2.1 Channel Speaker System
Created: May 18, 2015
No description available.
This is an example of a 2.1 Channel Speaker System that is regularly used in most personal computers or home theatres. This speaker system is rated 18watts rms at 10% THD each for the satellite speakers and 70 watts rms at 10% THD for the subwoofer. The circuit is composed of preamplifier stage, active crossover, and power amplifiers.
This kind of speaker system must have two or stereo satellite speakers and one subwoofer that is why the preamplifier stage is composed of two identical circuits to accept both signals coming from the left and right channel of the audio source. The preamp uses the Microchip MCP601T as its op amp and it has a passive equalizer based on a modified Baxandall tone control shelving at 100Hz for the bass and 10KHz for the treble.
At the active crossover stage, the signals coming from the left and right channels of the preamplifier will be filtered by two high pass filters for the left and right power amplifiers, and one low pass filter for the subwoofer amplifier. The crossover frequency was set at 120Hz with a 12dB/octave attenuation.
The three power amplifiers in this circuit are based on the TDA2030 and TDA1562 IC design of NXP Semiconductors. Two TDA2030 were used for the left and right satellite speakers and one TDA1562 for the subwoofer. The subwoofer uses the TDA1562 IC which is more powerful than the TDA2030 since low range frequencies consume more power than the mid and high range frequencies.