NHTPro A-10 Active Reference Monitors

NHT, well known for its audiophile home speakers, has expanded into the pro-audio market as NHTPro with a line of active reference monitors. Formed in

NHT, well known for its audiophile home speakers, has expanded into the pro-audio market as NHTPro with a line of active reference monitors. Formed in 1998 by Vergence Technology (the same company that started NHT in 1986), NHTPro offers three models: the small (4.5-inch woofer), self-contained M-00 ($375); the top-of-the-line A-20 ($2,000); and the midline A-10 ($1,250), which is reviewed here.

Whereas most active monitors house the power amplifiers and crossover units in the back of one or both cabinets (or in the subwoofer enclosure), the A-10 and A-20 employ external 2U rack-mount amp/crossover units. This approach lets NHTPro provide the benefits of self-powered monitors while sidestepping potential problems caused by having the power amps so close to the speakers. Both the A-10 and A-20 are self-contained monitoring systems, meaning that you cannot use the separate components with other systems.

CONTROL ISSUESThe A-10 control amplifier accepts both balanced and unbalanced inputs on either XLR or 11/44-inch TRS connectors. Although these inputs are wired in parallel, the manufacturer recommends connecting only one type at a time.

The system comes with red, 20-foot XLR cables for connecting the amplifier and speakers. These cables have a lower impedance than standard microphone cables; regular mic cables will fit, but using them would likely impair system performance.

The front panel of the A-10 amp provides three knobs for tailoring the sound to the listening environment. The first, labeled Sensitivity, has five settings-Mute and +11, +4, -3, and -10 dB-to enable gain-matching with a wide variety of equipment.

The second knob, labeled Boundary, allows you to tailor the bass response when the speakers are placed close to walls or other reflective surfaces that can cause bass buildup. There are two settings: the 0 setting is flat, and the 1 setting attenuates 50 Hz by 3 dB, affecting frequencies up to around 150 Hz.

Last, the Position knob has two settings, NF (near-field) and MF (mid-field). NF, which attenuates 20 kHz by 2.5 dB with no effect on frequencies below 3 kHz, is recommended for listening positions less than one meter from the speakers. MF, designed for positions more than one meter away, is flat.

ODD COUPLEThe A-10 speaker cabinets have a unique, asymmetrical shape with dedicated left and right units. The shape simplifies orientation of the speakers for optimal monitoring: when the backs of the cabinets are perpendicular to the listener (that is, parallel to the rear wall), the speakers are angled in properly toward the listener (when he or she is sitting in the sweet spot). A green LED indicates that the control amplifier is turned on and-a nice touch-that the system is correctly wired.

Even though the power amp is separate from the cabinets, the A-10s are still quite heavy-comparable, in fact, to powered monitors that contain their amplifiers. Evidently, the designers, free of the constraint of having to fit everything into the cabinets, were able to focus on optimizing the sound quality of the speaker housings. As a result, the cabinets seem tighter and more durable overall than many self-contained active monitors. This is reflected in the sound quality of the A-10s-although they employ only 6.5-inch woofers, they sound like much larger monitors. And, of course, there is no worrying about stray magnetism or heat from the amp causing sonic or operational artifacts-a proble m in some integrated active monitors.

TIGHT SOUNDThe adjective that best describes my lasting impression of the A-10s is tight-not in a pinched way, but in the sense of being solid and reliable. Although a tad on the bright side, the A-10 speakers are not harsh at all. I used them extensively for a two-month period and never found listening through them fatiguing. Indeed, the brightness might better be described as clarity. At any rate, I quickly came to rely upon the A-10s, whether arranging, sequencing, recording, or mixing.

The frequency response of the A-10s is balanced from 20 kHz down to approximately 75 Hz, with a 2 dB dip down around 55 Hz. Rather than attempting to trick your ears into hearing frequencies lower than is physically possible with a woofer and cabinet of this size, as some monitors do, the A-10s provide a natural-sounding balance of frequencies within the range allowed by physics. (For those of you who need more low-end extension, NHTPro is soon to release a subwoofer to augment the A-10 and A-20 monitor systems.)

Interestingly, at lower monitoring levels, the A-10s evidence a slight lack of presence in the upper mids, between about 1 and 3.5 kHz. However, when you turn them up to moderate or loud levels, the mid range blossoms and balance is restored.

Given their size, the A-10s present a solid soundscape. However, compared with certain larger powered monitors, they sound a bit small. If you consider the analogy of changing pixel resolutions on your computer monitor-everything is there and in the same relationship, only the size is changed-you will get an idea of what I mean. But in this case, the lack of very low frequencies feels appropriate. Were the low lows provided "artificially" (by porting or other design maneuvers), the A-10s' frequency balance and solid imaging might be disrupted. That said, I still would like to hear the A-10s with the proposed subwoofer.

NATURAL SETTINGSBe sure to experiment with the Position knob on the A-10 control amplifier. Unless you are more than five or six feet away from the speakers, I recommend using the NF setting, which sounds less bright than the MF setting. The MF setting could trick you into thinking there are more high frequencies present than there actually are, resulting in mixes that sound dull when played back on other systems. Based on the sonic characteristics of my studio and on my tastes, I ran the amp with the Position knob set to NF (high-frequency reduction) and the Boundary knob set to 0 (maximum bass).

Here's a trick I discovered: if you set up the control amp within reach of your listening position, you can use the Sensitivity knob to switch monitoring levels without disturbing your original control-room setting. This is unorthodox, of course, and technically speaking, it could create distortion or other artifacts. But it did not pose a discernible problem to my ears, and I dug the ease it provided. I ran the input at the +4 dB setting, which allowed me to check the mix at a low level simply by turning the Sensitivity knob to the +11 dB setting. To really crank it up, I switched to the -3 dB setting, and then I could return to my exact original level by switching back to the +4 dB setting . This "feature" would be helpful to anyone who needs to monitor at precise, consistent levels.

LEAN ON METhe more monitors I work with, the better I appreciate the value of monitoring on several systems throughout the tracking and mixing process. When you get a mix to sound great on a variety of monitors, you know you've nailed it. The A-10s seemed to provide an intangible characteristic missing from my array of monitors, and I thoroughly enjoyed working with them.

Would I rely on the A-10s alone for critical work? You bet. Any criticisms of their sound expressed in this review are, in the larger picture, minuscule and ultimately a matter of personal taste. I would have no problem relying on the A-10s for tracking and mixing professional projects.

The only functional drawback of the system is the separate control amplifier, which makes the A-10s perhaps not the best choice for folks whose work requires them to tote their monitors from studio to studio. But if you are staying in one spot, the A-10s may just rock your world. A