on the cup bottoms, not the side walls and not over the central compartment; the stock bass port felt is in place and not covered, either. Then, I put a layer of Paxmate over the AcoustiPack Lite. Tungsten putty Medium Mass Loaded in the baffles as described just above, 2 small cotton balls teased apart in all 3 dimensions placed perpendicular to the cup length but not covering the bass port felt (instead of 1/2 of one medium cotton ball - seemed like a good idea at the time; who knows?), Dynamat around the drivers on the ear side of the baffles, all else stock. I'm trying them with stock pads vs 840 pads with and without 1 Kleenex rear pad lifters. More later...
 
Quote:

I like your simple cup solutions above bmf.
Im not sure what you meant by that last part? the 2mm white creatology floppy felt im using doesnt touch the driver... it sits in the back of the cup. Im using this felt since it looks and feels like a consistant density teased cotton ball. here is a picture of the inside of my cups without the felt square... the picture is of a previous mod that i didnt like so ignore the square of facial sponge material. that sponge material made it sound stuffy. and the highs were gone. yes, i know thats alot of clay on the baffle. I have stock felt front and back of driver with no reflex dot.
 

 
M

 

 

[mmayer167]

 
Quote:

Oh, O.K. I misunderstood. I thought you put the 2 mm stiffened craft felt directly against the back of the drivers, over the stock white felt.

I'm not using "stiffened" felt.  It's roughly the same thickness of the stiffened stuff but its floppy as in you could ball it up like a cotton ball if you wanted lol. It is almost like paper towel if that helps describe how floppy it is! I cut a piece of it the same size as the driver and layed it in the back of the cup. If i get the energy to open these up again i'll take a picture since this really is the way im going to leave them. I'm using O2 pads for the moment until i can get a hold of fischer pads.
 
M

 

[drexman]

1.5 layer of transpore is more efficient than stock, but sounds the same? is it important to put the final layer on the center of the driver?
your stock pads are v1 or v2? i don't believe any other pad sounds darker and more muffled than v1, not to mention the comfort issue, lol...
Quote:

It's interesting, to me, is that 1 to 1.5 layers of Transpore tape is more efficient than the stock white driver felt.
 
Has anyone else noticed that 840 pads require more power than stock and sound darker than stock pads?
 


 

 

 

[bluemonkeyflyer]

I said Transpore "closely approximates" the sound of the stock driver material...in my opinion. 
 
I have whatever pads are on current production T50RP, so I assume v2.
 
Quote:

1.5 layer of transpore is more efficient than stock, but sounds the same? is it important to put the final layer on the center of the driver?
your stock pads are v1 or v2? i don't believe any other pad sounds darker and more muffled than v1, not to mention the comfort issue, lol...


 

 

 

[mmayer167]

To the rescue with some comic relief and pictorial of my mods for this monotonous thread.
 
meet monkey, a good sport saying hi to all you head-fiers out there!

 
Bass port situation. monkey is just showin off now...

 
O2 pads with built in driver cover

 
lifting up felt so you can see my stock bass port and uncovered hinge post.

 
here you can see my stock driver felt and clay situation, also how the felt is pressed into the back of the cup situated just how the driver sits.

 
Try this if you like. After all the mods i've done, this is the one i ended up with and is keeping me happy every time i put them on. It is very easy to do, totally reversable and doenst take lots of effort. I am using the O2 pads so if you have something different for pads which im guessing most of you do, be prepared for a possible different experience than what i'm having. If the bass is not to your liking try just 50% of ports covered with electrical tape. Or whatever % you like.
 
I hope these pictures are helpful to some of you.
 
M

 

[DaBomb77766]

Hm, so it appears as though the left cup suffers from slightly less isolation than the right cup after putting the silverstone acoustic foam in.  I'm guessing this has to do with the little connector box inside of it...?

 

[Twinster]

After longer listening session on my main rig (initial test was from test bench with portable amp) It might be over-damped now. First it does need more power and the bass is tight but I think it's too tight now. I like a bit of decay. I will try removing the Paxmate on the Plasticine (Was not very confident when I did it yesterday) I may have to re-open the bass port a bit. To be continued....(After reading my post from late lass night thinking I was close to perfection... Well it was late I guest. 

 

[mrspeakers]

Quote:

Arleus,

Wow, that's pretty weird (about the resonance). Especially given you've heard it even without cups. Only thing I can think up is that paxmate reduced damping of the driver by virtual expansion of cup volume, and some undamped resonance manifested at 1khz exactly. Maybe. If I'm right, adding something more sonically resistive/absorbtive to paxmate and also correcting driver damping is necessary. Or maybe it's due to interaction with baffle vents.

Cotton fixes the 1K resonance completely.  Has other benefits as well.
 

 

[rhythmdevils]

FWIW, in modding other orthos using O2 pads I found that the dust protector fabric that comes with them masks a lot of detail.  So much that I liked a mod without that disk and disliked it when I put the disk in. 

 

[mmayer167]

Hmm, I might give that a try! 
 
Thanks rhythm
 
M

 

[HDMan]

Quote:

Hm, so it appears as though the left cup suffers from slightly less isolation than the right cup after putting the silverstone acoustic foam in.  I'm guessing this has to do with the little connector box inside of it...?

I have come to the same conclusion, that the imbalance in L/R is from the mods inside the cups, maybe some new wood cups are the only remedy, with a recable.

 

[snakeeater69]

Is the imbalance that noticeable? I tried listening to mine for the imbalance and they sounded pretty much the same. Maybe my ears are not that great.

 

[DaBomb77766]

Quote:

Is the imbalance that noticeable? I tried listening to mine for the imbalance and they sounded pretty much the same. Maybe my ears are not that great.

Well, for me it was just a difference in sound isolation, not so much sound.  I presume it's because of the extra opening due to the 3.5mm plug.  Also, if you were to look at measurements of modded T50RPs, there always tends to be a small channel imbalance - could just be a coincidence, since it is of course DIY, or it could be the connector box.  Who knows.
 
Anyway, I just decided to put another roll of kleenex (puffs in my case!) under the back of the earpads and the comfort issues appear to have been mostly solved.  Clamping force has been increased marginally by this, but it's better than having my ears in pain by being squished against the front of the cup...