The world's first broadcast quality miniature portable audio mixer, the SQN-3, was produced in the Isle of Man in June 1980.

No sooner had development of the SQN-3 Series 2000 been resolved than improvements to the Betacam by provision of a stereo sound input led SQN's broadcast customers to demand a stereo mixer of similar size and performance to the SQN-3M. Development of the SQN-4S 4:2 mixer began. Those customers insisted that this mixer should feature twin Peak Programme Meters in accordance with standard British broadcasting practice. The challenge was duly met and the first prototypes of the SQN-4S were exhibited at IBC, Brighton, in 1984.

The series IVe was introduced in November 1999 and greatly pleased those who had been critical of the now superseded series IV. The second M-S decoder, on Channels 3 and 4, was omitted and switcing of the 4 Channel output was made a function of the connector rather than a front panel switch. A new limiter circuit took account of the fact that many users appeared to treat this device more as a compressor. Low current LEDs were installed for meter illumination in lieu of the earlier Betalites. Numerous other detailed improvements were included despite the continuing success of the SQN-4S in the market place, there had always been a pent up demand for an even smaller stereo mixer. The logical size for SQN to use would be the same as the ever popular SQN-3M, but just how useful could such a small mixer be, considering the limited space for controls?

In such a small case it would not be realistic to include all the facilities of the SQN-4S if the controls were to be accessible in professional recording work. After reviewing carefully the actual use that most recordists made of the SQN-4S, we concluded that by taking advantage of our considerable design experience, it would indeed be possible to provide what most people really needed in this small enclosure.

And so in June 2002, the first SQN-2S 4:2 mixer was produced. It features the same Peak Programme Meters (or VU-meters if preferred) as its parent SQN-4S and the same limiter circuits. It also has the same Mic amplifiers and facilities for Channels 1 and 2, but Channels 3 and 4, intended primarily for radio mic. inputs have reduced facilities. Its weight, 1.1kg is exactly half that of the SQN-4S and 0.2kg lighter than the SQN-3.