Discussion in 'Microphones, Speakers & Audio Processing' started by KC8EQF, Apr 4, 2019.
What damage? Unless you short the speaker amp out, and crank the volume up, no worries.
Now with that said, if you have tried an amplified speaker and it sounds bad, indicates you have a bad AF amp in your radio.
Yep. Dynamic transducers (microphones & speakers) really are pretty crude. In regard to NOMINAL (aka approximate) impedance, this is very interesting:
And, after all that, there are other factors that affect the sound that reaches the listener's ears. Further, no two listeners hear the same sound the same.
Keep in mind driving an external amplifier does not provide the same conditions as driving a speaker.
Your radio only has to provide essentially a signal 'voltage' with little current to affect your radio.
The current only amounts to the charge/ discharge of the amplifer input circuit.
An example of this would be a vacuum tube grid receiving signal voltage. Does current flow? Yes in the capacity between grid and ground plus any other path that maybe used to provide a general match and grid bias for that tube.
None of which approaches what it takes to drive a speaker.
If you had a poor experience trying an amplifier, something was done incorrectly.
To much drive, faulty amplifier or whatever.
Not sure what a vacuum tube has to do with this.
A 8 ohm amp will drive a 32 ohm speaker just fine, But a 32 ohm output may not drive a 8 ohm speaker very well.
The audio level will be low, And loaded way down.
I have an old National shortwave in storage that requires 8 ohm speakers. If I ever get to it, I figure a 24 ohm resistor in series will be plan A.
A solid state directly coupled(or thru a large value cap) amp will tolerate a wide range of impedances for speakers. If the output is transformer coupled, or it is a tube radio, you want to have a closer match. You could also look for 16 ohm speakers and use two of those in series. Those are not too rare, I don't think. I have some 25 ohm speakers that were from a house intercom/radio system, so there are odd values out there. Here is an actual listing for a 32 ohm speaker: https://www.ebay.com/itm/USED-RCA-1...288892?hash=item3406acd2fc:g:9rUAAOSw~rpZSDhM