Quote from: M3NTAL on August 23, 2014, 12:59:23 AM

The PFR-V1 was neat if it wasn't so painful to wear. They had a unique sound! (not complete shit, but not worthy of the pain+price)

Doesn't PFR V1 come with foam sleeves to not only improve bass but also cushion your ears?

I don't remember - I thought I had to purchase aftermarket ones along with the rubber o-ring to help improve low end. Either way - no amount of foam helps something pressing all its energy into your conch. Make any kind of joke you want off that statement.

Hi guys.

Those heaphones contain a resistor voltage divider inside cup

It's installed on driver PCB, probably they change some measurements (probably thick film resistors).

Rin (and a lot of speculative and ill informed websites) are a bit 'off' with their info.

The story behind the MA900 driver resistors is really quite simple...

The MA900 driver has a voice-coil impedance around 32 Ohm nominal (as a lot of drivers are).
When the mentioned resistors weren't there, there would be an impedance peak of around 200 Ohm (centred around 70Hz).
If you were to play that driver (thus without the mentioned resistors) from a 120 Ohm (or other high output R) amplifier the FR would show a peak of 9dB in the 70Hz region resulting in boomy bass on such amps BUT would  get  'correct' LF response on low output R amps.

Sony simply 'solved' that problem by paralleling a resistor of 22 Ohm to the driver (not 2 resistors).
The pictures out there show one of the resistors (the parallel one) to have a value of '220', however this simply means 22 + 0 'zeros' = 22 Ohm
This lowers the nominal impedance to around 13 Ohm and ALSO lowers the peak (centred around 70Hz to 19 Ohm.
The peak in FR (around 70Hz) using the same 120 Ohm output amp  is now reduced to +2.7dB. a reduction of > 6dB !

The extra 1 Ohm doesn't really do much (except f-up the damping factor of your near 0 Ohm output R amp but the cable also increases that resistance)
For those who want to know... if you remove the 1 Ohm (shorting or bypassing it) you will gain 0.6dB in efficiency (assuming the 22 Ohm is still there) and would lower the nominal impedance of 14 Ohm to 13 Ohm.

When you remove the 22 Ohm [220] and short the 1 Ohm [1R0] (as per the advice in that thread) you will end up with a headphone that sounds the same on a low output R amp but get a very boomy headphone when driven by a high output R amp.
Pick your poison.

That's the story ... and no ... the damping factor isn't changed when driven from a low output R amp but it IS lowered on a high output R amp.
But here as well... the 'boomy' bass you get has NOTHING to do with 'damping factor' and 'grip' but has everything to do with simple voltage division.

Is the stuffing in the pads a little uneven for anyone else?

I am enjoying mine straight out of the Geek Out 450.