scada said:
Who would be able to hear it?
You can 'feel' such frequencies (commonly things like feeling your sternum
pulsing), but you also have to be very careful. Some tones in this area,
can cause nausea in quite a few people. Normally, an electrically
controlled tuned Helmholtz resonator is used, rather than a traditional
'speaker', or a bass reflex system. Few standard transducers will go below
perhaps 10-15Hz. Even ULF Sonar systems commonly stop at around 18Hz. Few
transducers will be able to handle the 15:1 frequency range involved here
(band pass cabinets etc., have a very limited range).
The poster needs to find a transducer genuinely capable of handling this
frequency range _first_. No traditional 'speaker' on the market will do
so. Most will be active systems, with their own drivers, and this will
effect the signal input required. Seriously, expect to be suprised at the
price, and power requirements for such a transducer system.
The lowest frequency normally 'aimed at' for reproduction in a ULF speaker
system, is the 8Hz, representing the longest orgam pipe used in only the
very largest organs (most only go down to 16Hz). Also expect to run into
health and safety regulations at these frequencies. Since you cannot
'hear' them, and are unaware of the sound levels involved, regulations for
ULF audio, are usually tight.
Best Wishes
