[sheya]

Long time lurker, not sure that I've posted in this thread before.
 
I have run into a bit of a problem with my mod, and I am wondering if I could get some advice. 
 
Without getting into all the details, I have clay in the inside baffle, silverstone lining both sides of the inside of the cups, poster tak sealing the screw hole for the headband, and 4 large cotton balls inside.
 
I have decided to completely seal both cups.  Using test tones and my ears to measure the difference between the two cups, the left is louder than the right.  The left extends down to 10hz, and is pretty even from around 100hz to around 2khz.  The right is barely audible at 20hz, and much lower in volume in the sub bass until around 100hz (still a little softer there too).  It is also fairly even from 100hz to 1khz.  This difference exists if I swap ears for the cups, so it is not my hearing.
 
I have the baffle port sealed, the cups are sealed with silicon, the ports on the outside are sealed with rubber than JB Weld epoxy.  I replaced the input jack on the left cup with a new one and sealed it completely with JB Weld epoxy.  The hole at the top of the cup where the wire comes out is sealed only with having silverstone placed on top of it.  I have experimented with closing that hole on the right with masking tape, as well as gone back over the seals on the right with masking tape, but I still have this volume difference.
 
My question is, is it more likely that the left cup is leaking somewhere slightly, and thus has better bass response, or is the right leaking somewhere and decreasing the bass response?  I am reluctant to mess with the left cup as it seems to be very good, almost exactly what I want.  I want to fix the right cup, but I am not certain if I have a problem that results from a leak or a non-leak.
 
I believe I have read that a complete seal increases sub bass, so I am inclined to think that the problem is a leaky right cup, but I am curious to hear what others here might say, especially if they have encountered this problem themselves.  Interestingly, before I went in and super sealed the left cup, the right was the one that played lower and had more volume in the sub bass.  This reinforces the leaky = less bass hypothesis, but input is very welcome.
 
Thank you for taking the time to read my post.
 
-Aaron.

 

[bluemonkeyflyer]

Quote:

Long time lurker, not sure that I've posted in this thread before.
 
I have run into a bit of a problem with my mod, and I am wondering if I could get some advice. 
 
Without getting into all the details, I have clay in the inside baffle, silverstone lining both sides of the inside of the cups, poster tak sealing the screw hole for the headband, and 4 large cotton balls inside.
 
I have decided to completely seal both cups.  Using test tones and my ears to measure the difference between the two cups, the left is louder than the right.  The left extends down to 10hz, and is pretty even from around 100hz to around 2khz.  The right is barely audible at 20hz, and much lower in volume in the sub bass until around 100hz (still a little softer there too).  It is also fairly even from 100hz to 1khz.  This difference exists if I swap ears for the cups, so it is not my hearing.
 
I have the baffle port sealed, the cups are sealed with silicon, the ports on the outside are sealed with rubber than JB Weld epoxy.  I replaced the input jack on the left cup with a new one and sealed it completely with JB Weld epoxy.  The hole at the top of the cup where the wire comes out is sealed only with having silverstone placed on top of it.  I have experimented with closing that hole on the right with masking tape, as well as gone back over the seals on the right with masking tape, but I still have this volume difference.
 
My question is, is it more likely that the left cup is leaking somewhere slightly, and thus has better bass response, or is the right leaking somewhere and decreasing the bass response?  I am reluctant to mess with the left cup as it seems to be very good, almost exactly what I want.  I want to fix the right cup, but I am not certain if I have a problem that results from a leak or a non-leak.
 
I believe I have read that a complete seal increases sub bass, so I am inclined to think that the problem is a leaky right cup, but I am curious to hear what others here might say, especially if they have encountered this problem themselves.  Interestingly, before I went in and super sealed the left cup, the right was the one that played lower and had more volume in the sub bass.  This reinforces the leaky = less bass hypothesis, but input is very welcome.
 
Thank you for taking the time to read my post.
 
-Aaron.

 
 
Completely sealing the cups (cup vents, jack, ear side baffle ports) = Less Bass, "thin" sound, and less efficiency (need more power to drive), IME.
 
Removing internal cup vent felt = Too Much Bass that bloats into the lower mids and knocks out treble.
 
Leaking caused by poor seal at cup-to-baffle rims, stretched pad flaps, poor seal at pads-to-your head = Loss of Bass
 
The density and weight of your cotton may be different from side to side. Get a $25 digital scale with calibration weight from Amazon.
 
More cotton, acoustic foam, fiberglass, felt, rock wool, polyfil, etc. = more treble, less bass.... and vice versa
 
There is manufacturing variance from 'phone to 'phone as well as from Right to Left drivers of the same set of phones. I often have to alter the damping materials in one side or the other to balance them. REW and a measurement kit, or a SPL meter, tells you if you're balanced, or not.
 
You could try un-sealing the ear side baffle ports and making a 4 mm wide modified bass port at the the center of just 1 of the 4 cup vents instead of completely sealing them. 
 
Modified Bass Port = Controlled Bass aka less bass quantity, perhaps better bass quality
 
The pads you use make a Huge difference in FR.
 
Others do things differently with good results. There are many paths to good SQ but it will likely require a bit of trial and error tuning to balance them and get the SQ you like best. Don't give up...experiment!
 
Good luck

 

[jasonb]

Completely sealing the cups will pretty much eliminate all the bass. After you completely seal up the cups youll definitely want to do some sort of bass port.

 

[bruce108]

Thanks to bmp and others, when I had a channel imbalance I started by checking the seal on the earpads. That was it, problem solved.
 
A confession, getting the Shure pads on was unarmed combat, so I fudged it with electrical tape. Don't do this!
 

 

[TekeRugburn]

just a few more days and modding begins 

 

[bluemonkeyflyer]

Thanks to bmp and others, when I had a channel imbalance I started by checking the seal on the earpads. That was it, problem solved.

A confession, getting the Shure pads on was unarmed combat, so I fudged it with electrical tape. Don't do this!

 

Did you first turn the flaps inside out? Position the pad on the baffle. Roll over the top to 11 and 1 o'clock and hold in place. Continue along one side to about 8 o'clock and hold it in place. Do the other side to about 4 o'clock and hold in place. Then 7, 5, and turn over 6 o'clock.

 

[bruce108]

I do now - should have listened to you in the first place. Many, many thanks for all your work on these headphones: even with my amateurish first efforts, the improvement over stock is simply startling. Planning to buy a second pair so I can really go to town.

 

[Vanarian]

Guys I don't know if you feel the same but... I get the feeling that I'm being toyed with by my T50.
No madness here, let me explain : mines are still stock. Sometimes I feel like they do have punch in mids areas and not that much bass impact (I mean, I'm a Basshead kind). And sometimes if surprises me with a deep bass coming out of nowhere!

Playing with Accudio, I just listened to "Freakin'Me" by Jamie Foxx. Well the bass was like "POooow"! Just before I was listening to Evil from Hadouken. Bass was tight but shy.

No wonder about vocals, I never got disappointed once with them. Mids, well I spend time with equalizer to learn how to get the best, and it is here. But bass!

I don't understand, haha. The file quality does a great part, but some musics should be more bassy where they doesn't appear to be... While others should, if I was to only trust why it gives me in some songs, not be bassy. And it does the contrary of what I anticipate.

Please go and listen to Get your Freak On from Missy E. Then try for example Lying from you by LP. That is exactly what I mean.

 

[jasonb]

I feel the same way about the bass. Im not quite sure if its a good thing or a bad thing.

 

[chrislangley4253]

Quote:

Guys I don't know if you feel the same but... I get the feeling that I'm being toyed with by my T50.
No madness here, let me explain : mines are still stock. Sometimes I feel like they do have punch in mids areas and not that much bass impact (I mean, I'm a Basshead kind). And sometimes if surprises me with a deep bass coming out of nowhere!

Playing with Accudio, I just listened to "Freakin'Me" by Jamie Foxx. Well the bass was like "POooow"! Just before I was listening to Evil from Hadouken. Bass was tight but shy.

No wonder about vocals, I never got disappointed once with them. Mids, well I spend time with equalizer to learn how to get the best, and it is here. But bass!

I don't understand, haha. The file quality does a great part, but some musics should be more bassy where they doesn't appear to be... While others should, if I was to only trust why it gives me in some songs, not be bassy. And it does the contrary of what I anticipate.

Please go and listen to Get your Freak On from Missy E. Then try for example Lying from you by LP. That is exactly what I mean.

It's just the way the recordings are mastered maaaan.

 

[Xprime4]

After all the bmf mods i still cant get the bass quantity and punch was expecting. It made the bass goes alot lower which is agood thing but they dont react really well to eq imo.
Time to sell them i guess

 

[jasonb]

Can anybody compare the 840 pads against the Alpha pads? I kind of want to try the Alpha pads on my modded T50rp's, but would like to know what to expect compared to the 840 pads i'm using right now.

 

[MuZo2]

Quote:

Can anybody compare the 840 pads against the Alpha pads? I kind of want to try the Alpha pads on my modded T50rp's, but would like to know what to expect compared to the 840 pads i'm using right now.

BMF has done some headphone measurements with  Fischer FA-003 Pad taped onto the baffle, Fischer FA-003 Pad with 'micmacmo' Inner Tube Flap Mod, Shure Velour Pad, J$ Pad, MrSpeakers Dog Pad, MrSpeakers Alpha Pad, Shure 840 Pad, and Stock Fostex Pad.

See first page from http://www.head-fi.org/t/618659/fostex-t50rp-incremental-mods-and-measurements

 

[jasonb]

Well I just ordered the Alpha pads. If I for some reason like my 840 pads better, I'll just list the Alpha pads for sale on here. Do they need to be attached with the fabric tape like the 840 pads, or are these a more snug fit with a better seal?

 

[Tiemen]

Quote:

Well I just ordered the Alpha pads. If I for some reason like my 840 pads better, I'll just list the Alpha pads for sale on here. Do they need to be attached with the fabric tape like the 840 pads, or are these a more snug fit with a better seal?

 
See this:
http://www.youtube.com/watch?v=A6xT2UbATJQ
They are easy to attach.
 
I upgraded from the Dog pads to the Alpha pads on my zach915m modded T50RP.
The difference is huge, a much better sound and the comfort improved as well.