When a music signal passes through a crossover, it is delayed in time by the inductors used there. The larger the inductors, the greater the time delay. As there is no inductor (low-pass filter) in the signal path of the tweeter, the tweeter signal is not delayed and is emitted first, followed by the mid-range signal and finally the bass signal. Broadband impulses are therefore reproduced with time distortion and thus lose their dynamics and temporal coherence. The music appears less dynamic, and the attacks seem smeared.

In addition to the electrical delay, there is also a geometric signal delay because the tweeter cone is located further forward than the acoustic centre of the bass-midrange driver. However, the delay time caused by this offset is only 0.1 ms, in contrast to the electrical offset of approximately 2 ms.

It is therefore necessary to compensate for the time delay of the bass-midrange driver by delaying the tweeter by the corresponding amount so that both radiate simultaneously and acoustically recombine the original impulse. We achieve this with a special circuit that is integrated into the crossover. In other words, we delay the signal electrically.

Some manufacturers try to compensate for this by moving the tweeter backwards. However, with a delay time of 2 ms (which is a common value), this would require a rearward shift of 68 cm. This is absolutely impossible to achieve, as it would result in excessive reflection and diffraction effects on the surfaces and at the edges.

As our speakers all have very low crossover frequencies from the bass to the midrange (120 Hz to 166 Hz), and the ear is very insensitive in the bass range, there is no need for a time delay between the midrange and the bass. In addition, instruments in this frequency range naturally resonate much more slowly than the time difference generated by the coils.

Thanks to the uninterrupted reproduction with TDC, there is no longer any distortion in the acoustic phase of the loudspeaker, and the music detaches itself wonderfully from the loudspeaker, playing from "wall to wall" in the listening room and creating a perfect illusion of spatial sound.

The TDC technology, in combination with our ultra-steep crossover filters, creates perfect impulse reproduction for the first time in hi-fi history and can rightly be described as a game changer.