Sanus Verus speakers development core based on CTC (coherent transition crossover). Before 2005 - when CTC was founded- we tried different crossover topologies – active, passive types in various configurations:
- A true 1st order crossover without any correction circuits ( for that purpose we designed custom drivers- there was no tweeter in market to work with real 1st order electrical crossover without impedance correction circuit)
- Corrected 1st order crossover.
- 2nd,3rd,4th order crossovers in various transfer and time alignments.
- Active analog crossovers
Over time we realized general crossover sonic tendencies (which did not changed with different designs)-
a crossover with few parts and gentle slopes in general had more effortless,spacious, dynamic, lively, natural and coherent sound, letting speakers “disappear” more easily. Higher slopes xovers,on the other hand, had better focus, midrange palpability and did not let images “crash” at more complex recordings. With some efforts over time it was possible to reduce some general flaws of higher order crossovers, but it was just reduction, not elimination. In spite worse measured and heard performance low slope crossovers had some subjective “effortless” sound which was just more “right” to ears. At some point there was clear that it was impossible “to get everything” going in traditional way and also confess fact that we were going in circles. We started experiments then in quite radical way and founded some interesting combination of passive crossover implementation which we named coherent transition crossover (CTC).
CTC have quite unique characteristic common to low and high order crossovers. It‘s something between these two. Technicaly CTC is based on series type of passive crossover, but its implementation is unique in several ways, and one of them is the way both drivers and crossover components interact together. With only 4 discrete components forming high/ low pass function in whole speaker crossover Colibrea have more than 24db/oct slopes instead of expected 6db/oct roll off. We also should note that this happens in both drivers full acoustical output range. The nature of CTC also enabled to implement some other unusual decisions which determined basic of unique speakers sonic signature.
A further each CTC we made are encapsulated and potted in box to prevent from vibrations (under extreme conditions inside and outside speakers) and also industrial espionage. We don’t claim it’s an absolute revolution, but we also do not want to be responsible for poor implementation of CTC(which is realy hard to implement in speaker development with ordinary drivers) , degrading its name and Sanus Verus team efforts.