Sonos Amp – first look

Sonos Amp

The new Sonos amp is something that few consumers would ever consider as part of their music streaming setup. Sonos set out to correct that misconception.

GadgetGuy went to a hands-on session with the Sonos Amp, and indeed perceptions changed. Whereas AV specialists may buy truckloads of these, and rack mount them to power/control all manner of speakers in a home (or business) Joe and Jane Average may not appreciate the power of a 2.1, 125W-per-channel, amp loaded with Sonos smarts.

(Please assume all speaker references are passive – unamplified – except where we mention Sonos)

The first use case is bringing Sonos to your existing unamplified stereo speakers.  

The Sonos amp may cost $999, but many have amazing bookshelf, floor or ceiling speakers costing several times that. While Sonos capabilities are unique (dozens of streaming music sources, AirPlay 2, voice assistants etc) you could shell out a lot more for a Denon, Marantz, Sony, HEOS, Onkyo, Pioneer and more 5.1 AV amplifier and not get anywhere near the Sonos functionality.

The second use case is to add rear speakers and a sub-woofer

The Amp supports two Sonos One, Play:1, Play:5 as rear speakers and a Sonos Sub to get 4.1 sound. It decodes up to 5.1.

The third use case is to have two (or more) Sonos amps

The first controls the front speakers (2.0 or 2.1 with a wired amplified sub or a wireless Sonos sub) and another controls the rear speakers making 4.1.

Each Sonos amp communicates with the other over Wi-Fi 2.4Ghz or Ethernet, and that is where things can get interesting. Apparently, there is a great demand for rack mounting these to cover multiple speakers in different rooms and provide multi-room or party mode.

More Sonos Amp features

Sonos Amp
  • HDMI ARC for connection to a TV
  • RCA stereo for connection to a turntable (must have a built-in pre-amp) or another analogue sound source.
  • RCA out for a sub-woofer with adjustable cross over from 50-100Hz to ensure that it complements – does not down out – existing speakers.
  • Dual Ethernet Ports to enable hard linking of multiple Sonos Amps. It can also link over Wi-Fi N, 2.4Ghz.
  • Small – 21.69 cm square x 6.4 cm x 2.1kg. The Sonos App or touch controls on the front can control the Sonos Amp.
  • Works with all Sonos products including the Sonos Beam soundbar. And your TV’s IR remote will control it as well (if using HDMI ARC).
  • Trueplay compatible to tune the speakers to the room (Apple iOS only)
  • Can output in mono or stereo – useful for multi-room music.
  • And like all Sonos products, it will receive OTA updates for further functionality (OK Google Please!)

Is 125W RMS per channel into 8-Ohm speakers enough?

The demonstration was at Mojo Record Bar in York Street Sydney. Yes, I had one lovely Six Strings unpasteurised Pale Ale (made at Erina on the Central Coast of NSW close to where I live), so my head was clear.

Maximum volume on a pair of KEF Q750 floor speakers (about $4k for the pair) was 114dB with a THD of .0015%. Yes, 125W-per-channel is more than enough for a 50m2 space at half volume.

But given the Sonos Amp price, I would be more comfortable driving even lower cost speakers and seeing what its EQ app can really do.

BTW – the Sonos Amp can work equally well with 4-Ohm speakers and is stable down to 2-Ohm.

The elephant in the room is Dolby Atmos, Hi-Res support and no centre channel

Sonos Amp decodes 3.1 signals by sending them to the L or R channel – called a phantom centre channel. Centre channel is more for clear voice. During the demo, the 2.0 system was flawless with its speech enhancement mode.

Hi-Res is not necessary for music streaming or TV use – it supports CD-quality.

Dolby Atmos is now on most premium 4K TVs, and content availability is increasing. That is the Sonos Amp’s one Achilles heel. It supports 5.1 decoding but not spatial up-firing channels, e.g. 5.1.2 or 7.1.4. Yet I suspect its use cases and sound quality may compensate until they have a Dolby solution.

GadgetGuy’s take: I see the light

There are strong use cases for the Sonos Amp especially if you own speakers or are adding Sonance (or other), architectural speakers.

Sonos amp

The Sonos Amp is available from Sonos online and is a breeze for hi-fi buffs to install. But I strongly suggest you consider wider uses like multi-room or whole of home speakers. Sonos Australia can point you to AV integrators that specialise in that.

GadgetGuy Thomas Bartlett a.k.a. The Hi-Fi expert will be testing these soon.