Frequency response of speakers

Sparky

Sparky

New member
Hi all,
I was reading another thread here about digital audio chips and audio amplifiers and it got me thinking (again) about something I have wondered about for a while. It's common knowlege that a predator's hearing range (like a dogs) extends well above a humans. Most speakers cut off their frequency response around 20 KHz (the normal upper limit for frequency in a healthy human). Most audio devices, i.e. cassette players, mp3 players, audio amplifiers, wireless transmitters and speakers are designed with human hearing ranges in mind and are cutting off the high end frequencies that we can't hear.

Are the "e caller" shy animals hearing and not responding because a call is lacking it's natural high end frequencies? A distressed cottontail tape may sound good to us, but to a yote, like garbage. Try turning your bass all the way up and your treble all the way down on your stereo and tell me if you can hear a difference.

Maybe some of the commercial e-caller manufacturers here have some info on tests or studies?
 
Very interesting questions. These are things I've often wondered about. It'll be interesting to possibly see some opinions and answers.
dc
 
I can't answer these questions, but perhaps you may find what you're looking for here:

http://www.wildlifetech.com/pages/home.htm

Click on the Sound Tutorial link.

Just don't pay too much attention to the e-caller comparisons made here. Do your own research.

I use one of their callers and I love it, but I certainly don't believe it's given me any significant advantages over the other good e-callers. I've been hunting some tough areas lately and those call-shy coyotes just continue to ignore me and my $1000 caller... /ubbthreads/images/graemlins/laugh.gif
 
I can say that in my experience cats go for really high pitched stuff. For years I've used a Crit R Call Pee-Wee model to very good effect. In recording Crit R Call sequences I've noticed low end speakers ie the commonly used horns just don't have the dynamic range to reproduce the tones. Even to my tin ear. So I use a car stereo speaker and a small 7W amp that go to 20KHz.

MP3s will go to about 22KHz. The codec used in the MP3 determines what gets thrown away, the higher the resolution (sampling rate) the lower the compression, and the less tht ultimately gets tossed out. It's all done mathematically in the codec program so other than choosing a a higher sampling rate and there's not much to be done about it.

CDs use .wav files or even .mp3 files nowadays, and also go to about 22KHz. With .wav files there is no compression, nothing gets tossed. However, from everything I've gleaned off the audiophile sites that attempt to explain the MP3 codecs and how they perform compression, I have the sense that (at least at the highest .mp3 sampling rates) it'd be really splitting hairs to think that there's anything about a CD that outweighs the other improvements to be found with MP3s for our predator calling purposes. (Let the true audiophiles argue otherwise.)

As far as finding equipment for recording and playing sounds beyond the range of human hearing, you're getting a bit pricey and esoteric, but you might try a search for equipment that will record bat or orca sounds. I've found several such sites (unfortunately don't have the bookmarks for you on the machine I'm using at the moment). Prepare yourself for sticker shock, this isn't mass-produced consumer grade stuff.

LionHo
 
Back
Top