I've had a good look around and can't find any threads on ASR regarding this series of headphones from Fostex, using their RP planar-magnetic drivers, which are a very popular basis for modifications. I've been hacking away at a set of these for months now and have only recently struck upon a vaguely neutral, or at least listenable, frequency response. There are already various threads on other forums, articles published on audio websites, as well as plenty of commercially available mods, but I have problems with all of these, most of which boils down to a dearth of evidence for the modifications suggested, even the most popular ones. Let's make way for some more scientific based discussion.
The headphones I'm talking about, so you are clear and so we show up in search results:
My intention in making this was that we could share measurements we have made showing before/after a variable is changed, as well as measurements of our overall final products. I understand changing a single variable isn't necessarily always helpful, however e.g. it makes little sense to compare very breathable velour pads with non-breathable leather pads without also modifying the bass response via front or rear venting, as these two changes need to be made in tandem really.
Some guidelines I think would be helpful:
Stick around and hopefully I'll some findings of my own to share. It's tricky because once you have tweaked something to a point you're happy with you are cautious about reversing things in case you can't get back to that point again! Additionally, I'm a hypocrite because I'm lousy at making notes on what changes I've made, or even keeping past measurements at all, which is not scientific in the slightest. I might get hold of another pair just so I can make changes from scratch to share with you all.
I'll quickly share where I've got so far with my RPKIT50, as I'm happy to have finally produced something not awful. I've flouted pretty much all my above guidelines but I don't want to bog down this first post with before/after measurements etc. so just want to put this here to show one example of what is possible and to have a timestamp for where I got up to on this day!
My coupler is a cardboard box chosen to match the width of my head, with the contact area made of craft foam and acoustic damping foam, and measurements taken with a Superlux ECM-999 into a Scarlett Solo. The ~5kHz dip is not audible and needs investigating.
Thanks and look forward to seeing what others have come up with
The headphones I'm talking about, so you are clear and so we show up in search results:
- T20RP, T40RP, and T50RP, spanning three revisions (marks I to III)
- T60RP
- Massdrop T-X0
- RPKIT50
My intention in making this was that we could share measurements we have made showing before/after a variable is changed, as well as measurements of our overall final products. I understand changing a single variable isn't necessarily always helpful, however e.g. it makes little sense to compare very breathable velour pads with non-breathable leather pads without also modifying the bass response via front or rear venting, as these two changes need to be made in tandem really.
Some guidelines I think would be helpful:
- Please share details of your measurement rig!
- Unless you're using a coupler which complies with standards, it would be extremely useful to provide measurements against a well known reference, with limited unit variation, such as a Sennheiser HD6x0 series headphone. I know this doesn't at all confound the drawbacks of FPC measurements, but otherwise your measurement of what may look like a perfectly neutral T50RP mod is almost meaningless.
- Well-annotated graphs, comprehensible legends, and a reasonable y-axis resolution are welcome
- Restrained subjective description is valuable
Stick around and hopefully I'll some findings of my own to share. It's tricky because once you have tweaked something to a point you're happy with you are cautious about reversing things in case you can't get back to that point again! Additionally, I'm a hypocrite because I'm lousy at making notes on what changes I've made, or even keeping past measurements at all, which is not scientific in the slightest. I might get hold of another pair just so I can make changes from scratch to share with you all.
I'll quickly share where I've got so far with my RPKIT50, as I'm happy to have finally produced something not awful. I've flouted pretty much all my above guidelines but I don't want to bog down this first post with before/after measurements etc. so just want to put this here to show one example of what is possible and to have a timestamp for where I got up to on this day!
My coupler is a cardboard box chosen to match the width of my head, with the contact area made of craft foam and acoustic damping foam, and measurements taken with a Superlux ECM-999 into a Scarlett Solo. The ~5kHz dip is not audible and needs investigating.
Thanks and look forward to seeing what others have come up with