The 7521a comes outfitted with a variable 12dB per octave electronic crossover allowing you to optimize system tuning based on speaker location and accompanying loudspeaker components. 

 A variable bass boost circuit is provided to optimize the low fequency performance of your system. 

 Full range preamp outputs are provided facilitating multiple amplifier hookups without the need for costly Y-adapters or signal splitters. 

 High-level and low-level input are provided allowing you to interface the Reference 7521a with either an aftermarket or factory installed head units. 

CEA Rated: Yes 
Power Output: 97 watts RMS x 2 channel at 4 ohms and ? 1% THD + N 142 watts RMS x 2 channel at 2 ohms, 14.4V supply and ? 1% THD + N 
Signal-to-Noise Ratio: 83 dBA (reference 1 Watt into 4 ohms) 
Dynamic Power: 190 watts at 2 ohms 
Effective Damping Factor: 6.389 at 4 ohms 
Frequency Response (-3dB): 10Hz to 69kHz (-3dB) 
Maximum Input Signal: 5.5V 
Maximum Sensitivity: 240mV 
Output Regulation: .078 dB at 4 ohms 

 A variable bass boost circuit is provided to optimize the low fequency performance of your system. 

 Full range preamp outputs are provided facilitating multiple amplifier hookups without the need for costly Y-adapters or signal splitters. 

 The 7540a comes outfitted with a variable 12dB per octave electronic crossover allowing you to optimize system tuning based on speaker location and accompanying loudspeaker components 

 High-level and low-level input are provided allowing you to interface the Reference 7540a with either an aftermarket or factory installed head units. 
CEA Rated: Yes 
Power Output: 111 watts RMS x 4 channel at 4 ohms and ? 1% THD + N 278 watts RMS x 2 channel at 4 ohms, 14.4V supply and ? 1% THD + N 
Signal-to-Noise Ratio: 81dBA (reference 1 watt into 4 ohms) 
Dynamic Power: 164 watts at 2 ohms 
Effective Damping Factor: 6.315 at 4 ohms 
Frequency Response (-3dB): 10Hz to 100kHz (-3dB) 
Maximum Input Signal: 5.5V 
Maximum Sensitivity: 230mV 
Output Regulation: .088 dB at 4 ohms

 High-level and low-level inputs are provided allowing you to interface the Reference 5761a with either an aftermarket or factory installed head unit. 

 The 5761a comes outfitted with three variable 12dB per octave electronic crossovers allowing you to optimize system tuning based on speaker selections and location. 

 Optional remote level bass control available. 
CEA Rated: Yes 
Power Output: 56 watts RMS x 4 channels + 107 watts RMS x 2 channels at 4 ohms and ? 1% THD + Noise 148 watts x 2 + 287 watts x 1 at 4 ohms, 14.4V supply and ? 1% THD + N2 
Signal-to-Noise Ratio: 82dBA (reference 1 watt at 4 ohms) 
Dynamic Power: 117 watts (channels 1,2,3,4); 163 watts (channels 5,6) 
Effective Damping Factor: 6.373 at 4 ohms 
Frequency Response (-3dB): 10Hz to 57kHz (channels 1,2,3,4) 10Hz to 302Hz (channels 5,6) 
Maximum Input Signal: 6.3V 
Maximum Sensitivity: 250mV 
Output Regulation: .063dB at 4 ohms 

 The Reference 311a features a 12dB per octave electronic crossover, allowing you to optimize bass performance based on enclosure type and subwoofer selection. 

 Full-range preamp outputs faciliate use of multiple amplifiers without the need for noisy and expensive adapters or signal splitters. 

 Optional remote level bass control available. 

 Dynamic Bass Optimization™ (DBO) circuit – Provides variable filtering with adjustable "Q" below 100Hz, far beyond conventional "Bass EQ" circuits, by allowing the low-frequency output to be optimized for specific subwoofer applications. 
CEA Rated: Yes 
Power Output: 116 watts RMS x 1 channel at 4 ohms and ? 1% THD + N 
Signal-to-Noise Ratio: 81 dBA (reference 1 watt into 4 ohms) 
Dynamic Power: 347 watts at 2 ohms 
Effective Damping Factor: 6.398 at 4 ohms 
Frequency Response (-3dB): 17Hz to 302Hz (-3dB) 
Maximum Input Signal: 6V 
Maximum Sensitivity: 250 mV 
Output Regulation: .05 dB at 4 ohms 

 Full-range preamp outputs faciliate use of multiple amplifiers without the need for noisy and expensive adapters or signal splitters. 

 The Reference 611a features a 12dB per octave electronic crossover, allowing you to optimize bass performance based on enclosure type and subwoofer selection. 

 Dynamic Bass Optimization (DBO) - This provides variable filtering with adjustable "Q" below 100Hz, far beyond conventional "Bass Q" circuits, by allowing the low-frequency output to be optimized for specific subwoofer applications. Frequencies below an enclosure's tunign frequency can be attenuated, preventing damage to the subwoofer and allowing the amplifier's power to be better utilized. 

 Optional remote level bass control available. 
CEA Rated: Yes 
Power Output: 456 watts RMS x 1 channel at 4 ohms and ? 1% THD + N 657 watts RMS x 1 channel at 2 ohms, 14.4V supply and ? 1% THD + N 
Signal-to-Noise Ratio: 70 dBA (reference 1 watt into 4 ohms) 
Dynamic Power: 761 watts at 2 ohms 
Effective Damping Factor: 6.336 at 4 ohms 
Frequency Response (-3dB): 17Hz - 251Hz 
Maximum Input Signal: 6V 
Maximum Sensitivity: 250mV 
Output Regulation: .179 dB at 4 ohms 

 The Reference 1211a features a 12dB per octave electronic crossover, allowing you to optimize bass performance based on enclosure type and subwoofer selection. 

 Dynamic Bass Optimization (DBO) - This provides variable filtering with adjustable "Q" below 100Hz, far beyond conventional "Bass Q" circuits, by allowing the low-frequency output to be optimized for specific subwoofer applications. Frequencies below an enclosure's tunign frequency can be attenuated, preventing damage to the subwoofer and allowing the amplifier's power to be better utilized. 

 Full-range preamp outputs faciliate use of multiple amplifiers without the need for noisy and expensive adapters or signal splitters. 

 Optional remote level bass control available. 
CEA Rated: Yes 
Power Output: 854 watts RMS x 1 channel at 4 ohms and ? 1% THD + N 1300 watts RMS x 1 channel at 2 ohms, 14.4V supply and ? 1% THD + N 
Signal-to-Noise Ratio: 72 dBA (reference 1 watt into 4 ohms) 
Dynamic Power: 1516 watts at 2 ohms 
Effective Damping Factor: 6.357 at 4 ohms 
Frequency Response (-3dB): 17Hz to 302Hz (-3dB) 
Maximum Input Signal: 5.7V 
Maximum Sensitivity: 260mV 
Output Regulation: .132 dB at 4 ohms