I was recently introduced to the FiR Audio Frontier Series (late arrival to this forum), and I've been getting so much enjoyment from these IEMs.
Sharing some personal impressions, below, as a small way to give back to this audiophile community.
I recently spent a few early-morning hours listening and comparing several of the FiR IEMs - Ra6, Kr5, Ne4. Overall, I absolutely love the Frontier Series, though side-by-side comparison reveals significant differences between these three. (I haven't yet heard the Xe6 for comparison.)
If I had never heard the Ra6 or Kr5, the Ne4 would likely be a personal favorite IEM as they are a clear step-up from the Campfire Andromeda and Bonneville and Audio 64 U18t that I had previously been listening to and enjoying.
However, swapping these for the Kr5 is a huge step-up in bass definition and depth as well as soundstage size. The entire sound spectrum is well balanced with excellent dynamics in the Kr5.
These IEMs reveal detail and elicit emotion that I haven't felt before in songs that I've been listening to for years. They also pair incredibly well with the Cayin N8ii DAP and reveal its capabilities.
I personally prefer precision, detail and resolution over rich, thick bass and warmer tunings, so I expected that these Kr5 would be the sweet-spot in the FS line-up for me. However, I have to say, the Ra6 take the strengths of the Kr5 to another level and offer the most compelling and well-balanced sound I've ever heard in an IEM.
The Ra6 sound is powerful, immersive, expansive and yet incredibly detailed and precise. Listening to these IEMs makes me wonder if this is my actual endgame, as I can't imagine the presentation getting any better. I love that experience and have only felt it a few other times (with high-end stereo systems).
Overall ratings:
Ra6 - A+,
Kr5 - A,
Ne4 - B+
Based on this experience, I can't wait to see how FiR continues to innovate and improve on this incredible sound. Thank you for the outstanding engineering and audio quality!
Listening notes and impressions below. I've also enjoyed and been inspired by Paweł Szachno's excellent reviews and passion for these IEMs over at
Ear Fidelity.
DAP: Cayin N8ii (AB, P+, LdB)
Cable: Moon Audio Silver Dragon 4.4mm balanced
Kr5 impressions
Album: Tool, Fear Inoculum (2019)
Track: Pneuma
- Bass: kinetic bass, felt throughout head/shoulders
- Mids: clean, clear, echo/reverb
- Treble: crisp, tactile
Track: Chocolate Chip Trip
- Bass: punctuated bass drum, tight, fast, high-impact
- Mids: precise dynamics, instrument separation, deep black background
- Treble: crisp, precise detail
- Soundstage: extended, ultra-wide, open headspace, surrounded
Album: Modest Mouse, Strangers to Ourselves (2015)
Track: Coyotes
- Bass: warm, enveloping
- Mids: guitar detail, page turning
- Treble: recessed cymbals/snare
Track: Wicked Campaign
- Bass: thump, long decay, reverb
- Mids: vocal expression, breathing, sighs
- Treble: guitar pick
Album: Radiohead, In Rainbows (2007)
Track: Weird Fishes
Bass: subtle, sublime
Mids: intimate, expressive vocal inflection
Treble: sizzle, splash, punctuated
Ne4 comparison
- Bass: less defined, slightly cloudy
- Mids: engaging, easy to listen, well-defined
- Treble: clean, clear, precise
- Soundstage: smaller scale, less separation
Ra6 comparison
- Bass: rich, warm, luxurious depth, control
- Mids: precision balanced with tube-like warmth, instrument placement and detail
- Treble: absolute control, precision
- Soundstage: bigger! enveloping, spatial separation, swimming in sound
