JVC FX33 Mod. - Head-Fi: Covering Headphones, Earphones and Portable Audio

kramer5150 · #1 (**permalink**) 02-19-2007, 08:38 PM

I thought I'd start a dedicated thread, I posted this on that other thread-monster and it wasn't getting the visibility on page ~30.

Here you go!! Compared to a stock phone, this mod makes them brighter and increases upper mids and treble, so its no longer overwhelmed by the bass. If you already find the FX33 too bright or harsh, you may not like this mod. If you find the FX33 muddy, bass-bloated or congested this might be a mod for you. Readers should also note that this mod is not-reversible.

First you have to pull off the foam tips. Just gently pull them off with your fingers. They slide off with a little tugging. Once the foam tips are off, grasp the gray rubber tube with some pliers and pull them off. They should pop right off with a swift tug. There is a little glue that holds the rubber tube in place. I think other members have used different methods to remove the gray tube. Please feel free to post other methods!!

Use a sharp x-acto knife and cut / scrape off the paper filter screen. You can see in this pic there is a perforated metal mesh screen protecting the driver. So the driver is still relatively protected without the paper.

So... thats half of the mod. Give it a try. At this point, slide the gray rubber tube back on, and slip the foam ear-piece back over it and give a listen. It should be a LOT brighter than before. I found the brightness harsh and piercing. So... its on to phase 2.

Next take an old earpad foam from a junk-can and cut a small cube shaped piece out of it. Roll it up and insert it into the sound tube. The foam helps to attenuate the highs, and keeps earwax out of the sound tube. You can experiment with different sizes of foam. With larger foam pieces, the foam is compressed more dense into the tube, and more highs will attenuate. It is a trial and error kind of thing. I ended up cutting 3 different sizes of foam and using one that was just a little larger than the inside diameter of the plastic sound tube.

Heres the little foam filter piece. I used an x-acto knife and sliced up a KSC75 earpad cushion. Just cut a little cube, scrunch/roll it up and shove it in the tube. You don't need to cut it into a cylinder shape.

Once the foam piece is securely snug inside the tube, slide the gray tube back over the sound tube and pull the slieve back onto the tube.

Its a pretty night and day difference IMHO. I was comparing them to my nieces unmodded FX33 and the difference was very noticeable, even for her (a non-audiophile). I told her to keep whichever phone she liked best. She chose the black one, more for its looks. Of course you can combine this with any of the tip-mods. I find the stock tips the most comfortable, so I just leave them alone.

Good Luck!! and happy modding.

Mrvile · #2 (**permalink**) 02-19-2007, 08:41 PM

Thanks for the clarification. I will try this.

mcramen · #3 (**permalink**) 02-19-2007, 08:52 PM

it's always good to perform kramer mod on something.
I will do it if I get the pair in the future

Madgravity34 · #4 (**permalink**) 02-19-2007, 09:34 PM

What do you mean by "high frequency attenuation?" I took the paper out and listened to my fx33's without anything in there and the highs sounded to sharp for my tastes ( I love my vibes treble - for reference). If I put foam in them, will that help roll'off the highs to some extent, or does your statement mean that it will make the highs more noticeable than they already are?

sonic_rage · #5 (**permalink**) 02-19-2007, 10:19 PM

i just got a pair of marshmallows yesterday after hearing all the hype.

theyre pretty good for the money and are very modable.
though i dont think theyre better than the E2c as some have claimed.
ive already changed the tips on mine and removed the paper screen.
i still need to find some extra porous foam to tame the sibillance.

here's a quick webcam pic of mine with a pair tips from my E2c.
the fit is much better.

gp_hebert · #6 (**permalink**) 02-19-2007, 11:59 PM

Great mod, thx!

The more I listen to these headphones, the more I like them. When I first got them, I thought the sound was pretty muffled and the bass was way too loud. I burned them for 40-45 hours and they really opened up. Cleaner bass, pretty well defined mids, but the highs were still poor. I decided to remove the white paper and it was yet another amelioration: the highs were now very clean, maybe even a little bit too bright. Finally, I did your mod and now I'm a happy man!

The sound is better than my Senn PX100 for metal and rock and they only cost the third of the price, plus they have isolation. They can't touch my Super.fi 5 Pro in any aspect except maybe for comfort, but hey, they only cost 20$ !

ugester · #7 (**permalink**) 02-20-2007, 12:12 AM

Holy crap, this really makes a big difference! Before i couldn't stand listening to any fast metal with these since it would become a big, slow, muddy mess. Now it's tolerable, pretty good actually. I can't wait to change out my tips with e2c foams or something.

gp_hebert · #8 (**permalink**) 02-20-2007, 12:23 AM

Am I the only one who likes the stock eartips of the Marshmallows ? I tried all my Super.fi 5 Pro tips and I can't get a proper seal with any of them, even the bi-flanges which I usually use with the SF5P. If the Shure tips are very different from the UE ones, I'm willing to give them a try, but for the moment, I get a very good seal with the stock eartips.

PeterDLai · #9 (**permalink**) 02-20-2007, 12:48 AM

It indeed made a big difference, and though it sounds better, I still can't get over one aspect of the Marshmallows that wasn't fixed...

Do the voices sound "raspy"? Is this just a things with lower end canalphones? They just don't sound smooth...

The Marshmallows make my AKG K 81 DJ sound very cold and harsh.

SONGsanmanwah · #10 (**permalink**) 02-20-2007, 01:05 AM

If we use the original tips, there's no need to remove the grey tube, right?

kramer5150 · #11 (**permalink**) 02-20-2007, 01:09 AM

Quote:

Originally Posted by PeterDLai

It indeed made a big difference, and though it sounds better, I still can't get over one aspect of the Marshmallows that wasn't fixed...

Do the voices sound "raspy"? Is this just a things with lower end canalphones? They just don't sound smooth...

The Marshmallows make my AKG K 81 DJ sound very cold and harsh.

Yeah I think they have some harsh resonances in the upper mids, that is a characteristic of the raw driver. The paper filter, attenuates the upper mids... and this makes the resonances harder to detect.

one thing I have noticed with dynamic headphone drivers: If the drivers have resonant characteristics in the upper mids, adding foam sheets or perforated paper filters in front of the drivers does NOT clear up the resonance. Rather, it transforms those harsh resonances into muddy/congestion.

So... this mod helps to a certain extent to brighten up the overall sound. But, the drivers will always kind of have that signature sound.

It won't transform them into magic KSC75 slayers... but its still a step in the right direction IMHO.