Slide One

This unsurpassed technology is what we call VOLTAiR within our Professional Fidelity series. It lets you enjoy music on the same level as the mastering engineer.

Slide One

SPL Gemini

Mastering M/S Processor

Gemini is the first M/S Mastering Processor in 120V technology.

With Gemini, M/S processing enters the SPL Mastering series. Gemini is an M/S Encoder and Decoder. Mid signals (voice, snare, bass …) can clearly be seperated from side signals (guitar, spatial sounds, cymbals …) and can individually be processed. When working on the sum signal, M/S coding often is the best way to specifically get access to individual elements within a mix.

Gemini also provides the possibility to work on the stereo panorama. With the Balance control you can position the mid signal within the stereo panorama. With the Trim control, you can adjust the level of the mid signal in relation to the side signal. In connection with the Stereo Width control, the mixing ratio of both channels can be adjusted.

An Elliptical Filter, which can cut low frequency ratios of the side band is also provided.



  • Max. Input Level: +32,5 dBu
  • Input Impedance: 20 kOhms (bal.)


  • Max. Output Level: +32,5 dBu
  • Output Impedance: ‹ 100 Ohms (bal.)
  • Noise (A-weighted, Insert, Balance & Trim, Filter & Width = active): -98,2 dBu
  • THD & N (at +20dBu): › -110 dB
  • Common-Mode-Rejection (at 0 dBu): -79 dB
  • Transmission Bandwidth: 10 Hz-150 kHz

Power Consumption:

  • 0,11 Amp, 230V/50Hz, 24 Watt, 32 VA
  • 0,22 Amp, 115V/60Hz, 24 Watt, 32 VA


  • 230V/50Hz: 0,5 Amp
  • 115V/60Hz: 1 Amp


  • Standard EIA 19 Inch Housing/1U: 482 x 44 x 300 mm / ca. 19″ x 1.73″ x 11.8″ (front panel excl.)
  • Weight: 5kg / 11 lb