Just listened to some Fostex T50RPs today... WOW! - Page 89

So, I'm not the only one who loses a channel when the cable rotates on the cup? This is a documented problem?

Quote:

Originally Posted by immtbiker 

So, I'm not the only one who loses a channel when the cable rotates on the cup? This is a documented problem?

Yeah.  It seems to happen to pretty much everybody.  I'm not sure if its the jack, the plug, or both, but since you can't fit most right angle 1/8" plugs into the recessed socket I riped out the stock one and put in a new one flush with the outside of the cup.  When I was using the stock cable with the new jack it still cut out some, but less often then when both were stock.

If the locking tabs wouldn't break off when you inevitably remove the cable out of curiosity it wouldn't be as much of a problem, but the little tabs break straight away.

Quote:

Originally Posted by immtbiker 

So, I'm not the only one who loses a channel when the cable rotates on the cup? This is a documented problem?

I too have cable-rotation induced channel cut-out problem but with only one of the right-angle plugs I bought, so the problem (at least on mine) seems to be a matter of tight fit between the jack and the particular plug.
 

Its not reversible (at least not easily) but Dynamat on the back of the cup pretty much kills all of that stuff.

Quote:

Originally Posted by wilyodysseus 

I'm frustrated with the T50RP. The speed, detail, and frequency response is tantalizingly good, but no amount/configuration of felt and Blue Tack gets rid of the unpleasant upper-mid resonance for me. It isn't obvious with all music, but I can't listen to many female vocal tracks. Nellie McKay's "Meditation," for example, is painful.

Does anyone have suggestions for reversible mods that might cure the resonance, or is it time for me to sell these on so someone else can have a crack at them?

Have you put akasa paxmate foam on the inside of the cups?  That soaks up resonances very nicely.  No bass reduction either.

I don't recommend dynamat for the headphone cups, only the empty spaces on the panel holding the driver.  You get a cleaner, clearer, more detailed sound that way with better imaging.

Quote:

Originally Posted by Mad Max 

I don't recommend dynamat for the headphone cups, only the empty spaces on the panel holding the driver.  You get a cleaner, clearer, more detailed sound that way with better imaging.

Mine are slathered with Dynamat and I'm having a hard time imagining them being clearer, more detailed, of having better imaging than they do now.  I'm not saying its impossible, since I hope to eke out some more performance, but they're already better in those areas than anything else I own or have owned.

EDIT:

IME the dynamat and the Akasa do two different things.  The dynamat keeps the plastic (both the cup and baffle) from being excited by lower frequency waves, resonating with the driver and contributing its own placticky-sounding harmonics.  Eliminating those will tighten up the bass and clean up the mids.  The Akasa absorbs higher frequency waves and keeps them from being reflected back towards your ear which can mess up soundstaging and give the 'phones a "closed-in" feel.

They each do different things and I've got both in mine ATM.

I think the midrange glare problem being described indicates a reflection.  Felt isn't really all that absorbtive compared to paxmate unless it's really thick, so paxmate will probably help.  

The dynamat will certainly clean up the bass and midbass by reducing the vibrations in the plastic, but it'd be a surprise (and surprises of course happen) if damping resonances in the plastic extended that high in frequency.  

Ultimately, though, there are *many* varieties of tweaks that people have used.  It's impossible to make a specific suggestion to wileyodysseus without knowing exactly what mods are in place, as any suggest has to take into account whether he's changed or removed the felt over the driver on the ear side, what's damping on the back of the driver, etc.

yep, I guess dynamat+akasa could make a killer combo w/ newplast, but I found that the akasa already blocked the airflow and could easily muffle the sound if you don't make it 4mm thick everywhere...I'm afraid together they could really muffle the sound. There really isn't much room left in those cups once they're full of Akasa IME:

Bonsoir, Mssr. LeePerry.  

My akasa is about like yours inside, but I note you have the vent fully open?  When I tried this (using the transpore/micropore matrix on the interior side of the driver, I totally lost the deep bass and had a huge midbass peak.  I am currently running with the cup actually fully closed, nothing on the ear side of the driver, and as noted, the transpore micropore on the inside.  The bass is now really deep, very solid, and has very low harmonic distortions, though there may still be a bit of a upper bass/lower mid peak.  

What have you done on your driver damping, and how is the bass?

Quote:

Originally Posted by wilyodysseus 

I'm frustrated with the T50RP. The speed, detail, and frequency response is tantalizingly good, but no amount/configuration of felt and Blue Tack gets rid of the unpleasant upper-mid resonance for me. It isn't obvious with all music, but I can't listen to many female vocal tracks. Nellie McKay's "Meditation," for example, is painful.

Does anyone have suggestions for reversible mods that might cure the resonance, or is it time for me to sell these on so someone else can have a crack at them?

For me, the biggest culprit wasn't what was going on in the cup, but what was going on between the baffle and my ears.  Now, I have a piece of suede with the driver and vent cut out taped to the baffle, and it has made a huge difference in that regard.  Making changes there had a far bigger impact than anything I've done inside the cup. (currently, I have a thin layer of dynamat with the foil removed and a thin piece of quilt batting in there and that's it)

I used three squares of akasa towards the front of the ear (mind, I have the SA5000 pads so I had extra room).  This did a lot to clear the midrange...  

Quote:

Originally Posted by joelpearce 

For me, the biggest culprit wasn't what was going on in the cup, but what was going on between the baffle and my ears.  

Ditto.

Originally Posted by wilyodysseus 

 I have some 4mm Silverstone foam on the way. If lining the cup doesn't fix the problem, I'll try some of it between the baffle and ear, as Joel suggests.
 

Some closeup pics would be sweet, it might very well be the exact same foam as the Akasa...same thickness.

Yeah, I like the idea of putting Akasa foam at the front of the driver...pinna damping \o/
 

Originally Posted by mrspeakers 

 

Bonsoir, Mssr. LeePerry.  

 

My akasa is about like yours inside, but I note you have the vent fully open?  When I tried this (using the transpore/micropore matrix on the interior side of the driver, I totally lost the deep bass and had a huge midbass peak.  I am currently running with the cup actually fully closed, nothing on the ear side of the driver, and as noted, the transpore micropore on the inside.  The bass is now really deep, very solid, and has very low harmonic distortions, though there may still be a bit of a upper bass/lower mid peak.  

 

What have you done on your driver damping, and how is the bass? 

I already posted the pics several times:

Since those pics I've also added newplast in all the tiny holes around the driver, blocked the hole that connects to the front, removed the stock felt before the driver, put a big disc of thick felt before the driver and angled the sa5k earpads.

When I remove the felt discs, the sound becomes bass shy and utterly shrill(exactly like when you remove the foam discs before the DT770 drivers)...and when I block the side vents, the SS shrinks up and become very 2D'ish...it really cripples the drivers potential to my ears, as they very much need to breathe IME.

How's the bass? Amazing. As my nickname implies, I'm a die hard reggae fan and this phone is the Mount Zion to me. Newplast sounds amazingly "neutral"(night & day over blutack, oh yes), the sa5k earpads(once slightly angled) bring a stunning 3D SS and very tight/clear low end bass, and the felt I put before the drivers balances the sound perfectly(can't tell more about the latter, I got it from a friend who's a majorly OCD'ed ortho head, this thing sounds wunderbar).

I should get a T20RP(non-MKII) this week, I wonder if it'll kill the T50RP...somehow, I doubt it. The R&D that's been put in this phone is very much audible.