[HAM] bass and rotating lesley drum, Benjamin

[benjamin]

  " I'm curious though if the bass rotor design of a normal leslie will effectively "rotate" lower bass frequencies and not just affect the higher bass frequencies..." 

Lower bass frequencies ; from about 100-120 Hz and lower till audible more or less between 25 or 30 Hz  will not have very much of a 'doppler' effect since the change in frequencie will be so minime that you will not hear the difference , what you can hear is the change in Volume from the sound giving some kind of 'tremolo ' I would say .. 
Plus these frequencies are difficult to locate in a closed place   , allthough you can think that you hear the bass changing ,   it will not be the fundamental basswave  but the harmonics that will give you the impression of the Lesley effect ..try it out you got the  drawbars on the hammond to experiment .... 
in all modern small and mediumsized bookshelf speakers the really low dawn bass waves ( under let's say 50 or 60 Hz ) are hardly present but the 2nd harmonic from the original basswave will give you the impression that you hear the bass .. it 's an utopia to think that a small bass enclosure can produce really low down thundering basswaves ... it's like a car engine you want muscle : you need big engines with big pistons , if you want low penetrating bass you need big speakers and big bass reflexes or horns  , ever seen a BASS Saxofone ?? it's a thing that measures about 2.5 metres ! I've seen it only once in my life 
and Bass waves  under 150 Hz are very dufficult to locate where they are coming from , not like higher frequencies .. that's why lesleys are so effective on the harmonics with their turning top horn (plus the dummyfor weightbalance) 

it's also the bass waves that need big powerfull amps .. for tweeters and midrange a small 20 watt amp can do wonders  while for the bass you will need easaly 50 or 100 watts to produce some decent sound , I talk about rms or effective continuous wave measured watts, not silly  peakpowers and the likes ...