Modding the Sennheiser pc350 headset - Page 10

Well, perhaps you just like lighter lows? However, these cans do not perform especially well, they use the HD 595 drivers and when compared with said 'phones, they lack in lows and are perhaps a tiny bit bright. Some might go deeper into describing the sound signature difference, but inferior bass is what almost every owner acknowledges.

I've listened to the HD 595 on multiple occasions, with and without amps, from different sources, and then I drove the PC 350 with my main rig ..and I was unhappy, less pronounced, weaker lows than what I got out from the HD 595. This mod brought the PC 350 on-par when it comes to the lows, they changed other things too, but the main point is that this mod fixes the key problem that stands in the way of enjoyment for most.

So, the PC 350 isn't a bad 'phone by any means really, most people just want more out from them after listening to the HD 595 and comparing them. Or some people just are bassheads and they want all the boom they can get

Thanks, I've enjoyed this mod so much that I feel my duty is to spread the joy!

Hmm. Well, I don't have a drill to do a job like this, and I don't think I'm going to buy one just to do it.

I read something about heating a Thumb Tack up and piercing?

MY main concern is hitting the drivers by accident. A Thumb Tack is the right length? I read some post about doing it, any suggestion?

I mean I maxed the headset to 100% and these things vibrated pretty much.

The drill doesn't have to be anything special, just a normal little dremel, I paid 13 euros for mine, it came with lots of bits and other drillheads, and it has served me for over three years now. They aren't expensive at all, as you don't need professional quality tools for this mod.

The thumbtack heating & piercing method probably works wonders, I can imagine you could do that with any pointy metal object, a nail, a needle etc.
You don't need to worry about hitting the driver, the driver is on the other side of the enclosure, so as long as you drill/pierce the holes into the other end of the plastic casing, and don't push any deeper than you need to, you'll be ok. Even if you do push deep, there's quite enough space and you'd need to be really really careless to damage anything.

You can see the driver's rim on the side of the enclosure, and by looking at the crescent you can estimate where the driver is, as it is circular, and you can see that you've got a lot of space to work with when doing the holes

The part you should be most careful in is the opening of the cans, the wires are delicate and you need to find all the screws to make the opening procedure as light on the 'phones as possible. Stuff is only as durable as how you treat it, that should always be the motto when modding any tech

Mkilbride I did not have a drill handy, so a short hot nail did the trick - keep it for on fire until it becomes red and then make a hole. Just make sure to select the right place for a hole - check the pics first. In this case you can hardly damage anything and in fact you don't even need to push it, if nail is hot enough it will work like a charm and pierce plastics without any extra pressure applied.

I just got a set of PC350s this week, I'm using them with a Denon AVR3803 receiver as an amp, with an Xbox 360 as the source. I have a Steelseries xbox adapter on the way so that I can hook them up for chat.

The sound is definitely a bit congested at the moment, definitely a smaller soundstage than I'm used to with Sennheiser cans. I'm sure it will improve as they break in, but I figure giving the driver a little more freedom to move (by doing the mod) should help immensely in that department.

I'm going to dive into this mod this evening, I'll let you know how it goes... planning on two small holes (3/32"?) and packing with cotton.




Slightly related question... have any of you compared the headphone output from a decent receiver to a proper headphone amp for this sort of thing? The Denon has more than enough power to drive the 'phones even with their high impedance, but I'm wondering if there will be any significant sonic benefit beyond that for this type of use.

Second question on the same subject... for headphone audio (and particularly gaming), has anyone done a comparison on Dolby Digital 5.1 source audio that is downmixed by the receiver to stereo, compared to using PCM stereo direct from the source through the signal chain? I know that on many movie soundtracks on DVD and Blu-Ray the DD track is superior even when downmixed to stereo, but for gaming I'm not clear on what the best practice should be.

Did the mod last night. The sonic results are very good so far! These actually have a proper transition across the center of the soundstage now, before they sort of "jumped" from left to right without a clean transition during sounds that sweep evenly. Bass is definitely improved, and the lower midrange is much more articulate. The "congested" feeling has gone away entirely, and the upper mids are smoother. Female voices in particular are now much richer, I tested using Diana Krall's Live in Paris DVD and was much happier with the "honey and bourbon" tonal quality of her voice, which didn't come through well at all prior to the mod. Once they finish breaking in, I think these (modded) cans are going to be very capable on music.

I did the mod slightly differently... in looking at the driver enclosure, I realized that the area where most people are drilling the holes sits in very close contact with the outer shell of the headphones, which may be the reason some people are reporting "chuffing" after the mod... the clearance is almost nil there. I chose to vent from the top end of the enclosure, or the "side" if you have the driver sitting face down, directly into an open void area around one of the screw standoff columns.

Pic 1, you can see where I drilled at the top end, with two 3/32" holes (2.38mm):




Pic 2, you can see the area where the holes vent, I have indicated with the red arrows:



The blue arrow points to the edge of the cosmetic shell that covers the center area of the main housing. I didn't realize at first, but the outer cosmetic shell of the headphones isn't attached by anything other than double-sided adhesive tape, which you can see in the photo is a sort of reddish-brown color.

I figured this out inadvertently when I overpacked the cotton in the middle and popped one of them free. I'm going to have to go back in and superglue it in place, it doesn't seem to want to hold well now and separates slightly at the top edge.


Pic 3, showing the cotton batting that I used to fill the void space in the headphone:



I used too much cotton between the driver housing and the shell area of the face of the main housing, as you can see in the photo... my final result has a much thinner layer of cotton in the center area compared to what you see in the photo. The most important areas for damping seem to be the void spaces around the edges, especially if you vent directly into the open space like I did. I filled in those areas pretty well with cotton, not packed tightly but enough to fill the space completely.


I am concerned slightly by the thin cosmetic shell that is "stuck" in place, it seems less than ideal construction. Once I superglue the shell in place I may use some very small/thin pieces of Dynamat to damp the housing further. An alternative to that might be to experiment with some sort of fine grating material to replace the cosmetic shell entirely, to convert these to semi-open cans? Running without the shells on temporarily to see what the result is like would answer the question without actually fabricating anything first. I'm not sure if I'll get around to that sort of experimentation or not, because these do sound significantly better already.

Anyone else experimenting?

Getting these phones in a few days, I guess I'll try the mod! Thanks for all the information in this thread.

Long time reader first time poser.

Had to register to thank you Porter, I have had my headset moded for about 6 months now and while sounding vastly superior bass wise to the original design, your idea of holes on the side of the case near an open air pocket improved the bass level, and quality 10 fold. I plugged up 3 of the 4 holes I had in the usual location and made 2 small holes where you suggested. Amazing difference!

Anyways just wanted to let you know how much of a difference your suggestion makes over the already fantastic sound from placing the holes in the original location. Great work

Yeah, nice work Porter! That just might take this mod to the next level. Hadn't thought of placing the holes there, but that really does seem like a plausible course for improving this mod. Cheers

No problem! Thanks for your hard work prior!

Wow. Wow. Wow.

I just purchased this headset and after a bit of google-fu, I came across this thread.

Boy, am I glad I found this! Originally, I thought these headsets were good for what they were...a pretty good gaming/VOIP headset. Pretty decently sonically, but not real powerhouses or anything. After this mod I feel like I actually have some pretty good headphones now. Now I can enjoy my music between business calls on my softphone. THANK YOU VERY MUCH!

Now, it's time to do some research on a decent, yet inexpensive headphone amp for these guys. They are plugged directly into my X-Fi xtrememusic and its not producing enough power for me. I refuse to use any EQ to make up for it as well.

I plan on getting the PC350 by the end of the month and it looks like this is a must for these. I like the way you drill the holes on the side Porter. Looks like I might do a 2 and 2 configuration when I drill my holes.




I been looking at the Little Dot I+ to go along with my HT OMEGA CLARO Plus+ or/and X-Fi Titanium Fatal1ty Champion Series cards that I have.