If by fault you mean one/both channels losing volume, join the club. EarSonics, via the manual or web site, does not specifically mention filter maintenance/replacement. They give you a crude "cleaning" tool (brush), which IME simply packs the crud in denser. Nothing worked for me so I removed them (metal sleeves and all) and was pleasantly surprised when I found I generally preferred the unfiltered sound. Generally, the sound is more detailed and forward, with less congestion, but sound just as clean as stock/filtered (maybe more so). They remind me a bit if the Etys ... speaking of which ...
I do own the Etymotic ER-4S, which come with replacement filters and a handy removal tool....
(One or both of these removal tools from Etymotic should work with SM3. They are $1.50/ea. Note that these are for filter removal only. Ety. 'phones have filters that are optimized at a mounting depth when simply fingernail-pressed flush with nozzle body. As mentioned below, the EarSonics have a deeper default filter position (below flush); my Shure 530 also have a deep-mounted filter. )
Knowles (microdriver OEM) calls them dampers: Here's a macrophoto from the Knowles web site:
"Dampers are acoustic cloth screens for insertion inside acoustic tubing. These damping elements are used between the receiver outlet and the ear canal to smoothen the frequency response. Various acoustical resistances and sizes are available."
Design/Application guide is here, and here. Note that the main parameter is Nominal acoustical resistance (also see acoustic impedance). So, for Green damper, its: 1500 Ohms. In the second technical PDF --TB-14: The effect of acoustic damping plugs on receiver response--note the effect (FR curves) of various dampers and NO damping. Also note that distance from the driver(s) (i.e, position of nozzle filter) affects FR--I don't know what it is for EarSonics, tho' filter mount-depth (position) may be an effective/fun-to-play-with DIY tweak. The filter (and its sleeve), as I elucidated above, has other effects on performance, which may or may not be affected by FR ...i.e., dynamics and speed (Knowles should measure/publish CSD waterfall curves for these filters). Bottom line: the filterless response curve may look terrible on paper but sound quite good, as many of us have stated.
The white piece is one type screen, and an engineering dwg. is here.
Knowles also carries Wax Protection units:
There are several on these product pages. DigiKey has the green one (correct for SM3???) for sale here. But that price $96.12/ea. !!!!!!!!!!!!!!!!!!!!!!!! Typo, mistake??? Here's another source with saner prices.
Or maybe best (and cheapest=$2.00) source is none other than Westone:
Me ... I won't be going back to ANY filter. I did not care for the SM3s UNTIL THIS SERENDIPITOUS DISCOVERY. If you've seen my posts and reviews of the SM3v2, you'll note that I have been pretty disappointed, despite all the hype these IEMs have somehow "achieved".
Filter removal is not a panacea ... but it helps ....... one reason may be removal of the metal filter sleeve itself, which takes up quite a bit of that limited ID (inner diameter) of an already limited ID (e.g., compare to that of dynamic IEM like IE-8, etc.) -- so, this equates to microdriver (esp., bass/mid driver) moving more air with greater ease (I still suspect that that long, narrow nozzle is not doing the SM3 sonics much good, other than part of some sort of bass-reflex system and/or as a waveguide)...clearly, that damper sleeve in the first image (above) is a waveguide, given that smaller/narrower tip.
....whatever the case, removal helps ... at least for my ... uh ... "ear sonics".
While were on this topic ...
As I also recently posted, one of the SM3's came apart on me -- I had to super-glue it back together. (Sigh... poor filter design and cheap construction. ... can an IEM this $$ get worse?!). While apart, I got a good look and feel for the innards/guts ...noticed the flimsy plastic shell seems to have a lot of hollow cavities. One of my biggest peeves about the SM3's sonics is its cartoony/plasticky/"artificial"/"CGI" sound. If I'm crunching on some food while wearing them, I can hear the reverb in the shell. Hmm...maybe some silicone or spray-foam filler for these cavities may improve things?? Stay tuned....
Edited by alphaman - 1/2/13 at 2:23pm