Yamaha NX-70A Review

Design

• Available in black or white
• No parallel lines

We’re hardly in KEF LS Luxe territory where design is concerned, but nevertheless the Yamaha NX-70A are mildly unusual lookers and mildly interesting as a result. There’s nothing odd about the cabinet dimensions – but the gently curved front baffle and the rather more aggressively curved rear serve to make the speaker look softly triangular when viewed from above.

There are no parallel lines here, and this of course is handy when it comes to minimising internal standing waves. View the cabinet from the dead-ahead, meanwhile, and it becomes apparent that the rear of the cabinet is taller than the front – so the 5mm thick aluminium top plate slopes forward somewhat.

Despite the relatively complex nature of the cabinet design, though, gratuitous design flourishes are few and far between. No matter if you go with the black or white option for finish, there are copper-coloured accents visible – the horseshoe-shaped heatsink at the rear of the top-plate, the manufacturer badge on the front of the top-plate, the input/output plates on the rear of the speaker, and the brightwork surrounding each driver, are all in this colour.

As has long been the case with Yamaha, the standard of build and finish that’s in evidence here is basically impeccable. The wooden cabinets (and their aluminium top-plates) are screwed together flawlessly, and are finished to a very high standard. The exposed screw-heads on the top-plate won’t be to everyone’s taste, mind you.

Yamaha is not alone in offering bespoke stands for its wireless stereo speaker system, but the fact the SPS-70A stands cost around £500 per pair means they’re merely expensive rather than extortionate (and, again, it means we’re not in KEF LS Luxe territory). The speakers bolt to a top-plate that’s exactly the same shape as the foot of the speaker, and there’s some cable-management in the pillar too. Soft or pointed floor spikes are provided.

Controlling the NX-70A can be done in a couple of different ways. There are no controls on the speakers themselves beyond a few buttons on the rear of the primary speaker to initiate Bluetooth pairing, wireless connection to the secondary speaker, let it know if it’s the left or right channel and what-have-you.

The primary speaker has a display panel at the bottom of the front baffle that let you know what’s what as regards volume level, the tune that’s playing and so on (the secondary speaker has a matching panel but it’s not a display – it simply has a tell-tale to let you know it’s powered on).

And the supplied remote control handset looks and feels nice enough, and gives you control of volume, power, input selection and the basics of playback.

Features

• 320 watts of Class D power
• Harmonious Diaphragm driver technology
• Synergistic Drive circuit design

Don’t imagine Yamaha has been sitting on its hands while its most obvious rivals all stole a march in the premium wireless stereo speaker system market. Better late than never, after all – especially if it’s the development of a selection of racy-sounding technologies that have held you up all this time.

To start at the end: each NX-70A uses a 30mm dome tweeter and a 130mm mid/bass driver, bolstered by a rear-venting bass reflex port, to deliver sound. That’s a big tweeter, sure – but even more unusually, the tweeter and the mid/bass driver are made of identical material.

Harmonious Diaphragm is a blend of Zylon (a synthetic polymer fibre) and spruce wood. The idea of using the same material across both drive units is to be able to offer absolute consistency of tone over the entire frequency range.

Each tweeter is in receipt of 60 watts of Class D power, while each mid/bass driver gets 100 Class D watts to deal with – an all-in total of 320 watts of amplification really ought to prove adequate in any realistic scenario.

In an effort to enhance sound quality, Yamaha has developed the Synergistic Drive unified circuit design, which sees each drive unit connected directly to the amplifier circuit. By being better able to manage the flow of the electrical current using this technology, goes the theory, the distortion inherent in traditional amplifier/speaker interactions is minimised.

Naturally it is critical to the process that the drivers and the amplification are developed simultaneously as a dedicated pair. The upshot of all of this extremely thorough engineering is, according to Yamaha, a frequency response of 50Hz – 35kHz (when the speakers are wired together – it modulates to 50Hz – 21kHz if you prefer a wireless connection).

Yamaha Parametric Room Acoustic Optimiser (or YPAO to use its only slightly snappier abbreviation) is the company’s proprietary automatic sound optimisation technology, and is accessed via a bundled microphone that measures the characteristics of the room the speakers are positioned in.

There’s a socket on the rear of the primary speaker into which the mic can be connected, and it’s no kind of hardship to run the YPAO routine using the MusicCast control app.

The app allows access to each of the available sources and also offers playback and volume control. There are a number of EQ adjustment options available too. There are 40 (!) slots for Favourites (which can be playlists, songs, radio stations or whatever you fancy, really), the ability to build and access a quick playlist from various sources, create a number of routines (for instance, all power off) that can be accessed quickly and easily.

And then there are further possibilities if you’re using other MusicCast equipment – building a surround-sound or multiroom system are the most attention-grabbing. The overall layout of the app is a little busy and crowded, but there’s no disputing its thoroughness or its stability. 

Connectivity

• Wi-Fi and Bluetooth
• HDMI eARC
• Roon Ready

The primary speaker also includes all wired and wireless connectivity. Bluetooth 5.3 is on board, and it’s compatible with the plain vanilla SBC and AAC codecs. Dual-band Wi-Fi is also available, and this means the system is compatible with Apple AirPlay, Google Cast, Spotify Connect and TIDAL Connect.

In addition, the NX-70A is Roon Ready and internet radio is available too, along with access to a podcasts platform and DLNA-compliant storage on a common network.

You may prefer to use Ethernet, of course, and there’s the relevant socket as part of the suite of physical connections. It lines up alongside an HDMI eARC socket, a digital optical input, a USB-A slot and a 3.5mm line-level analogue input.

Outputs run to a pre- for a subwoofer and an RJ45 for making a physical connection to the secondary speaker (the secondary speaker has a corresponding RJ45 and a mains connection – and that’s the lot). By prevailing standards there’s not a lavish amount of connectivity here, but nevertheless the NX-70A will support a fairly extensive system.

Any and all incoming digital audio information is pored over by an ESS ES9017S DAC chipset that’s capable of dealing with files of up to 32-bit/384kHz PCM and DSD256 resolution. If the speakers are wired together, everything is up- or downscaled to 24-bit/96kHz resolution, and this drops to a reasonably healthy 24-bit/48kHz resolution if they’re connected wirelessly.

Sound Quality

• Poised, beautifully balanced presentation
• Detail and dynamism in more-or-less equal measure
• Expresses rhythms with real confidence

If you came for shock and awe, Yamaha is probably not all that unhappy to disappoint you. There’s nothing showy or gratuitously attention-grabbing about the NX-70A – its many charms are altogether more grown-up than that.

That’s not to say it’s short of vigour, or that it is unwilling or unable to attack those recordings that require it. But this is a balanced and poised system, and it’s not prone to bluster.

Once through a 24bit/192kHz FLAC file of Nina Simone’s reading of Pirate Jenny (downscaled by the Yamaha, of course) reveals a lot of what the NX-70A is about. Its approach to the frequency is very nicely balanced, with no area over- or underplayed and due attention paid at every stage.

Low frequencies are deep, solid, properly shaped and alive with variation – details of texture and timbre are readily available. The top of the frequency range is a nice combination of bite and substance – there’s a kind of benign assertiveness to the way the Yamaha delivers treble sounds that suits its overall attitude of quite polite authority.

In between, the NX-70A delivers that inimitable vocal in the most eloquent and revealing fashion. Detail levels are sky-high, with a huge amount of information regarding character and attitude (both peerless) made available as readily as the stuff around tone and timbre. Simone is possessed by the character she’s singing about during the course of this recording, and you won’t hear that fact communicated any more readily by any even remotely price-comparable alternative.  

The tonal balance is just as judicious. The Yamaha is almost fanatically neutral in this respect, seeming to add or subtract nothing where temperature is concerned – any suggestion of heat or hint of chill in a recording will almost certainly be inherent in the recording or the work of the source.

Soundstaging is expansive, coherent and controlled. There’s a fair amount of free space between the elements of a recording, so each one gets elbow-room in which to operate – but at the same time there’s a reasonable sensation of unity and singularity to the presentation. The sound has no problem escaping the left/right confines of the cabinet, and there’s a fair suggestion of height to the stage too – but what’s most impressive is the unequivocal way in which every element is locked in position and secure in its space.

Switching to a vinyl copy of Julian Cope’s Peggy Suicide allows the NX-70A to demonstrate its talent with dynamic variations of all kinds. It breathes deeply enough to make the upshifts in intensity and volume both obvious and significant, and it pays sufficient attention to allow harmonic variations to be apparent too.

And this recording also allows the system to showcase its talent with rhythmic expression – low-end information is tightly controlled at the point of attack, and there’s real confidence to the way rhythms are described as a result.

It also allows the Yamaha to reveal a decent capacity for drive and attack, too. As I started by saying, this is not the sort of system that’s going to grab you by the lapels – but neither is it undemonstrative or in any way passive. The more vigorous the content you’re playing, the more direct and positive this system sounds – but at no point does it ever threaten to lose the run of itself.

Should you buy it?