I need to combine two audio inputs into one - mixed not switched

[Bladeguy]

I need to combine the external speaker output from my cb (Cobra 75 WX ST 3.5mm mono jack, "The external speaker should have 4-8 ohms impedance and be able to handle at least 4 watts.") with either the 3.5mm output from my phone (into the aux input on head unit) or the rca output from my sony head unit (into the low power input on amp). I have a high quality system with a 4 channel amp on my motorcycle so I want the sound quality to remain top notch. Also the solution must be compact and run on 12v DC.

Thanks!

 

[americanaudiophile]

First you need to reduce the output of the CB to line level with one of these
http://www.crutchfield.com/p_142LOC80/Scosche-LOC80.html
Then you need a mixer to combine them. You can build a passive mixer like this one
http://www.instructables.com/id/Altoids-Tin-18-Stereo-Mixer/
or buy the same one prebuilt
http://www.ebay.com/itm/Passive-Stereo-Audio-Mixer-3-5mm-/191901977924
No power required. If you are worried about the sound use higher quality metal film resistors and better wire but I doubt you would notice the difference.

 

[Bladeguy]

First you need to reduce the output of the CB to line level with one of these
http://www.crutchfield.com/p_142LOC80/Scosche-LOC80.html
Then you need a mixer to combine them. You can build a passive mixer like this one
http://www.instructables.com/id/Altoids-Tin-18-Stereo-Mixer/
or buy the same one prebuilt
http://www.ebay.com/itm/Passive-Stereo-Audio-Mixer-3-5mm-/191901977924
No power required. If you are worried about the sound use higher quality metal film resistors and better wire but I doubt you would notice the difference.

WOW - this is exactly what I need! The only other piece is a 2 rca male to 3.5mm which I am sure I can find. Thanks!

 

[Bladeguy]

Hello - follow up question - i had bought a cheap external CB speaker. I cut the wire out of the external speaker jack from the CB to hook up to the line level. One wire is black and one is black with a white stripe. Which is positive and which is negative? Thanks!

 

[Bladeguy]

First you need to reduce the output of the CB to line level with one of these
http://www.crutchfield.com/p_142LOC80/Scosche-LOC80.html
Then you need a mixer to combine them. You can build a passive mixer like this one
http://www.instructables.com/id/Altoids-Tin-18-Stereo-Mixer/
or buy the same one prebuilt
http://www.ebay.com/itm/Passive-Stereo-Audio-Mixer-3-5mm-/191901977924
No power required. If you are worried about the sound use higher quality metal film resistors and better wire but I doubt you would notice the difference.

Hello - follow up question - i had bought a cheap external CB speaker. I cut the wire out of the external speaker jack from the CB to hook up to the line level. One wire is black and one is black with a white stripe. Which is positive and which is negative? Thanks!