Installing and Adding Speakers to an Old Stereo / Radio

• 

  retiredfeline on 27/10/2017 - 21:21

  +1

  Unclear to me but sounds like you want to run it outside of a car? But then you talk about getting power from the car battery for the amp. If you do, you will need to get a power adaptor lead.

  Each speaker would be connected between one speaker wire and ground. Be sure to be consistent in the sides used for each speaker so that they are not out of phase.

  The amp you linked to would be connected to the speakers using banana jacks, as advertised.

  You won't be able to use the same speakers for the radio and the amp, unless you run the radio output into the aux in of the amp, another lead required.

  Be careful with polarities throughout, use a meter to check, otherwise one reversal and you let the smoke out of the device and it stops working.

• 

  Hoju on 27/10/2017 - 21:40

  Thanks for that, yes I want it inside the car, running off the battery.

  So I can power the radio from the battery pos terminal, but not sure how one would power an amp?

• 

  Hoju on 27/10/2017 - 21:44

  Also, any thoughts on if small speakers advertised as tweeters can be used just alone as car speakers?
  https://www.ebay.com.au/itm/Vehicles-Car-Flush-Mount-Metal-P…

• 

  retiredfeline on 27/10/2017 - 21:55

  I think you will find small speakers will be drowned in car noise. Don't you have decent sized speakers already mounted in your car?

  You'll need a power lead one end of which has a plug for the amp and the other connected to the battery positive and ground. Probably the same place the radio draws power from. After the fuse for sure.

  You might want to find a friend versed in electrics to help you.

• 

  Hoju on 27/10/2017 - 22:02

  Nah no speakers, it's a really old car.
  I was hoping you guys could be versed in electrics!
  :)

  GOt somewhere to go from now though, thanks

• 

  retiredfeline on 27/10/2017 - 22:10

  Even old cars usually had a spot for mounting speakers, worth looking around, maybe in the doors, maybe under the dash, maybe under the rear shelf.

  You need a mate on the ground to help you with the critical details.

• 

  altomic on 27/10/2017 - 22:12

  what model car?

  • 

    Hoju on 28/10/2017 - 06:21

    What the… wouldn’t let me post an eBay link.

    Anyway, it’s a fiat 500. Some heathen had cut into the door cards and mounted speakers but they went pretty fast.

    I could probably mount some kind of compact speakers that have a surface mount to attach over nut and bolt.

• 

  Hoju on 28/10/2017 - 09:08

  I'm thinking a mini amplifier
  A bit like this

  But would then need some kind of DC plug converter to convert the + and - from the battery to a DC plug to power the amp, plus would need to somehow wire the two speaker wire outputs from the radio to RCA cables to match the amplifier input.

  Thoughts on if that would actually work?

• 

  retiredfeline on 28/10/2017 - 09:53

  The thing is, a hobbyist would put together the required cables with wire and plugs.

  You might be able to get a power cable with a suitable plug at one end, cut off the other, strip the wire and connect to the car power. A hobbyist might have a dead power supply they can cut the cable off. See this package https://www.amazon.com/dp/B01N34QK4N/ for the picture of the power cable, but it's hard to see what size the power barrel plug is.

  Similarly for the aux in, you need a cable with a 3.5 mm stereo jack or RCA jacks at one end, then strip the wire from the other end and connect to the speaker output of the radio.

  Then for the speaker wiring you need 4 banana plugs and speaker wire to run to where the speakers are mounted.

  And for long lasting connections you need to solder wires together rather than twisting, then insulate with tape.

  That's why you really need someone on the ground to help.

  • 

    Hoju on 28/10/2017 - 11:34

    Ah nice, that looks like a good one.
    Yes what I wasn't sure of was if you could take an existing DC input plug andwires, and strip them to solder on the external + and - supply from car battery

    Also the 3.5mm input, does it have 3 poles / wires - ie is it a challenge to convert the 2 wire output from car stereo to the 3.5mm wire to supply the aux input of the amp?

    • 

      retiredfeline on 28/10/2017 - 11:47

      Yes, the 3 connections are L, R and ground. (Check Wiki for the correspondence between L, R and ring, tip. But often L is white, R red, and ground black on these cables.) They would go to radio's L speaker, R speaker and ground respectively.

      I'm assuming throughout that the signal ground is the same as power ground for both the radio and the amp. If not, smoke.

    • 

      retiredfeline on 28/10/2017 - 14:22

      Oh and one more thing, you will need to connect the radio to an external antenna. There should be a socket on the radio that accepts a coaxial cable.