Multiple Compression Modes
SQ1D features a “Vintage” switch allowing the selection of the default RMS sensing compression mode, or when engaged, an emulation of many older compressor designs with exponential attack and release envelopes. When used in conjunction with the “Hard Knee” switch, SQ1D provides several different forms of compression to suit a wide range of programme material. By default, SQ1D offers a Soft Knee response, however when the “Hard Knee” switch is activated, a Hard Knee response is provided instead.
With both mode switches inactive the compressor behaves in the default RMS and Soft Knee modes. This gives the slowest (and most subtle) feel to the compressor envelopes. The soft knee curve combines with the adaptive RMS attack and release times to produce gentle envelope responses that are ideal for compressing sung vocals, but which can still be aggressive enough to limit transients when needed. The Soft Knee curve also reduces the adaptive nature of the RMS detection slightly, providing a little more manual control of the envelope timings than is the case below.
When the Hard Knee response is used with RMS mode, the compressor operates in a more clinical way with a more defined transition between under threshold and over threshold - this is better suited to limiting style compression. A small amount of the soft knee curve is still retained keeping the sound reasonably natural but with no modification of the compressor envelope. This means that attacks are more aggressive, but it also allows the adaptive nature of the RMS detection to operate to its fullest extent. This mode is good for natural sounding limiting of speech.With the “Vintage” switch active and the default Soft Knee response selected, the compressor employs a dual time constant, linear attack profile. This produces extremely subtle attack and release curves during the onset of compression that are largely independent of the envelope control settings. As the compressor is driven harder (i.e. signals further over threshold) the soft knee effect reduces, gradually returning manual control of the attack and release times to optimise capture of larger transients. Like the RMS modes, this compressor mode is very adaptive making set up of the envelope controls relatively easy. The peak sensing, however, increases harmonic overtones, which add a “Vintage” brightness and sparkle to the programme, producing extremely transparent and lively sounding compression of acoustic instruments.