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

[warchild]

Quote:

Probably no effect at all.
 


 

The holes are an attempt to reduce or remove the reflective surface of the plasticine.

 

[rhythmdevils]

Yeah it's one of many things here that seem like a good idea but has little effect.  The idea is that an uneven, bumpy surface breaks up reflections to reduce resonances in the enclosure.  But plasticine and takk and clay have horrible reflective properties, plastic sounds better acoustically, and the pattern doesn't do enough to change that.  But it's not going to do any harm to punch holes, so it's the kind of thing you might as well do.  And it's pretty. 

 

[MarioImpemba]

A 15kHz sound-wave is still almost a 1" λ.

 

[KneelJung]

Quote:

Brian,
 
Being that the connection appears solid, there still might be some issues with making a solid connection to the actual solder plate itself.  Where it stands, I'd suggest buying the Permatex rear window defogger repair kit for about $12 - $13 at an auto parts store. 
 
I don't think heating up the soldering iron to do more work is a good thing this time. 

Thanks Wayne. I just ordered the Permatex kit from Amazon. I hope it works because paired with the Sparrow they were sounding very good. Ordered a Sheepdogs CD too .

 

[wje]

Quote:

Thanks Wayne. I just ordered the Permatex kit from Amazon. I hope it works because paired with the Sparrow they were sounding very good. Ordered a Sheepdogs CD too .

Oh man, I thought you'd go local to get it from an auto parts store.  I wish I knew - I could have sent you 1/2 a bottle and the brush to get yours all fixed up.  I don't think I'll use the rest of my paint.

 

[KneelJung]

Quote:

Oh man, I thought you'd go local to get it from an auto parts store.  I wish I knew - I could have sent you 1/2 a bottle and the brush to get yours all fixed up.  I don't think I'll use the rest of my paint.

Tried Walmart and they didnt have one, looked up conductive paint on Amazon and your Permatex kit showed up, clicked add to cart, then proceed to checkout. The Sheepdogs CD was already in there, procecss order, bada bing, bada boom...Amazon Prime, and it will be in my mailbox possibly Thursday, definitely by Friday.

 

[Kibble Fat]

As soon as I get my measurement system going I'm considering doing a full factorial DoE/RSD using the most popular mods... has anyone done this? I'm not sure how I would quantify the results with an output as complex as a frequency response or waterfall plot -- the question would be how to break that up into response variables. Can I get polynomial coefficients of an assumed transfer function?

Maybe forgetting the DoE/RSD and just doing one mod at a time from stock trim would be the easiest. Each mod would have an approximate EQ effect but the problem would be combining EQs as I'm sure certain mods become more/less effective with the introduction of a new mod.

 

[shrimants]

I just got a pair of these. I'm having a little bit of trouble pinpointing what the purpose of all the various mods are, and I feel like a wiki entry detailing the exact proceedures would be useful.

Has anyone tried a fully open or fully closed mod on these? Also, how did smeggy figure out the dimensions for his cups?

My only problems with the headphones right now is that 1) they dont fit on my head. I have to extend them past the bendy portion to get the cups to conform to and seal with my head. Otherwise they remain parallel and dont seal against my jawbone area. I gotta lift them 1-2 inches off my head and hold them in place. 2) I want to recable them or at least mod a 3.5mm - 3.5mm cable to be able to fit them because otherwise I have no way to connect the quarter inch jack and actually listen to them.

 

[DeathDomokun]

You can get the v-moda cable if you'd like, it's $10 +shipping.
As for the wiki entry; http://www.head-fi.org/a/fostex-t50rp-modification-summary-links-wiki

 

[DeathDomokun]

My first pair just arrived, after a brief listening period I've done the following to the left cup/side
Sorry for double post

 

[BmWr75]

Quote:

As soon as I get my measurement system going I'm considering doing a full factorial DoE/RSD using the most popular mods... has anyone done this? I'm not sure how I would quantify the results with an output as complex as a frequency response or waterfall plot -- the question would be how to break that up into response variables. Can I get polynomial coefficients of an assumed transfer function?
Maybe forgetting the DoE/RSD and just doing one mod at a time from stock trim would be the easiest. Each mod would have an approximate EQ effect but the problem would be combining EQs as I'm sure certain mods become more/less effective with the introduction of a new mod.

Another quality practitioner I see.  

 
You might for a response variable consider measuring the deviation from 0 dB at a bunch of different frequencies (30 Hz to 20k Hz) and then calculating a standard deviation using the squared differences.  Each measurement would of course have to be normalized to a 0 dB average at a specific frequency selected in advance.........isn't this usually at 10k Hz if I remember correctly?
 
The most accurate mod would then be the one with the lowest standard deviation from 0 dB across the frequency range.
 

 

[ri_toast]

 
Quote:

I just got a pair of these. I'm having a little bit of trouble pinpointing what the purpose of all the various mods are, and I feel like a wiki entry detailing the exact proceedures would be useful.
Has anyone tried a fully open or fully closed mod on these? Also, how did smeggy figure out the dimensions for his cups?
My only problems with the headphones right now is that 1) they dont fit on my head. I have to extend them past the bendy portion to get the cups to conform to and seal with my head. Otherwise they remain parallel and dont seal against my jawbone area. I gotta lift them 1-2 inches off my head and hold them in place. 2) I want to recable them or at least mod a 3.5mm - 3.5mm cable to be able to fit them because otherwise I have no way to connect the quarter inch jack and actually listen to them.

I can help with some of this, besides the v-moda cable ANY mini stereo plug will fit. People prefer (i imagine) a 90 degree plug, a straight plug will work. Just because the original plug has a lock position it looks like a proprietary cable system, it's not.
 
The headphone can be bent, under the rubber headband is steel. Do this at your own risk. Many have and improved the seal.
 
LLF has a suspension Mod that lifts the headband depending on where you place holes or how long the band is. I took an old headphone, removed the band, punched holes attached the elastics at the sides and at the top (bit of velcro) so the band doesn't flop around. The headphone sits about an inch off my head, feels secure with a little spring action. You'll like it, it's cheap to try and reversible.
 
 

 

[DeathDomokun]

Well I cut out a part for the bass port on the right side and I prefer that to the left. I'm gonna cut out a part for the bass port on the left side.
I've also put some electrical tape over the bass port, what effects will poking holes give me? Does it matter whether I start at the top or the bottom?
Can't wait until I get some good pads.

 

[Kibble Fat]

I just got a pair of these. I'm having a little bit of trouble pinpointing what the purpose of all the various mods are, and I feel like a wiki entry detailing the exact proceedures would be useful.
Has anyone tried a fully open or fully closed mod on these? Also, how did smeggy figure out the dimensions for his cups?
My only problems with the headphones right now is that 1) they dont fit on my head. I have to extend them past the bendy portion to get the cups to conform to and seal with my head. Otherwise they remain parallel and dont seal against my jawbone area. I gotta lift them 1-2 inches off my head and hold them in place. 2) I want to recable them or at least mod a 3.5mm - 3.5mm cable to be able to fit them because otherwise I have no way to connect the quarter inch jack and actually listen to them.

I wasn't particularly impressed with the stock T50RP at the meet and I didn't bother listening to the ThunderPants... yet here I am. Funny how that works

I reterminated my cable with Neutriks/Reans after cutting it in half to 5 feet: 3.5mm male on the 90deg cable, 3.5mm female on the 1/4" cable. What surprised me was the use of IEM-gauge enameled wire in the stock cable, but I guess that explains why it's so light.

Another quality practitioner I see.

You might for a response variable consider measuring the deviation from 0 dB at a bunch of different frequencies (30 Hz to 20k Hz) and then calculating a standard deviation using the squared differences. Each measurement would of course have to be normalized to a 0 dB average at a specific frequency selected in advance.........isn't this usually at 10k Hz if I remember correctly?

The most accurate mod would then be the one with the lowest standard deviation from 0 dB across the frequency range.

I was afraid you'd say that. That's a lot of testing or rather a lot of data entry. Again, I would be testing each popular mod like adding cotton or adding Newplast to the driver perimeter -- not collections of mods like the latest BMF etc -- to get responses for each for a pre-determined number of frequencies (maybe 10?) or over specific frequency ranges. The frequency ranges could be a simple as bass, mids, and treble but again, this would be hard to quantify unless Room EQ Wizard can integrate the FR curve (lol!). Now that I think about it, full factorial testing for 6+ mods sounds a bit much (64+ trials) so opting for lower resolution would be key. I'm starting to like my second idea more if only to have some documentation for noobs like me. The shortfall of this would be not having information on mod interaction.

 

[hans030390]

Quote:

I just got a pair of these. I'm having a little bit of trouble pinpointing what the purpose of all the various mods are, and I feel like a wiki entry detailing the exact proceedures would be useful.
Has anyone tried a fully open or fully closed mod on these? Also, how did smeggy figure out the dimensions for his cups?
My only problems with the headphones right now is that 1) they dont fit on my head. I have to extend them past the bendy portion to get the cups to conform to and seal with my head. Otherwise they remain parallel and dont seal against my jawbone area. I gotta lift them 1-2 inches off my head and hold them in place. 2) I want to recable them or at least mod a 3.5mm - 3.5mm cable to be able to fit them because otherwise I have no way to connect the quarter inch jack and actually listen to them.

Just wanted to answer your fully open or closed question. Some people have tried making them fully open, but the results have been pretty poor. I know LFF completely seals his modded T50RP (goes beyond just covering the vents in the cups as well), but no one else knows what other mods he uses along with that (and no one ever will).