I did the mod and wanted to say "THANK YOU!!!". This is what I always knew these headphones should sound like. I did not need to add any clay to my headphones though as the design is slightly different when compared to the images that you used, and instead of using the permeable membrane tape that you suggested using to cover the two outer bass ports I used a needle to puncture the two outer membranes three times in the shape of a triangle calculating that the needle hole and remaining material would replicate the tape and it seems to work. Thank you again for sharing, now I am listening to my copy of, "AC/DC Live: Collector's Edition" as it should be heard!!! \m/ \m/
Sennheiser HD-428 / HD-428s Modding Guide - January 2013 - Page 5
- 109 Posts. Joined 6/2012
- Location: Michigan
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A while back I actually took a dremel to the internal driver cup (the one with the ports on it) and cut it off completely. With the bare cups and no internal driver cup, the resonance is insane, unbearably bad, and the bass is so much louder than the rest of the frequencies that it completely drowns everything else out.
I ended up adding some modeling clay to the back, which cut resonances and the bass down by a bit, then, since the back of the driver itself is OPEN (like it's a skeleton frame driver, you can poke the back of the membrane from the back of the driver, not sure what the actual term for this is) I put a layer of micropore tape over the driver itself. This cut the bass down by a fair bit, so it's now at the level of a somewhat bass heavy set of cans.
I'm pretty sure I threw them out, so if anyone has the rough dimensions of the internal cups, that would possibly be helpful in moving forward with this. Tuning the volume of the whole cup may have an effect on the bass. There's still, unfortunately, not a very good soundstage with these. No matter what I tried, they simply will not open up.
They are now $25 on Ebay, I just got 2 in the mail, they look brand new, as does the packaging, but it says the condition are factory refurbished...
I already had a set, that just sat there because they were less than all that, after just the tape a thin layer of clay they are now my go to pair, even though I own a pair of MS2's, ATH-AD700, and a very much modded Fostex T50RP. I personally blame wje for making me spend money to play with these really cheap headphones, because they DO sound so good, these are going to be xmas gifts after I am done rewiring, recabeling, and them taping and laying down some clay on them that is.
Now to go back to my Fostex modding to try and get it sounding this good.