Naim's more affordable streaming player gets very close to its pricier NDX, says Andrew Everard – and has the potential to go further

Since the Naim ND5 XS arrived in my system, I seem to have been asked by someone just about every day how it compares with the NDX, to which it plays the role of junior sibling.

After all, the NDX, at a fiver short of £3000, was on the receiving end of a very enthusiastic review in these pages, and the £1950 ND5 XS represents a very worthwhile saving – enough to fund an amplifier good enough to show what it can do, and leave change toward a pair of speakers.

So what exactly is the ND5 XS? Well, it’s a network music player, designed to stream music from a computer or dedicated network attached storage device over a home network, and can also stream internet radio. As the model designation suggests, it’s basically an NDX written slightly smaller scale, and designed to sit alongside the company’s XS series components, which are a step up from the entry-level 5i  products.

The ND5 XS comes in the same slimline casework as the rest of the XS series, making it the better part of 2cm shorter in stature than the NDX – 7cm plays 8.7cm. But that obvious difference aside, there’s little to distinguish the two outwardly, beyond a slightly different rear-panel layout and the replacement of the RS232 connector on the NDX, used for upgrades, with a mini-USB socket for the same function on the newer ND5 XS.

A DAB/FM radio module, factory-fitted, is an option, and like the NDX the ND5 XS can be upgraded with the addition of one of Naim’s external power supplies. The 555PS or more recent XPS units are options, but just released is a new slimline supply , the £1595 XP5 XS.

The ND5 XS can also be connected to Naim’s offboard digital to analogue converter, simply called the DAC, or directly to the digital inputs of the Supernait, and also has conventional analogue outputs – on both RCA phonos and Naim’s preferred locking DIN socket – and a choice of optical and electrical digital inputs, so external sources can be run through its onboard conversion.

In addition there’s a system automation connection, allowing automatic source selection and volume control with suitable Naim amplifiers and preamplifiers, as well as control of other components. This is ‘driven’ by the company’s n-Stream remote ‘app’, running on an iPad, iPhone or iPod Touch.

The ND5 XS will play uncompressed WAV and AIFF (and lossless FLAC) at resolutions up to 192kHz/24-bit, Apple Lossless (ALAC) at up to 96kHz/24-bit, and MP3, Windows Media Audio and Ogg Vorbis compressed files at up to 320kbps. Via its vTuner implementation it can access a huge range of internet-streamed radio stations, and Apple AirPlay capability is expected very soon (and may be in place by the time you read this).

Within, there’s digital technology derived from the Naim DAC, with upsampling, in-house digital filtering and Burr-Bown conversion, and Naim’s own DSP-based signal buffering and reclocking, under the control of a SHARC 40-bit processor. The sections of the player are galvanically isolated from each other to reduce the possibility of interference.

PERFORMANCE
As is usual I found wired connection – from my NAS device to the ND5 XS via a Netgear gigabit switch – proved the most stable and reliable route in the somewhat Wi-Fi-device-heavy environment in which the Naim was tested. The idea of the switch is that the data from my NAS devices – three at the last count – goes direct to the player rather than through my main wireless router.

In fact, with wired connections for most of our computers – through a separate switch – all the wi-fi is doing most of the time is handling various handheld devices, such as the iPod Touch and iPad I used to control the Naim.

All that done, the simple sum-up is that the ND5 XS is very close to being as good as the NDX across a wide range of music. It’s not quite there, the more expensive player having a rather more extended and confident bass with large-scale orchestral music, a shade more openness in the midband that simply makes voice and instruments sound just that little bit more real, and better definition in the treble.

The result, especially with higher-resolution recordings, is more than noticeable, with the NDX seeming to give the listener just a little more of everything, and thus drawing you more effectively into the music. But that shouldn’t detract in any way from the ability of the ND5 XS, which is a remarkably accomplished player of content from low-bitrate rips of historical recordings.

Listened to in isolation, it’s often amazing just how much detail the ND5 XS trawls from familiar recordings, and with good rips of CDs it’s a match for some very upmarket CD players, making it a viable replacement for ‘physical media’ in a topnotch audio system.

Alongside the NDX – and I had both running into the amplifier at once, enabling me to flip between them – it’s fascinating how close the two are.

However, once you add the XP5 XS power supply to the ND5 XS, things change: suddenly you have a player with more power and authority than the NDX can muster, along with that sense of a lifting of another veil between listener and music; tracks have more sparkle and ambience, notes attack and decay with just a little more realism, and again there’s that sense of ‘more of everything’ that the NDX offers over the ND5 XS alone.

But then you should expect that, given that the ND5 XS/XP5 XS combination will set you back just over £500 more than the NDX. As it is, the ND5 XS will be all the player many buyers will ever want – I certainly wouldn’t be disappointed if it was the only source component I had –, but with the option of giving its performance a very significant boost when funds allow.

Of course, when you add the XP5 XS power supply to the NDX, things take on a whole new complexion – but maybe that’s a story for another time…

Design notes: Phil Harris, Naim Technical Support
As computer-stored music moves out of the shadow of CD, Naim’s Phil Harris explains what this ‘hi-res’ content is all about.

Asked about the advantages of higher-resolution files, he says that ‘As the sample rate increases then so does the maximum frequency that can be reproduced. The notes may not extend to the (theoretical) 22kHz maximum of even CD reproduction, but the harmonics of notes that give music its ‘feel’ do – and well beyond too!’

‘As the bit-depth increases (from 16-bit to 24-bit), then the potential dynamic range of the recorded signal increases. With 16-bit the theoretical dynamic range is 96dB; with 24-bit that increases to 144dB.’

But not all ‘hi-res’ recordings are quite what they seem: ‘the production and mixing can involve a pass through a compressor to  increase the level of quiet portions of the music and reduce the loud bits.

‘Also be aware that just because an audio file might be 24-bit/192kHz, it doesn’t mean that the source data or the source recording that was used to generate it was capable of that bandwidth or that dynamic range.

‘It’s perfectly possible to create a 24-bit/192kHz file from a 16-bit/44.1kHz ‘CD’ source, and the high-resolution file can actually sound worse than the 16-bit/44.1kHz original. So don’t get tied up in just a “bigger numbers are better” game.’

Technical specification
Price £1950
Networking Wired/wireless Ethernet
Inputs Three digital – two electrical, one optical
Outputs Electrical digital, analogue audio on RCA phonos and DIN
Other connectivity USB, mini-USB for software/firmware updates, system automation connections
File formats played WAV, FLAC, Apple Lossless (ALAC), AIFF, AAC, WMA, Ogg Vorbis, Internet radio vTuner
Options/upgrades DAB/FM radio module, XP5 XS/XPS/555PS power supplies, Naim DAC
Accessories supplied Remote handset, Wi-Fi antenna
Dimensions (WxHxD) 43.2x7x30.1cm