Connecting PC to my car radio Help!

Hello,

A car radio operates with 4 ohms + 4 ohms at the front and 4 ohms + 4 ohms at the rear, which means two pairs. It can also operate with 8 ohms + 8 ohms, but only at the front or only at the rear, so just one pair.

Some car radios can handle two pairs front + rear at 2 ohms.

Typically, the transistor used in a car radio is a TDA7294 rated at 50 watts continuous in 4 stereo channels stable at 4 ohms. Depending on the original connection of the car radio, for example, 4 channels in series at 2 allow the possibility of connecting either one pair at 8 ohms or two pairs at 4 ohms. Conversely, 4 channels in parallel at 2 allow the possibility of connecting two pairs at 4 ohms or two pairs at 2 ohms; this depends on what the car radio in question can support (all this is specified in the manual).

Warning: you should never connect one pair of 4 ohms and one pair of 2 ohms or 6 ohms or 8 ohms together, otherwise the amplifier will become unstable and burn out. Always connect an identical impedance.

The power of a speaker does not indicate what it will output but only what it can absorb, so it won't prevent the amp from amplifying correctly. There is a margin with the 25W max per channel to reach an acceptable sound level without pushing it to the limit (3/4 of the total volume to avoid damaging it). Besides that, choosing a pair of speakers with a sensitivity above 88dB will allow the amp to breathe.

Ensure that the car radio is well-ventilated in the designated compartment; a 12vdc fan can be very useful.

Yes, it should work, no risk for the PC or the car radio.

hi

you have to try to know

Hello,

There is absolutely no danger. A headphone output only delivers a few millivolts, which are unlikely to saturate or damage a line input.

In general, there are no issues with the input of an audio device.

It is the power outputs (speakers) that can pose a danger of short circuits or impedance (resistance measured at a given frequency).

In any case, your PC headphone output has the same characteristics as that of an MP3 player.

Best regards

Thank you for your responses, I will order my cables and connect this.

I have another question:

I would like to add 2 speakers in addition to the 4 I have originally, knowing that I only have four outputs behind my car radio at 4 ohms, and I want to be able to cut the 2 new ones with a switch, so I can turn them on or off whenever I want without risking damaging the outputs of the car radio.
How should I connect them to maintain 4 ohms and be able to cut them out while staying at 4 ohms?
Because if I connect:
#1/output AVG + a new one here at 4 ohms
#2/output ARG
#3/output AVD + a new one here at 4 ohms
#4/output ARD

On #1 and #3, connecting in parallel will give me 2 ohms, and that risks damaging the car radio? How should I do it and where to put the switch? Should I put in 2?

I would advise you to make series connections to achieve an 8-ohm load on your 4-ohm outputs instead of 2 ohms. Indeed, as I mentioned, while there is no risk on the input side, we should not lower the impedance on the output side.

Of course, you will lose power, but you will gain safety.

There are articles explaining that modern amplifiers are protected in case of impedance division of the speakers, but I have no idea what the situation is for car radio-type power amplifiers.

I cannot give you advice on this setup, especially since you want to install a switch that would change the load while in operation.

Thank you for the information.

D'accord, voici la traduction : "I dismantled the speakers from my car, they are 10 ohms at the front, I haven't taken the back ones out yet but I think they are the same 4 everywhere, I will check that. My car radio is the: SA-6770USB, here is a link: http://soundvox.co.za/products/carCDwithUSB/SX-6770usb.htm so can I connect them to it? In the manual, here are the specifications:
Power output 70w x 4@4ohms, 14.4VDC
Operating voltage 11-16VDC, negative ground
Speaker output impedance: 4~8ohms
Line output voltage: 2 Volts."