SPL Transient Designer 4 Quad-Channel Envelope Dynamics Processor

The Transient Designer offers a completely new technology for level-independent shaping of the dynamic response of a sound: For the first time it is possible to control the attack and sustain behaviour of a signal in a very simple way! Unlike other dynamic devices, the processing is not goverened by the signal level but rather by its dynamic envelope, so all signals (loud and soft) are processed equally.

With no effort, you can accelerate or slow down attack and prolong or shorten sustain portions of all kinds of percussive signals, such as bass drum, snares, toms, congas, etc. Let them jump into your face or flatten them with a turn of a single knob. Booming toms for example are dried up in seconds — it's almost like being able to change the amount of drum damping after the recording. Your idea of a kick drum sound is a kick drum in the words best sense? Just dial it in.

The same applies to virtually any other signal: Amplify or reduce the picking sound of an acoustic guitar, hold the sound of the strings longer, reduce the reverb time of a choir, actuate the piano pedal “electronically", turn down the slap bass a notch or give it even more attack, etc.

The Transient Designer provides a revolutionary concept for dynamic processing rendering controls such as Threshold, Ratio and Gain superfluous. The Transient Designer provides a very elaborated automation, so while the processing going on inside the box may be very complex, the user has to deal with just a pair of intuitive controls.

Differential Envelope Technology
SPL's Differential Envelope Technology is the first analog solution for level-independent shaping of envelopes allowing transients to be accelerated or slowed down and sustain prolonged or shortened. The degree of dynamic processing required to do this couldn't be duplicated even using a chain of several conventional compressors, yet only two controls per channel are required to allow the user to completely reshape the attack and sustain characteristics of a sound. Attack can be amplified or attenuated by up to 15dB while Sustain can be amplified or attenuated by up to 24dB, enabling weak drum sounds to be made much more percussive and powerful, or for over-percussive transients to be softened. All necessary time constants (Attack, Decay and Release) are automated and optimised adaptively in a musical manner according to the characteristics of the input signal. This results in natural sounding signal processing and fast operation.

How does it work?
The Transient Designer uses envelope followers to track the curve of the natural signal so that optimum results are guaranteed regardless of the input signal's dynamics. Because of the level-independent processing inherent in Differential Envelope Technology (DET), manual threshold adjustments are not required.

Sound benefits

• The attack of a bass drum or a loop can be emphasised with a single control to increase the punch and the penetration in the mix
• Sustain of a snare or room-sound can be shortened very musically to clean up the mix for more transparency
• Acoustic or electronic instruments become "in the face" sounds or can be smoothened with lower attacks
• De-verb capability! Less Sustain shortens reverb flags of any sound (more elegant than gates do)
• New panorama effects based on different dynamic effects per channel – try this with loops for example

Other features and connectivity
For stereo operation the Link function connects channel pairs (1 and 2 and/or 3 and 4). Linked channels are controlled by the same side-chain voltage so as to maintain a coherent and stable stereo image. When operating in Link-mode, the control elements of the first (or third) channel, including the Active switch, control the second (or fourth) channel, too.

Each channel is equipped with a relay hard bypass circuit to ensure a minimum signal path when the process is bypassed and to provide power fail safety. The Signal-LEDs allow to quickly monitor the signal flow, which is particularly important if the four channels are connected to a patchbay. The Transient Designer is fitted with XLR-connectors for balanced operation. To improve signal quality, SPL has developed a new hybrid-component balanced input/output stage using all laser-trimmed resistors with a tolerance of 0.01%. This approach has resulted in an exceptionally high CCMR (common mode rejection) better than -80dB at 1kHz.