A few days ago, I had the opportunity to test my M9 with some dongles. My intention was to try out popular pairing dongles like the Questyle M15, Moondrop Dawn, RU7, etc. However, none of them were available at the store I visited. Despite this, I didn't leave the store feeling disappointed; in fact, the visit was quite delightful. I ended up testing three dongles: Qudelix 5K, 7HZ 71, and the mighty Hiby FC4. All of the tested dongles were connected to my LG V50 via a type C cable, with their 3.5mm sockets linked to my G5 amp section, which seemed to have zero coloration to the sound source. Here are my impressions of each:
Let's start with the Qudelix 5K, which surprised me the most, but unfortunately, in a negative way. I have no idea how it sounds when played via Bluetooth or its dedicated software, as when connected to my phone via a type-C cable, there is no soundstage whatsoever. Everything is confined inside my head, with the sound barely extending beyond my eyes. There are absolutely no left-right stereo effects.
Initially, I thought this might be due to the specific track I was listening to. However, upon switching to other sources, the differences were significant. Elements that should have been positioned on the left/right side were pushed as far as possible to the left/right stereo side of the soundstage. The Apple dongle boast a far more expansive soundstage. I just don't understand why the 5K is so highly praised within the community.
That being said, the separation is very good. Unfortunately, that's about the only positive aspect. The SE output is weak, and I had to turn the knob on my G5 all the way to its maximum to hear the sound clearly despite that, the sound is still tiny. I'm really curious about how the balanced output could potentially improve the situation. At the moment, this is as bad as an audio source can get.
Moving on to the 7HZ 71. Wow, wow, just wow! This little device is worth every single penny. It projects the elements in a song as far as they can go, creating a very wide soundstage that is completely opposite to what the Qudelix offers. It even surpasses the FC4 in terms of soundstage width. But that's not its only achievement; the dynamic range on this tiny dongle is on another level. It's super dynamic and incredibly fun to listen to. The bass is lean, fast, and hits amazingly hard. Combined with its very energetic treble presentation, it gives the M9 a very enjoyable, vibrant, and fun sound.
The downsides? Well, there aren't many. The note size (although note weight is great) is slightly smaller compared to other sources, and the energetic treble can be a bit glaring and grainy at times. However, this is not a problem with the M9 at all. This dongle is designed with a fun sound in mind, and these minor issues can be easily overlooked. The midrange imaging is a bit blurry as well, with less focus compared to other sources. But overall, it's a great product with excellent value.
Lastly, let's discuss the FC4. It produces a very calm, refined, and mature sound. It has a strong bass presence, substantial note weight, great timbre, non-offensive treble, and a focused, big, and authoritative midrange. The only thing that bothers me about the FC4 is its soft bass impact and lack of dynamics, which I found in the 7Hz 71. Again, the soundstage is slightly narrower compared to that of the 71, but the difference isn't substantial.
Setting aside these mentioned downsides, the FC4 is actually a great product. However, it's unfortunate that it isn't compatible with the M9's sound signature. It is probably a better match for already fun and dynamically sounding IEMs, rather than the M9, which has a flatter sound signature.