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Permalink Reply by Timothy Hunter on June 25, 2018 at 10:16pm

well it depends on the type of amp circuit it is. sometimes you can bridge the outputs of a stereo amp  to a single speaker. 

you can either feed the mono input to both l and r and use two speakers. 

you can use L and R as a 2 input amp  each channel has their own speaker or if its bridgeable into 1 speaker. or you can just use 1 side and 1 speaker and use it as a mono amp. the unused channel will still use a little bit of power so it might not run quite as long from a battery.

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Permalink Reply by Paul Craig on July 1, 2018 at 9:39am

You can use a single/mono input to 2 amp circuits for stereo output or a mono input to a amp that has stereo output.

The output wattage is listed as double, but in reality it's 2 circuits giving the same output that's only half of the listed output. Example: a 20 watt stereo amp is basically 2 10watt channels leading to their own speaker.

Stereo amps need 2 speakers to be stereo. If both outputs are wired to 1 speaker, you could run into issues with overload to the amp circuit or speaker coil depending on parameters.

What amp/amp circuits are we speaking of? What are the amp/amps specs?  What are the speaker specs?

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Permalink Reply by Joe Williams on July 2, 2018 at 11:33am

The amp is this one:

https://www.ebay.com/itm/TDA7297-AC-DC12V-2-15W-Dual-Channel-Digita...

The intended speaker is an old Kicker 3.5" 2 way, rated at 40 watts.

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Permalink Reply by Kigar on July 2, 2018 at 3:43pm

I tried one of these using two little computer speakers in a cigar box.  It has a mono jack into both channels.  Pretty lo-fi but it was only a couple bucks.  You won't get much out of it without a preamp, I just use a pedal.

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Permalink Reply by Joe Williams on July 2, 2018 at 4:09pm

I don't care about much volume. I just play on the front porch. These things are just toys to me. It's fun making them and learning a bit about how they work. That's really my only interest at the point. Here was the first one.

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Permalink Reply by Paul Craig on July 3, 2018 at 6:31am

That amp is a 2 channel amp rated 15watt max at 4-8ohms per channel for a combined 30watts for both. It's just 2 15watt channels and not a true 30watt.

Use 2 speakers. If you wire both channels into one speaker, it will likely damage the speaker coil due to overloading the ohm impedance. Just one speaker on one channel of a stereo amp will leave out some of the sound range if it's true stereo and not just 2 mono amps paired together.

So try the speaker on each channel to see if there's a difference on either one. Use the speaker on the one that works best til you can get another speaker. If it's just 2 mono paired, it won't matter which side.

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