SCL6 is a brand new scalable transmission codec developed by MQA. Considered one of its USPs is enabling high-quality wi-fi music streaming between a supply and receiver, equivalent to a smartphone and a pair of wi-fi headphones, at comparatively low knowledge charges.
Consider it as a rival to the likes of aptX HD and LDAC, with SCL6 claiming it could possibly protect extra data from the unique sign with the added bonus of additional scalability.
We lately travelled to MQA’s Huntingdon HQ to talk to the person behind the codec, Bob Stuart and expertise it for ourselves. And right here’s what we thought…
A little bit of background
As a result of nature of the expertise, all-digital audio codecs lose data after they’re packaged and despatched through wi-fi and SCL6 claims that utilizing its methodology of packing and unpacking loses the least quantity.
The primary function of the demonstrations we noticed was to point out how efficient SCL6 is at doing this, whether or not being performed over a Bluetooth, wi-fi or Extremely-Vast Band wi-fi connection.
Not solely does SCL6 declare to lose much less data, additionally it is absolutely adaptable and scalable, so it could possibly range its knowledge charge from 20Mbps (lossless) all the best way right down to 200kbps (lossy) relying on the standard of the wi-fi connection between the sending gadget and receiver. Because the connection will get weaker, SCL6 will scale down and decide up in actual time as quickly because it begins to get stronger.
It’s additionally value flagging right here that SCL6 can work with any file sort so this is applicable to something from an MQA file to a WAV or FLAC out of your favorite high-res streaming service. For it to work, although, you will want each the sending and receiving units to assist it, e.g. your smartphone and a pair of wi-fi headphones.
Sound high quality
After a dialogue and presentation on all issues SCL6 we have been guided into MQA’s demo room at its Huntingdon headquarters. It’s really the room the place every bit of MQA tools accredited by them for licensees is listened to, so it’s set as much as be as revealing as potential.
Trying on the footage, you would possibly suppose it’s fairly a compact set-up however because the staff evaluates utilizing nearfield listening it isn’t an issue. The system has been designed to focus purely on codecs and it’s all about extracting element within the sign processing. It makes use of a closely modified pair of floorstanding audio system, broad bandwidth amplifiers and a high-end DAC so the system majors in extracting element from the music being performed.
We begin the demo with a brief pattern of music by Shelby Lynne in 24-bit/96kHz. It’s being performed in what Bob refers to as MQB, which is sometimes how the staff internally refers back to the core sign that comes out of the primary unfold of an MQA file and is usually what you get out of the Tidal app. On this demo, it’s enjoying at 4.6Mbps. Bob then switches in realtime to enjoying the identical monitor in SCL6 working at 660kbps, which is across the center of Bluetooth vary.
And we’re shocked at simply how related the 2 tracks sound. Particulars such because the reverb and echo round totally different parts, and the dynamic intent of the monitor, appear to come back by means of unscathed. To additional emphasise the minimal affect SCL6 is having on the music, Bob then switches to enjoying the ‘error’, which is successfully the info enter minus the output. This enables us to listen to simply how a lot data is being misplaced when the SCL6 codec is in use. And it is just about inaudible.
Subsequent we hear one in every of Beethoven’s cello sonatas performed at 16bit/44kHz CD high quality – and Bob switches from this to the identical monitor in MP3 after which proceeds to play its error sign. The quantity of modulation noise, i.e. digital distortion, you may hear is sort of startling and instantly apparent.
It’s such as you’re listening to a messier, harsher, extra brittle model of precisely the identical monitor – it’s lots of data that’s being thrown away by the compression on an MP3 file. Bob then switches to enjoying us the error of the SCL6 model of the identical tune at simply 330kbps and, though there’s a bit of little bit of distortion in there, you hear loads much less of the meat of the unique tune – this means it’s eradicating much less of the very important data of the monitor.
To listen to SCL6’s scalability in motion, Bob reveals us a desktop App that’s been made right into a plug-in which may be accessed by means of Audirvana, the digital music participant. It permits him to play a monitor, and regulate in actual time the bitrate of the music by merely shifting his finger up and down a sliding scale on his touchscreen laptop computer.
We’re performed a CD-quality file of Oscar Peterson, Milt Jackson and Ray Brown enjoying Nature Boy in SCL6, beginning excessive up the vary in lossless high quality earlier than dropping right down to round 300-500kbps. You continue to appear to listen to some compression going down, however the texture of the xylophone, the sense of refinement and the rhythm of the monitor appear to come back by means of comparatively unscathed.
Preliminary verdict
It was fascinating to take heed to a demo that wasn’t essentially about sounding higher than different options on the market, however about being extra environment friendly and dealing with the digital data higher.
Listening to the quantity of knowledge some codecs throw away as a consequence of compression was a little bit of an eye-opener as was the demo of the codec’s scalability – the variety of steps it was in a position to undergo was very spectacular, as was its obvious skill to keep up the essence and authenticity of the unique on the lowest knowledge charges. It’s an fascinating, thought-provoking expertise which may have a big effect on wi-fi audio – all we’d like now are appropriate sources and receivers so we will take it for a spin!
MORE:
What’s SCL6? All of the information on the way forward for wi-fi audio
MQA pronounces new hi-res MQair codec for wi-fi units
I attempted aptX Lossless Bluetooth – and sure, we will all sit up for it (with warning)
