There is no question that the Naim NDX is not an inexpensive network audio player. It will relieve you of $5145 before you even think about any of its optional, performance-enhancing upgrades. Now if you wanted a far more economical option you could buy a Squeezebox and a DAC. These will cost considerably less and will provide the same facilities: playing music off a media server through UPnP, providing a route for internet radio, and converting the digital output from other source components. But will they do it with the same conviction and finesse? The NDX must have something rather special under its hood to warrant that five-grand ticket.
The Digital Age
The NDX is not just a network streamer: it also offers other devices access to its internal 24-bit/192kHz DAC, which is based upon the technology employed in Naim's top-of-the-range external DAC. This is a convenient benefit for anyone who is expanding their digital media capabilities, providing, as it does, three separate S/PDIF inputs. These two transformer-isolated coaxial and one buffered optical will all accept signals at up to 24-bit/192kHz resolution. The UPnP playback is capped at 24-bit/96kHz, however. For the streaming connoisseur who wants the ideal set-up, I would still suggest connecting the NDX to a Naim DAC, the latter powered by an external supply. I use an XPS in my own system but have heard a demonstration at Naim's factory which culminated with both the NDX and DAC being powered by individual 555PS supplies. I was surprised, being a long term subscriber to Naim's philosophies regarding power supplies, to discover that I preferred the system with just the single additional supply powering the DAC, the same arrangement I use at home. I felt the external supply on the NDX contributed little to the performance of the demonstration system.
Having heard the dramatic improvements adding power supplies can make to Naim components, I can only surmise that the company's near legendary attention to detail has diminished the reliance of the NDX on external supplies. Maybe it simply does not guzzle Amperes the way some other equipment does. Or perhaps the circumstances of the demonstration were, on this occasion, masking the differences. The attention to detail aspects of the design comfortably fill an eight-page white paper, available from the company's website, that explains the implementation of the data buffering, galvanic isolation, clock functions, oversampling, filtering, and suchlike that contribute to the performance of the NDX.
The NDX will operate wirelessly 'for convenience' but offers its finest and most reliable performances when connected by wire. As Naim states: "Delivering music over a network is not difficult, but doing it well requires an attention to detail that is still surprisingly rare in today's market." If you are prepared to pay this price for a player that boasts numerous features purely to ensure the pristine transfer of data, along with Naim's legendary exacting retentiveness about the smallest of details, why should attaching it by a length of Cat6 cable pose any problems for the audiophile who wants the finest performance? Using wireless with equipment at this performance level makes absolutely no sense to me.
To stream music from computers and NAS drives units, the NDX uses the well-established UPnP protocol. Naim has written a version of this for its own components, the HDX and UnitiServe, which will conveniently function as UPnP servers. I tested the NDX using these and the more widespread Asset and Twonky servers installed on two NAS drives. I auditioned the NDX in my predominantly Naim active system (a SNAXO 3-6 electronic crossover feeding three NAP 250 power amplifiers driving active DBL loudspeakers) although I also listened to it through a Creek integrated amplifier and a pair of NEAT Petite SX stand-mounts. All the equipment was positioned on Quadraspire Sunoko Vent supports and wired with Chord Company Sarum interconnects and Tellerium Q Ultra Black speaker cables.
The foremost attraction of the NDX, though, is that it combines the traditional Naim temporal conviction with the cosmetic depth and richness that one normally associates with American high-end equipment. I discovered myself making notes about the textural qualities of instruments and voices while listening through it. It effortlessly and consistently distinguished the wiry twang of a Telecaster playing alongside a meatier sounding Les Paul, and was equally forthcoming with the timbral complexity of bows on violins and cello in a string quartet. What is more, it vividly displayed the differing tonalities of modern and ancient horns in orchestral ensembles.
Despite the straightforwardness with which the Naim revealed all these fine distinctions and nuances, there was never any impression of the sound being at all disjointed, chromium-plated, or missing any fluency. This is a problem that frequently befalls hi-fi equipment in its attempts to convey ever more detail. The NDX managed to sound natural and unforced at all times, and made it easy to listen to music that one would never describe as 'easy listening'. Helping it in this respect was a very well balanced frequency response with an explicit but controlled performance, particularly at the extremes of the spectrum. The bass and percussion of Nanci Griffith's It's Just Another Morning were both credibly and naturally presented but the piano and singer's voice were the real coup de grace with not a trace of their digital origins audible. The beauty of Griffith's voice and tone were overwhelmingly authentic, which helped convey the emotion in her vocals and encouraged me to play Late Night Grande Hotel, the rip of the 1991 album from which this track comes, in its entirety. Twice. Throughout there appeared not to be an instrument or voice in the mix that wanted for greater detailing or increased realism. Further enhancing the honesty of the performance was the subtlety of the dynamic gradation that, again, lent the presentation a truly delightful analogue quality. All of this was complemented by a well organized albeit artificial soundstage, which convincingly demonstrated the skills of the producers, Peter van Hooke and Rod Argent.
Dynamics and microdynamics certainly seemed to be a major weapon in the armoury of the NDX. This was perhaps best demonstrated by Terence Trent D'Arby's album, Vibrator, in particular tracks such as Resurrection, which are beautifully produced and engineered, and exemplify extreme dynamic contrast. The NDX, for example, revealed gently struck cymbals playing behind a choir singing forte while TTD screamed into the microphone. The control it exhibited under such circumstances was consistently impressive and, at times, truly remarkable: its ability to reveal detail hidden away in the depths of a mix (especially in combination with the Naim DAC/XPS power supply) in a totally natural fashion with no artificial highlighting was thoroughly rewarding and satisfying.
I mention the Naim DAC and XPS because these already feature in my system and it is natural and always far too tempting − for me to exploit them. However, the NDX is a very capable performer using its internal DAC and analogue output connections and I did most of my listening in this configuration.
While the NDX is a noteworthy performer in hi-fi terms it is even more outstanding in the way in which it conveys music and the emotion within it. Much of this is a result of the Naim's legendary dexterity with timing information and the accuracy with which it conveys ADSR envelopes. This ensures that you hear a performer's phrasing exactly the way they intended you to hear it. This, I feel, is what separates it from other exceptional and often much more expensive − streamers that can match its hi-fi performance but cannot equal its ability to communicate in musical terms. The NDX performs surprisingly well on Internet radio, but is, of course, constrained by the signal that it is receiving. Regardless, Naim and California's Radio Paradise have teamed up to offer a 320kbps AAC feed that demonstrates just how acceptable internet radio quality can be. Its low bit-rate cannot be concealed but the presentation of the NDX somehow ameliorates this deficiency and renders the normally unpalatable far closer to reasonable.
Given a decent source, the bottom end of the NDX displayed quite awe-inspiring power especially through the Naim DAC, which is itself not overly reserved in this respect. This paid dividends with bass lines like that on Money for All on the David Sylvian album Sleepwalkers, and less overtly so on works such as Jose Carreras' Misa Criolla, where it created a truly atmospheric and dramatic portrayal of the recording space.
As I noted at the outset, the Naim NDX is quite an expensive piece of hi-fi machinery... but it is also an invitingly expressive piece of machinery that not only articulates the words a singer uses but also conveys the emotions behind them. It is an astoundingly plausible and persuasive audio player with all manner of vocal music, in particular. In short, it makes listening an experience that is filled with genuine soul and frequently reverie. And that is something that is extremely difficult to quantify and nigh on impossible to put a price on.