The response of a resonant chain of spheres to
changes in holder material and precompression is studied at
ultrasonic frequencies. The system is found to be very sensitive to
these parameters, with the creation of impulsive waveforms from
a narrow bandwidth input seen only for certain chain lengths
and holder materials. In addition, careful experiments were
performed using known amounts of precompression force, using
a calibrated stylus arrangement. At negligible precompression
levels, impulses were generated within the chain, which were then
suppressed by increased precompression. This was accompanied
by large changes in the propagation velocity as the system
gradually changes from being strongly nonlinear to being more
linear. Simulations using a discrete model for the motion of each
sphere agree well with the experimental data.