Spotify Premium on Mac > iFi ZEN DAC Balanced > iFi ZEN CAN Balanced > IER-M9 w/ Sony Hybrid tips + 4 Core 22AWG OCC SPC Litz 4 cable
I'll keep this brief:
My main drivers over the past year have been the 2014 Sony flagship XBA-Z5. Despite their age, I've yet to encounter anything around the $500 price point that matches their unique speaker-like presentation. I'm primarily a bass and soundstage head, so the Z5 fit the bill nicely, but I wanted to more out of them technically.
I bought the M9 blind, and kept my expectations checked, having read that they didn't match the Z5 in terms of soundstage, and having found the tonality of the all-BA Fearless S8F decidedly uninspiring despite its V-shaped tuning. I had also previously owned the AK T8iE MKII and extensively auditioned the Campfire Andromeda OG, and was frankly underwhelmed by their performance given their entry price.
Let’s just say the M9 has single-handedly disabused me of the notion that TOTL IEMs offer only “incremental refinements” above mid-fi units. To my ears, the M9 sit confidently in a class of their own, just below the IER-Z1R, and well above the AK T8iE MKII, Campfire Andromeda OG, and Fearless S8F.
Crucially, as several users have noted, the M9 are especially sensitive to tip selection and insertion technique. From my listening experience:
Non-ideal fit = Stuffy, overly-warm, thick, laidback, blunted transients, small soundstage
Ideal fit = Clean, quick, precise, open, airy soundstage, extended treble
Due credit to @CoryGilmore for the following tips:
- Use the smallest sized tip that provides the deepest possible insertion and seal without creating a vacuum/suction effect
- Pull the top of the ear up and back when inserting IEM—this minimises pressure from within the ear canal, and mitigates the vacuum/suction effect.