I have a CB radio in my car that has a PA function (talk into the mike and it comes out a speaker on the outside of the car). The CB radio says to connect a 5watt 8Ohm speaker. I would like one louder than that so I have attached a 15watt 8Ohm speaker. It works, but obviously is not any louder. My questions is: what sort of small amp can I use to make the speaker louder? I assume I just need something that will step up the 5watts from the CB radio to the 15watts the speaker can handle. Is that correct? Any specific recommendations?
Any amplifer, with a 12v power supply, a high-level input, and around 15w output will fit the bill. Start looking on eBay, I'm thinking that'll be your best bet.
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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
eBay was the first place I looked. They only 15 watt amps there though are big guitar amps. The closest thing I've found is the 17.5 watt amp seen here
https://www.oselectronics.com/ose_p29.htm, but I'm afraid that will damage the speaker.
That 17 watt mono amp won't damage anything, and should do the job just fine. Nice site there, BTW. I'm going to save that link for future reference.
Or if you want to find something with a more finished appearance, look for a used car audio amp rated at 30 to 40 watts per channel at 4 ohms. With your 8 ohm speaker (on one channel), the rated output would be cut in half because the load is 8 ohms instead of 4.
A 15 watt speaker is not very much different than a 5 watt speaker. Use any old mid driver out of a discarded home speaker. They are lying around in attics and basements everywhere.
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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Thanks to the response. Though I am a long time tinkerer, I am new to this whole speaker thing so please bear with me. I just want to confirm a few things: The speaker I have says 15watts max power and 8 watts nominal power.
If I get the 17 watt amp mentioned earlier, I won't damage the speaker and will increase the volume a noticeable amount. Is that correct?
My only other concern is the power going into the amp. Will the CB's power output (5watts) damage the amplifier?