Just listened to some Fostex T50RPs today... WOW! - Page 92

I tried two, that did the thick.  Perhaps my felt is a bit thicker, or you had a different treatment on the back of the driver?  Anyhow, thanks for the tip!

You know, it's interesting how the physics of speaker design and headphone work.  The nature of the driver's proximity to the ear, vs. dealing with different wavelengths of sound reflection and absorbtion in a room really changes how I have to think about things like "what is between the driver and the ear?"  

In a room, generally the less the better, but in part this is because you're not nearfield, and usually speakers are designed for far-field effectiveness.  In a phone, the ear/phone interactions are at much higher frequencies than one usually worries about in a speaker, so the notion of sticking extra materials between ear/driver is just hard to wrap my instincts around.  Just saying...  

Back to listening.  Burning Spear Live in Paris sounding pretty darn fine.

very nice mrspeakers, its good to hear about successful balancing acts with the t50s, right now my mids are over the top, the bass is big and the treble seems recessed due to the volume of the mids and bass, do you have the vent open? or is it covered completely?

I wanted to be original with the althorn, but oh well, guess I just do the paxmate modding like everyone else

Vents have original felt on them.  But with the SA 5000 pads, the volume of air around the driver is much greater than with the stock pads, so it's not apples/apples and this may not be the right balance with regular pads.  I'll play with my other set later.  There's only so much time...  

I'd love to see a picture of what you have on the ear side of your cups. Still can't visualize how you are using the paxmate squares there. I'm still finding that mine sound much better with wool felt over the driver than when I just put felt around the driver opening (too harsh). I'm using stock pads still so I'm sure that is a big part of it.
 

Quote:

Originally Posted by mrspeakers 

OK, so I've been playing further and have got these babies SINGING.  I've been tuning against LCD-2's as a reference.  Still note a replacement, but I continue to be shocked at how far these have improved over stock.

 

I have hybridized some of leeperry and joelpierces work.  Here's the current config:

 

Outside:

1) SA 5000 pads with Paxmate risers on the back of the cup

2) On the ear side, stock felt removed and a stiff poly felt (very minor acoustic effect to reduce sibilance) 

3) 3 ~1cm x 1cm of Paxmate in a "V" pattern pointing  to the front of the head (kills residual midrange bloat)

 

Inside:

1) Stock white gauze removed from driver back and replace by transpore (the white gauzy one.  Felt still to be tested)

2) Stock felt on cup vent

3) Plasticine (modeling clay) in Red, Yellow and Green  to mass load the front baffle

4) Paxmate on all interior surfaces of rear cup

 

These mods have resulted in a very detailed presentation, with a substantial increase in treble, yet with the midrange cleared up, timing and space increased, and prodigious bass.  

 

If anything, there's still a tad too much treble at the top, cymbals sound a bit too splashy.  I am betting replacing the transpore with felt will fix that by reflecting less top-end back into the driver.  It may open the mids up, too, for the same reason.  That's my theory, and I'll know tomorrow.  

 

 

Quote:

Originally Posted by mrspeakers 

OK, so I've been playing further and have got these babies SINGING.  I've been tuning against LCD-2's as a reference.  Still note a replacement, but I continue to be shocked at how far these have improved over stock.

 

I have hybridized some of leeperry and joelpierces work.  Here's the current config:

 

Outside:

1) SA 5000 pads with Paxmate risers on the back of the cup

2) On the ear side, stock felt removed and a stiff poly felt (very minor acoustic effect to reduce sibilance) 

3) 3 ~1cm x 1cm of Paxmate in a "V" pattern pointing  to the front of the head (kills residual midrange bloat)

 

Inside:

1) Stock white gauze removed from driver back and replace by transpore (the white gauzy one.  Felt still to be tested)

2) Stock felt on cup vent

3) Plasticine (modeling clay) in Red, Yellow and Green  to mass load the front baffle

4) Paxmate on all interior surfaces of rear cup

 

These mods have resulted in a very detailed presentation, with a substantial increase in treble, yet with the midrange cleared up, timing and space increased, and prodigious bass.  

 

If anything, there's still a tad too much treble at the top, cymbals sound a bit too splashy.  I am betting replacing the transpore with felt will fix that by reflecting less top-end back into the driver.  It may open the mids up, too, for the same reason.  That's my theory, and I'll know tomorrow.  

 

 

Tried this, I find that sibilance is a problem with just micropore on the back of the driver. Thick felt on the back of the driver fixes this but you also lose much of the high end, although the lower end is improved. 

Okay, I think it MIGHT have to do with the fact that you have SA 5000 pads, I switched to AD700s pads today and the sibilance is much, MUCH worse. Although my stock pads were raised with studio foam. 

Well, it's certainly an interesting exercise in tradeoffs.  

I did a total rework tonight on 1 set, for giggles.  I stripped it down to the bones.

1) I reapplied plasticine (in place of blue tack) in the "Bob Marley Signature Edition" palette of Red, Yellow and Green.  I'm sure that color selection had a positive influence on the sound.

2)  I removed the tape from the back of the driver and went with a stiff felt.  

3) Paxmate still covers the interior of the cup.  

Now the difference kicks in.  With felt on the back of the driver they sounded terrible with felt on the ear-side.  No top end, and bottom totally bloated and fat.  The mids began to breathe a bit, though.

So opened them back up.

4) Taped over the vent.  Presto, bloated bass gone.  The vent is clearly correlated to how much bass output there is, and whether this is good or bad is a function of how much back-loading is on the driver.  With the fabric surgical tape, I think there was a very little airflow, so the tape was acting like a second diaphragm, reducing the motion of the driver.  Opening the vents allows the second diaphragm to move more freely be easing back pressure, so the moral of the story is that felt allows the bass to flow pretty freely from the driver into the cup, so a vent causes excess bass.  A bass head would probably like this open, but the sound was just too thuddy and wooly for me.  

5)  To liven up the top end, I again removed the felt from in front of the driver, leaving it bare.  Sibilance is totally gone.  I guess the taught and hard surface of the tape was reflecting high frequencies back into the driver, causing standing waves (which was exacerbated in the range of sibilance) while the felt lets them through into the cup, where paxmate sucks them bout (I'd estimate a 3-6db difference in top end).  With the felt on the inside and the driver bare there is a more transparent sound for the high-end.    

6) There was a bit of midrange glare, so I took some paxmate and surrounded the cutout for the driver.  Midrange greatly improved.

Best sound I've gotten so far from the T50.  The midbass and upper bass excess of the last version is gone.  Male vocals sound less chesty, but when the bass is jamming, you feel the solidity and rhythm.  I think it was Joelpierce who noted that the tape messes with the mids.  It's true.  I'd avoid tape.  My suspicion is the adhesive closes too much of the surface off to airflow, so it's really just closing off the cup for most anything but bass capable of flexing the tape, and bouncing the mids and highs back into the driver, which was why the sound became quite bright, and I had to layer felt.  It sounds WAY better now.  

As noted, the pads definitely change the sound, so this may require more tuning for those with different pads...

EDIT:  I am using electrical tape on the outside of the vent, and experimenting with tuning.  I'm actually finding that a small vent, about 20%, extends the bass without a boominess, gives a bit of a lift, but also opens up the soundstage slightly.

Quote:

Originally Posted by mrspeakers 

Well, it's certainly an interesting exercise in tradeoffs.  

 

I did a total rework tonight on 1 set, for giggles.  I stripped it down to the bones.

 

1) I reapplied plasticine (in place of blue tack) in the "Bob Marley Signature Edition" palette of Red, Yellow and Green.  I'm sure that color selection had a positive influence on the sound.

 

2)  I removed the tape from the back of the driver and went with a stiff felt.  

 

3) Paxmate still covers the interior of the cup.  

 

Now the difference kicks in.  With felt on the back of the driver they sounded terrible with felt on the ear-side.  No top end, and bottom totally bloated and fat.  The mids began to breathe a bit, though.

 

So opened them back up.

 

4) Taped over the vent.  Presto, bloated bass gone.  The vent is clearly correlated to how much bass output there is, and whether this is good or bad is a function of how much back-loading is on the driver.  With the fabric surgical tape, I think there was a very little airflow, so the tape was acting like a second diaphragm, reducing the motion of the driver.  Opening the vents allows the second diaphragm to move more freely be easing back pressure, so the moral of the story is that felt allows the bass to flow pretty freely from the driver into the cup, so a vent causes excess bass.  A bass head would probably like this open, but the sound was just too thuddy and wooly for me.  

 

5)  To liven up the top end, I again removed the felt from in front of the driver, leaving it bare.  Sibilance is totally gone.  I guess the taught and hard surface of the tape was reflecting high frequencies back into the driver, causing standing waves (which was exacerbated in the range of sibilance) while the felt lets them through into the cup, where paxmate sucks them bout (I'd estimate a 3-6db difference in top end).  With the felt on the inside and the driver bare there is a more transparent sound for the high-end.    

 

6) There was a bit of midrange glare, so I took some paxmate and surrounded the cutout for the driver.  Midrange greatly improved.

 

Best sound I've gotten so far from the T50.  The midbass and upper bass excess of the last version is gone.  Male vocals sound less chesty, but when the bass is jamming, you feel the solidity and rhythm.  I think it was Joelpierce who noted that the tape messes with the mids.  It's true.  I'd avoid tape.  My suspicion is the adhesive closes too much of the surface off to airflow, so it's really just closing off the cup for most anything but bass capable of flexing the tape, and bouncing the mids and highs back into the driver, which was why the sound became quite bright, and I had to layer felt.  It sounds WAY better now.  

 

As noted, the pads definitely change the sound, so this may require more tuning for those with different pads...

 

EDIT:  I am using electrical tape on the outside of the vent, and experimenting with tuning.  I'm actually finding that a small vent, about 20%, extends the bass without a boominess, gives a bit of a lift, but also opens up the soundstage slightly.

 

Tried this, and I'm liking it. Top end is back, but I find sibilance is still present without anything in front of the drivers, I'm thinking some kind of thin paper felt would fix this?

EDIT: just thought I might want to add that the bass just doesnt seem quiet right on tracks like 07 Also Sprach Zarathustra, Staccato 2, Nr. 12 (R. Strauss, Opus 30) from the Ultrasone reference disk. 

B&H finally has them back in stick, so I ordered mine, I'm happily awaiting them to arrive, hopefully by monday.

Can anyone tell me if this is the mk2 box?

I'm pretty sure the boxes are the same.  It looks the same as box I got and mine are the MKII.

That's the same box my MKII came in.  =]

Thanks, the seller says they were purchased late 2008

Fostex T50RP IN STOCK NOW AT BHPHOTOVIDEO BUY BUY BUY!!!!