Phase Technology dARTS DFS-660-T Speaker System Review

Build Quality
PRICE $48,000 as reviewed

Audyssey MultEQ XT Pro room equalization
Variable-axis soft-dome tweeters on surrounds
All speakers are biamped or triamped
Status LEDs on amplifier are bright and can’t be dimmed
Requires professional installation

When it comes to the evolution of loudspeakers, Phase Technology has an enviable pedigree filled with innovation. The company’s newest dARTS speaker/amp package is a spectacular achievement that mitigates the effects of room acoustics and creates a highly theatrical, intensely musical experience that’s extremely rare.

One day last summer, I found myself grumbling more than usual as I stood staring at 550 pounds of speakers and amps that Phase Technology had shipped to my house. (Actually, because the gravel road I live on is very unfriendly to tractor-trailers, I had to drive to the depot, load a couple of pallets of heavy boxes into two vehicles, drive home, and then unload it all.) The gear makes up the top-of-the-line version of the company’s new, second-generation dARTS system. Unfortunately, dARTS is an unwieldy acronym. It stands for Digital Audio Reference Theater System, which means you’re being redundant if you call something a dARTS system. So from here on, I’m going to refer to it as a dARTS package. (At least dARTS is better than what we would have gotten from the name that the company had originally chosen for the lineup, Superior Home Audio Reference Theater System. Yes, sHARTS.)

The first dARTS packages came out in 2005, and I was fortunate enough to review one of the initial installs of the so-called 525 Custom Box, a 5.1-channel system that cost $17,500 (plus installation). Short version of the review: “If you can afford it, buy it.” Obviously, dARTS packages aren’t cheap. And the one under review here, a 7.2.4-channel package, will set you back more than two-and-a-half times that, at $48,000 for just the hardware. (All dARTS systems are quoted as packages; individual elements are not sold separately.) In case the thought has crossed your mind that dARTS is a do-it-yourself kind of package, it isn’t, so there’ll be installation charges on top of that.

Speaking of installation, Ken Hecht, Phase Technology’s VP of R&D, suspiciously got lost on the two-hour drive from the airport to my place in the woods and didn’t arrive until after I’d unboxed the gear and set most of it up. In fact, I’d almost finished running the extra speaker wires. (Every speaker is either bi- or triamped, a situation I hadn’t pre-wired my home theater for.) But he did arrive eventually, which was good because at that point I had no idea what to do with the amp-end of 23 sets of speaker wires and 13 RCA interconnects.


The whole idea that started Ken’s 15-year-long odyssey of creating dARTS was to design and build a loudspeaker system that would sound the same regardless of the room it was installed in. It took him two years of intense R&D to come up with a solution that sounded awesome, but it was complicated to install and calibrate. After being introduced to a new company called Audyssey and their core technology, MultEQ, Ken reluctantly scrapped what he’d done and signed up Phase Technology as one of the first manufacturers to incorporate MultEQ XT into its products.

It’s About Time
Some readers may be familiar with MultEQ. It has been around for well over 10 years and has shown up in products from a variety of companies besides Phase Technology, including Denon, Marantz, Onkyo, McIntosh, NAD, and IMAX. For those who haven’t got a clue about the who, what, or why of MultEQ, I can describe it in five words: It’s a room equalization technology. Of course, that’s like saying the USS Nimitz is a boat.

MultEQ was designed to solve the same problem that Ken was working on: eliminating (or at least minimizing) the distortion that’s caused by sound reflecting off the various surfaces in the listening environment. Sound bouncing off the walls, ceiling, floor, window treatments, and, heck, even extremely large animals is the most significant reason why speakers and subwoofers sound different in different rooms—and can even sound dramatically different when they’re moved from one spot to another in the same room. A subwoofer placed in a corner will sound noticeably louder than one in the center, away from any walls. There’s more going on, however, than basic changes in frequency response.

The multiple reflections off all those surfaces don’t arrive at your ears at the same time. This gaggle of incoming reflected noises confuses your brain as it tries to figure out where the initial sounds came from. (It’s like playing the Marco Polo game, only with a million Marco Polos.) Nor do these echoes arrive at every seat in the room at the same time, so your perception will change depending on where you sit.


MultEQ is a clever approach to minimizing frequency and time delay issues. In general, it involves three main steps. First, a microphone measures the response in the room at multiple locations. Second, the MultEQ software crunches the numbers. Third, the program automatically creates equalization filters for each speaker. There are quite a few similar technologies that are used by other companies, with varying degrees of success. Like MultEQ, they typically offer different levels of resolution, require a differing number of measurements, or affect varying frequency ranges based on the available processing power in the hardware. MultEQ comes in four flavors that can handle three, six, eight, or—in the case of the MultEQ XT Pro version used in the dARTS packages— up to 32 measurement positions. Audyssey says you start to get diminishing performance returns after 12 measurement points in most average-size rooms, and that’s the number of measurements we took when it came time to calibrate this dARTS package. (That would be the package that I’d done most of the work lugging, unpacking, and installing all by myself. Not that I’m bitter. )

Two for the Sound of One
There are two series within Phase Technology’s new dARTS lineup: the 535 and the 660. The important difference between the two is the size of the room each system is designed for. Regardless of series, every dARTS package is engineered to provide cinema reference level of 105 decibels SPL peak at the main listening seat. The 535 series is for rooms ranging from 2,500 to 8,000 cubic feet, depending on the form factor of the speakers used. The 660 series can nail that 105-dB SPL in rooms as “little” as 5,000 to 18,000 cubic feet. Within each series, there are several mini-series (or packages) that refer to basic variations of loudspeaker configurations. Both the 535 and 660 series have Freestanding, In-Wall, and Custom Box packages (the last for installation behind screens or cloth wall panels). The 660 series also includes a Tower package.

Even though my home theater is only a shoe or two more than 2,300 cubic feet, we decided to go for broke (figuratively and literally) and install a dARTS 660 Tower package that we modified for a 7.2.4 configuration. The speakers included the package’s DFS-660-T towers, DFS-660-C center, and, for the rear and back surrounds, 660-SURR on-walls (bipole/dipole switchable). To that, we added two pair of Phase Technology’s DC-660-R coaxial speakers, mounted in the ceiling for the front and rear height channels. Doubling down on the bass, the company swapped out the 660 Tower package’s 12-inch DFS-112 subwoofer and sent two 15-inch DCB-115 SUB units, which is an option for the 660 system.


dARTS Parts
Every dARTS package starts with Phase Technology’s DP4000-IA amplifier/controller. Because it’s outward functionality is strictly as a multichannel amp (the “controller” inside handles the factory-tuning, crossovers, and MultEQ XT Pro filters), it’s totally agnostic as far as which preamp/processor (or A/V receiver with requisite analog pre-outs) you use with it. I used the front end of an Onkyo TX-NR3030 AVR. Nor does it care which sound format you use, be it Dolby Atmos, DTS:X, or Dolby Pro Logic; all the surround processing takes place in your pre/pro. The only limitation is the number of available input channels, which is eight for each DP4000-IA (with your choice of XLR balanced or unbalanced RCA connections). This 7.2.4 Atmos configuration required a total of 12 input channels, including a shared LFE channel that fed both subwoofers through a Y-adapter. So we used two DP4000-IAs.

The DP4000-IA is a beautiful 21-pound beast with a black brushed aluminum enclosure, auto on/off capability, and a 12-volt trigger input and output. Since most dARTS channels are biamped, there are actually 16 Class D switching amplifiers in the box, two for each channel input. Power output is rated at 125 watts per amp into 8 ohms (250 watts into 4 ohms); that’s power output to each driver (or driver grouping in the case of ganged mid/woofer pairs) in a biamped or triamped speaker (all-channels-driven performance is not specified). Along with the 16 speaker-level outputs, each DP4000-IA has a pair of line-level RCA subwoofer outs.

Phase Technology
(855) 663-5600

javanp's picture

Guessing you haven't seen Hacksaw Ridge yet ;) shame you didn't check that out on this system.

Concerning the system itself. I like everything about the DARTS systems but man--that price. Even if my budget was $50,000 for a system I think I'd still find myself questioning if there weren't better options out there for the money--you could put together a very nice Trinnov-based system for the same amount. To have a 7.2.4 based system in the same price range seems a bit audacious.

dommyluc's picture

I always find it refreshing when a reviewer for this magazine is so blown away by the performance of a product that he acts like a kid in a candy store, and also like we all felt the first time we got our hands on a really good audio/video system.
And thank you so much for praising the Dolby Surround upconversion of two-channel music. I, like Mr. Wilkinson, have always found that Dolby Pro-Logic IIx Music Mode does an absolutely phenomenal job of spreading a stereo recording across a multi-channel speaker array. I do not have even close to a dARTS package in my 12' x 20' living room, just 6 very good-sounding BIC Adatto satellites and matching BIC center and a 100-watt sub, along with an Onkyo 110 WPC network receiver. But when I play a great recording, like "Gaucho" by Steely Dan, or "Switched-On Bach 2000" by Wnedy Carlos, or any of the hundreds of other classical CDs I have ripped to my hard drive in WAV format, and use the DPL IIx music processing, people who happen to be here cannot believe that I can get such wonderful sound out of such an inexpensive audio system, and I know that the Dolby has a lot to do with that. It's hard to think that everyone doesn't use it, even with rinky-dink systems like mine. LOL!

pw's picture

Way too expensive and the "pedigree" is just not there..
I guessing that the high price could be folded into you Home Loan..