1GDW wrote:
> All,
> I have seen a couple posts indicating that the sound from small
> speakers, say two watts, has limited projection in the outdoors. I
> interpret from this that live bird song may carry farther. Why
> doesn't sound from speakers project well in the outdoors? Would a
> small birds live song carry a longer distance than it's recorded
> song played through a two watt speaker? A two watt speaker at
> close range sounds pretty loud to me when something is played over
> it. I wouldn't interpret small bird live song as being any louder.
> Is there something different between the sounds? If it is just
> volume, how much power would it take to replicate a small birds live
> song.
I stated the observation that placing a speaker outside playing and then
walking out to see how far it was reaching will show it's not reaching
very far.
Part of this is that the energy projected by the speaker often has very
little to do with the watt rating. That's generally some form of
measuring how much electricity is used. Often just the peak instant, not
sustained sound energy.
The second part is the speaker is designed to project a local pattern,
generally into a enclosed space. It does not focus the sound much at all
but depends on the surrounding walls to do that. So the energy is going
in all directions without coming back when outside.
I don't know a lot about the sound levels of birdsong, but frogs are
projecting really high volumes. Many are operating at 120 dB or greater.
They also frequently choose locations for their acoustic projection. And
they often call in mass.
Birds also project the sound directionally to at least some extent.
While a small speaker is usually not reproducing the birdcall all that
accurately, I don't believe that's a problem. I think it's primarily a
design not made for projecting into a large volume. And that the natural
environment is very sound absorbing. Before the current systems with
their highly inflated power figures, in the days of tube amplifiers it
was possible to run a large auditorium PA system with 15 or 30 watts,
often less. Some of that was different speaker design. Speakers
converted electricity into sound more effectively. Modern speakers have
to cope with much larger electrical loading and desired sound volumes. I
don't believe that modern speakers are near as efficient.
Anyway, the real test is still the same, set it up, and walk out and see
how far it's getting.
I believe that a pa system horn speaker might be better. There is a
reason for their design, and it is to project sound out a good distance
into a large volume.
Otherwise you are really only "calling in" birds that are right at you.
A couple watts speaker of the usual current type is good for maybe 20'
if working with frogs. In my experience.
Walt
________________________________________________________________________
________________________________________________________________________
|