Network resources

One thing I noticed as I chose my “Room” – which I’d called “Office” – as the speaker for AirPlay was how quickly and smoothly the music switched over. I switched back to music provided by my server, and it was just as fast and smooth. Sonos has been at this since 2005 and it has clearly nailed down effective network operation quite thoroughly.

But that age shows in other less positive ways. For example, when I set up the system there was no obvious way to play the bulk of my local music – about a terabyte of the stuff – which resides on my Synology Network Attached Storage. Looking through the settings of the app, I saw that there were options for “Show Media Servers” and “Show UPnP Servers” which were switched off. I switched them on but I could see no difference.

That was puzzling. Just about everything that doesn’t come out of Apple supports music served up via the industry standard DLNA protocols. But not Sonos, apparently. I last looked closely at a Synology product a couple of years ago. At the time I wrote (elsewhere) that “Only a couple of DLNA-style servers are supported [by Sonos], and Synology is not one of them”. I must have been able to find some resource about Sonos then that I can’t find now. Oh well.

Music Library

But digging around the settings menu I found something called “Music Library Setup”. That allowed me to add a network share. I’ve done this stuff before – you add the network path to the folder you want to make available, along with username and password. But it’s not particularly user friendly.

Once done there was a fair wait while the app ran through the specified folder and indexed all the tracks. Remember, there was 0.98TB of music in there, more than 30,000 tracks. I didn’t hang around to time the indexing but went off and did something else for a few hours.

Sonos Amp
Setting up a network share

That done, the Sonos Amp was able to deliver much of my NAS music. Much of it, but not all of it. Specifically, it’d play the stuff sampled at 44.1kHz or 48kHz, but none of my high-resolution music. Of which I have rather a lot.

Again, this speaks to the age of the system. Back in 2005, just about nobody (except for DVD Audio enthusiasts) had 24 bit, 96kHz music.

Listening

The amplifiers in the Sonos Amp are, as I said, rated at 125 watts each into 8 ohms. And 200 watts each into 4 ohms. They are Class D amps, which means high efficiency. Even after running it as fairly high levels for several hours, the unit became only modestly warm.

I used my KEF R300 loudspeakers with this amp. They are more than revealing enough should there have been any performance deficiencies. There were none.

Sonos Amp

The amplifier happily drove the loudspeakers to whatever level I wanted, cleanly, clearly and with zero audible distortion. That they support low impedance loudspeakers means that purchasers have a wide range of loudspeaker options.

I mostly listened to the material from my server and to Spotify music. But to round things out, I plugged the output from my NAD phono pre-amplifier into the line inputs and span some vinyl. The usual problem of low levels for vinyl was immediate apparent. But there’s a setting in the app that gives you a choice of ten levels for the analogue input. I set that to 9/10 and that approximated the level of the digital sources.

Even with vinyl, bass was tight and extended. There was no particular emphasis on surface noise. Imaging was more than adequate. Few would not enjoy the sound.

Subwoofer

The loudspeakers I used are very satisfying down to below 40 hertz so I didn’t feel tempted to use my subwoofer. But I did figure I ought to explore the subwoofer options a little. There are control options for the subwoofer in the app settings. You can adjust its level, the crossover and invert the phase. The online manual doesn’t say much about these, especially the last. Inverting the phase can help meld the sound from the subwoofer smoothly with the main speakers. Generally, you choose the setting which provides the higher perceived bass level around the crossover point.

The crossover point itself can be adjusted between 50 and 110 hertz. I had hopes that this would control not just the subwoofer (that is, implement a low pass filter for the subwoofer output) but also control the output to the main speakers. If it were to do that, it would filter out the specified bass so they didn’t have to attempt to handle it. However, it seemed to make no difference to the signal the main speakers received.

TV … and others

You can connect the Sonos AMP to a TV via HDMI. With my LG OLED TV, at least, it connected smoothly and easily via ARC and delivered the sound from the TV to a far high quality than the TV itself could manage.