NAD M17 & M27 Masters Series Surround Separates Review Highlights

Starting with the M2 Direct Digital Amplifier in 2009, NAD has become one of the most progressive manufacturers of digital amplifiers. Its DAC architecture simplifies the signal path using a hybrid technology that brings error correction to new levels. The latest addition to the Masters Series, the M17 Surround Processor and M27 Seven-channel Power Amplifier brings this development into the home theater. The M17 offers support for all major audio codecs, a fully balanced signal path, and an upgradeable HDMI module. The M27 packs seven channels into a relatively small lightweight chassis while still cranking out 180 watts-per-channel and is also fully balanced.

NAD M17 & M27 Masters Series Surround Separates Review

NAD M17 & M27 Masters Series Surround Separates Highlights Summary

  • High-end construction and build quality
  • Can play to extreme volumes without issue
  • Super-clean and detailed sound
  • Carved-from-billet monolithic design
  • NAD-specific Audyssey and EARS surround modes
  • Fully balanced signal path

Introduction to the NAD M17 & M27 Masters Series Surround Separates Review

Back in 2009, NAD introduced the M2 Direct Digital Amplifier and by doing so, brought forth a whole new concept in amplifier design. That product eliminated the digital-to-analog conversion instead using noise-shaped error correction to reduce distortion and create a signal path free from jitter.


M17 Surround Processor

  • Design: Seven-channel Preamp/Processor (Pre-Pro)
  • Codecs: All, Including Dolby TrueHD and DTS-HD Master Audio
  • MFR: 20 Hz – 20 kHz, ± 3 dB
  • THD+N: 0.005%
  • Input Sensitivity: 40 mV
  • Signal to Noise Ratio: >90 dB (A-weighted)
  • Output Level: >2 Vrms
  • Dimensions: 6.4″ H x 17.1″ W x 15.25″ D
  • Weight: 24 Pounds
  • MSRP: $5,499 USD

M27 Seven-channel Power Amplifier

  • Power Output: 7 x 180 watts (4/8 Ohms, 20-20,000 Hz, at Rated Distortion)
  • MFR:  3 Hz – 100 kHz, ± 2.5 dB
  • THD+N: 0.005%
  • Dimensions: 6.2″ H x 17.1″ W x 15″ D
  • Weight: 31 Pounds
  • MSRP: $3,999 USD
  • NAD
  • SECRETS Tags: NAD, NAD M17, NAD M27, Surround Separates, 2014 Surround Sound Reviews, 7-channel Surround Sound

As it has developed digital amplifier technology, NAD has turned to a self-oscillating Class D design from the Dutch company Hypex. I first saw this in the D 3020 desktop amp  and was astounded at how loudly and clearly it could drive my large 4-Ohm Axiom towers. I couldn’t help but think this could be a really good thing when applied to a surround system.

Not bothering with something as “me-too” as a receiver, NAD has gone straight to separates with new additions to the Masters Series. Today I’m checking out the M17 Surround Processor and its companion M27 Seven-channel Power Amplifier. With exotic features like a balanced signal path and a front-panel touch-screen, these boxes can easily anchor a high-end theater and drive any speakers you choose to connect. And they do it all without being large or heavy. Let’s take a look.


Design of the M17 Surround Processor

NAD M17 & M27 Masters Series Surround Separates Review

The M17 Surround Processor is one of the most minimalist designs I’ve ever seen. The only mechanical control is a volume knob which moves with silky-smooth precision. If you’re looking for the power button, you’ll find it masquerading as a small touch-key on the top edge of the front panel.

The rest of the chassis is made from aluminum and steel in both stamped and cast forms. It’s a unique look with natural and gray shades and softly rounded corners. The NAD logo on the left front glows a warm orange in standby and white when the power is on. The feet can be used two ways. By default, they are solid-metal spikes but if you don’t want to mar your shelving, magnetic discs with rubber bottoms can be attached. You still get the effect of the spikes without damaging the furniture.

A large screen dominates the front. It’s color-capable although only the startup screen shown in the photo actually contains color. In operation it shows the source and volume level in large text and other information in smaller fonts across the bottom. It doubles as a touch-screen if you want to set options without the remote.

NAD M17 & M27 Masters Series Surround Separates Review

Around back you’ll find every kind of connection imaginable. For an all-digital user like myself, there are six HDMI inputs and two outputs. The outputs will only display a single stream and operate simultaneously. You also get four coax and four TOSLink inputs along with two outputs each. If you’re wondering about the LAN port, it’s only for control by NAD’s AVR Remote App. There is no support for AirPlay or other streaming functions.

Even though analog components are becoming rare in the world of home theater, the M17 accommodates pretty much anything you’d care to connect. There are seven stereo inputs, along with two component video and two composite video. There are enough outputs to send signals to four zones; all of which can be managed in the processor’s menu. If you’re looking for multi-channel inputs, you won’t find them here.

Control options are equally extensive with Ethernet, RS-232, and four IR inputs. There are also three 12v trigger outputs and one input.

For connection to the power amp, you get both RCA and XLR connectors. The XLRs output two volts continuous and up to seven volts peak. They are also fully balanced which places the M17 in extremely rarified territory. It’s also the least-expensive balanced processor I know of at present.

Video support comes in the form of the aforementioned six HDMI inputs plus two each of component and composite video. Analog sources can be transcoded to the HDMI outputs for a single connection to your displays. The HDMI module will pass 3D and 4K signals and can be upgraded to HDMI 2.0 in the future. The M17 performs no video processing on the signal aside from overlaying the OSD.

On the digital audio side, both Dolby and DTS lossless codecs are supported. The M17 will also accept DSD but the front panel still says PCM when playing SACDs. Room correction is covered by Audyssey MultEQ XT and includes a calibrated microphone. In my opinion, a product at this price should include the latest XT32 version of Audyssey but NAD does throw in its own flavor of Audyssey along with NAD EARS, a proprietary surround mode.

NAD M17 & M27 Masters Series Surround Separates Review

The M17 includes two remotes – a large metal wand and a small palm-sized unit for Zone 2 functions. The metal handset is one of the most handsome and sleek units I’ve seen. It’s fully backlit and includes a sensor so it won’t light up unless your room is dark. You can program it to control eight additional components through a learning function, and you can load code libraries for other NAD products. It also supports macros and punch-through commands. Once you’ve handled it, you’ll want to make it your main controller; I know I did!

NAD M17 & M27 Masters Series Surround Separates Review

The photo above shows the magnetic feet and solid aluminum USB thumb drives that are packaged with both components. You don’t get a printed manual, only a setup guide. But the full documentation is included on the drive. The feet are there in case you don’t want the spikes to mar your furniture. They’re solid metal and have rubber bottoms.

To keep up with the ever-changing landscape of digital sound, NAD incorporates internal upgrade capability into many of its components including the M17. Masters Series dealers can replace any internal circuit board to add things like HDMI 2.0 and the like. At the time of this writing, a new module is in the works that supports BluOS from Bluesound. This will add multi-room wireless streaming to any Bluesound compatible speaker or amplifier. It’s a great way to pipe your hi-res tunes around the house with minimal installation effort.


Design of the M27 Seven-channel Amplifier

NAD M17 & M27 Masters Series Surround Separates Review

I remember a scene in The Matrix when Morpheus says, “Some rules can be bent. Others can be broken.” Obviously someone at NAD took that to heart when they conceived the M27. We all know the rule that states, “Power amplifiers must be large and heavy.” When the box arrived on my doorstep, I grabbed it expecting difficulty and back pain to ensue only to find it weighed far less than the usual 75-100 pounds. It is in fact only 31 pounds in weight which is barely more than the average receiver.

The chassis complements the M17 perfectly with a nice combination of natural aluminum and gray panels. There are no status lights in front; only a border around the NAD logo that glows orange in standby and white in operation. Like the M17, there’s a touch sensitive power button at the top center of the front panel. The feet are just like the M17’s, spikes with an option to attach magnetic rubberized discs that are more furniture-friendly.

Ventilation is prodigious on top with 12 large grill openings. I can tell you though, after a two-hour AC/DC concert video that I played really loud, the heat level was incredibly low.

NAD M17 & M27 Masters Series Surround Separates Review

On the back are beefy five-way binding posts plus RCA and XLR inputs for each of the seven channels. Choose your connection type with a small selector switch. The front panel light can be dimmed with a tinny toggle above the power switch. There’s also a 12v trigger input so the M27 will awaken on when the M17 is turned on.

NAD’s Amp Technology

Since the introduction of the M2 integrated amp in 2009, NAD has continued to develop its digital technology in the D 1050, 3020, and 7050 hybrid amps; and even the VISO iPod dock. The M27 Seven-channel Amplifier represents the latest chapter in NAD’s unique approach to Class D topology.

We all know by now that Class D’s chief advantage is its efficiency. More-common Class AB units shed a lot of heat as they do their thing but Class D uses almost all of the available current to amplify the signal and therefore runs much cooler while drawing less power. Where Class D designs have lagged is in their management of negative feedback and its effect on distortion. NAD actually embraces that feedback and uses it to reduce noise, increase the damping factor, and linearize frequency response.

Last year, we saw Hypex’s UcD modules used in the D 3020 (review link). The new M27 and M22 (two-channel) amps use nCore, which improves the modulator component for more accurate feedback subtraction and pulse-width modulation generation. The net effect is a far cleaner and grain-free delivery than typical Class D amps based on the Bang & Olufsen modules.

The entire signal path is designed for the lowest possible impedance. Even the speaker protection relays have been eliminated in favor of an electronic solution that shields your transducers from accidental overloads. The forward signal path is free of capacitors and the amplifier is DC-coupled from input to output.

All of this, along with the balanced topology, results in extremely low distortion, low signal-to-noise-ratio, and a virtually inaudible noise floor.


Setup of the NAD M17 & M27 Masters Series Surround Separates

If you’ve installed a receiver, a surround processor is no different. NAD’s setup menu is called up via the remote and you can set your source, speaker, and listening mode options using a simple text-based system. My only complaint here is that in order to see the OSD, you must connect a display. Even though the M17 has a large touchscreen, it won’t show you the menus.

First up however are the cable connections. I only used a single source, an Oppo BDP-93, but hooked it up via HDMI and coax. I like to use S/PDIF when listening to Redbook audio because it’s much lower in jitter than an HDMI connection. I finished the wiring using Blue Jeans XLR cables between the M17 and M27. And don’t forget to set the M27’s input switches to the appropriate input before plugging in the grounded power cord.

My speakers are all-Axiom – LFR1100 mains, VP180 center, and QS8 surrounds, plus an EP800 subwoofer. The LFRs require two channels of amplification so I was able to use all seven channels of the M27. Their signals are managed by Axiom’s proprietary DSP module which is connected between the processor and amp for the main channels only.

Configuring sources is very simple. Each input is numbered and can utilize any of the rear panel connections. You just have to specify which input and output to use for analog and digital signals; then choose a name. In my case, I set up two sources to correspond to the HDMI and S/PIDIF connections from my disc player. I prefer this method to having the inputs named for me.

If you want to set up the speakers manually, just enter distances, sizes, and crossovers in the Speaker Setup menu. To play the test tones, press “Test” on the remote and dial in your channel levels with an SPL meter.

To use the Audyssey MultEQ as I did, plug the supplied microphone into the left channel of the Audio 1 input and choose Audyssey Auto Calibration from the menu. You can measure up to eight locations before running the calculation routine. Once complete, the levels, crossovers, and distances can be altered if you wish. EQ options are Audyssey, NAD, and Flat. I found the Audyssey curve better for movies and concert videos while NAD’s configuration was superior for music.

You also get Audyssey’s Dynamic EQ and Dynamic Volume. These are designed to optimize sound when the volume level is below reference. I found that regardless of how loud or soft I played the M17/M27 combo, they were best left off.

Now that we have a heartbeat, it’s time to do some watching and listening!


The NAD M17 & M27 Masters Series Surround Separates In Use

After listening to a few preliminary clips, I felt the best setup was to use Audyssey with film content and no EQ with music. NAD has included its own response curve which can be called up via the remote. It worked well at smoothing room modes in all content and sounded fine for music but I preferred the standard curve for movies. During my music listening sessions, I ultimately enjoyed the M17/M27 combo with no EQ at all.

NAD M17 & M27 Masters Series Surround Separates Review

Normally I use very familiar material for audio reviews but for my first selection I broke with tradition and dropped the AC/DC Live At Donington Blu-ray in the player. I’ve only watched it once before and it’s been a few years. This group is best experienced loud so I cranked the volume up to just shy of deafening. The Masters Series combo delivered a super-detailed and super-clean presentation with every instrument and crowd sound intact. And I don’t believe I had ever understood Brian Johnson’s screaming vocals so well!

NAD M17 & M27 Masters Series Surround Separates Review

I followed with a few of my favorite movies on Blu-ray; Transformers: Revenge of the Fallen was up first. I like to use the opening scenes of this film to demo my theater to friends because it’s pretty much non-stop bombastic. Picking out dialog among all the aural chaos can be pretty difficult but the M17/M27 combo handled every element with care and refinement. The frequency balance was ensured by Audyssey but there was no trace of the muddiness that EQ can sometimes impart. In fact, I was able to enjoy it at a more moderate volume level because even the most subtle details were highlighted with ease.

The Ten Commandments is nearly 60 years old now and the 2013 Blu-ray release does a superb job with its vintage monaural soundtrack. Little details like the clink of Nefretiri’s jewelry or the swish of Rameses’ robes are beautifully brought out. The dialog, which can sometimes sound chesty in old films, was rendered without any trace of harshness and in perfect clarity. The lush musical score which plays almost constantly throughout the film sounded super-clean and thoroughly modern; an amazing feat considering the orchestra was likely recorded with a single microphone.

To test the noise floor of the M17/M27 combo, I could think of no better film than Gravity. The opening sequence (before the mayhem begins) is solely made up of radio dialog between the two astronauts and mission control. The voices are compressed as they should be but the sound designer has done a masterful job of placing them in the appropriate part of the surround envelope to make the scene seem more immersive. The blackness of space was beautifully rendered by the perfect silence between phrases. The noise floor here is just as black as the star-field on my projector. And when someone spoke, the superb channel separation told me exactly where that person was.

NAD M17 & M27 Masters Series Surround Separates Review

Moving on to music, I again turned to the unfamiliar. I had just received Metallica’s Kill ‘em All in the mail and was anxious to hear some of their early material. Like all their albums, it’s mixed with compressed dynamics and little in the way of care or refinement. Despite less-than-stellar material, I was able to hear the instruments clearly separated, even during the heaviest guitar distortion. James Hetfield’s vocals were also nice and crisp though much younger-sounding then they are today.

Next I went for a little slide guitar with Led Zeppelin’s In My Time of Dying from Physical Graffiti. Listening to Jimmy Page is always a pleasure and I just loved how I could hear every pick attack and every part of every chord no matter how chaotic the music became.

NAD M17 & M27 Masters Series Surround Separates Review

Turning to the classics, I discovered what these new Masters Series separates are truly best at. From the opening trumpet solo in Mahler’s Fifth Symphony, I was transported not just to the concert hall but the lush German countryside that Mahler saw outside his cottage when he wrote the symphony in the summers of 1901 and 1902. I can see new owners of these components becoming inspired to buy multi-channel SACDs because high-res and surround is truly something special and the M17/M27 combo exploits that technology to the fullest.

Moving on to Shostakovich, I went for the Kirov Orchestra on SACD and their performance of the neo-classical Ninth Symphony. This work is almost chamber-like and therefore benefits from clear instrument separation and delineation of individual parts. I had no problems hearing the finest details in the bassoon cadenzas that are featured in the fourth movement. When the brass section was called on to shine, I felt as though their bells were right in front of me.

I finished up with a 2-channel Redbook CD of Dvorak’s New World Symphony. To get the most out of a recording with merely average fidelity and resolution, I engaged the Enhanced Stereo mode. This seemed to provide the widest soundstage and the most lively presentation. My second-favorite surround mode was NAD’s EARS. It has a good deal more presence than the usual Dolby Pro Logic and DTS NEO:6 programs. I was also able to enjoy the quietest sections more thanks to the supremely-low noise floor and rich dynamics that extended down to the most subtle details.

My takeaway from several extended listening and viewing sessions is that the best way to enjoy the M17/M27 combo is to use Audyssey EQ for film (mainly for its control of the deepest bass) and no EQ for music. Surround recordings are simply magical on this system and once you’ve explored the high levels of refinement available, you’ll want to upgrade all your music to high-res formats.


Conclusions about the NAD M17 & M27 Masters Series Surround Separates

NAD M17 & M27 Masters Series Surround Separates Review


  • Super-refined sound that’s never harsh or edgy
  • Full support for common audio codecs
  • Fantastic remote
  • Beautiful modern design


  • No AirPlay or network streaming features though a Bluesound upgrade is in the works

As you can see, there isn’t really anything to dislike about the M17 & M27. Considering the technology and quality, the price doesn’t seem out of line when compared to other high-end components. That being said, I still look forward to the day when audio this good comes in a less-expensive form.

You’ll notice I haven’t said much about Class D vs Class AB. Many writers talk about the character and nuances of Class D and how they differ from the AB topology that’s so common in receivers and power amps. The fact is, once I started listening to the Masters’ Series, I forgot about all that.

It’s really difficult to say that any particular surround separates are better or worse than another. There are so few choices available that no manufacturer is going to put out a bad product. Differences in usability certainly exist but as far as sound quality goes, it comes down to what kind of character you want. My regular setup is an Integra 80.1 processor and Emotiva XPA amplifiers. They are clean, loud, and detailed. They remind me of a well-oiled machine that cranks out sound without protest.

The NAD combo is more like an experienced craftsman who personally and painstakingly labors over every note of music before gently releasing it to the speakers. It’s not to say that the M17/M27 combo is polite. If you want loud, you can split your eardrums without difficulty. And the M27’s heat level will barely rise above room temperature while doing it. It’s just that there’s a refinement, sweetness, and accuracy present that I haven’t heard in other Class D products.

In the simplest language, the combo sounds amazing no matter what the volume level. There’s no sweet spot; it’s just sweet no matter what. If you’re looking for high-end theater separates, you’d do well to audition the M17 Processor and M27 Amplifier. I greatly enjoyed my time with them and give them my highest recommendation.