The challenge for powered subwoofers and their amplifiers
Audio quality and power efficiency have long been at odds when it comes to amplifier design. Traditional Class AB amplifiers， which account for about 90 percent of all amplifiers made， are capable of producing prodigious power and excellent sound， but do so at the expense of efficiency. In fact， up to 50 percent of these amplifiers’ energy is wasted， dissipated as heat. Heat becomes an added liability when such amplifiers， in the case of powered subwoofers， are enclosed in a speaker cabinet. Class D switching amplifiers， on the other hand， run cool and occupy relatively little space. Compact， lightweight and efficient， they are a sensible choice for the latest applications， especially when used for powering subwoofers. Typically， however， the sound quality achieved by typical Class D designs has not been suitable for the best audio applications， but new technology has improved these designs to compete with the best of traditional amplifier topologies.

Enter BASH® amplification
BASH (Bridged Amplifier Switching Hybrid) amplifiers represent a “best of both worlds” solution for subwoofer amplification， combining the sound quality of Class AB with the efficiency of Class D amplifiers. While a Class AB amp uses fixed supply voltage regardless of input signal， BASH uses a modulated switched mode power supply that tracks the input signal， supplying only the necessary voltage to the Class AB amp as needed. The latest BASH technology has gone through three core evolutions and is further refined in these latest ELAC Debut subwoofers.

Push-push/Pull-pull configuration
The SUB 2090 and SUB 2070 deliver perfect， clean and distortion-free reproduction of low frequencies， employing a push-push/pull-pull arrangement of the two woofers that eliminates vibrations and mechanical resonances. Positioned opposite to one another but electrically driven in parallel， the acoustical output of both drivers is added up， but the mechanical forces cancel one other. Hence， no mechanical distortion remains to compromise the purity of the bass spectrum.

Down-firing driver
Allowing for more flexible speaker placement and to minimize ventilation noise， the bass reflex port of the SUB 2050 and SUB 2030 is directed out the bottom of the enclosure in a down-firing orientation.

Advanced Bluetooth® control
SUB 2090， SUB 2070 and SUB 2050 subwoofers incorporate an advanced， digital control system. Analog rotary potentiometers and switches have been replaced by a digital signal processor (DSP)， which allows users to adjust the subwoofer conveniently and accurately. All parameters， such as volume， cutoff frequency， phase etc.， as well as the automatic calibration function， can be conveniently adjusted with the help of the ELAC app.

Auto power On/Off
Debut subwoofers will detect when audio is being sent to the unit and power the unit on. Also， to conserve energy， the subwoofer will power off after a long period of inactivity.