This is going to be a long initial review. I just received my first set of Custom Molded In Ear Monitors from Alclair. I went with the Spire 6drivers. I did alot research on which company to go with and narrowed it down to 64Audio and Alclair. Having read amazing reviews of Alclair's Customer Service I decided to go with them. Alclair have 2 things over 64Audio, lower pricing and No gimmicky marketing. Although I have 0 experience with 64Audio. Maybe their fancy technology is audibly superior to other IEM manufacturers. I went with the Spires over the CMVK because I didn't want a Bass heavy IEM because I do sing background vocals and hoping to sing lead on some songs in the future. I was hoping to get the perfect IEM for me the first try and never feel like I want to upgrade. And boy did Alclair deliver. Some Background: Im a Hobby bass player in 2 gigging bands. Most venues we play have house sound and engineer, but occasionally we bring our own. Im the only member in both bands that sometimes uses IEMs, all other members use wedges. I'm tired of having monitor issues and damaging my hearing with loudness wars over our guitarists and drummers, so I moved to IEMs. Ive been using Westone UM30s on and off for 2 years. They are great entry IEMs but I could never get them to fit comfortably AND stay seated in my Ears throughout a gig. They would often pop out, mostly because I move around alot on stage. I typically go DI out of my Amp or DI out of my Two Notes Cab M on my board, to FOH. I have a wired Behringer P1 Headphone amp mounted to my board with a 3.5mm extension cable taped to my Instruments cable. 1 input from Console, 1 input directly off my Cab M or preamp pedal(Mesa Subway orDG B7KU v2). This config gives me easy access to turn up my bass in my Monitor mix without Asking the Engineer, if need be. Although many sound guys have been good/great and didn't need to blend in my board bass. Initial Impressions of the Alclair Spires: The packaging and presentation is excellent. Everything feels premium. They come in a nice leather case with a great detachable cable. I opted for the optional Plastic hard case for gigging, but honestly probably don't need it. I got them in Transparent Red with my initials in White on the shells. Fit and Sound: I was worried that my Audiologist impressions wouldn't be a good fit because she didn't use a bite block, which I now know is recommended. Alclair asks if a Bite Block was used during the impressions. First time putting them in I know these would be a Massive upgrade over my Universal Westones. They fit great. They stay seated in my ear while moving around. No discomfort, no fatigue, etc.. The first track I played through these IEMs was Pneuma-Tool. The soundstage was shocking. I didn't expect such great soundstage and instrument separation from IEMs. They rival my Sennheiser HD650s and Hifiman HE560s Open back headphones. I can easily pinpoint each tracked guitar during this intro. The percussion sounds so good. The bass response is excellent. The low extension and clarity is better than what I expected. I can feel the bass drum of Danny Carey, and his toms have great spacing. The bass is Very present without being overpowering. Mids and highs sound great as well. These dont sound "veiled" and no sibilant frequencies. Overall Im very pleased and impressed with the Alclair Spires. I have yet to use them in a live setting, but I don't foresee any issues with these. Everything about them is a massive upgrade over Westone Universals. If you're on the fence about getting Custom Molded IEMs, I think they are 100% worth it, and don't hesitate to checkout Alclair. Their customer service has been excellent.