Audio Note AZ-2 Speakers
Quality Quasi Folded Horn Design, Highly Musical, Very Compact Floor-Stander
The AZ-TWO is a floor standing, rear loaded, folded quasi parabolic horn design witha rear facing mouth, and uses two drive units per cabinet. It is very efficient and offers the amplifier an easy ʻloadʼ, making it highly suitable for our range of superior quality, low powered valve amplifiers.As a company, our main aim is to design and manufacture equipment that provides the maximum sonic performance for the price, and to achieve this we use many unconventional solutions. In our quest to deliver an affordable, compact, high sensitivity, wide frequency responseloudspeaker to suit ʻreal worldʼ rooms, we reinvestigated and re-evaluated the main principles of rear loaded horn cabinet design. This research, coupled with our expertise in driver, cabinet and crossover development, has resulted in a loudspeaker that not only redefines the quality / price relationship, but more importantly offers an emotionally engaging performance that is quite in a class of its own.
If you examine the vast majority of conventional loudspeaker designs, you will discover that they have very poor acoustic impedance characteristics, resulting in low efficiency. In contrast, a correctly designed horn loaded system allows the acoustic impedance to be optimized for the driver across several octaves, resulting in higher efficiency and better dynamic power transfer from the amplifier.However, horn designs are not without their challenges, and one of the greatest problems is physical size. For a simple horn the lower cut-off frequency is directly proportional to the effective diameter of the mouth; a cut-off frequency at - 3dB of 50Hz, would require a horn with a mouth area of 3.8 square meters.Clearly unsuitable for most domestic purposes!
So, we had to find a method of reducing the size requirement whilst maintaining the low frequency response. By re-configuring the size and shape of the rear horn flare, the (increasingly capacitive) throat impedance is off-set to a point below the cut-off frequency. This, combined with positioning the loudspeaker in close proximity to a corner further reduces the radiation impedance, and effectively increases the bass horn moth area by a factor of around x16 (x8 when placed against a rear wall), which provides a substantial boost at low frequencies.As with all Audio Note (UK)loudspeakers, no corners have been cut in terms of component and driver quality despite the modest price of the AZ-TWO. The woofer is the high quality unit found in the AN-E, and is combined with an upgraded version of the AN-K's 3/4" tweeter, a heavy-duty crossover featuring air core inductors, Audio Note (UK) silver plated speaker terminals and Audio Note (UK) AN-D internal wiring.
Consistent performance is a major issue in loudspeaker design and unfortunately all drive units vary slight from each other, even if they look the same and have the same basic specification. Many loudspeaker manufacturerʼs will tell you that they provide “computer matched” crossovers, and whilst this may be true in one sense (each crossover may have been matched to have the exact same capacitance, inductance and resistance) this essentially “passive” method does not adequately take into consideration the mechanical and acoustic variance present in the drive units themselves, where minute differences in acoustic behaviour will result in quite substantial differences in performance and sound.Therefore, to obtain the best possible combination of drivers and crossovers, we have developed a dynamic matching process. This ensures that each loudspeaker in a stereo pair matches aʻmaster curveʼ, and also its partner.
If you examine the vast majority of conventional loudspeaker designs, you will discover that they have very poor acoustic impedance characteristics, resulting in low efficiency. In contrast, a correctly designed horn loaded system allows the acoustic impedance to be optimized for the driver across several octaves, resulting in higher efficiency and better dynamic power transfer from the amplifier.However, horn designs are not without their challenges, and one of the greatest problems is physical size. For a simple horn the lower cut-off frequency is directly proportional to the effective diameter of the mouth; a cut-off frequency at - 3dB of 50Hz, would require a horn with a mouth area of 3.8 square meters.Clearly unsuitable for most domestic purposes!
So, we had to find a method of reducing the size requirement whilst maintaining the low frequency response. By re-configuring the size and shape of the rear horn flare, the (increasingly capacitive) throat impedance is off-set to a point below the cut-off frequency. This, combined with positioning the loudspeaker in close proximity to a corner further reduces the radiation impedance, and effectively increases the bass horn moth area by a factor of around x16 (x8 when placed against a rear wall), which provides a substantial boost at low frequencies.As with all Audio Note (UK)loudspeakers, no corners have been cut in terms of component and driver quality despite the modest price of the AZ-TWO. The woofer is the high quality unit found in the AN-E, and is combined with an upgraded version of the AN-K's 3/4" tweeter, a heavy-duty crossover featuring air core inductors, Audio Note (UK) silver plated speaker terminals and Audio Note (UK) AN-D internal wiring.
Consistent performance is a major issue in loudspeaker design and unfortunately all drive units vary slight from each other, even if they look the same and have the same basic specification. Many loudspeaker manufacturerʼs will tell you that they provide “computer matched” crossovers, and whilst this may be true in one sense (each crossover may have been matched to have the exact same capacitance, inductance and resistance) this essentially “passive” method does not adequately take into consideration the mechanical and acoustic variance present in the drive units themselves, where minute differences in acoustic behaviour will result in quite substantial differences in performance and sound.Therefore, to obtain the best possible combination of drivers and crossovers, we have developed a dynamic matching process. This ensures that each loudspeaker in a stereo pair matches aʻmaster curveʼ, and also its partner.
Room Placement
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 assymetrically 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-One 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-One 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.
If only a rear wall is available, it is still possible to get a fine boom-free bass response, and experimenting with the angle and distance to the rear wall is absolutely necessary inorder to get a good result. The inside rear corner of the speaker can be very close to the wall, as little as 5 centimeters is acceptable, with the speakers placed as far apart as the room allows.
With only a wall behind the speakers the bass output will roll off quicker than in the corner position, as the acoustic amplification provided by the room boundary (the wall) is less than half of that of the corner.
Another much overlooked area of acoustics is the material choice for the drivers. It is vitally important that the sound and characteristics of an individual drive unit are complimentary to those of its chosen partner, so that when an instrument is reproduced by both drive units (which is almost always the case), the upper range does not sound detached from the lower range and visa versa. This is an aspect of performance that cannot be measured by even the most sophisticated test equipment; it can ONLY be judged by listening.
It has become very fashionable to use all manner of exotic materials (beryllium, diamond, carbon fibre, ceramics etc.) as cone materials in modern drivers, mainly because it gives the impression that the manufacturer in question is making great strides in their research into better sounding speakers.The sad fact is none of thesematerials work as intended, as they all have their owndistinct sonic signature. No instrument manufacturer in their right mind would dream of making a trumpet from carbon fibre or Beryllium for example, or a cello or violin from aluminium or plastic (not if they were serious anyway!), so no matter how the crossover is designed, this sonic signature will be present when the speaker reproduces music. It may be less obvious and audible with some types of music, but ultimately the chosen material will always imprint some of its own signature on whatever sound is reproduced.
The best performance is achieved by corner placement and if placed in a corner, the AZ-One 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.
If only a rear wall is available, it is still possible to get a fine boom-free bass response, and experimenting with the angle and distance to the rear wall is absolutely necessary inorder to get a good result. The inside rear corner of the speaker can be very close to the wall, as little as 5 centimeters is acceptable, with the speakers placed as far apart as the room allows.
With only a wall behind the speakers the bass output will roll off quicker than in the corner position, as the acoustic amplification provided by the room boundary (the wall) is less than half of that of the corner.
Another much overlooked area of acoustics is the material choice for the drivers. It is vitally important that the sound and characteristics of an individual drive unit are complimentary to those of its chosen partner, so that when an instrument is reproduced by both drive units (which is almost always the case), the upper range does not sound detached from the lower range and visa versa. This is an aspect of performance that cannot be measured by even the most sophisticated test equipment; it can ONLY be judged by listening.
It has become very fashionable to use all manner of exotic materials (beryllium, diamond, carbon fibre, ceramics etc.) as cone materials in modern drivers, mainly because it gives the impression that the manufacturer in question is making great strides in their research into better sounding speakers.The sad fact is none of thesematerials work as intended, as they all have their owndistinct sonic signature. No instrument manufacturer in their right mind would dream of making a trumpet from carbon fibre or Beryllium for example, or a cello or violin from aluminium or plastic (not if they were serious anyway!), so no matter how the crossover is designed, this sonic signature will be present when the speaker reproduces music. It may be less obvious and audible with some types of music, but ultimately the chosen material will always imprint some of its own signature on whatever sound is reproduced.
