An 8 Channel Synthesizer

Specify the fundamental frequency and the amplitudes (in decibels, or db) for the first 8 modes, and the resulting sound wave (normalized to -3 db) will be plotted and played for three seconds. The top of each scroll bar corresponds to 0 db.

You need a Java-capable browser to be able to work with the synth applet.

Try the following:

Using Audacity, open this sample of a horn note.

Select about 0.1 seconds of the sample using the mouse, and choose "Plot Spectrum" from the "Analyze" menu.

From the first drop-down menu on the right, choose "8192", and from the second choose "Log frequency":

Mouse over the peaks (which start at around 200 Hz). Notice that they are approximately at multiples of the fundamental at 200 Hz.
When you mouse over the peak, it displays the frequency and the level in db. For the first 8 peaks, the levels are
0, 0, -4, -6, -8, -10, -6 and -12

Adjust the scroll bars for the mode amplitudes to look like those on the plot. It is easiest to do this by moving each scroll bar all of the way to the top, then clicking on the lower scroll pointer once for each decibel below 0 (so, for example, you click 4 times for -4 db).

Play the sound and compare the result to the original sample.

Of course, more voices and greater precision would produce a more accurate sound.

Enjoy!