So today I finally got a chance to open these bad boys up. I pretty much followed the Rastapants template exactly because it seems to address the resonance issues in the chassis (mass loading baffles, and acoustic foam) and then leaves room to adjust for preference (bass port tuning, dampening material choice). What I thought would be a quick 20 - 30 minute process ended up taking closer to 2 hours. I took pictures along the way, so I thought I'd share:
The only non-drying modeling clay at my local crafts store, Michael's, was this Crayola one. I was very soft, which made it a bit messy to work with, but it did the job. I want to find something in between the density of this and dynamat eventually.
Baffle is mass loaded. I followed the Rastapants color scheme to pay homage to mrspeakers. I used a screwdriver to poke holes to break the smooth surface.
Added a couple of strips of dynamat to the inside of the cup to mass load them. I don't think this is part of the official Rastapants configuration, but I have tons of Dynamat sitting around so I figured it couldn't hurt. I think MacedonianHero mass loads the inside of his cups with Dynamat. If anyone needs Dynamat, shoot me a PM.
I lined the acoustic foam (Silverstone brand bought off Amazon) on the inside surface of the cup on top of the Dynamat.
Only used 1/10th of one sheet of acoustic foam, out of the two sheets that came in the package. So, I probably have enough leftover to do 19 more headphones. If anyone needs acoustic foam, shoot me a PM and I'll gladly send you some.
Peeling off the white felt on the driver. While technically this is an irreversible mod, that doesn't make it unchangeable. So, if I don't like the sound, I can always find similar material to put back on to bring it close to stock. But with it off, I could choose any material under the sun so taking it off was a no-brainer to me.
Back of the driver in the nude. There is no dust cover on the back of the driver, so if you peel off the white felt, I'd recommend putting on another material for a bit of protection.
Stiff felt from Michael's that I'm using for the back of the driver.
I used rubber cement to apply the stiff felt Here is a picture of the finished driver with the white vent cloth removed.
I'm using electrical tape on the outside of the cup for now, so that I can easily try different amounts to see which one I'll settle on. With the entire vent open. Right now I'm settling on blocking all except one vent.
My SRH840 pads don't arrive until next Wednesday, so I'll likely wait until then to take the front driver cloth off. I did take a couple of strips of double-stacked acoustic foam and stuffed them underneath the earpad. Here's a picture of one inside the earcup, next to the other strip.
So, how does it sound? In one word... wow.
I only listened to this in stock form for about half an hour, but these are a clear improvement in every aspect, imo. Both ends are much more extended. Previously the bass did not extend very deep, and didn't have much impact. Listening to hip-hop songs, it was missing the lower registers which made music annoyingly thin. Well now the sound is much fuller, as the lower frequencies fill up much more space -- similar to switching over from laptop speakers to desktop speakers.
The treble has brightened up for the better. While the treble was rolled off and stuffed behind the midrange before, the details now pop out at you to give your brain a steady stream of stimulus. It's still not a bright headphone by any means, but it's detailed and exciting (with the right recordings) without being harsh.
The clarity in the midrange has gone up two or three notches. All of the elements in the music is much more defined and give a greater sense of transparency. In stock form, things were much too syrupy with all the cup resonances bouncing around. It made it almost seem like you're listening underwater.
Soundstage is very 3D and seems to have widened -- although it may just be perceived that way because the treble has brightened up.
These have that very distinctive orthos flavor, that you either love or hate. They give a great sense of weight to vocals and instruments that are much more realistic than traditional dynamic drivers after you wrap your head around the orthos sound.
Right now, I'm very pleased with how far $74 can get me. There are still a few things I want to play around with -- specifically bringing the upper mids a bit out more. The tonality of alto sax is a tad off on mine, and it's not quite airy enough for acoustic guitar pieces just yet. I'm hoping removing the earside driver felt will air things out. But as of right now, after running these through my test tracks for the past three hours, I can say that I'd be perfectly happy with these being my only set of headphones. They're not better than the LCDs (I'd have to wait until mine get back so I can really A/B them to get more indepth), but they do so many things right and don't have any gaping flaws.
Big thanks to mrspeakers, joelpearce, leeperry, MacedonianHero, Kneeljung, bluemonkeyflyer and all the contributors in this thread
Edited by Questhate - 9/17/11 at 9:24pm