Check headphones and audio playback systems with a free online tone generator that provides accurate frequency control from 20 Hz to 20 kHz. Play sine, square, sawtooth or triangle waves and compare left and right output independently. The built-in sweep mode makes it easier to notice frequency peaks and dips, while preset tones provide quick access to commonly used test frequencies a... https://aitoolspros.com/tools/audio/tone-generator/