- Fri Nov 21, 2008 4:34 am
#59577
Alright, I've received a request from a buddy that I'm not sure how to fill.
I'm building an airsoft prop for one of my buddies to be used in one of his simulations. Here's the lowdown; He wants me to build a bomb of sorts, that when it goes off, plays the sound of a "huge explosion." We're not talking a simple really loud siren here, he wants and explosion noise that can be heard from pretty far away. They play in a wooded/forested area that is probably 1000acres, and he wants to be able to hear it (if possible, the whole ~2miles), or something like, within 500ft. I know that is very ambitious, so I want to deliver the best I can.
What I've got planned is to use a PIC and possibly some memory media (to store the audio samples), and either drive some amplifier directly (using the PWM module on the PIC, probably limiting me to 8 bit samples (10 bit if i want to get creative with the storage and conversion)), or drive a DAC and then an amplifier of sorts (allowing for whatever the dacs resolution is for... resolution). I plan on using .WAVs (with or without the header info, depending on some factor I've yet to realize, ).
My question is, what makes a speaker loud, and where can I find a reasonably priced one (i'm planning on buying from mouser or digikey, if they don't have it reasonably priced, odds are hes not going to be able to hear across the field). II've read about SPL, the speakers all have variable SPL across the spectrum, but they all have a power rating as well. SPL obeys the inverse square law, so the higher the SPL, the louder the noise (from any distance), and the "further" it will reach. So then, what is the power rating for?
Also of note, the prob will be battery driven, but the batteries are good quality NiMH packs (10C+ drain, >= 7 cell batteries, >= 2000mAh).
Any suggestions or comments are greatly appreciated!
-Nate
P.S., this speaker caught my eye, no idea if it's going to perform how I want, but it was cheap, decent wattage (of the selection), and high SPL.
http://mouser.com/Search/ProductDetail. ... Y41Q%3d%3d
I'm building an airsoft prop for one of my buddies to be used in one of his simulations. Here's the lowdown; He wants me to build a bomb of sorts, that when it goes off, plays the sound of a "huge explosion." We're not talking a simple really loud siren here, he wants and explosion noise that can be heard from pretty far away. They play in a wooded/forested area that is probably 1000acres, and he wants to be able to hear it (if possible, the whole ~2miles), or something like, within 500ft. I know that is very ambitious, so I want to deliver the best I can.
What I've got planned is to use a PIC and possibly some memory media (to store the audio samples), and either drive some amplifier directly (using the PWM module on the PIC, probably limiting me to 8 bit samples (10 bit if i want to get creative with the storage and conversion)), or drive a DAC and then an amplifier of sorts (allowing for whatever the dacs resolution is for... resolution). I plan on using .WAVs (with or without the header info, depending on some factor I've yet to realize, ).
My question is, what makes a speaker loud, and where can I find a reasonably priced one (i'm planning on buying from mouser or digikey, if they don't have it reasonably priced, odds are hes not going to be able to hear across the field). II've read about SPL, the speakers all have variable SPL across the spectrum, but they all have a power rating as well. SPL obeys the inverse square law, so the higher the SPL, the louder the noise (from any distance), and the "further" it will reach. So then, what is the power rating for?
Also of note, the prob will be battery driven, but the batteries are good quality NiMH packs (10C+ drain, >= 7 cell batteries, >= 2000mAh).
Any suggestions or comments are greatly appreciated!
-Nate
P.S., this speaker caught my eye, no idea if it's going to perform how I want, but it was cheap, decent wattage (of the selection), and high SPL.
http://mouser.com/Search/ProductDetail. ... Y41Q%3d%3d