Adding a single speaker to a van stereo system

[zeeklumpkins]

I have a conversion van and wanted to add a single speaker to an existing SM 30BT car stereo system. It is a basic kind of setup with front and back speakers.I wanted to just add in a single 4 ohm speaker to one of the channels.
The goal: I wanted install some of those sound reactive strip lights to the van (there are recessed areas along the roof where I could attach the lights) with the sound sense box in the storage space near the front. There are no speakers there so I wanted to basically run a single small speaker to where the sound sensitive box is to drive the lights.
How would I go about wiring that up, if possible?

 

[americanaudiophile]

You would have to connect the speaker in series to safely run it since the minimum load of that stereo is 4 ohms.
It would affect the volume of the channel you connected it to so may not be a good idea. Safe to try it though.
I would suggest that you try it without the additional speaker first. The sound sensor may be sensitive enough to work without it.
Worse case you could connect a very cheap power amp board to one of the preamp outputs just for the sensor speaker. 1-2 watts would probably be OK.
https/www.ebay.com/itm/20W-HIFI-Mono-Channel-LM1875T-Stereo-Audio-Amplifier-Board-Module-DIY-Kit-/311551143279?_trksid=p2385738.m2548.l4275

 

[zeeklumpkins]

You would have to connect the speaker in series to safely run it since the minimum load of that stereo is 4 ohms.
It would affect the volume of the channel you connected it to so may not be a good idea. Safe to try it though.
I would suggest that you try it without the additional speaker first. The sound sensor may be sensitive enough to work without it.
Worse case you could connect a very cheap power amp board to one of the preamp outputs just for the sensor speaker. 1-2 watts would probably be OK.
https/www.ebay.com/itm/20W-HIFI-Mono-Channel-LM1875T-Stereo-Audio-Amplifier-Board-Module-DIY-Kit-/311551143279?_trksid=p2385738.m2548.l4275

That sounds very cool. If I used the power amp, would I connect the power amp+4ohm speaker in series with the existing speaker or parallel? The sensor seems to have a range in inches testing it with the existing speaker so I can first try the series configuration then get that amplifier if the quality is noticeably reduced in the van.

 

[americanaudiophile]

The amp connects to a preamp out of the headunit not the speaker connections..