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

Transpore really isn't far off even in consistency.  It just feels a bit more gummy or thick I guess.  As far as materials go, its damn close.

FWIW, IMO...Transpore (3M flexible clear) tape closely approximates the stock white sound signature in 1.5 to 2.0 layers offering clarity sound quality.
 
Johnson & Johnson Secure-Comfort tape also does a good job and offers a warmer sound quality with 1.0 to 2.0 layers.
 
Both are perforated. Use more for less bass and greater treble. Use less for more bass and less treble.
 
3M Micropore tape (3M gentle paper tape) did not work for me because it strangled all frequencies with just one layer; worse with more layers. Others got different results with various configs.
 

 
Quote:

questhate said:

So has anyone found a similar material to the white felt on the back of the driver? 
 
I know BMF has found that about 1.5 to 2 layers of Transpore has a similar sound, but anything of similar consistency? 
 
I think I saw LFF and someone else suggest dryer sheets, and rhythmdevils suggested coffee filters. Is there anything else I'm missing? I tossed my stock felt a long time ago, so I don't quite remember what they felt like.
 
 

Click to expand...

 

Alrighty, O2 vs Lyr (lorenz tubes) out of an ipod via lod...  my bifrost was here and gone since it was sans usb and i ordered a usb... these are basic feelings from limited listening time. I did all my listening with my t50rp's
 
Dave Matthews "Dodo" -   Lyr- kick drum felt more realistic and decay of initial transient was quicker. Snare had better resolve and i could actually hear the snare beads vibrating after the strike. Tambourine was easier to pick out.   
                                     O2- Vocals felt more forward but overall still balanced. sub-bass from kick drum was less. Overall things felt a bit less clean and crisp, although it was still taught and punchy (I feel this is due to the way the O2 levels the playing field across the freq spectrum and doesn't highlight stuffs ie: tambourine through lyr ). Saxophone rasp was clearer with o2. Soundstage was less with the o2.
 
I didnt get into more than that song since im tired and it was pretty clear the lyr is crisper and more dynamic. The o2 is no giant killer obviously but it wasnt hard to listen to the O2 after the lyr! I respect the simple versatile sound coming from the O2 and it will be my go to for certain things. It is pleasing to listen to and is very good at picking apart recordings. If you have a bad recording its gonna sound bad, if its good its gonna sound good. 
 
It is hard to evaluate this amp since it doesn't have a flavour of its own, it sort of takes on whatever you throw at it. I might even name my O2 "Chameleon"... 
 
Cheers to all you folks building your O2 or soon to get one! It really is good, there is no mistaking that.
 
M

I was thinking of building a beta 22 monster because you can do it for around 400$ if you only do two boards and the power supply, and you get a high-powered reference-class amp while you are at it. Of course it does not matter how good your amp is at a certain point, if your DAC is inferior you will not get all you want out of it. Aye, there's the rub

Ok. Now I'm getting closer to perfection (For me anyway). I just complete my third iteration on the T50rp and the result is very close to the RP2 from MrSpeakers.
 
Here's a summary of the mod:
 

1. Back baffle with plasticine all around. to the level of the ribs.
2. Cover plasticine with Paxmate around driver.
3. Kept the white felt behind driver. ( First variant from RP2)
4. Cover back of driver with stiff 2 mm craft felt.( Here I was planning to use soft felt thinking i was breathing better to compensate for the stock white felt but to my surprise the stiff felt has less resistance).
5. Use Dynamat in bottom of the cup. Not on the wall like RP2. (Second variant from RP2)
6. Cover bass port felt with black tape completely. (Third variant from RP2)
7. Cover the cup with Paxmate all over including the center post.
8. Removed the black felt from the front baffle.
9. I did not add Paxmate on the front baffle around the driver because I'm using the SRH-840 pads and they already have the middle cover with a thick material that act like Paxmate (To me).
10. Use about 8' of rubber sleeve removed from a Grado tick cable (about 1/4') and put it all around under the pad (Not just the back) and it make them very comfy but also improve the soundstage.
11. Add the suspended Leather headband a la LFF for added comfort.

 
I have now the hi frequency presence that I was craving from my previous mod and the mid are just amazing (Ortho !!!) and the bass is pretty good and well controlled. I was a bit skeptical when I read that the bass post was to be completely closed and thought the bass was going to be choked but no it's sound very good and balanced.
 
I would normally have pictures but my T50rp with the SRH-840 look like all the other already posted before.
 
Again thanks to all the pioneers of this thread. It's with members like you that make this hobby so much fun...and sometime expensive but the T50rp is the best return in SQ for a low investment.  (And very easy to do )

Hm, how much of a difference/what kind of a difference does putting the acoustic foam on top of the plasticine in the baffles make?  I have trouble picking out the changes between the different mods, myself...

I dont know if its worth the loss in cup volume... each time I take stuff out of the cup from the extreme damp mods it sounds much better imo. all i have now is some akasa in the back of the cup with a bit of 2mm floppy felt on top behind the driver. best yet.. simple is best no doubt.
 
M

Hmm.  A loss of volume shouldn't be what's causing the problems as long as you have an adequate amp, right?

It looks like two of the mods considered the "best" right now, the Thunderpants and Paradox, are highly damped, and require far more power than stock...is this also the case with the RP2 and any of the recent BMF revisions?

I meant cup volume like cubic centimeters and i didnt think it was worth using paxmate on baffle since it takes up more cup space. Not filling up the cup with so much stuff has sounded the best to me. It is best to just tune with your ear. try not to pay too much attention what others are doing
 
M
 

Very happy to see you guys pairing up the T50 with the O2.
 
To me, that is 2/3 of my endgame rig. To me....it's that good!

Thanks for the infomation you guys provided here.......Thanks a lot.
 
 
I do love my moded-t50rp.
 
 
Can we put Dynamat or plasticine outside of the cup?
 
Coz, we need the cup volume inside,,,if we put too much stuff inside the cup ,the volume will decrease dramatically .
 
so if we can stick the Dynamat or plasticine outside the cup, maybe the SQ will upgrade one big step.....
 
Coz, to load mass, outside or inside dosn't matter.... 
 
Then ,we can use  something to cover the outside..........
 
 
I will try it later.....
 
 
anyway,,,,,Thank again for you guys'  so great and hard work....Thanks.
 
PS: and I also think that we should pay more attention to the tiny space between the driver and baffle,,,this space should be filled by plasticine to make the driver more stable or to prevent the driver from shaking.
 
John
2011/11/08 
 
 
 

Yes, it's bizarre. At this point, I would assume that my experience is pretty anomalous. For anyone interested, the paxmate I had on the ear-side had a little square cut out for the fully open vent hole, but covered the 3 partially open vent holes around the driver. I wonder if that's something to do with it.
 
As another question, are we reaching any kind of consensus on whether adding paxmate around the driver inside the cup has any benefits? I've not tried it yet - will probably be next on the list.
 
Quote:

nevod said:

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.

Click to expand...

 

Quote:

arleus said:

Yes, it's bizarre. At this point, I would assume that my experience is pretty anomalous. For anyone interested, the paxmate I had on the ear-side had a little square cut out for the fully open vent hole, but covered the 3 partially open vent holes around the driver. I wonder if that's something to do with it.
 
As another question, are we reaching any kind of consensus on whether adding paxmate around the driver inside the cup has any benefits? I've not tried it yet - will probably be next on the list.
 

Click to expand...

I have a thought.. Try to listen to your headphones not sealing them to head - just lift them a little. Would the resonance be prominent then? If yes, I speculate that indeed putting paxmate on earside resulted in underdamping your drivers. Some increase in damping can be provided by covering or completely closing baffle vents, but it may not help, and direct driver damping would be needed.
 
On the paxmate on cup side of the baffle - I think that it depends on the height of the cup. If two layers of paxmate can stay here without being compressed, then use it. If there's not enough space, use something thinner, fill it with cotton, etc. One might try to cut paxmate across the height axis actually. Still, as it's, I think, better to have more dense material near the cup, one may have no paxmate near the driver, but have some of it closer to the ridge of the baffle, so the baffle and cup layers of paxmate would compress against each other.
 
 

FWIW: I found over-damping to cause bass bloom muddying the midrange and hiding the treble. That said, if it sounds good to you, that's all that matters. The more stuff stuffed inside the cups increases damping and reduces sensitivity so more power is needed for a given SPL.
 
Quote:

twinster said:

Ok. Now I'm getting closer to perfection (For me anyway). I just complete my third iteration on the T50rp and the result is very close to the RP2 from MrSpeakers.
 
Here's a summary of the mod:
 

1. Back baffle with plasticine all around. to the level of the ribs.
2. Cover plasticine with Paxmate around driver.
3. Kept the white felt behind driver. ( First variant from RP2)
4. Cover back of driver with stiff 2 mm craft felt.( Here I was planning to use soft felt thinking i was breathing better to compensate for the stock white felt but to my surprise the stiff felt has less resistance).
5. Use Dynamat in bottom of the cup. Not on the wall like RP2. (Second variant from RP2)
6. Cover bass port felt with black tape completely. (Third variant from RP2)
7. Cover the cup with Paxmate all over including the center post.
8. Removed the black felt from the front baffle.
9. I did not add Paxmate on the front baffle around the driver because I'm using the SRH-840 pads and they already have the middle cover with a thick material that act like Paxmate (To me).
10. Use about 8' of rubber sleeve removed from a Grado tick cable (about 1/4') and put it all around under the pad (Not just the back) and it make them very comfy but also improve the soundstage.
11. Add the suspended Leather headband a la LFF for added comfort.

 
I have now the hi frequency presence that I was craving from my previous mod and the mid are just amazing (Ortho !!!) and the bass is pretty good and well controlled. I was a bit skeptical when I read that the bass post was to be completely closed and thought the bass was going to be choked but no it's sound very good and balanced.
 
I would normally have pictures but my T50rp with the SRH-840 look like all the other already posted before.
 
Again thanks to all the pioneers of this thread. It's with members like you that make this hobby so much fun...and sometime expensive but the T50rp is the best return in SQ for a low investment. 

 (And very easy to do )

Click to expand...

 

 
Quote:

mmayer167 said:

I dont know if its worth the loss in cup volume... each time I take stuff out of the cup from the extreme damp mods it sounds much better imo. all i have now is some akasa in the back of the cup with a bit of 2mm floppy felt on top behind the driver. best yet.. simple is best no doubt.
 
M

Click to expand...

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?
 
 


Quote:

mmayer167 said:

I meant cup volume like cubic centimeters and i didnt think it was worth using paxmate on baffle since it takes up more cup space. Not filling up the cup with so much stuff has sounded the best to me. It is best to just tune with your ear. try not to pay too much attention what others are doing

 
M
 

Click to expand...

Agreed. Try reported mod configurations for yourself and draw your own conclusions. Give feedback of your results whether favorable or not.
 
 


Quote:

call001 said:

Thanks for the infomation you guys provided here.......Thanks a lot.
 
 
I do love my moded-t50rp.
 
 
Can we put Dynamat or plasticine outside of the cup?
 
Coz, we need the cup volume inside,,,if we put too much stuff inside the cup ,the volume will decrease dramatically .
 
so if we can stick the Dynamat or plasticine outside the cup, maybe the SQ will upgrade one big step.....
 
Coz, to load mass, outside or inside dosn't matter.... 
 
Then ,we can use  something to cover the outside..........
 
 
I will try it later.....
 
 
anyway,,,,,Thank again for you guys'  so great and hard work....Thanks.
 
PS: and I also think that we should pay more attention to the tiny space between the driver and baffle,,,this space should be filled by plasticine to make the driver more stable or to prevent the driver from shaking.
 
John
2011/11/08 
 
 

Click to expand...

 
 
 

Remove the dust cover and its adhesive around driver down to the bare baffle plastic.
 
 

 
I used an x-acto chisel blade. Be careful it does not slip and cut yourself!
 


Dynamat applied around driver, self-adhered to the baffle plastic. 
Roll it out with something like a dry cell battery.
Cut out a notch for the baffle pressure equalization vent.
 
 
 

Cover with self-adhesive felt to seal the goo and prevent reflections off the Dynamat constrained layer of aluminum (?).
 
 
 

This Less Is More mod did not work as well as Medium Mass Loading shown in next photo.
 
 

 
Medium Mass Loading the Less Is More mod from baffle edges/compartment and tapered up to the driver perimeter. This gives a bit more bass than flush mass loading only the baffle compartments.  Medium Mass Loading seems to improve SQ, too, but that may just be placebo. 1/2 of one medium cotton ball teased apart to the length and width of the cup bottom and not over-laying the black bass port felt seems to improve SQ, too. Test these mods and decide for yourselves.
 
 

 
Medium Mass Loading the "Transpore 1.5" mod with Tungsten Putty. The baffle compartments are Flush Mass Loaded; compare with slightly more putty in the baffle compartments of the picture, above. 1 full layer and 1 half layer of Transpore over naked drivers after removing the stock white felt. The 1/2 layer is trimmed to the width of the central line of grid openings and placed perpendicular over the full layer. 1 layer=more bass. 2 layers=less bass and more treble. 1.5 layers=my preference. Paxmate in cup bottoms. 1/2 of a medium cotton ball as described, above.
 
I can play the Transpore 1.5 mod, the BMF 6v3.2 (identical to Transpore 1.5 mod except the stock white driver felt is intact instead of using Transpore tape), and the Less Is More mod straight out of my MacBook Pro. They do sound better out of my Dacmini, though.
 
 
 
 
Quote:

arleus said:

Yes, it's bizarre. At this point, I would assume that my experience is pretty anomalous. For anyone interested, the paxmate I had on the ear-side had a little square cut out for the fully open vent hole, but covered the 3 partially open vent holes around the driver. I wonder if that's something to do with it.
 
As another question, are we reaching any kind of consensus on whether adding paxmate around the driver inside the cup has any benefits? I've not tried it yet - will probably be next on the list.
 


 

Click to expand...

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.
 
 

Dampening improves SQ at the cost of efficiency so, yes, my modded sets require a bit more power to play at the same SPL as stock sets; not a great amount more. I often play right out of my MacBook Pro at work with plenty of headroom for 80 to 90 dB which is where I tend to gravitate. IME, over-damping requires much more power, reduces the soundstage, and produces more bass that eventually becomes boomy and messes with the midrange and treble...anyone else noticed this?
 
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?
 
Quote:

dabomb77766 said:

Hmm.  A loss of volume shouldn't be what's causing the problems as long as you have an adequate amp, right?

It looks like two of the mods considered the "best" right now, the Thunderpants and Paradox, are highly damped, and require far more power than stock...is this also the case with the RP2 and any of the recent BMF revisions?

Click to expand...