So Audeze's new groovy tips arrived in the mail - and out of all of the tips I've tried with my iSine 20 so far (and there have been many) I will say that these have made the single biggest improvement to their sound.
I love the 20 but the main criticism I have of them, sound-wise, is that while it has a well-extended treble, its upper midrange isn't really its forte & it can come across as being somewhat unfocused and veiled. This is especially noticeable with the 3.5mm cable.
The new tips take care of that completely. They lift that veil and tidy up those exact frequencies and make them noticeably cleaner, faster and more impactful.
So far I've found the difference to be most stark in piano music. Having played the piano for more than 30 years now, I've never been convinced by how the 20 rendered pianos - it never conveyed adequately the sonic impact of hammers striking each note.
Using these groovy tips is the auditory equivalent of triggering autofocus in a camera.
I won't be going back to the old ones.
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Full disclosure: I received these tips at no cost. Audeze were in the process of sending me a replacement iSine cable and I asked about the tips as they had not yet been listed for sale at the time, and Chris Berens was so good as to throw in a packet of them.
Thank you Chris and Audeze for the amazing customer service for someone who lives halfway across the world from them.