KOSS 60 Ohm enclosure mod

[jupitreas]

Hello all,

I've always been a fan of the famous KOSS 60Ohm driver used in the classic Porta Pro, KSC75, UR-40 and other headphones. This 60Ohm driver is perhaps the best example of an economic driver that delivers performance that is way above its price range. There are many mods of this incredible driver. Here is mine

I always wondered what a proper high-end Koss headphone would sound like. Obviously, Koss has the electrostatic ESP950; however, I really wonder what a high-end KOSS attempt at a dynamic-driver headphone would sound like. I decided I'd build something that would embody this idea based on KOSS' arguably best dynamic driver - the famous 60 Ohm driver.

Here is how I went about building this vision. I got a used, broken PRO4AAAT, which is the current high-end KOSS open dynamic model. I fixed it up (turns out it was just a cable issue) and realized that it sounds terrible. I decided to take it apart and realized that it would be fairly easy to transplant KOSS 60Ohm drivers into this enclosure. I ended up cutting up my UR40 and experimenting with all kinds of damping to get the best sound. In the end, I realized that it was best to leave this can as open as possible. I replaced KOSS' ridiculous vinyl pads with velour pads that I bought off of eBay (Beyerdynamic DT700 series would also fit). I also added a bigger, real-leather covering for the headband. Finally, my vision was complete: this is what a KOSS high-end dynamic driver, open-back, circumaural headphone should sound like I sure hope that KOSS takes some advice from this and makes a proper dynamic-driver behemoth, since this is definitely a company that deserves some success. All hail KOSS

Lets move onto the sound for a little while. These bad boys basically sound very similar to the PortaPros and the KOSS UR40. Compared to the PortaPro, they have a signifcantly better sound-stage. The bass is a little deeper but not quite as well defined (it is still relatively clear though). The mids and treble are unchanged from the PortaPro but there is more high frequency extension available and this is sometimes (but rarely) noticeable in some very well-recorded albums or games that use wide dynamic-range special effects (Mass Effect 3, Dark Souls). Generally speaking, I'd classify this as a relatively flat can that adds some fun/bombast to whatever scene it is used for. It is a fun can but not extremely so.

Here are some pictures, I'll post some more detailed pics of the innards soon. Please go ahead and ask me any questions you might have

[CrowdAds]

[Marvin the Martian]

Nice! They don't look DIY at all. And having had PortaPros, KSC75's, and KTXPro1's, I have an appreciation for the 60 ohm driver too.

[The DarkSide]

Excellent mod!!! I thought they would look DIY, but it looks professionally built. Sweet,...

[IDvsEGO]

very cool. I have a set of ksc75 that I never use because the clips suck. I have been hanging on to them to do a mod like this.