The Realistic Mach 2 is a stereo floor speaker sold by Radio Shack. Each Mach 2 has a power handling capacity of 160 watts, with a frequency response of 24 to 40,000 Hz. The Mach 2 is classified as a three-way speaker, meaning it is equipped with a tweeter for high frequencies, a midrange speaker and a bass speaker. When the speakers are connected to a stereo receiver with a subwoofer and other components, you can set the crossover to improve the performance of the system. The crossover control tells the receiver which audio frequencies to send to the Mach 2 speakers.
Turn on the power to the stereo system and play back an audio source, such as a CD. Adjust the volume to a comfortable level.
Dial the crossover control knob on the stereo receiver to a setting at least 24 Hz or above. This is the lowest end of the audio frequency response range that the Mach 2 speaker can reproduce. Setting the crossover at 24 Hz or higher will direct all audio frequencies above this level to the Mach 2 speakers.
Adjust the crossover setting to between 60 Hz and 100 Hz when the Mach 2 speakers are used with a powered subwoofer. This directs all low-frequency effects below 100 Hz (or 60 Hz, if that setting is used) to the subwoofer. Sending these frequencies to the subwoofer takes some of the burden off the Mach 2 speakers so the overall system operates more efficiently.