Atomic Instrument: SixTen Monitor System

Occasionally, a piece of gear comes along that impresses me enough to reach out to Tape Op and make an effort to write a review. The Atomic SixTens have done just that.

Founded in 2014 by Norman Druce and F. Reid Shippen [Tape Op #125], Atomic Instrument may be best known for their outstanding large-format console replacement power supplies. After Norman and Reid parted ways in 2016, Norman continued building power supplies but also ventured into speaker design; his real passion. Norman designed a few different models, but according to Atomic, the SixTens are by far his best-sounding monitor. Sadly, Norman passed away last fall, but Atomic is thankfully alive and thriving. Atomic's Misty Druce and their chief electrical engineer Bill Horne (who is an incredible talent in his own right) have vowed to keep Norman's vision alive.

I've seen the Atomic badge from time to time on console power supplies, so I'd been familiar with the brand name. But over the past few years, I kept seeing photos of these retro-looking monitors in use at some big studios (Third Man Records [#127] and Electric Ladyland), but also by some of my engineering heroes: Vance Powell [#82], Dan Auerbach [#127], Zach Brown, Craig Alvin [#137], and Bobby Holland, among others. I was definitely intrigued, so when the opportunity came along to get a pair into my room, I jumped.

The first thing I noticed immediately about the SixTens – they are HEAVY! These monitors are passive, and the weight is due to a multi-material design (a cabinet within a cabinet) to render the cabinet inert. The second thing that immediately struck me is the unique and striking appearance. The SixTen was originally designed for Dan Auerbach and Collin Dupuis while producing and recording Lana Del Rey's Ultraviolence. Norman delivered a powerful monitor that was capable of full range and high output in a hip, vintage-looking package – a nod to the beloved Altec 612s. Admittedly these monitors have such a unique appearance – especially sitting next to my traditional-looking Amphions. But, I have actually developed a fondness for them – I do love how they look! The SixTens have a rear-firing 10-inch sub, a 6.5-inch paper cone mid driver, and a ring radiator tweeter developed by Frank Neilson of Scan-Speck fame.

After much heaving and grunting to get these monitors into position, I connected the dedicated (included with purchase) external amp to the monitors via a pair of speakON cables. The amp is a class D design (high power, low distortion), offering a staggering 1240 watts (620 watts per channel)! The SixTens are bi-amped, sending 500 watts per channel to the rear-firing sub and 120 watts per channel to the mid/tweeter drivers. The crossover between the sub and mid drivers is a proprietary hybrid passive and active filter built into the amp, crossing over at 120 Hz. The SixTens use a passive discrete crossover (built into the monitor) between the midrange and tweeter at 2.6 kHz. Years ago, Norman had mentioned to me that the sub-range is generally the limiting factor with headroom, which explains the generous power sent to each sub driver.

As if all of this isn't interesting enough in design, here's where it starts to get cool. There are some control options on the rear of the amp, designed to tailor the sound of the SixTens to your room: Two knobs that control the level of the mid/tweeter drivers for each monitor allowing the user to dial in the amount of mid/tweeter relative to the sub! How cool is that? These monitors are anchored around their ability to deliver pristine sub levels, so the sub is prioritized and remains fixed, soaking up that 500 watts per channel. Want more sub? Dial down the mid/tweeter levels. Want less sub? Turn up those mid/tweeter levels. The other user customization feature is a three-way switch that introduces a slight dip in the mids. You can run the monitors flat or introduce (approximately) a 2 dB or 4 dB dip, centered at about 740 Hz. I chose to run mine flat.

It's important to note that the power amp does have internal fans. I was admittedly critical of that at first, as I have a one-room studio where my gear has to be noise-free. But after placing the amp and firing it up, it wasn't a big deal. The fans utilized are super quiet. I trust Atomic when it comes to power supplies. After all, that's how they built their reputation.

I was diligent with my efforts to place these monitors in their optimized location. For reference, my room is around 17 by 15 feet, and treated using GIK products with acoustician Jeff Hedback guiding the design. Eventually, we settled on a placement around 5.5 feet apart, with the tweeters on the outside firing just behind my head. I also use Dirac Live [#133] room correction software and set it to solely deal with the low frequencies around 350 Hz and below – always problematic for rooms my size.

I found the phantom center to be well defined, with vocals firmly in the middle and a nice 3D stereo image. And that bass! I have always had a hard time sorting out the low end, but it has been such a different experience on these monitors. Round, articulate, and punchy! Sometimes I find many monitors to have a boomy, smeary low end – but not with the SixTens. Tight would be a decent description of the low end here. The top end is also quite nice – not harsh or fatiguing at all. I am pretty sensitive to bright monitors, but I found the SixTens to be extended and smooth in that regard. Reverb trails were easy to distinguish, and EQ moves became fairly obvious. The dynamics of these monitors were responsive, and I did not have any problems in hearing compression settings.

The first word that came to mind when I fired these up was "effortless." I think the power amp has a lot to do with that; high power and low distortion. These monitors handled everything I threw at them with ease. It's hard to describe hearing the limits of a power amp, but I'm feeling the opposite of those limits in the SixTens – effortless, open-sounding, and transparent. I do not hear the sound or character of the cabinets at all, if that makes sense? The monitors seem to disappear, and all that's left is the music – a trait I've found in other monitors of high quality, and I've found here as well.

I wouldn't call the SixTens overly clinical monitors. ATC monitors are described as being super detailed, and I've owned a pair of SCM25As [#101]. The SixTens are not similar, nor do I want them to be. They have enough detail to work but to not get lost in the minutia. Everything feels cohesive and fun to listen to, which is important to me. These monitors are vibey, yet clear, and held up very well at lower listening levels – quite linear in that regard. They maintain their cohesiveness and balance, which is something that other monitors struggle with when operating at low levels.

Atomic does not publish any measurements for these monitors, so I cannot offer any conclusive descriptors in terms of how far up and down the frequency spectrum they reach, or how flat they are, or what their harmonic distortion levels might be. If there is one thing I've learned over the years, it's that monitor choice is highly personal and room dependent. Even if Atomic had specs, the influence of different rooms and ears could all lead to different experiences and conclusions. All I can offer is my experience with them. And that is a very, very positive one.

At $6500, this monitor system is probably going to be out of reach for most home hobbyists. However, if you are in the market for monitors in this price range or higher, I highly recommend an audition. They absolutely can compete with the bigger names. In fact, having owned more expensive monitors than these, I'd even argue that these punch above their price point. The SixTens are one of the best gear purchases I've made in a while, and will not be leaving my studio. One thing that cannot be understated with Atomic is their commitment to customer service. It is simply second to none. That is often a quality lacking in many bigger name brands. During my conversations with Norman, I found him to be equally passionate about his designs and my satisfaction with the results. The same has carried on with Misty and Bill. They were immediately accessible, and went out of their way to make me feel part of the Atomic family; a family I'm glad to have found.