October 2023

World Premiere Review!
Coherent Audio Trim Tens Floorstanding Loudspeaker Review
Shining a spotlight on the music.
Review By Paul Schumann

  After my first year of college, I inherited my Dad's Dynaco ST-70 amp and PAS preamp. The Jensen drivers in the speakers he built before I was born had fallen apart and he wanted a simpler system to listen to music. Over the summer I worked at a sandwich shop and saved my money to buy a new pair of speakers. When I finally socked away enough dough, I went to the audio salon I had been haunting for nearly a year. Surprised I was going to actually buy something, I got the royal treatment.

Looking back, I'm amazed at the wide variety of transducers I listened to that day. I'm not going to drop any names, but a lot of famous early 1980s speakers were in the shop at that time. They also had a pair of well-known horns hooked up to a receiver, which, to be frank, sounded awful. I ended up buying a pair of speakers made by a company no longer in existence, ADS L620s. Those L620s were with me through undergrad, graduate school, and the early years of my marriage. But did I miss out on an opportunity?

Unlike regular acoustic suspension speakers, high-efficiency horn loudspeakers live off that all-important first watt. If that first watt isn't the best, then things can get pretty nasty. Hooking them up with a solid-state receiver of that vintage with all that negative feedback was not a great way to show them off. High-efficiency speakers love highly refined low-powered amplifiers. In my opinion, single-ended triode amps work the best. But they didn't even sell tube amps at that store. Shoot, you couldn't buy a new tube amp in the city then. It's too bad I couldn't have listened to them under better conditions. But the time wasn't right for that to happen.

If you had told me back then, forty years later, I'd be reviewing audio equipment and have the opportunity to listen to all of this amazing gear, I would have pinched myself. Nowadays, there are loads of sublime low-powered amps and high-efficiency speakers to pair them with. I'm always on the lookout for new, interesting equipment meeting that criteria, so in 2019 I was intrigued when Rick Becker of Enjoy the Music.com listened to Coherent Audio at the Toronto Audiofest and raved about them. I reached out to Frank of Coherent Audio and we started to make plans for a review of his Trim Tens floorstanding loudspeakers.

Then the giant monkey wrench called the Pandemic hit and put everything on hold. I lost touch with Frank after that. Then this summer, Coherent Audio somehow bubbled back up my consciousness, found my old emails, and sent a fresh inquiry. Frank was delighted to hear from me after all that time and told me he had a pair of Trim Tens his distributor could send me. Two weeks later, two tall boxes arrived at my front doorstep.

Unfortunately, when I slid them out, I discovered that one of the drivers had broken loose due to some rough handling by the shipping company. Frank was able to talk me through reattaching the driver and in one afternoon I was able to get it back up and running. I guess I can now add speaker repair to my resume.

So what is it about Coherent Audio that interested me in the first place? As I mentioned, all of the speakers Frank makes are high-efficiency and have a nominal impedance of 8 Ohms. This makes them easy to drive with low-powered amps. The Trim Ten is rated at 94 dB/1W/1m and I was able to easily drive it with my three Watts per channel Mullard 3-3 amplifier. In addition to this, all of the Coherent Audio utilizes Radian dual-concentric drivers. Properly designed dual-concentric can come close to that mythical point-source driver. These drivers are designed to be used for pro audio, but Frank has unleashed their potential by hooking them up to their exclusive XD crossover. This crossover is minimalist in the number of parts utilized and this lack of complexity allows the drivers to be more revealing.

Coherent Audio's Trim Tens floorstanding loudspeaker uses 10" Radian drivers with ferrite magnets. In the middle of these drivers are 1.75" aluminum dome tweeters with a waveguide. To extend the high-frequencies, Frank has added a 150kHz Piezo Super Tweeter. All of the wiring is 16-guage Duelund tinned copper and crossovers utilize Coherent Audio's custom-wound coil and Mundorf Supreme classic caps. Supreme Silver Oil caps are also available in an upgrade. The boxes themselves are rear-ported and made of particle composite board with a mahogany veneer. I found them quite attractive and felt they upgraded the look of my living room.

I'm going to have to admit to something. My reviewing technique is pretty haphazard. I just like to have music on while I do other things. If something catches my ear, I will stop and pay closer attention. I know it's not very scientific, but it's how I roll. It adds a sense of mystery and discovery to the process. One of the records I had a moment with was the Lyrita recording of Vaughn Williams's Piano Concerto and John Foulds's Dynamic Triptych. I don't know what those Lyrita audio engineers had for breakfast that day, but they were on their game.

The vinyl of this album does such a great job of conveying the power of the symphony orchestra it startles me every time I listen to it. With the Trim Tens, the power and majesty were taken to the next level. The Sforzandos in both works were handled with such aplomb, I never heard any strain. Additionally, the Trim Tens did an excellent job of rendering the authority of the concert and piano.

A lot of movie soundtracks don't sound the best on a high-end audio system. Many have been compressed to sound good, yet be unobtrusive in a movie theater. An exception to this is Hans Zimmer's soundtrack for The Thin Red Line. The CD I have of this was encoded in HDCD format, which was gaining popularity until Sony's proprietary SACD format was introduced. Luckily, my Linn CD player decodes HDCD and the results can be quite stunning. This soundtrack not only utilizes a symphony orchestra but also gongs, Tibetan bells, and two choirs. Throughout the entire album, the strings sounded sweet and never harsh. The track The Lagoon is a real test of the bass of any audio system with its opening gongs and the striking of various bells.

With the Coherent Audio Trim Tens floorstanding loudspeakers, I felt those gong strikes in my chest. "Journey Into The Line" starts with pulsating woodwinds, which are accompanied by string players bouncing their bows to sound like a clock ticking off the seconds in PPP (triple pianissimo). This is where the Coherent Audio Trim Tens shine. Their ability to resolve this level of detail at such a low volume is remarkable.

I know what some of you are thinking, sure the Trim Tens sound good with classical music, but do they rock? Sometimes to get myself moving when I am preparing dinner, I'll put on something a little more energetic. On one of those occasions, I dropped the needle on Who's Next. Before I could even leave the living room, I was sucked in by Keith's over-the-top drums and stopped in my tracks. Then my head started involuntarily bobbing as John joined him on bass.

Sure enough, as soon as Pete's power chords chimed in, I was wind-milling to my air guitar. That last action made me realize that my rotator cuffs weren't what they used to be and I wondered how Pete had done it for all those years. No matter, I stood there and continued to rock out until the first side was over. I started playing the second side and reluctantly slunk back into the kitchen. I did sneak into the living room a few more times, but dinner wasn't going to make itself. Even rockers gotta eat!

Another rock ‘n' roll moment that took me aback was when I put on R.E.M.'s Murmur. With the Coherent Audio Trim Tens floorstanding loudspeakers I was feeling down that day. One of my cures for the blues is to put on one of those Athens, GA bands. After grooving to "Radio Free Europe" and "Pilgrimage", the song "Laughing" started and I was jarred by Bill Berry's rimshots. I had listened to that record dozens of times and never experienced that before.

I could continue to give you examples of how the Coherent Audio Trim Tens speakers impressed me while they resided in my living room. No matter what music I played through them, they never sounded stressed or strained. Dynamic nuances shined through and musical details were revealed without etching. The bass was deep and powerful, mids smooth, and highs extended. They reproduce properly reproduce the tonality of instruments and the human voice. They do all this, with just a few watts.

But here's my caveat. Coherent Audio's Trim Tens floorstanding loudspeakers are very revealing. If you power them with less-than-sublime amplification, you might be disappointed. This doesn't mean you have to spend megabucks on an amplifier. There are lots of nice low-Wattage amps out there that fit the bill without breaking the bank. If you are willing to go the extra mile, the Coherent Audio Trim Tens floorstanding loudspeakers will reward you for your effort. Then your system will be able to shine a spotlight on your favorite music.

Specifications
Type: Dual-concentric floorstanding loudspeaker
Frequency Response: 30Hz to 20kHz (+/-3dB) 
Up to 150 kHz with Super Tweeter
Sensitivity: 94dB/W/m
Nominal Impedance: 8 Ohms
Connectivity: Five-way loudspeaker wire binding posts
Dimensions: 14" x 13.5" x 36" (WxDxH)
Price: $6599 in Tiger Maple or Mahogany Figured, add $260 for other veneers.

Company Information
Coherent Loudspeakers
Voice: (905) 518-1240
E-mail: coherentspeakers@gmail.com  
Website: https://www.coherentspeakers.net