Picture of Sennheiser PC350 bass mod
For all you Sennheiser PC350 owners out there who find the headset lacking bass there is the following mod.
I did not come up with the original idea, but it was lacking a proper instructable.

I recently bought a new soundcard and while the sound output was superb, I found the headset itself was lacking some bass.
stumbling the web I found that there were some users that modded the casing of the drivers with a couple of holes which would greatly add to the bass from the headphone.

At first I didn't believe it, but because I could always close up the holes again I decided to give it a shot.
The reason it works is because the PC350 is a closed system, adding the two holes allows the air to flow more, adding more bass response. This is however at the cost of fidelity. Which is the reason I decided to close mine back up.
Maybe I originally made the holes too big, I will address the sizing in the instructable itself.

**NOTE: opening up your headphones voids your warranty, if you do not want this then this instructable is not for you**

Step 1: Tools needed

Tools needed:
- Small phillips screwdriver
- 2 mm drill
- Cordless drill
Alternatively, you could heat up a paperclip, or small screwdriver tip, then use it to melt a hole. This way, you don't have to worry about shavings getting in to your driver.

I'm excited to do this mod, but since I got my pair refurbished I will wait until my warranty is up to try it.
Pointy (author)  KiyoshiAphelion3 years ago
A small soldering iron or any of your suggestions would work.

However, you will definitely be pushing material inside during melting.
A drill-bit is designed to extract chips from the part.

It's just a matter of slowly inching the last drilling parts and not forcing the drill in.
Let it do it's work.

When you hit exactly the right amount of pressure and drill-speed you get these nice curls of plastic coming out of the hole, this is what you're aiming for. :)
thegeeke3 years ago
As an audio engineer I have to say that there is too much emphasis on bass in today's world. :)
Pointy (author)  thegeeke3 years ago
True,like I said in the instructable: I closed the holes I made, because it was just too much.
This is definitely a mod for those bass lovers out there (and there are quite a few).

Still I would've liked this set even more if they had just a tad more bass. =)
thegeeke Pointy3 years ago
Have you tried adjusting the EQ? If it's just a little adjustment, that can be done from the EQ. (Or maybe you already have that turned up all the way?)
Pointy (author)  thegeeke3 years ago
EQ is already adjusted
thegeeke Pointy3 years ago
Ahh... Oh well. I figured that if you knew to add "vents" you would probably know about the EQ... but it never hurts to ask! ;)