Begun, the planar IEM wars have! That's what a certain fictional Jedi Master would have probably said had he seen what's happening here. I knew this was coming the minute the 7Hz Timeless became a raging success in the IEM world, and such is the nature of R&D in ChiFi audio that a successfully adopted new driver simply won't withstand any exclusivity contracts. Both the OEM behind the driver and new clients will find ways to change things just enough for it to classify as a new driver, which has thus far led to four such entries using the new 14.x mm planar magnetic drivers, where "x" seems to range from 2–7 mm. The various implementations are different takes on the U-shaped tuning, and mostly well balanced and tuned out of the box. The general theme is to go with a full-range implementation across the entire usable frequency range that is then given a unique take courtesy a different closed-back shell paired with accessories. So when Raptgo came out of nowhere with a product that is not only an open-back set, but one using a novel piezoelectric hybrid driver combination as well, it was already asking to be heavily considered.

At $239, the Raptgo Hook-X is the most expensive of these new IEMs that are finally making a good case for planar magnetic drivers to be used and tried out. I think it's no secret that I am a fan of planar drivers in headphones, and the more good entries we get in IEMs the better it is for those who prefer this form factor. With the Hook-X, you do arguably get better accessories for the money, including a modular cable and multiple Spinfit-style ear tips which all seem to have been developed in conjunction with the IEM shells and acoustic chamber inside. It's a cohesive system that comes together for a distinctive experience of good bass with an enhanced sense of space throughout, as well as the best overall treble response execution out of the various new planar IEMs. The PZT driver adds icing on the top of this cake, but be warned that a good fit may result in sharp resonance if you are sensitive to it. While I am complaining, I wasn't happy to see the noticeable channel imbalance in the upper mids, although this is clearly a case of driver matching, so your mileage may vary.

Ultimately, there is plenty to like here, as listed out. The Raptgo Hook-X is a safe set at $240 that makes a strong case for itself even considering the much wider IEM market as a whole, purely with its design and driver implementation. I have yet to come across other PZT driver IEMs, and certainly finding one which uses PZT drivers for bone conduction to add a certain je ne sais quoi will be even harder. This is a set that adapts well to many different music genres, though it would work well for an online call, too. You can even wear it outside and have a better awareness of your surroundings without letting it affect your listening experience much, and the bass response is tuned with the open-back shells in mind to where taping off the grille makes the experience noticeably worse. This is not just another re-branded set using off-the-shelf parts. Instead, it is an exercise of an established OEM showing what it can do on its own. So while there are some potential issues, and there will no doubt be other contenders coming up in the coming weeks and months, the Raptgo Hook-X has done enough to overthrow the 7Hz Timeless as my best overall planar IEM pick in the current market.