Just listened to some Fostex T50RPs today... WOW! - Page 621

Quote:

Originally Posted by preproman 

 

 

Thanks Keith,

 

You tried it out yet?

Ordering tonight.

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

Quote:

Originally Posted by hipster2010 

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.

Thanks for the clarification and for taking the time to elaborate. I think the large size of the ear hole on the pad and your impressions fall in line with my generalizations although I am a bit surprised that the size of the ear cavity didn't result in a bit of a loss in detail or top end.  

I put my prototyping on hold. I'm not convinced that a small, deep ear hole will improve on the SQ I can get from off-the-shelf ear pads like the 840s or Hifiman ones.

Quote:

Originally Posted by FraGGleR 

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?  

To maximize bass, definitely play around with the amount of cotton in the cups. (You might actually need more cotton to get the best balance.) Also, plug the small hole in the baffle but leave the slots on the cups unchanged from stock. 

The adhesive on the stiff felt may impact the sound. The felt is pretty permeable to sound and air movement. But the adhesive may prove to be pretty impermeable.  

Quote:

Originally Posted by FraGGleR 

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?  

After you try V8, you might want to try DBV #3 as described in the link in my signature. It's detailed and should be fairly easy to follow. I think the SQ is superior to V8. Might be interesting to see for yourself which is better. I find that a modified bass port (involving the 4 cup vents) is not necessary with DBV #3 but it's still an option to try during tuning.

Another method for making a sort of modified bass port involves the baffle-to-cup rims. Even when tightly screwed down, there is still some leakage. Sealing all, or all but a couple of centimeters, of the rim circumference functions as a modified bass port.

Dynamat is not permanent. It comes off pretty easily with a flathead screwdriver. I've done it several times, no problem. Just go slowly. Get it started with the screwdriver, grab it with your fingers, and pull...and repeat.

If you want Dynamat inside the cup floors, you can cut and notch it to fit around the shock absorber posts. Turn it upside down and place in the cup "wells" so that the metallic constrained layer is Down and the butyl layer faces Up. This application will allow it work the way it was designed. Secure it in place with a few dollups of rubber cement. That will make it easier to remove if you don't like it. Then, cut and place your Paxmate Plus or Acoustipack Lite directly onto the Dynamat's butyl layer. 

Don't cover the cup vents and their stock black felt inside the cups Unless you want Less bass quantity; the quality will still be good, and tighter. Completely sealing the cup vents may increase sub-bass ringing below -25 dB. I can't hear it but you may.

Seal the baffle ports if you want a bit more bass and lower treble quantity but at the risk of pressure equalization problems as the weather and barometric pressure changes.

Also, what micmacmo said about self-adhesive felt - its adhesive will effectively seal vents and baffle ports so don't use it unless you want them sealed.

Cheers

Thanks alot guys.  I am excited to see what I can do.

Quote:

Originally Posted by preproman 

 

 

Thanks Keith,

 

You tried it out yet?

I received my "Moongel Damper Pads." They are very similar to plastic worms used for fishing. 

Quote:

Originally Posted by bluemonkeyflyer 

 

I received my "Moongel Damper Pads." They are very similar to plastic worms used for fishing. 

and what specifically is that? Pads as in earpads?

Quote:

Originally Posted by bluemonkeyflyer 


leperry posted about it a couple of days ago. It's sold as drums dampers.

Keith 

Those TP-1s look cool man.  How do they sound, compared to...  Lets say to a BMF :)

Quote:

Originally Posted by bluemonkeyflyer 


Different.
They are beautiful. The picture doesn't fully capture the hand carving details. The Mother of Dragons would be pleased.

Khaleesi "YES"

FYI Shure Pads Measurements with Kobalt Digital Calipers Model # 293883:

HPAEC840 Pads:

88mm width x 106.5mm length x 25.5 mm height - These fit the Fostex T50RP.  Currently $15.49 on Amazon.

HPAEC440 Pads:

86mm width x 103.5 mm length x 19.5 mm height - These may fit the Fostex T50RP.  Currently $7.49 on Amazon.

HPAEC240 Pads:

82.5 mm width x 100 mm length x 24.3 mm height - These probably won't fit the Fostex T50RP.  Currently $5.49 on Amazon.

Just thought I'd share that I took my modded T50RP's to a mini meet in Chicago this weekend and was able to compare it to an LCD-3 for a good bit of time on a pretty decent source and amp (ALO Pan-Am).  I'm not going to say they were a match, but I no longer feel the need to upgrade my headphones just yet.  I understand the passion on this thread a little more now.  As some external validation, a guy from an audio review site was there and tried out my T50RP's and was stunned.  He doesn't think they are quite a match overall, but he almost enjoyed the T50rp's more because their mid-centric signature as I currently have it are more his style.

So far, I have dampened the baffle with plasticine, added acoustic foam and felt to the cups (just the basic amount) and unrolled some cotton balls into the cups.  I also slightly reduced the size of the baffle port using tape and a needle. I am also using Shure SRH840 pads.  Still looking to increase the bass and maybe reduce the slight midbass hump.  Treble is as prominent as I like, but I suppose I could try to refine it a little.

Thanks again to everyone on this thread for your work and help.

Quote:

Originally Posted by FraGGleR 

Just thought I'd share that I took my modded T50RP's to a mini meet in Chicago this weekend and was able to compare it to an LCD-3 for a good bit of time on a pretty decent source and amp (ALO Pan-Am).  I'm not going to say they were a match, but I no longer feel the need to upgrade my headphones just yet.  I understand the passion on this thread a little more now.  As some external validation, a guy from an audio review site was there and tried out my T50RP's and was stunned.  He doesn't think they are quite a match overall, but he almost enjoyed the T50rp's more because their mid-centric signature as I currently have it are more his style.

 

So far, I have dampened the baffle with plasticine, added acoustic foam and felt to the cups (just the basic amount) and unrolled some cotton balls into the cups.  I also slightly reduced the size of the baffle port using tape and a needle. I am also using Shure SRH840 pads.  Still looking to increase the bass and maybe reduce the slight midbass hump.  Treble is as prominent as I like, but I suppose I could try to refine it a little.

 

Thanks again to everyone on this thread for your work and help.

"Some Additional Bass and Treble Tuning Tweaks" located Here.  Scroll down past Graph #55, following "DBV #3 Rock Wool Mod Steps."