I use this controller since October 2005.
He manages a small system composed of the brand and RF14 speakers subwoofers SUB15P driven by QSC amplifiers.

This controller is expected to make bi-amplification only with a cutoff frequency of 100 Hz with a slope of 24 dB / octave (Linkwitz-Riley).
They come with a subsonic filter to 20Hz and Qualibre another filter to 22 kHz ultrasonic Qualibre.
The connection is done in and out on Neutrik XLR, balanced input and unbalanced output.
The high pass part of the spectrum is run in stereo, while the bottom is a single mono XLR output. To use an amp bridged or parallel mode.
There is also the possibility to control the gain of the low by a potentiometer on the front.

The quality of its rendered with such equipment is impressive. Fishing mad, no default. it does not bleed, no overlap of frequencies. In short, this is good.

At presentation, the controller is very small.
Indeed, it fits on a 1U front painted aluminum and about 15cm deep. The rest of the unit is in sheet steel painted black.
The build quality is very serious.

The only worry is that the manual is in French, only in Spanish and English.

Its price, while not exorbitant, is already substantial. Since it was 595 Euros HT Sennheiser costs. This gives us a 711.62 Euros.
But when you see the quality that this little controller is capable of providing a system, it's worth the cost.

Finally, I n'imagime not run my system with anything other than the CT1, so the top is made. And if it again, it would without any hesitation.