- A sound has fundamental 440. How could it be ring modulated to
give a tone at 110 Hertz with only odd partials? How could you then fill in the
even ones if you wanted to?
- A sinusoid with frequency 400 and unit peak amplitude is squared. What
are the amplitudes and frequencies of the new signal's components?
- What carrier and modulation frequencies would you give a two-operator FM
instrument to give frequencies of 618, 1000, and 2618 Hertz? (This is
a prominent feature of Chowning's
*Stria*[DJ85].) - Two sinusoids with frequency 300 and 400 Hertz and peak amplitude
one (so RMS amplitude 0.707) are multiplied. What is the RMS
amplitude of the product?
- Suppose you wanted to make FM yet more complicated by modulating the
*modulating*oscillator, as in:

How, qualitatively speaking, would the spectrum differ from that of the simple two-modulator example (Section 5.5)? - A sinusoid at a frequency is ring modulated by another
sinusoid at exactly the same frequency. At what phase differences will the
DC component of the result disappear?