I have an audio PA which rated at 4ohms 22W in bridge tied load or 2ohms in stereo mode. What will possibly happen to the audio PA when I connects a 3.2ohms speaker parallel with 16ohms speaker in bridge configuration? Which in my own understand that the resultant impedance is 2.7ohms can eventually burn the pa. Am i right? I am also looking for an analog cmos switch which I able to enable/disable the 16ohms speaker. The switch must able withstand max 1A and 14V peak value and Ron must be ultra low <1ohms. Has anybody come across this component? Please tell me. Thank you in advance.
Possibilities are higher distortion (this might endanger the tweeters) and increased power dissipation in the amplifier. If the amplifier is designed badly it may blow up. But then it probably isn't a great pity ;-) With an arrangement like this you can't set the volume on the two speakers separately. Because they're different, they may produce very different sound levels when driven with the same signal. Whether that matters or not depends on your situation, but I imagine it could be very inconvenient. A CMOS switch is not a particularly good idea for this task. Why can't it be a good old electromechanical relay?
If the PA has some overload protection, you will get only distorted sound. Else it will go kaput. No, and likely it does not exists. Use a relay! Or, for the same price, a second amp (chip). JP
It might survive. Maybe the designer wrote 4 Ohms minimum in the spec when it can actually handle 2.6 Ohms. Or maybe not. I can say this with confidence; the 3.2 Ohm speaker will be blaring and the 16 Ohm speaker will put out very low volume, and this will remain true no matter what amplifier you use. Add a 16W or larger 4 Ohm resistor in series with the 3.2 Ohm speaker and the volume levels will be reasonably close to each other and your amp will be within it's rated limits.
