Yep. Most male voices have some asymmetry. No clipping or tricks needed to modulate more in the positive direction, assuming the modulator is capable.
Brian... give this a try ...a good quality microphone directly to the vertical input of an o-scope ...normal hortz sweep for audio range ... as the Steves have mentioned there is considerable asymetry in the voltage swing but the area under the curves ( + and - ref to zero base line) are equal ... interesting ...73....John
