IEM users beware of noise floor, even for low sensitivity models like the Solaris 2020 (94 dB SPL @ 1kHz: 6.54 mVrms). It seems this is not an uncommon issue for even the most highly regarded portable DACs including the Chord Mojo, so not really a fault, just a mismatch. It sounds great with Focal Clears, but my only use case for the RU6 is with IEMs on the go.
The Grand Maestro is an incredible IEM in many ways.
The vocal boost tuning switch changes it from a mostly balanced mids/vocals recessed sound signature, to a mids/vocals forward powerhouse. The difference is anything but subtle.
The tuning modules modify the sub bass frequency by a few decibels. Changing the sub bass opens up the head stage and allows the other frequencies to “shine” through.
This is not a dedicated bass head iem. The bass is excellent, but it doesn’t overpower. This is an IEM capable of presenting music clearly and concisely throughout the frequency range.
Grand Maestro has the best head stage I have experienced on any IEM to date. Width, height, and depth are excellent on all three axis, and, instruments, vocalists, sound effects, etc. present from all 3 dimensions of the stage.
Thus IEM is worthy of consideration.
Pros:
* Excellent sound with the Subtonic Storm.
* Delivers enough power to drive one of the most demanding IEMs in existence.
* Solid construction
* Compact form factor
* Responsive UI
* Beautiful design
Cons:
* The buttons are very easy to press by mistake, especially with the case on.
* Battery life is not very good. They advertise 5 hours in class A balanced and I'd say that's accurate.
* Can't be used as a Bluetooth DAC
* Latency in USB DAC mode (this is common to all Android DAPs)
* Gets very hot during extended listens in class A mode.
* Audio stream compatibility (with Plex). I tried watching a movie from my Plex server on this DAP and found that it had frequent stuttering and no audio. I eventually found out that audio streams with two channels would play fine, but any more than that could not.
Full review here: https://wolfhawkaudioreviews.com/2023/05/19/hiby-r6-pro-ii/
