The CS3.7 is THIEL's newest full-range model. Jim Thiel considers it to be their finest-sounding speaker yet.

Based in Lexington, Kentucky, THIEL Audio has been building high-performance loudspeakers since 1977. Audiophiles around the world know and respect THIEL for their unswerving pursuit of accurate sound reproduction. Their small family of speakers combines rigorous engineering and meticulous craftsmanship inside and out.

The newest member is the model CS3.7, a 3-way full-range floorstanding speaker that replaces the CS3.6, one of the most highly regarded and best-selling high-end loudspeakers of the past 15 years. It was my good fortune to spend two weeks evaluating the CS3.7s in my 2-channel home system. I wish I could have kept them for two months.

Getting started

The CS3.7s replaced a combo of ACI's Sapphire III stand-mounted monitors and Titan powered subwoofer, which I've owned for over 10 years. Standing a few inches under four feet tall and tipping the scales at 91 pounds apiece, the CS3.7s are much larger than the Sapphires. Still, I think few people shopping for true full-range speakers would find their size imposing in a medium-sized or larger room. This particular pair wore a beautiful natural cherry finish.

Placement can make or break any speaker's performance, so I started off playing it safe by positioning the CS3.7s exactly where my Sapphires had resided in my basement listening room. That put them about 8 feet apart, 8 feet from the "sweet spot" in the center of the sofa, and a couple of feet out from the front and side walls. The speakers were "toed in" a bit (angled inward toward the sweet spot). Since the floor is carpeted, I installed the four heavy-duty screw-in floor spikes supplied with each speaker.

This pair of CS3.7s were among the very first produced, with serial numbers 005 and 006. THIEL recommended giving them a minimum of 100 hours of "break-in" before doing any serious listening. Makers of high-quality loudspeakers generally recommend a break-in period ranging from 50 to 400 hours to allow the driver diaphragms to limber up for optimum performance. After connecting them to my system (see details here), I dropped a CD in the tray and set the player on infinite repeat. Since my time with the CS3.7s was limited, I only gave them 20 hours of break-in before first sitting down to listen.

Initial listening impressions

I've been interested in THIEL speakers for years, partly because they consistently receive rave reviews, but also because I've always considered myself a disciple of the "lean and clean" school of music reproduction as opposed to "lush and romantic." I've tried to assemble a system that digs out musical details and presents them with depth and dimensionality. Euphonic sound that "warms" or "pretties up" the music isn't for me; I want to hear everything, warts and all. And that's exactly what the CS3.7s delivered.

Rather than dragging out test CDs or old favorites, I began by playing some discs that had been in heavy rotation during the previous few months. The CS3.7s' sound immediately struck me as detailed, clean, and extraordinarily revealing, with very low distortion. On track after track I heard details that I'd never noticed before.

This open, transparent quality gave me the sense that I was hearing the recording and not the speaker. The CS3.7s didn't impose any perceptible sonic signature on the music the way some speakers do. High-quality discs sounded spectacular, but the limitations of some so-so recordings were more clearly on display than when heard through my Sapphires. An example is the 4-Track Recording Session CD by the Zimbabwean dance band The Green Arrows. This is not a polished recording to begin with, but the stinging electric guitar leads seemed a tad edgier through the THIELs. Of course, the speakers had barely begun the break-in process.

The speakers' sound continued to improve almost on a daily basis. I'm sure part of that perception resulted simply from me getting used to the THIELs' presentation. Several friends and colleagues came over on a few evenings — everyone I mentioned the CS3.7s to wanted to check them out. You'll find more about those sessions on page 3, but before relaying any more listening impressions, I want to touch on the technological and design aspects that distinguish these speakers.