Advanced (ADV. Sound) has been working on its M5 series for a while now and already released M5-1D (review link) and M5-5D, each being equipped with a large single DD and 1DD+4BA. M5-11D has also been under development, but it’s been quite a while since the radio silence and I’m not sure if it’s even going to hit the market or not.
Though what’s for sure is that they are actually working on a new EST IEM called M5-6D. EST (electrostatic) drivers are the biggest trend going on in the audiophile industry and ADV sure couldn’t be missing out.
With a driver configuration of 4BA+2EST, it seems like 6D uses 2 Sonion BA for the lows, 2 Knowles BA for the mid, and 2 Sonion EST for the highs. Pricing is yet to be decided as well as the exact release date, but ADV commented that it will likely be released until this December. I’m quite a fan of Sonion BA for their quality bass performance, so I’m much looking forward to these.