I have been experimenting lately with Emulator X as a synthesizer rather than a sampler, i.e., using only primitive sources (impulse, noise, etc.) and generating new timbres based on the filter section and other features of synth engine.
In one such experiment, I have built several patches based purely on the impulse responses of filters. By setting the Q of each filter (or each section in the Morph Designer), a highly tuned impulse response is produced. The center frequency can be controlled by keyboard input, thus creating a primitive but “playable” instrument. The following example uses a cascade of tuned two-pole filters on a single voice:
The more complex Z-plane filters can also be used to generate interesting impulse responses, though they are more difficult to control in terms of pitch:
In each of the examples above, the responses decay very quickly, yielding short percussive timbres. Longer decays require narrower-band filters, and even though the E-MU filters have very high Q (resonance), most are not narrow enough when compared to the filters used in resonance modeling The exception is the rarely used Contrary Bandpass filter:
The impulse response of this filter is a nearly pure exponentially-decaying sinewave. Combining several voices with different center frequencies, complex resonance models can be generated.
Of course, these examples are far less efficient than the resonance-modeling tools Open Sound World, but by combining the models with Emulator X's modulation features, effects and voice management, some more interesting instruments can be created.