I always try to make the best out of my hi-fi components. With electronics, I don’t feel at home, but concerning sound transducers no one finds mercy from my modifying appetite. And so I reflected how the sound of the Etymotic ER-4S could be improved. I judged the foam plug to be better sounding, but wasn’t convinced of the tiny plastic tube inside of it, which actually elongates the narrow tube of the ER4 transducer. Without that, I reflected, the sound could disperse in a more natural way in the wider ear canal. So I shortened the whole foam plug comprising the plastic tube to the length of the transducer’s tube. That way the sound was very convenient and clearly more natural than originally. I further experimented with noise protection foam plugs: cut to 2/3 of their length and pierced by an awl (their coated original «outside» placed on the downside!), they fitted very well onto the transducer’s tubes – their tip with the filter inside lying open marginally above the foam. Thus the sound was at its optimum: much more natural, without any coloration – very clearly noticeable especially in comparison to the white plastic tips, which sounded «pressed» and narrow in comparison.
Another way of sound improvement, which leaves the appearingly better isolation of the white plastic tips intact, is to cut the latter’s upper lamella away, comprising the inner «tube». Thus the virtual elongation of the transducer tube is avoided. For perfection, the hole can be widened up a bit by a scissor. Thus the sound is improved in a imilar way as the foam alternative, but suffers a trace from a coolish overtone. I’m quite sure that the reason for that is to find in reflections between the smooth surface of the plastic and the ear canal – substantially reduced in the case of the more absorbing foam tips.
Then came the day my new Corda arrived at me. But what a disappointment: today of all days both of the Ety filters were plugged – nothing but a low, dull sound… A necessarily logical scenario when you think of the open lying filter tips… (although my ears are always clean, of course!). Second misfortune: I found only one reserve filter in the filter tool’s hollow handle! What to do now? I’m not a modern man – no mobile phone, no credit card –, so I can’t order some filters from Etymotic Research.
I found a solution: took the filters out of the transducer, took the filter membrane out of their tiny metal tubes… and replaced it by some soft, porous foam (yellow instead of green – who cares!). After some tries, I found the right density: approx. the fivefold of the tube's volume (hard to estimate), pressed into it with the aid of the metal tip of a pencil. By the way: once I dared to listen without the filters – this way the sound is very bright, plainly unenjoyable. Variation of the foam density allows a very fine tuning of the sound balance – the less foam, the brighter –, fascinating! In addition, the sound via such soft-foam filtering has lost the tiny (metallic) harshness at the upper end of the audio bandwidth perceivable with the stock filter – without any roll-off tendency.
Altogether, the sound is barely recognisable in comparison to the original one. It's far more realistic, there's no coloration at all, a more credible soundstage (although ostensibly placed in the head). Considering the Etys' manifest qualities, such as phenomenal transient response, unbeatable resolution and their fabulous intimacy thanks to the immediacy of the sound transmission avoiding outer ear reflections: in one word: nearly the perfect reproduction – if not even more...
Some further experiments with additional coating of the complete outside of the foam plugs (except the one facing the eardrum) using contact glue have resulted in a significant low-bass enhancement – too much for my taste: it reminded me of a slightly mistuned bass reflex system.
Finally, for the protection of the filter foam against dirt, I folded a round piece of nylon gauze over the transducer before putting over the foam tip. By the way, it's important that it isn't tense – otherwise the sound would be damped.
JaZZ
Another way of sound improvement, which leaves the appearingly better isolation of the white plastic tips intact, is to cut the latter’s upper lamella away, comprising the inner «tube». Thus the virtual elongation of the transducer tube is avoided. For perfection, the hole can be widened up a bit by a scissor. Thus the sound is improved in a imilar way as the foam alternative, but suffers a trace from a coolish overtone. I’m quite sure that the reason for that is to find in reflections between the smooth surface of the plastic and the ear canal – substantially reduced in the case of the more absorbing foam tips.
Then came the day my new Corda arrived at me. But what a disappointment: today of all days both of the Ety filters were plugged – nothing but a low, dull sound… A necessarily logical scenario when you think of the open lying filter tips… (although my ears are always clean, of course!). Second misfortune: I found only one reserve filter in the filter tool’s hollow handle! What to do now? I’m not a modern man – no mobile phone, no credit card –, so I can’t order some filters from Etymotic Research.
I found a solution: took the filters out of the transducer, took the filter membrane out of their tiny metal tubes… and replaced it by some soft, porous foam (yellow instead of green – who cares!). After some tries, I found the right density: approx. the fivefold of the tube's volume (hard to estimate), pressed into it with the aid of the metal tip of a pencil. By the way: once I dared to listen without the filters – this way the sound is very bright, plainly unenjoyable. Variation of the foam density allows a very fine tuning of the sound balance – the less foam, the brighter –, fascinating! In addition, the sound via such soft-foam filtering has lost the tiny (metallic) harshness at the upper end of the audio bandwidth perceivable with the stock filter – without any roll-off tendency.
Altogether, the sound is barely recognisable in comparison to the original one. It's far more realistic, there's no coloration at all, a more credible soundstage (although ostensibly placed in the head). Considering the Etys' manifest qualities, such as phenomenal transient response, unbeatable resolution and their fabulous intimacy thanks to the immediacy of the sound transmission avoiding outer ear reflections: in one word: nearly the perfect reproduction – if not even more...
Some further experiments with additional coating of the complete outside of the foam plugs (except the one facing the eardrum) using contact glue have resulted in a significant low-bass enhancement – too much for my taste: it reminded me of a slightly mistuned bass reflex system.
Finally, for the protection of the filter foam against dirt, I folded a round piece of nylon gauze over the transducer before putting over the foam tip. By the way, it's important that it isn't tense – otherwise the sound would be damped.
JaZZ
