The Sonos Transfer reveals a Bluetooth speaker can sound nice
Audiophiles are sometimes dismissive of mainstream manufacturers and applied sciences. Take Sonos, the largest identify in wi-fi audio. Whereas many acknowledge their audio system sound good, it’s often accompanied by a qualifier like “for a wireless speaker,” or “when I’m listening to music in the background.”
It’s been my expertise that wi-fi audio system are sometimes aggressive with some costlier conventional hi-fi audio system, regardless of their comfort – so now I wish to put that to the check. In the present day’s topic is the $399 Sonos Transfer, the corporate’s first moveable, IP56-rated, Bluetooth-enabled speaker. My colleague Callum Sales space beforehand supplied his ideas on the speaker here – it’s price studying his evaluation for a broader perspective. I’m simply right here to speak in regards to the knowledge.
Over the previous yr, I’ve taken a extra technical method to my audio critiques, capturing their efficiency via frequency response measurements that research present might be correlated extremely with person choice. I nonetheless truly, you recognize, pay attention to the audio system earlier than taking the measurements, however capturing the info offers permits me to supply a extra goal perspective that’s much less coloured by ideas like “this is a Bluetooth speaker, it’s not supposed to sound great.”
As a result of, so far as I’m involved, it does sound nice. My impression was the Sonos Transfer sounded surprisingly balanced in my residence, even earlier than utilizing the speaker‘s “Auto TruePlay” characteristic that may alter the speaker‘s sound routinely relying on the place it’s positioned. Let’s see the way it achieves this.
The Sonos Transfer is a troublesome speaker to measure as a result of its drivers are in an uncommon configuration. It has a reasonably typical 3.5-inch woofer, however its tweeter truly fires downward right into a “waveguide” that then spreads the sound round a small slit that wraps across the majority of its circumference.
This has two theoretical advantages. One: it helps make certain the speaker sound good irrespective of the place you’re standing. It outputs almost the identical sound 90 levels to its aspect because it does proper in entrance. Two: because the Sonos Transfer is designed to be super-durable, the skinny, sloping waveguide protects the tweeter by minimizing the probabilities that one thing will make contact with the delicate element.
In an effort to seize the speaker‘s efficiency, I take advantage of a quasi-anechoic measurement method that primarily filters out wall reflections from the info. I then repeat these measurements at a number of angles to point out how the sound radiates across the speaker, as a result of what we hear isn’t just the primary sound that reaches our ears, however a mixture of the direct sound with very first reflections from our partitions.
Lastly, it’s essential to notice that research by researchers equivalent to Floyd Toole and Sean Olive have proven us that, opposite to common perception, most individuals like roughly the identical steadiness of frequencies of their audio system. The overwhelming majority of individuals desire a sound that’s “flat.” In a typical room, what’s perceived as flat is definitely a slight downwards tilt from the underside of the frequency vary to the highest due to reinforcement of the bass and absorption of excessive frequencies.
Let’s see how the Sonos Transfer does. First, now we have the direct sound – the sound when the speaker is aimed straight at you. Be aware that I’m not but together with the bass efficiency on this knowledge.
Eesh. It appears we’re not off to a great begin, however bear with me. Usually, we’d need the sound to be flat all over for this measurement. We see huge dips and peaks within the treble right here, possible attributable to the reflections throughout the waveguide.
We see a barely cleaner efficiency if we seize a “listening window” common, which accounts for the truth that most individuals aren’t completely centered or nonetheless when listening to audio system. That is a median of measurements inside a 30-degree horizontal and 10-degree vertical window. I’ve additionally added within the bass efficiency to this graph, which was captured utilizing a separate nearfield measurement method. You possibly can see the bass extends cleanly right down to 40Hz – a powerful consequence. The highs nonetheless aren’t trying nice although:
However keep in mind what I stated about listening to a mixture of the direct and mirrored sound? As a result of the Transfer isn’t a speaker most individuals will sit straight in entrance of and pay attention to love a hi-fi speaker, it appears the corporate prioritized a balanced, virtually omnidirectional radiation as an alternative of the direct sound. On this picture we see the 2 graphs above, in addition to how the Sonos Transfer measures out to 90 levels:
Although the treble nonetheless appears messy, word the way it stays an identical distribution even all the best way out to 90 levels.
To make some sense of the messiness within the highs, we take a median of a number of measurements within the vertical and horizontal planes, producing one thing known as an “Early Reflections” curve, proven in blue. This common primarily summarizes crucial sound to achieve our ears and extra intently represents how we’d understand sound in a typical listening setting.
You possibly can see the response tilts down pretty easily from the bass to the treble, which implies that the speaker ought to primarily be perceived as pretty near “neutral” as long as you’re not listening from very shut. We’re not too delicate to slim peaks and dips, and this can be a higher consequence than some correct hi-fi audio system. I believe the curve could be even smoother if I’d taken measurements in tighter intervals. The information above additionally tells us that in a stereo setup, this speaker’s extensive dispersion leads to an enormous soundstage; one thing I believed in my very own stereo listening.
Lastly, like most good audio system, the Transfer makes use of digital sign processing to boost bass efficiency. The trade-off is that Sonos locations a quantity restrict on the bass to guard the drivers from going kerplunk. On this subsequent suite of measurements, the info is not quasi-anechoic, so it contains room reflections and the total bass extension, and due to this fact appears wavier in its decrease half. We will see how the bass efficiency adjustments from 50 p.c quantity to 100 p.c.
The Sonos Transfer places out a exceptional quantity of bass for a small speaker as much as about 85 dB- which is louder than comfy for most individuals within the first place. It extends right down to about 40Hz, which is greater than most correct bookshelf audio system. It won’t put out the loudest bass outside, the place there are fewer reflections to strengthen the sound, however 85 dB needs to be greater than loud sufficient for many indoor eventualities. When you move that degree, the bass is restricted to 100Hz, which isn’t too unhealthy.
Crucially, the above graph additionally reveals that in a typical room, the squiggles within the earlier quasi-anechoic knowledge are of little relevance – the speaker primarily has a balanced distribution of frequencies(with the anticipated downward tilt) when you issue within the reflections of a typical room. (Be aware the notch round 50-80Hz is an artifact of my room, not the audio system).
The Sonos Transfer might not be the head of hi-fi, however it’s a speaker that appears to rigorously steadiness general sound high quality with its meant use as a Bluetooth speaker and its promise of great sturdiness. It could “just” be a Bluetooth speaker, however it’s clear some actual consideration went into its acoustic efficiency – as one would hope for $399. Sonos could make merchandise for on a regular basis shoppers, if the Transfer is something to go by, its audio chops aren’t any joke both.
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Revealed January 23, 2020 — 00:38 UTC
ProductTransfer by Sonos