Yamaha NX-70A review

Stereo wireless streaming speakers from Yamaha: two boxes, but the simplicity of an all-in-one system. There's no extended system required, because the speakers contain both amplification and a streaming system (here Yamaha’s MusicCast), so that as a minimum you could just place the speakers, cable them up and start enjoying your hi-fi – with high‑fidelity streaming on offer, an HDMI TV connection, and control from a well-established multiroom-capable app.

And these are most definitely hi-fi, with several of the compromises more generally involved with all-in-one systems going out of the window. There's no lack of stereo separation here, nor any questions over whether a particular manufacturer is able to excel across the hi-fi chain: Yamaha’s MusicCast streaming is well-established, the company makes award-winning amplifiers and AV receivers, and it also has a strong record in loudspeakers going back to the 1950s.

And as musical instrument makers, the Japanese company might even claim a unique insight into the sounds which form our music in the first place.

We were delighted to have the new NX-70A speakers in for review in Sydney, as they were first revealed to the world here in Australia, at the Sydney Hi-Fi Show back in May. Euro-Yamaha had hoped to hold their reveal for the recent High End Vienna, so in Sydney they were slightly anonymised, their product cards redacted, our reportage restricted!

Now at last we can tell all, and listen in earnest, to see how these streaming active speakers neatly straddle the convenience of an all-in-one system with the sonic strengths of genuine stereo hi-fi.

Build & drivers

The Yamaha NX-70A speakers are substantial standmounters, available in black or white, and unusually shaped, with fairly subtle rounded curves and a top plate which rises to be higher at the back (335mm) than the front (315mm). Either side of the rear back spine, a selection of inputs sits among a back plate of lovely shining copper-coloured metal.

The speakers port fairly traditionally to the rear but the cabinets also have grille openings to the rear with more copper-accenting, and most unusually in a curved strip on the top. These we presume to be for passive cooling of the internal electronics: thermal management rather than acoustic design.

Perhaps unusually, that top plate doesn’t have any control buttons, such as a local volume control; it’s clean aside from the grilles at the back, Yamaha’s ‘tuning fork’ logo at the front, and four structural fasteners which secure the top plate to the main cabinet of MDF, enhanced to mitigate vibration, with the front baffle reinforced with a 25mm panel (designed, we’re told, using a laser Doppler Vibrometer). The very front panel layer is an ABS plate, shaped to incorporate a new tweeter waveguide. All this is beautifully integrated, kept clean and attractive up front, with the cool tech stuff going on mainly at the back.

One feature easily overlooked is a small white light and a text display in the black section at the bottom of the left speaker; the display shows the input or song information and other messages. The right speaker has just the white light. The text display might be useful if you’re up close in a desktop situation, but it’s too small (for our old eyes) at a normal listening distance. If you find it intrusive you can set the dimming options to zero, though even this is not quite ‘off’, but then this text panel sometimes shows error messages (e.g. ‘Version Error’ during a firmware update), which might be useful to see.

You get a rather nice half-size remote control included, with a copper-ringed central circle. A set of optional stands is available (A$799.99 in Australia), in the same black and white colour choices as the speakers.

The pricing of the NX-70A ranges them as obvious competitors to, among others, KEF’s established wireless speaker range, and specifically the KEF LS50 Wireless II. But the Yamaha aesthetic is very different, partly by virtue of using separate 30mm tweeters and 13cm woofers (compared with KEF’s single coaxial driver) and also by going for a taller, more conventional if quirky look, compared with the fat curves of the KEFs, which look rather as if inflated to the point of bursting.

Both drivers in the NX-70A use the same material blend, described by Yamaha as their ‘Harmonious Diaphragm’, as used also in the company’s highest hi-fi speakers. This combines wood fibre from spruce (which Yamaha notes is used in its grand piano soundboards) with the synthetic polymer Zylon, a material to which Yamaha switched after its period favouring beryllium, which is an excellent lightweight alkaline earth metal, but sadly a highly toxic one to work with.

By contrast Zylon is more easily manipulated, yet an extremely strong polymer claimed to have an acoustic velocity comparable to beryllium and a tensile strength 1.6 times higher than Kevlar. Its versatility for use in tweeters as well as woofers provides the possibility of a tonally-matched sound across the full frequency range.

Each driver has its own dedicated amplification module (so an active system, rather than merely powered). Yamaha claims to have taken great efforts to optimise these relationships, announcing a new arrangement called Synergistic Drive: “an innovative unified circuit design,” says the literature.

“By connecting the speaker unit directly to the amplifier circuit, the system precisely manages electric current flow, minimising distortion that is fundamentally rooted in conventional amplifier and speaker interactions.”

You might this would be something which could apply to any active design, yet it implies a technology “unique to Yamaha”. Further investigation reveals the use of current feedback around individual drivers, detecting distortion as variations in electrical current and aiming to reduce it in real time. This reduces the negative effects of distortion caused by Eddy currents, says Yamaha, and specifically addresses third harmonic distortion. It reminds us of the feedback in Yamaha’s YST subwoofers.

So Synergistic Drive is Yamaha’s particular take on active speaker design, raised to higher hi-fi levels of priority than on Yamaha’s smaller active speakers and soundbars.

Room correction is another thing possible by having processing, amps and speakers all in one package. Yamaha not only here includes its YPAO (Yamaha Parametric room Acoustic Optimiser) straight out of its AV receivers of renown, but also provides a bundled microphone for the purpose, rather than the common practice of leaving such crucial measurements instead to the vagaries of a smartphone microphone.

Ins, outs, and apps

Physical inputs are fairly limited, which is typical of the smart speaker breed: that back panel hosts one minijack analogue input, one optical digital input, a USB-A slot, and one HDMI eARC/ARC input with CEC.

This last plays back audio from whichever HDMI socket on your TV is marked for HDMI ARC, and makes these speakers ideal for flanking your TV to provide sound for all your entertainment, not merely music. We have no hesitation in recommending the solution of stereo speakers either side of your TV rather than a soundbar in front of it.

Additional socketry provides a subwoofer output, so you can add depth if you need it (only in a larger room, we’d say), and an Ethernet socket if you can give the NX-70A a wired network connection; otherwise MusicCast will help make the Wi-Fi link to your network. This MusicCast app controls everything from input selection to streaming and even multiroom sharing between rooms.

The left and right speakers can connect to each other wirelessly, so there’s no need to run a cable between them. But you can choose to do so using the very coily Ethernet-style cable provided, length three metres, so still allowing good separation between the two boxes. Using the cable provides stability in a busy Wi-Fi environment, and also allows a higher digital connection rate which actually doubles the highest frequencies these speakers can deliver: they go up to 35kHz (-10dB) when using a wired connection, only 21kHz (-10dB) when using Wi-Fi. From this we assumed (and Yamaha confirmed) the wireless connection to use a 48kHz sampling rate with the cable raising this to 96kHz, both at 24-bit.

There is Bluetooth available for direct streaming, but we note its codecs are limited to the lower SBC and AAC codecs, so MusicCast here can provide preferable and higher-quality ways to stream. This is also true of AirPlay 2 streaming, currently limited (by Apple, not Yamaha) to the AAC codec at 256k, even though it’s capable of far more.

You can get higher quality using Tidal or Spotify via their Connect versions, which means just using the service’s native app as the controller, and directing the music to flow straight from the internet to the speakers at whatever quality you’re paying for.

There’s also Google Cast here, good from Android phones and devices.

But if you store music actually on your device, the most reliable way to play is the tab for ‘This iPhone’ (or whatever) at the top of the MusicCast app’s interface. This seems to send the file at full quality, most likely via some UPnP/DLNA in the background. We hear the difference in our listening notes.

Yamaha MusicCast also allows multi-room playback, combining ‘rooms’ within the app so that any MusicCast device can share its inputs with any other MusicCast devices in the home. Given Yamaha’s MusicCast ecosystem of products runs from small wireless speakers to hulking AV receivers, this is potentially a powerful method of home unification.

The NX-70A speakers are also Roon Ready, if you have invested in this music organisation software.

Also under fingertip control in the MusicCast app there is internet radio, a Podcast section, and ‘Server’ access, which instantly found various file shares on our home network, through which we could then navigate through folder structure or artist/album lists slightly laboriously (no permanent library is created). Files loaded via USB are accessed in a similar way.

All these will benefit from the DAC implementation here, using an 8-channel 32-bit ESS DAC, the ES9017S. We were told that “3× channels of differential output are combined and then sent to the tweeter and another 3× to the woofer, creating a more precise representation of the original signal with wider dynamic range and lower noise levels as it’s combining 3× versions of the conversion to capture more detail.” (We’re just gagging to ask ‘so why not 4×?’ but we’ll let it lie.)

Many ways to play, then: let’s fire them up.

Listening sessions

Set-up proved fairly simple whether or not the stands were attached for use in the music room, or simply sat on a firm surface either side of the TV as we used them later with HDMI; for such surfaces they have pre-attached silicone feet. We gave them the Ethernet-style cable connection between the speakers to ensure we heard them at their best.

We also gave them a wired Ethernet connection to our network, and this cable was coming from the right, a bit strained to reach the left speaker which has all the inputs. The speakers are very clearly labelled as to left and right, arriving with huge cardboard covers telling you so, but the first thing we did once inside the MusicCast app was to check if we could switch left speaker with right. And yes we could, so we were able to restore cable neatness, hoorah. (We later found a button on the back which can do the same thing.)

Since our environment already has MusicCast elements in residence, adding the NX-70A was just a case of selecting ‘add device’ then scrolling down a very long list, which shows how many MusicCast-enabled products Yamaha has released. When you get all the way to the NX-70A, it’s not there! An enquiry to the local Yamaha team revealed that Yamaha puts new products at the top, above ‘A’, but doesn’t think also to include them in the right place. This oversight aside, we had the NX-70A connected pretty much instantly, and checked for a firmware update.

We ran background internet radio and AirPlay 2 streams from an iPhone for a good week just to have the speakers soaking through, as it were. This was when we discovered that playing music stored on our phone via AirPlay 2 sounded radically different to playing the same files via the ‘My iPhone’ tab of MusicCast. It’s a great demonstration of what such transmission does to your files. Playing the beginning of Kate Bush’s Aerial Tal via ‘My iPhone’ at 16/44.1, the vocal had a quicksilver edge while the gentle piano beneath was richly toned across the soundstage from left to right; we could hear the pedal being lifted. All that was just gone when playing via AirPlay: softer, blander, less in the way of life and dynamics.

Spotify and Tidal users can do better; selecting these services within MusicCast simply opens the native app and you choose the Yamahas as the target. Because MusicCast has already allocated these to become a ‘Room’, it is this ‘Room’ you’ll see as the target, rather than the Yamahas themselves. This can be confusing, especially if you have two streaming devices in the same room. If you want to see ‘Yamaha NX-70A’ as the target for streaming services, then just name the MusicCast room as ‘Yamaha NX-70A’.

If you want Apple Music at better quality, currently we could only suggest the extended workaround of having an AppleTV 4K playing Apple Music into your TV, and then out via HDMI into the Yamahas.

The ‘Server’ option within the MusicCast app looks for files on your network. We have assorted old NAS drives humming away around the home and MusicCast found them all. Not all such platforms do so.

Even more conveniently we attached an old WD powered hard drive to the USB-A slot, and could thereby play our collection of high-res albums through the Yamahas.

And playing from this USB drive we really found what a high level of hi-fi performance the NX-70As could achieve. The guitar on Audio Alchemy’s Marrakesh at 24-bit/96kHz sounded delightfully clear and clicky-edged, while the bass sounded not so much as if it was emanating from the two speakers but more as if a small bass guitar cabinet was somewhere in the middle of them, so like the real thing was the bass fullness and tone. There’s a double-time section in the middle of this track which showed also the system’s speed, keeping up with the gaps in the machine-gun bass notes: individually punchy, no blur. We used this section to find our ideal speaker positioning, which in our room locked the bass into the best combo of tightness and depth with the ports 22cm out from the rear wall, close enough to suit general use with TVs as well as making stereo lounge use convenient. Nor does their treble fade excessively off-axis, though keep the tweeters at ear height to enjoy best imaging.

There was an almost alarmingly real delivery of the percussion that somehow sits in 3D among Chick Corea’s piano and ensemble on his Australia Concerto No. 2; this wildly dynamic piece burst unrestrained from the Yamahas with all its impressive imaging and ping-pong bursts of sound intact – exactly the kind of spread that would be lost on a smaller all-in-one system or speaker. The Yamahas bring all the hi-fi qualities of proper speakers, without compromise from stuffing electronics inside, we’d say, and quite possibly benefitting from all that Synergistic Drive! With the Chick Corea they sounded simultaneously musical and clinical, laying out the soundstage with both width and depth, everything in its place to make this whole popping piece stand forth in a three-dimensional presentation, among which we could still hear the wide ringing roll-off of a China boy cymbal, or the gaps between separate rolls of the brushes on the snare, the richness of orchestration around Corea’s marvellously close-miked piano (home territory for the Yamahas) which brought this piece to life. They did the same with a super-crisp delivery of Herbie Hancock’s Cantaloupe Island and its still more extreme ping-pong elements; during the piano solo the left channel was silent like a hole in the Matrix.

They can certainly rock, as proven by their smashing out of Yes’ studio version of Heart Of The Sunrise (24/96) with thrillingly tight and real drums to the fore. Alan Parsons came through as DSD 2.8MHz files no problem (it’s good to quad-DSD), all our FLAC and WAV tests played fine (up to 384kHz), and the speakers absolutely excelled when blasting out The Eagles’ Life In The Fast Line at 24-bit/192kHz, again spreading the panned guitars wide while pumping out a bass that was tight and full. They go loud with glee.

YPAO Volume & YPAO Room Calibration

We were by now preferring not to engage the YPAO Volume option (as opposed to the room calibration, see below). This YPAO Volume slider (under the MusicCast app’s sound settings) had been on by default as a kind of loudness EQ “to hear balanced low, mid and high frequencies clearly at all levels”. It may be useful at lower levels, but for anything higher it often seemed to have a mildly deleterious effect when playing at a decent volume; on the Eagles specifically it had softened the bass pedal, taking realism out of the rhythm section, while mildly veiling the wonderful airiness up top that the Yamahas were otherwise delivering.

Happily you can toggle this YPAO Volume on and off easily at the top of the sound settings panels, so it’s easy to try for yourself, and develop a preference.

YPAO room calibration, though, is a different thing, combining a parametric EQ with what Yamaha calls RSC (Reflected Sound Control). Kudos to Yamaha for including a proper puck microphone with the NX-70As, rather than relying on phone speakers to achieve what is an extremely complicated job, attempting to measure room characteristics and then adjust the speaker EQ accordingly.

To do this, you construct the little cardboard stand for the puck, then attempt to balance it where your head might be for listening; you certainly won’t be limited by the length of the cable attached to the puck microphone, as this is long enough to wrap twice around the Moon and back. (Recoiling the YPAO microphone cable to fit back in the plastic bag is the key challenge facing reviewers when returning any so-equipped Yamaha review item.)

With the puck in place, you set the measurements off, and it’s very quick – slightly longer if you’ve attached a subwoofer. Two hisses, two whoops and it’s over. Accept the scan, and you can then toggle YPAO on and off to see if you like the results.

It seemed accurate, identifying and correcting a bass dip which we know to exist in our lounge room, pleasingly less critical of our music room’s response. We tried using the correction in the lounge: sometimes it seemed to clarify the upper bass, sometimes it seemed to mask the clarity of things, like Diana Krall’s vocal on Here Lies Love, softened back significantly, the spread and openness of the mids and highs also crushed, and everything slightly monofied. Of course that’s just us, in our room. Again it’s free to try, so try it.

Meanwhile there are plenty of other tone controls inside the MusicCast settings (with sophisticated Finite Impulse Response EQ filtering, we gather), so plenty more to play with. The app also links to a separate IP browser interface for network tweaks.

They worked well as HDMI TV speakers (or optical if no HDMI ARC); indeed the speakers proved ideal for movie sound, with dynamics and spread and especially dialogue clarity all in a league which no soundbar would match. (Yamaha also kindly adds a dialogue enhancer slider in the app settings, should it be required.) There’s apparently no attempt to respond to Atmos soundtracks with virtual processing; thank heavens for that. Stereo clarity is invariably to be preferred.

We almost forgot to mention the remote control. We had quickly became accustomed to using the MusicCast app for everything, especially as this app is not like some others which disappear or disconnect when momentarily not in use; the MusicCast app returns to being fully active as soon as selected. However, the physical remote can be very handy for quick actions, especially when the phone rings, and feels just that bit more sophisticated in the hand, especially when enjoying just a music session, screen off.

Verdict

Any final issues, however minor? We have to say no. The NX-70A speakers were easy to set-up, easy to address using an established and powerful app, and they sounded great. We even liked the clever packaging.

For their best sonic results just find the purest path to playback (keep Bluetooth and AirPlay for convenience use only), and get banging out your tunes. The Yamahas do not sound in the least bit processed or woofed up in the bass like so very many all-in-one systems, and especially the smaller wireless speakers. These are genuine hi-fi speakers, made active, wireless, and streaming.

Yes, at the price, you might attempt to build a separates system which combines a great streamer with a great amp and great speakers; you would potentially gain flexibility of replacement and repair/replacement. But you would lose all the convenience, the minimising of component count, and we don’t think you’d get a much better sound either. Yamaha is experienced in streaming, in amplification, and in loudspeakers. They’ve done top work in bringing all that together so effectively, so synergistically, in the NX-70A.

• See all our Australian reviews from Sound+Image and Australian Hi-Fi magazines