Edit - after looking at jello's measurements, I've determined that my PH6 headphones came with PH4 pads.
I wanted to post an update on my comparison of the original Brainwavz HM5 earpad versus the PH4 pads that came on my Pandoras. I measured both the VI's pads and the Brainwavz pads:
PH4 - 22mm deep from grill of driver to end of pad, low resilience w/ pleather
Brainwavz HM5 "original" pad - 30mm deep, higher resilience w/ pleather
So, the HM5 pads are 36% deeper than the FAD pads. Additionally, I have the following thoughts:
- Bass response is better from the FAD pad, it's punchier and fuller. The HM5 pad still has great bass response, in fact I'd say it's almost more analytical in that regard than the stock pad - sort of like hearing and knowing the bass is there, versus it being inside your head. I think this is a preference thing - I do find that some music that isn't mastered very well can be more loosey-goosey with the bass elements and it can be overwhelming on the stock pad
- I experienced resonance issues with the HM5 pad - sort of like listening to a sound system (i.e. speakers) in a room that is not acoustically treated. Lots of hard surfaces, bouncy sound, etc. Basically, it seems like, in the little room that is in between your head and the driver, sound is bouncing around. Maybe it's because the HM5 pads are more spacious. On some tracks it actually can sound great, particularly with acoustic guitar - I tested this on Johnny Cash's American IV: The Man Comes Around and in some cases I prefer the HM5 pad to the stock pad. That said, if you're listening to something with a lot of mid-high frequency synth or electric guitar, it can sound strained and... well just not right to my ears. Verdict: I prefer the stock pad.
- The HM5 is tremendously more comfortable than the stock pad. That said, I came from using Grado SR-125i's for 6 years and various not so comfortable gaming headsets, so to me the Pandora Hope VI's are pretty comfortable, and I prefer the sound from the stock pad enough to deal with any comfort difference between it and the HM5 pad.
Sound wise, I found that switching from the headphone amps built in to my Maverick Audio TubeMagic D1 Plus DAC and my Meridian Explorer DAC to a dedicated JDS Labs Objective2 headphone amp improved sound quality a lot (thanks to jello for making the recommendation in an earlier post). As I'm sure you know if you're reading this, the Pandora Hope VI has an incredibly low input impedance of 8 ohms. This is lower than any headphone I've ever used, and according to a lot of people out there can result in frequency imbalance and distortion when paired with an amp that doesn't have a low enough output impedance.
The output impedance of the MavAudio DAC ranges, but the lowest rating is listed at 16 ohms. The output impedance of the Meridian Explorer is 5 ohms, assuming you have the revised one (the original had an output impedance of 22 ohms or something). I know output impedance and input impedance both change with load but for the sake of simplicity I'm not getting in to that. This yeilds a 8:16 (1:2) for the MavAudio and a 8:5 for the Meridian
damping factor, which according to a lot of folks is not ideal. The Objective2 has an output impedance of 0.54 ohms, yielding roughly a 16:1 damping factor, which is far more ideal.
The results from making this change are immediately apparent: bass is more controlled, less overwhelming, and more detailed. The sound is much more balanced than before. The main reason I bring this up is that if you are considering changing earpads to reduce bass or otherwise change the sound, I would consider your amplification source and do the math on what the damping factor is. I don't know if there's a magic number, but I know switching to the O2 made a difference for me.
I hope this helps some people!
