While some IEMs standout based on the material and the finish of their shells, the first thing you notice with Penta’s in your hand is the unique shape. Milled from solid aluminum piece, the shells are very compact, have rounded edges with sexy wavy design lines, and a very comfortable ergonomic fit inside the concha area of my ear. While the surface of the shells is anodized, the milled Meze logo on the faceplate reveals the aluminum material underneath, and the same on the inner part of the shell where you have milled L/R letters, and 2 vents.
One of the vents, referred to as Pressure Equalization System (PES), has a unique drilled shape to control the airflow which regulates the internal chamber pressure around the driver assembly. And btw, absolutely zero dynamic driver flex. The nozzle also has aluminum finish with 3 precision milled sound bores that bring out the sound from connected internal metal sound tubes (also precision milled). You are not going to find typical plastic tubes and dampeners inside the shell, instead Meze uses metal sound tubes, each one precisely cut to control the amount of air volume in front of the driver.
As the name of this IEM suggests, we are dealing with Penta-hybrid configuration of DD and 4BA drivers inside the shell. Based on the internal diagram, 4BA drivers are split into groups of 2 each. While it wasn’t specified in the spec, I assume DD is for the bass, one pair of BAs is for the mids, and the other pair of BAs is for the high frequencies, with each group connected to its corresponding metal tube going to a separate sound bore at the tip of the nozzle.
I analyzed RAI Penta sound performance driven by LPGT while playing a variety of test tracks, such as Agnes Obel “The curse”, Sandro Cavazza “So much better” (Avicii remix), C-Bool “Never go away”, Ed Sheeran “Shape of you”, Alan Walker “Darkside”, Galantis “Hunter”, Iggy Azalea “Black widow”, Indila “Boite en argent”, Counting Crows “Big yellow taxi”, David Elias “Vision of her”, and Michael Jackson “Dirty Diana”.
Penta has a natural full-bodied tonality with a nicely balanced signature. The presentation of the sound is slightly laid back, not too much in your face. I’m hearing a natural organic sound with a relatively coherent hybrid tuning, not too crisp or too analytical, but still will a decent amount of clarity and good retrieval of details. It doesn’t stand out with super resolution or fun bass slam, it’s more for a natural non fatigue enjoyment of the sound.
By the nature of Penta tuning, don’t expect surgically separated layering of the sound with air in between, but you certainly should expect a distinct separation of vocals and instruments with the sound never getting congested or veil. This particular tuning is intended for enjoying the music rather than analyzing its micro details.
Soundstage had a very good width and depth expansion, not exactly on 3D holographic level, but it creates a natural space with a convincing positioning of instruments and vocals. You can easily distinguish and pin-point every sound in space, nothing is exaggerated.
Low end has a deep sub-bass rumble with a smooth analog texture that adds a fuller body weight under the mid-bass punch which has slightly above average speed/decay, not quite as fast as BA performance, but a little faster than average dynamic driver. The bass sounds natural and realistic, not super tight or very articulate, but with a very good control for a dynamic driver, without spilling into lower mids.
Lower mids are neutral and with a good amount of natural body which adds to an overall sound characteristics without adding too much to the thickness of the sound. It also creates a nice coherent transition from bass to mids, unlike some hybrids where you can hear a disconnect between DD and BAs. Upper mids have a good level of detail retrieval and natural resolution, never getting bright or thin. The lift around 2kHz is well executed and helps with clarity. It especially shines when it comes to vocals, both male and female, you can hear a very natural, organic, clear tonality.
Treble has a good extension, decent definition, modest amount of airiness and sparkle, not too much, just a moderate amount without going over the top. You are not going to miss the details of your crash cymbals, but the sparkle and the sizzle will be smoother. This makes the sound non-fatigue, without a single hint of sibilance, great for an extended enjoyable natural listening.
Once you get into listening, sometimes you just forget this is a hybrid IEMs with DD and 4BAs, because tuning is very coherent, with all drivers working in a balanced natural unison.