For most audiophiles, listening to a pair of AT-1s for the first time on demanding material with extremely low bass is a bit of a shock. Loudspeakers of this modest size with a pair of small 514-inch woofer-midrange drivers just arent supposed to do thatshake the room. But the AT-1s deliver that kind of impact. Even at moderate levels, there is a degree of bass power combined with acoustic detail rarely experienced in speakers of any size or price. In the case of the AT-1, hearing is believing.
In short, H-PAS technology provides greater extended low frequency range, and/or greater output, with increased dynamic range and impact at those extended low frequencies. It can be scaled to fit many size cabinets, small to large. Higher SPLs are inherent to the design, as is low distortion, which in turn negates any requirement for costly high-power amplification.H-PAS does not require the use of special drivers, any kind of on-board electronics or outboard equalization -- it is a purely passive system, completely compatible with all AV receivers and stereo amplifiers. Employing a unique cabinet design, the elements of the different speaker technologies are cascaded one to another in such a manner as to pressurize and accelerate the very lowest frequency back waves as they travel through the cabinet. These waves are then radiated into the room through a vent at the lower front of the cabinet. There is an acoustic crossover from the vent to the bass drivers and the upper bass and midrange regions are propagated directly from the woofers cone. An important additional feature, integral to the design, is an acoustic bass trap. Signals travel through this internal passive resonance/harmonic distortion line filter to further reduce unwanted distortion for clean, tight bass. As a result, the AT-1 delivers extended deep bass with high output levels, and exceptionally low harmonic distortion. The central tenet of this new design approach is somewhat counter intuitive. Instead of using heavy, low-resonance drivers to achieve low bass, H-PAS utilizes quick, high-resonance bass drivers. The internal matrix of the cabinet takes the back wave of the driver below its resonance and pressurizes and accelerates it before it exits the vent. This acceleration increases the impact of the highly pressurized air flow in the enclosure when it leaves the vent. The result is both extended low bass and greatly improved dynamic range at such lower frequencies. The internal workings of the cabinet (using very specific, mathematically-derived ratios between the various cabinet/driver relationships) are such that the low frequency efficiency of the system actually increases with decreasing frequencyexactly the opposite of conventional system behavior, where output below resonance drops rapidly. H-PAS produces a reciprocal output of the high-resonance drivers natural rolloff, yielding flat acoustic response to well below that of conventional designs using like-sized drivers and cabinets. The use of lighter, higher-resonance woofers also means that the AT-1s H-PAS system exhibits lightning-fast transient response and incredible bass detail compared to the slower high-mass, low-resonance drivers needed to achieve reasonable deep bass extension in ordinary speakers.
- Type: H-PAS, M-T-M
- Woofers: (2) 5 1/4" long excursion GLH Graphite Loaded Homopolymer
- Tweeters: 1 1/8" low-resonance soft dome with 4 mm oversize low-throw surround and integral back chamber/heat sink
- Frequency Response: 29Hz 20kHz 3dB
- Nominal Impedence: 6 Ohms
- Crossover Frequency: 2kHz
- Crossover Type: Parallel; 2nd-order LP, 3rd-order HP
- Sensitivity: 89dB
- Recommended Power: 20 200 Watts RMS
- Dimensions w/ grilles (W x H x D): 8 7/8" x 41" x 13 3/4 " (227 x 1041 x 348mm) Feet add another 1" to height
- Weight (ea): 54 lbs; 25kg ea