PICMICRO --> 1hz speaker

Hi to all !

Im looking for shematics on how to connect ( and where to get ) 1 - 15
HERTZ speaker on picmicro 16F877. The program will generate 1-10 hertz
but i must be sure that i have made correct hardware connections with
the speaker.

btw. where to get such speaker ( for such low freq. ) ?

Regards,
Mark

 

Who would be able to hear it?

 

I dont know about the speaker, but you could use a cheaper micro
(PIC10F200).

Luhan

 

Could you possibly describe what you're wanting to do with this setup? I'll
assume that you know that 1 - 10hz is inaudible?

Some speakers can be damaged by this low frequency as the coil inductance
cannot help limit current.

Chris

 

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

 

@Luhan
Thank you for your suggestion about the chip but i have some 877 left
from my last design.

@Roger Hamlett
Everything that you have described is correct and i am aware of this.
Im using this for medicine project and in the range of cca 35 cm. You
are suggesting the transducer. Can you point me where i can get one ?

As you have written, i will have some problems with defining and
"hearing" those freq.
What are you suggesting, what should i do to define those freq. ( with
hardware ) and is there some option how to see if those freq. are
correct ?

Is there some schematisc ... ?

Mark

 

Heh! The Brown Noise! It's about 50 or 60 HZ - if it's loud enough, your
anus resonates, and you can't hold your feces. Butyric acid is the stuff
that makes you puke. ;-)

But back to the original question - can you really imagine the transducer
that could actually put any significant acoustic energy into the air at
1 Hz?

I'd think you'd feel it kind of like an annoying, intermittent breeze:
"Whiff, whuff, whiff, whuff...".

Cheers!
Rich