Most users set the channel volume to maximum and then lower the master volume. This is incorrect. The manual explains the "unity gain" method:
Features 4 input channels, making it ideal for combining microphones, guitars, and audio players simultaneously. Portable & Reliable: audio choice qm4 manual better
To get the best performance from your system, follow these manual setup steps based on professional PA system guidelines : Most users set the channel volume to maximum
Heat is the primary cause of component "drift," which makes the amp sound muddy over time. making it ideal for combining microphones
: Features combo 1/4" and XLR inputs on each of its four channels, making it versatile for microphones and instruments alike.