Fostex T50RP Incremental Mods and Measurements
Apr 6, 2013 at 9:10 AM Post #451 of 2,832
Clever. This is very helpful...Thank You!  I now have a good reason to order the Beyer Gel Pads.
 
Would you post a picture of the versatile Transpore tape applicaton? Did you cover the entire ear side of the driver?
 
Quote:
All semblance of awesomeness is restored. In fact, I think I like this a bit more since I feel like this has a bit snappier midbass, the subbass is given a little bit more volume, and the mids is a bit more prominent. I feel like the soundstage is a wee bit smaller, but like it has a larger sense of air than the standard DBV#3.

So what did I do to make the Beyer gel pad work?
MATERIALS



1. Beyer gel pads
1a. the included foam disk. Shown is its transparency.
2. Soft felt made from 100% polyester fibre (in this case, mine is from Creatology) cut in the size of the whole baffle
3. Dense rubber piece (the ones like those exercise mats) at 2mm, cut in the size of the felt area on the baffle.

Not shown: 3M Transpore tape.

PROCEDURE

So the first trial I did is to stack 3, then 2 then 1a on top of each other before putting 1 on using The Amazing Electrical Tape. That resulted in post #449. Amazing on first listen but then I started to notice some sharp spikes around 11k area.

Tried to fix them using these melamine foam scrap I have around (my supply is running low so I try to save as much as I can without cutting more from a block).


Putting them in front of the driver ear-side did little to no change.

My next trial is to took out the huge felt piece altogether and go from there. Much much better now. No treble spikes that I find painful, and this results in my impressions at the top of the post; the only difference from the final result is that the mids is a bit shouty/too forward for this midrange lover.

I figure that I have to put something in front the driver to tame the mids. Melamine foam doesn't work, and looking at the BMF Emergency Care Pack I have, there's nothing that I can put ear-side without compromising ear comfort. Then I spotted the transpore tape and I said "Why not?".

Apply directly to forehead onto the driver, making sure not to overlap the tapes. I needed two pieces of tape to cover the driver without closing the baffle port. Then put 3 on, then 1a and then 1.


The result is an amazing variation to DBV#3 with a better sealing pad perfect for the cold weather**.

**I've been running the beyer gel pad the longest time, and that included my time in Malaysia. Sweaty as all heck.

As I write this post, I have been listening to more music that I'm very familiar. I think this has a bit more detail in bass and upper mids, but no perceived detail that's usually the result of over-eager treble (all of this is inclusive with the impression at the top of this post).
I suggest you try it out, since you have more material to try and you know your way how to make measurements that made sense. :p

 
Apr 6, 2013 at 9:32 AM Post #452 of 2,832
Clever. This is very helpful...Thank You!  I now have a good reason to order the Beyer Gel Pads.

Would you post a picture of the versatile Transpore tape applicaton? Did you cover the entire ear side of the driver?


No, since that would be too much resources used. :p I just apply the transpore on top like this.


I don't know what would happen if it overlaps but I think nothing good would be it.

The other piece of tape seen there is just a piece of double-sided tape I used to not let the rubber mat piece moving when I put on the pads again. I thought the friction with the stock felt was enough, but earlier on I found out that it's not.
 
Apr 6, 2013 at 9:45 AM Post #453 of 2,832
Thanks. I did not mean to ask if you covered the entire ear side dust cover, just the ear side driver opening...which is what you did :)
 
So, doing so did not reduce your bass and mids? Interesting. 
 
Congrats on tuning this mod. I'm happy you were able to solve the Beyer Gel Pad + DBV #3 dilemma. Pads make a significant difference in SQ and each type of pad requires its own tuning, as you have shown.
 
BTW, are the Beyer Gel Pads mounted with electrical tape around the pad-to-cup junction? Or, do you use double-sided tape, too?
 
Quote:
No, since that would be too much resources used. :p I just apply the transpore on top like this.


I don't know what would happen if it overlaps but I think nothing good would be it.

The other piece of tape seen there is just a piece of double-sided tape I used to not let the rubber mat piece moving when I put on the pads again. I thought the friction with the stock felt was enough, but earlier on I found out that it's not.

 
Apr 6, 2013 at 9:56 AM Post #454 of 2,832
Thanks. I did not mean to ask if you covered the entire ear side dust cover, just the ear side driver opening...which is what you did :)

So, doing so did not reduce your bass and mids? Interesting. 

Congrats on tuning this mod. I'm happy you were able to solve the Beyer Gel Pad + DBV #3 dilemma. Pads make a significant difference in SQ and each type of pad requires its own tuning, as you have shown.

BTW, are the Beyer Gel Pads mounted with electrical tape around the pad-to-cup junction? Or, do you use double-sided tape, too?


Oh, whoops. :p

IMO the transpore does reduce the mids a bit, or at least clean it, since without it, the mids seem a bit shouty and forward. Nothing too noticeable or obvious on bass, although I think that the subbass seem to be a bit more clear and bass overall seem to be tighter.

I just used electrical tape to mount the pad, since the pads are round instead of the oval baffle, so thin double-sided tape won't reach. I think thick, foam ones can be used, but the foam disc that come with the pads could block it.
 
Apr 6, 2013 at 7:07 PM Post #458 of 2,832
Quote:
Headfonia tells that T40rp MKII and T50rp share the same driver. Is it possible to use the T40rp without any disadvantages?
 
@BMF: Did you receive my mail? :)

 
Yes, I posted about this a few pages back in this thread. To get it damped like the T50RP, you have to remove the plastic rectangles from the vents inside the cups and substitute a layer or two of felt. They come off easily with a mini screwdriver or X-Acto knive. Save them in case you want to go back to stock or for making a modified bass port - they're already the perfect dimensions so all you have to do is decide the size and placement of the the 3 to 5 mm hole.
 
Check your PM :)
 
Apr 7, 2013 at 9:44 AM Post #459 of 2,832
Quote:
Pad Rolling 
 
For a look at measurements for 8 pads on an All Stock T20RP mk2, go to the bottom of Post #1 in this thread.

 
EDIT: I corrected and added information about the measurement method.
 
Apr 7, 2013 at 1:10 PM Post #460 of 2,832
BMF, point of clarification, please. Was the pleather lining the ear hole of the FA-003 pads (both the innertube modded and stock ones) the soft stuff, i.e., the same material that the rest of the pad was made of. I have a set where the ear-hole lining is thicker and stiffer than the rest of the pad and a set where it's the same material throughout. They sound quite different. Thanks, eh? 
 
Apr 7, 2013 at 1:30 PM Post #461 of 2,832
Quote:
BMF, point of clarification, please. Was the pleather lining the ear hole of the FA-003 pads (both the innertube modded and stock ones) the soft stuff, i.e., the same material that the rest of the pad was made of. I have a set where the ear-hole lining is thicker and stiffer than the rest of the pad and a set where it's the same material throughout. They sound quite different. Thanks, eh? 

 
Good point. On closer inspection, the pleather is different for the 1st and 2nd pads in the top row. I'm sure the first one is FA-003 with soft pleather all around and inside the ear hole. The 2nd one may actually be an HM5 pad. Its pleather is stiffer all around and inside the ear hole. 
 
Apr 7, 2013 at 3:15 PM Post #462 of 2,832
Quote:
 
Good point. On closer inspection, the pleather is different for the 1st and 2nd pads in the top row. I'm sure the first one is FA-003 with soft pleather all around and inside the ear hole. The 2nd one may actually be an HM5 pad. Its pleather is stiffer all around and inside the ear hole. 

 
Thanks, BMF. I found that softer pads delivered better bass too. 
 
BTW, these NVX angled pads were mentioned on the forums a while back. I picked up a set. They are very similar to the soft FA-003 pads, except they are angled forward. Similar soft pleather, flap and stuffing materials and comparable outer diameter. However, the inner actual diameter/size of the ear hole might be a bit smaller, which may constrain the bass slightly. Also, if the clamping pressure is high, I think the stuffing might get squished down and the angle diminished. 
 
I haven't installed them on any T50RPs yet, so I can't offer any opinion on how they affect sound . I'll try your DBV#3 cottonball mod shortly. (BTW my cotton weighs 0.6-0.7g/ball vs your ~0.3.g/ball. So even here, the simple matter of "a cotton ball" seems to be variable. I'll keep you posted.)      
 
Apr 7, 2013 at 6:10 PM Post #463 of 2,832
Quote:
 
Thanks, BMF. I found that softer pads delivered better bass too. 
 
BTW, these NVX angled pads were mentioned on the forums a while back. I picked up a set. They are very similar to the soft FA-003 pads, except they are angled forward. Similar soft pleather, flap and stuffing materials and comparable outer diameter. However, the inner actual diameter/size of the ear hole might be a bit smaller, which may constrain the bass slightly. Also, if the clamping pressure is high, I think the stuffing might get squished down and the angle diminished. 
 
I haven't installed them on any T50RPs yet, so I can't offer any opinion on how they affect sound . I'll try your DBV#3 cottonball mod shortly. (BTW my cotton weighs 0.6-0.7g/ball vs your ~0.3.g/ball. So even here, the simple matter of "a cotton ball" seems to be variable. I'll keep you posted.)      

What are the dimensions compared to FA-003 pads? Or, are they Too Big, Too Small, or Just Right?
 
RE: Cotton balls, rolls, etc - Different weights, densities, dimensions....What you have may work, or not. As you know, there's only one way to find out.  :)
 
Apr 7, 2013 at 9:47 PM Post #464 of 2,832
Quote:
Pad Rolling 
 
For a look at measurements for 8 pads on an All Stock T20RP mk2, go to the bottom of Post #1 in this thread.

 
Yikes the J$ is quite a roller coaster at the end there. I wonder why that is... at first I thought maybe because it had high inner walls to cause reflections, but several of the others are like that too. Maybe because it's the most round of the bunch?
 
Apr 7, 2013 at 10:15 PM Post #465 of 2,832
Yikes the J$ is quite a roller coaster at the end there. I wonder why that is... at first I thought maybe because it had high inner walls to cause reflections, but several of the others are like that too. Maybe because it's the most round of the bunch?


Could be. I don't know. I'm just the messenger. :cool: Don't shoot.
 

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