bird listening device speaker

[356mag]

I have a bird listening device with headphones. I want to put a speaker on the device instead of head phones, but I can only find 8 or 4ohm speakers. Assuming that head phones are about 34ohm impedance, how do I design a matching network for my project? If I put a 30ohm resistor in series with the 4ohm speaker, my guess is that I’ll probably ruin the output amp on the bird listening device and I would have to buy another one. Got any suggestions?
356mag

 

[woody]

No putting a resistor in series will not damage your amp. But you will have very little output from the speaker. They do make speakers in the 30 ohm catagory but again your device will probably not have nearly enough power for them. And you may also run into the problem of feedback.

 

[jplesset]

Best bet is to add an amplifier. The headphone output will likely run the "line in" on any reasonable integrated amp or receiver.

 

[sreten]

Hi,

Doesn't make any sense in terms of a portable device.

You clearly can't go round miking up bird song and playing
it back through a speaker without feedback issues at high
loop gain, and your speaker interfering with the very
thing your trying to monitor naturally in the first place.

Playback of recordings through speakers is trivial.

rgds, sreten.