As a company our main aim is to design and manufacture equipment
which gives you the maximum sonic performance for the price.
And to do this we use many unconventional solutions and the AZ-Series speakers are no exception to this.
All the AZ Series speakers share the following design features:
Rear loaded folded quasi parabolic horn with rear facing mouth;
Floorstanding with built-in spikes;
High efficiency, and more importantly best possible dynamic power transfer behaviour to maximise acoustic output to power input.
In our quest to deliver a compact high sensitivity speaker with good room interface we have reinvestigated and re-evaluated all the main principles of horn loaded cabinet designs, and this knowledge coupled with our expertise in system dispersion and associated crossover design, has resulted in a speaker system that redefines not only the quality-price relationship at any level which is important when making basic comparisons to the competition, but more importantly the AZ Series speakers offer an emotional quotient of reproduced acoustic performances that is quite in a class of its own.
The vast majority of directly radiating diaphragm designs have very poorly matched acoustic impedance resulting in the characteristically low efficiency, in contrast a horn loaded system where a suitable geometric design of the horn mouth and internal expansion rate allows the acoustic impedance to be optimised to match that of the driver across several octaves, resulting not just in higher efficiency but also in better dynamic power transfer from the amplifier.
This better matching achieves two important benefits, firstly the efficiency is greatly increased and secondly, the resistive termination presented to the diaphragm reduces the amplitude of any response anomalies.The greatest problem of horn loaded systems is physical size. For a simple horn the lower cut-off frequency is directly proportional to the effective diameter of the mouth when radiating into free space, for example a cut-off frequency at - 3dB of 50Hz would require a horn mouth area of 3.8 square meter! Clearly unsuitable for most domestic purposes.
The most important consideration must therefore be to first reduce the size requirement whilst maintaining the low frequency response. To do this the rear of the diaphragm needs to be loaded by an inductive impedance component. This can be designed by re-configuring the parameters of the horn flare to off-set the increasingly capacitive throat impedance below the cut-off frequency. This, in combination with a speaker position that takes advantage of close proximity to room boundaries (wall or corner) reduces the radiation impedance further. With corner positioning the bass horn mouth area is effectively increased by a factor of 16 when placed against a wall, providing a substantial boost at low frequencies.
In the AZ-Series horn, rear diaphragm radiation is controlled by critically positioned acoustic impedance matched foam, further aiding low frequency performance by levelling out the amplitude of standing waves.
In common with our more conventional ported speakers, the Zero AZ Series speakers are designed to be placed very close and at an angle to a rear wall or preferably with the rear horn mouth firing asymmetrically into a corner close to he side walls, this positioning has been chosen because being a horn it improves bass response and low frequency cut off for reasons already discussed.It is vitally important to understand that the proximity of the AZ-Series to the rear wall or corner, if you experience problems with the bass, try moving the speaker closer to the wall, or try to change the angle of the speaker.
The best performance is achieved by corner placement and if placed in a corner, the AZ-Series should be angled so that the on-axis line of the drive units crosses about 1 - 2 meters in front of you, with the back corner of each speaker almost touching the side wall. Even in a hotel room it is possible to reduce the boom and bass resonance to a more than acceptable minimum, whilst still retaining good attack and depth of bass.