The multi-chamber acoustical transformer

This is the most often question we are asked: where the subwoofer is hidden? Really spectacular is the bass performance of small and light 4-5'' drivers. The answer is in the special loudspeaker enclosure, acting as "virtual subwoofer".
We offer a fully new type of bass enclosure, called as multi-chamber acoustical transformer. This technology matches the loudspeaker acoustical load in wide frequency range. An actual lower cut-off frequency of 16-18 Hz was achieved in real prototypes, with efficiency gain over 20 dB at lower frequency!
In fact, this enclosure replaces the bass woofer - our two-way loudspeakers have the same bass performance, as usual three-way ones. Bulky low-frequency crossover is no more needed. Since the multi-chamber transformer provides stronger acoustical load to the driver, its displacement and corresponding distortion is reduced heavily.
Multi-chamber technology was successful, so that we use it in all our loudspeakers. The innovation has been confirmed in 2008 by Russian Patent № 2377738 RU.


A bit theory: Multi-chamber transformer is a complex geometry structure, where the acoustical impedance decreases from the driver to the radiating port. In first chamber after the driver, high pressure and low air flow are presented. In last chamber before the port, it transforms to low pressure but high air flow, that matches more to low open air acoustical impedance.
From math point of view, this structure is identical to a horn or expanding waveguide. Its input impedance is matched with the driver, and the output one - with open air load.

By changing of elements geometry, linear frequency response can be formed, and phase / group delay can be corrected. Multi-chamber transformer works in a frequency range up to 3-4 octaves, with fast roll-off at upper frequency. An efficiency gain over 20 dB at lower frequency can be achieved above the same driver in an infinite baffle, .
Comparing to usual vented boxes, our enclosure expands the frequency range up to 1 octave, or provides increased efficiency by the same lower frequency. Moreover, unlike the resonance kind of vented box or band-pass, the multi-chamber transformer is an aperiodic system with linear phase and group delay response.