

Listening with Leo's switch tuning 'ON', if I were to describe it in one sentence - very coherent, natural, musical tuning with top tier technicalities in the best possible way. If you are looking for a top tier all-rounder, look no further than the Pentara. With the amount of drivers and crossovers, it is impressive to achieve such technical details and tuning at a truly flagship level. Buy with confidence if this is what you look for
Pronounced and very high quality, tight, punchy, textured, controlled bass. Mids with enough warmth, emotion, note weight. Never thin or analyctical. Treble that provides clarity, detail, and air without sharpness and fatigue for me. Very deep and wide soundstage that expands like a sphere. Excellent resolution and imaging. No congestion. I do not have issues with anything in the frequency range that I can fault personally like I do with other IEMs. Everything just sounds right. Nothing sounds artificial or weird. Not recommended for bassheads seeking for more bass but rather for those that want neutral-warm leaning sound with pronounced and elevated bass.
UM's tuning switch '1' leans slightly less bass quantity, more clarity, and opens up the soundstage a little bit
Two different tunings that are noticeably different but useful from each other rather than being inferior. Easy to use the switches that compliment each other with tacticle sound
90% of the time I will prefer the switch on with Leo's tuning because it invokes a lot more emotion and dynamics with the elevated bass and warmth in the mids. Just my preference
Fairly easy to drive but scales with power or better DAC/AMP
Only major gripe I have is that the stock cable sucks tbh. Not ergonomic, heavy, stiff, minor microphonics, emits a minor sinewave hiss with my DAP as a USB DAC which I do not have with other cables. Recommend using a better cable up to user's choice
I notice that the treble does get a little spicy with poorly mastered songs with elevated treble though that is fairly rare
Lack of accessories and unboxing experience is not a big deal if you are ultimately chasing the sound anyway
As a self-proclaimed Astell fan and current owner of an SP3K, I hesitated quite a bit before upgrading to the SP4K, wondering if it was a halfway point (like an SP3.5K). I also wasn't particularly interested in an open-source Android system. Fortunately, I decided to take the plunge. The SP4K has turned out to be a complete surprise, to the point that it's the best DAP I've ever heard in terms of sound quality. A huge soundstage, bass with a texture I've never experienced before, and an astonishing level of detail. A total success.
These punch way above their price point. Very good bass for ba drivers that doesn’t make me miss dynamic drivers. Great technical performance, extended treble but not harsh. Love this set!