[dstarr3]

I have an Audio Technica A900x, which originally had a single fixed cable that was getting stiff and ratty, so I modded the headphone to have a 3.5mm connector at each cup so I could use them balanced or single-ended just by using a different cable.



After reassembling the headphone and giving it a listen, there's distinctly a lot less bass on the right side now compared to the left. What would contribute to a closed headphone cup losing bass? To make room for the 3.5mm connectors, I had to remove some plastic material from the cups, but I tried to seal everything back up by stuffing some Sugru around the connector and molding it into place so that there wasn't any new openness in the cup. Any material I removed, I basically just replaced with Sugru after fitting the connectors.

That all being said, the right side has less bass now than the left side. So what would contribute to that? Would loss of bass indicate that I sealed it too well or not well enough? Or might I have done something else wrong? I did technically rewire everything using wire recycled from the removed headphone cable, but I don't think a simple rewiring would cause specifically a bass drop, and only on one side.

Let me know your thoughts. Thanks in advance!

 

[NA Blur]

Sounds like the cup is no longer sealing correctly. A lack of bass is an indicator of an open headphone or poor seal. Another thing to check is the ground / negative terminal on the rewire. Perhaps the ground wire has come loose?

 

[FoxFlair]

From what I understand it definitely shouldn't be the wiring. If the wiring was messed up, it should result in a quieter side due to the resistance, not less bass. and obviously a short circuit wouldn't work at all.

 

[dstarr3]

From what I understand it definitely shouldn't be the wiring. If the wiring was messed up, it should result in a quieter side due to the resistance, not less bass. and obviously a short circuit wouldn't work at all.

Right, that was my thinking, as well. I don't have any means of measuring frequency response, but just listening to a tone generator with my ears, the right side bass completely rolled off below about 60hz, but everything up from there sounded fine on both sides.

 

[FoxFlair]

In my opinion, rolled off sub bass tends to result from too much venting, from the front of the headphones, like where your pads are not the back of the cup. Its possible when removing plastic you opened up a pathway for venting from the back of the cup, to reach the front of the speaker/ where the pad is. maybe remove the pads and see if there's a hole somewhere around the speaker?

 

[dstarr3]

In my opinion, rolled off sub bass tends to result from too much venting, from the front of the headphones, like where your pads are not the back of the cup. Its possible when removing plastic you opened up a pathway for venting from the back of the cup, to reach the front of the speaker/ where the pad is. maybe remove the pads and see if there's a hole somewhere around the speaker?

I actually did do exactly that. I had to remove some material that would've isolated the front and back to accomodate the connector. Once I put the connector in place, I packed the area with Sugru to seal that part back up, but I guess I did an at least somewhat inadequate job of that on the right cup. I guess I'll crack the cup back open and see what I can see.

 

[FoxFlair]

I actually did do exactly that. I had to remove some material that would've isolated the front and back to accomodate the connector. Once I put the connector in place, I packed the area with Sugru to seal that part back up, but I guess I did an at least somewhat inadequate job of that on the right cup. I guess I'll crack the cup back open and see what I can see.

Depending on where the hole is, it might be possible to just remove the pad and look for a noticeable hole on the front plate around the speaker so you hopefully don't have to open it up again

 

[dstarr3]

I ended up not being pleased with this mod altogether, I didn't like the cable connectors poking straight down, jabbing me in the neck. So I did a complete teardown on the headphone again and measured, modeled, 3D printed, and affixed some Audeze-style angled connectors. Much more usable this way.

While disassembling my previous mod, the Sugru and my application of it did really seem to make a great seal, so I can only guess my problem was a bad solder job somewhere the first time. Either way, everything sounds great this time around. Extra careful to make good seals and solid soldering. Absolutely loving this headphone again now. Thanks for the pointers!