Just listened to some Fostex T50RPs today... WOW!
Sep 25, 2012 at 9:24 PM Post #9,286 of 11,345
Quote:
 
Well, this is the pimp daddy of vibration damping: http://www.youtube.com/watch?v=GpesXpPoN8c
 
Good luck fitting them inside the T50RP cups, though....but you could always stick them on the outside 
evil_smiley.gif

Yet Another potential modding component from "The FrancoAudioPhile Innovator", leeperry, who told us all about Paxmate Plus, Acoustipack Lite, and Newplast.
 
Ordered from Amazon for less than $6.00.
 
Thanks!
 
Sep 25, 2012 at 10:29 PM Post #9,287 of 11,345
I wonder if it's anything like the sorbothane that was mentioned earlier in the thread. Sorbothane comes in sheets of varying densities...but it's more expensive, of course.
 
Sep 26, 2012 at 12:48 AM Post #9,288 of 11,345
Quote:
Well, buy.com had a "buy three, get an extra one for free" together with free shipping on those Moongel's so I couldn't resist and bought a whole bunch of those, they do wonders as isolation feet! But cutting them nicely in order to fit into the tiny squares of the baffles seems rather hard to accomplish because this is really not stiff whatsoever and cutting them to the right dimensions is easier said than done IMO, much like cutting jelly....This said, it would prolly be one of the best material for the job indeed and it's feather-light too.
 
Or you could install small patches in the four corners of the T50RP cups.
 
I was personally wondering how to put them to good use in the yamies, maybe replacing the stock felt that stands in front of the vent holes.

Gonna go check my local instrument shops to see if they carry these stuff
These should definitely be difficult to cut... maybe cookie cutters are the best bet.
 
Though the felt was used for other purposes than vibration damping in the yammies though? You can remove them and the driver won't be moving around thanks to the pressure from baffle... I think?
 
Sep 26, 2012 at 1:39 AM Post #9,289 of 11,345
Quote:
Well, buy.com had a "buy three, get an extra one for free" together with free shipping on those Moongel's so I couldn't resist and bought a whole bunch of those, they do wonders as isolation feet! But cutting them nicely in order to fit into the tiny squares of the baffles seems rather hard to accomplish because this is really not stiff whatsoever and cutting them to the right dimensions is easier said than done IMO, much like cutting jelly....This said, it would prolly be one of the best material for the job indeed and it's feather-light too.
 

 
Or depending how soft they are, you could probably just mash them into the crevices... maybe.
 
I doubt they'd be any more effective than dynamat or other contrained layer dampeners though. Some browsing online finds a lot of people saying they don't do anything that tape can't do for vibration control on a drum, but it's just more convenient for placing/removing. Still, never know until you try. 
 
Sep 26, 2012 at 12:18 PM Post #9,294 of 11,345
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Decided to take the J$ pads off of my D5000 and put them on my T50rp 
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Sounds incredible. Soundstage opened up  at the cost of maybe just a little less forward mids. Detail seems to be the same. Bass is very similar, maybe a tad bit lighter. Obviously comfort is much better now. I think these pads have given me the sound that I've been looking for in headphones. The D5000s were really close, but I felt that the bass was a tad bit boomy and felt like it put a bit too much sound pressure on my ears after wearing them for awhile. My T50rps now sound very similar, but with a tighter, less prominent bass, better detail and clarity, and slightly more forward mids. They also have better isolation and less sound leakage. After I add some padding to the headband these will also be as comfortable too!

Hey, Hipster, I meant to ask you about the size of the ear hole on the J$ pads. How big is the opening (width and length, please)?
 
I was working on an experiment, seeing how a pad with a smaller ear opening (comparable to the original T50RP pads) and a fat, angled cross section would affect the sound. Here's what they look like:  
 
Left is a T50RP OEM pad. Middle is the prototype. Right is an 840 pad.
 
 

 

 
The sound of the prototypes was similar to what you mentioned: A generally brighter sound with very smooth mids but limited bass. No obvious improvement in soundstage. (Note that I didn't add flaps to the prototypes, I just taped them to the baffles with double-sided tape.)
 
I tried a range of other pads (also 003/HM5, Hifiman and JVC RX900) to figure out how different hole geometries might impact sound. I think that the smaller hole limits bass, regardless of the total volume of the ear-hole cavity. (In other words, a shallow, wide opening will produce more bass than a deep, narrow opening.) But a smaller hole tends to produce better detail with less "smearing." 
 
Also, when it comes to bass reproduction, a good seal between the pads and the baffle is just as important as a good seal between the pad and the listener's head. Or so I've surmised.
 
Sep 26, 2012 at 12:31 PM Post #9,295 of 11,345
Quote:
Hey, Hipster, I meant to ask you about the size of the ear hole on the J$ pads. How big is the opening (width and length, please)?
 
I was working on an experiment, seeing how a pad with a smaller ear opening (comparable to the original T50RP pads) and a fat, angled cross section would affect the sound. Here's what they look like:  
 
Left is a T50RP OEM pad. Middle is the prototype. Right is an 840 pad.
 
 

 

 
The sound of the prototypes was similar to what you mentioned: A generally brighter sound with very smooth mids but limited bass. No obvious improvement in soundstage. (Note that I didn't add flaps to the prototypes, I just taped them to the baffles with double-sided tape.)
 
I tried a range of other pads (also 003/HM5, Hifiman and JVC RX900) to figure out how different hole geometries might impact sound. I think that the smaller hole limits bass, regardless of the total volume of the ear-hole cavity. (In other words, a shallow, wide opening will produce more bass than a deep, narrow opening.) But a smaller hole tends to produce better detail with less "smearing." 
 
Also, when it comes to bass reproduction, a good seal between the pads and the baffle is just as important as a good seal between the pad and the listener's head. Or so I've surmised.

Very interesting idea. Look forward to hearing what you discover. The opening on the J$ pad is 1 7/8" x 2 9/16". The angled part is 1 1/8" tall while the opposite side is 7/16" tall.
 
To clarify the post you quoted. The difference I noted were between my T50rp and D5000. When talking solely about the changes in the T50rp, I felt that the J$ pads increased soundstage, added just slightly more bass (primarily sub-bass), made the mids just slightly less forward, and I didn't notice much/if any change in the highs. Obviously they increased comfort too.
 
Sep 26, 2012 at 3:19 PM Post #9,298 of 11,345
Thanks for all the work in this thread!
 
I have begun in earnest now that I have all the materials.  I am generally following the BMF V8 tutorial mainly because of how detailed it is (Thanks Bluemonkeyflyer!).  I have put Claytoons plasticine into the main holes in the baffle and have spread some cotton balls (couldn't get any of the cotton roll for a reasonable price) in the cups to start.  Pretty low on bass, and the treble is pretty prominent.  I think I need less cotton.
 
Before I go too much further, I wanted to see if someone could simply summarize what I can do to maximize controlled bass.  If I dampen the cups too much with Dynamat and acoustic foam, will that impact the bass?  Dynamat is pretty much a permanent install from what I understand, so I will skip it if it will kill the bass too much.  I'd like a fairly balanced set of headphones, but skewed towards the bottom if it is going to lean any one direction.  I have Shure pads that will help the bass from what I understand.  I will also be covering up the vents with tape and then adding a small hole to the tape.
 
Also, I could only find stiff craft felt with a sticky back.  Does anyone think that this will negatively impact the felt's impact on sound?  
 
Sep 26, 2012 at 4:12 PM Post #9,300 of 11,345
So... I did a variant of BMF DBV#3...
 
Adhesive felt (facing ear) on Adhesive foam sandwich in the ditches, thin layer of gauze, 70x70x8mm of grodan, thin layer of guaze, thin layer of cotton balls, stiff felt sq with medical plastic tape behind driver, plasticine in all baffle holes, 840 pads.
 
Sounds better than when I started... I did this all at work, so I don't have my amp or DAC here.... I was more worried that each side would sound different than each other, but I can't notice that.
 
Felt on Foam idea taken from: http://www.innerfidelity.com/content/diy-modification-sennheiser-hd-800-anaxilus-mod
 

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