So what about the audio? Here NAD brings out the big guns. At the heart of the Viso 1 is the company's top of the line 'Direct Digital' amplifier, the same amp seen in its $6,000 Masters Series M2 DAC. This bypasses the circuitry of the iPhone/iPod and takes their digital signal directly allowing it to process the audio directly. As such the Viso 1 is a bi-amplified system with digital crossover and NAD quotes the frequency response as 33Hz – 28kHz (-6dB), notably wider than the GenevaSound Model M for example.
As for the speakers themselves NAD has fitted the Viso 1 with a 1in aluminium dome tweeter mounted coaxially in the 2.75in (7cm) midrange drivers plus a 5.75in (15cm) subwoofer. Total output is quoted at 80 watts, 15 per channel to the stereo drivers and 50 watts to the sub. This less than the competition. The B&W's Zeppelin Air and Monitor Audio's i-deck 200 manage 150W and 140W respectively, while the highly portable Arcam rCube still cranks out 90W. That said wattage can mean as much to audio quality as megapixels to photography and the Viso 1 still packs a punch.
Bass response is what impresses most. NAD's 33Hz response figure is significant as it is a lot lower than both the Zeppelin Air (51Hz) and the i-deck 200 (60Hz) and this is noticeable on particularly bass heavy tracks where detail is retained at low volumes while it holds together without any significant distortion even at maximum volume. Equally worth of praise is the Viso 1's high range which delivers great clarity and rewards listeners of jazz and classical music in particular.
Flaws? If anything the bass will prove a little heavy for some and on big beat tracks this can overpower the midrange robbing it of depth. For all its bass prowess the Viso 1's 80W output does come into play and it won't fill a large room like the Zeppelin Air or i-deck 200. Meanwhile stereo separation is narrow, obviously so when compared to the 45 degree tilted speakers in the rCube. Another minor irritant is the remote control, while simple and with excellent range, it makes the Viso 1 give a confirmatory beep every time a track is skipped.
What brings the Viso 1 strongly back into our affections, however, is its implementation of Bluetooth. Granted it may not be the lossless-capable AirPlay, but even without aptX the DAC did a remarkable job of cleaning up the signal making it almost indistinguishable from being docked. Trying it with a aptX-friendly Motorola RAZR the results were astonishing and we'd challenge any audiophile to distinguish it from a wired connection. Non-Apple devices need an answer to AirPlay and for our money this is it, though a great deal of credit must go to the Direct Digital amp. We suspect the future for docks is to include both AirPlay and aptX.