What does a multiple tone generator do?
It plays several pure tones at the same time and lets you control each one separately. A single tone tells you whether a speaker can reach a frequency. Two or more tell you what happens when frequencies meet — which is where most of the interesting behaviour lives.
Each channel here is its own oscillator. Change the pitch of one and the others stay exactly where they were. The mix runs through a limiter, so adding channels raises the detail rather than the distortion.
What are beats, and why do they matter?
Play 440 Hz and 444 Hz together and you don't hear two notes. You hear one note that pulses four times a second. That pulse is the beat, and its rate is simply the difference between the two frequencies.
This is how tuning by ear works. As you bring an instrument closer to a reference pitch, the pulsing slows down. When it stops, you're in tune. It's far more precise than trying to judge two pitches side by side, and it's why the beat rate is shown on this page as soon as two channels land within 40 Hz of each other.
Things worth trying
- Tune by beats. Set one channel to your target pitch, play your instrument against it, and slow the pulsing until it disappears.
- Hear an interval. Try 220 and 440 for an octave, then 440 and 660 for a fifth. Simple ratios sound settled; awkward ones sound tense.
- Build a chord. 440, 554.37 and 659.26 Hz make an A major chord out of nothing but sine waves.
- Test intermodulation. Play two loud tones through a speaker. If you hear pitches that aren't either of them, the speaker or amp is distorting.
- Check a three-way system. Put 60, 1000 and 8000 Hz on separate channels to see whether the woofer, mid and tweeter are all working.
- Pan them apart. Send one tone left and another right to hear how your room treats each side.
Why does the volume drop when I add tones?
Because eight tones at full level would clip. The page shares the available headroom between the channels that are playing, so the total stays in a safe range. Individual channel sliders still work exactly as you'd expect — they set the balance between tones.
If a mix sounds quiet, raise the volume on your device rather than pushing every channel to 100%. That keeps the tones clean.