My car has 4 speakers, I might want more. Here are my questions. What happens if I just twist two wires together and plug it into the back of the head unit? (Run two speakers from each output in the head unit) Power loss? Do I have to use an amplifier for any additional speakers I might want to add? Do I delete the wiring from the speakers to my headunit then run a wire from the head unit to an amp and hook up, say 6 speakers to it? Thanks
Well, it depends on what you want to do. If you hook the speakers in series you will increase the resistance, which will decrease the overall volume. I forget what will happen if you wire them in parallel - that might stress the radio's output transistors a bit much. Depending on how much output the radio has, what speakers you put in, and how loud you want it, you may not need an amp. With an amp, you'd run the radio output wires to it, and then run the speakers from the amp. Hopefully the radio would have a "line-out" for this. If you want to add more speakers while replacing the existing ones you could purchase speakers with half the resistance ("impedance") as measured in ohms. Lets say you want to put in one more on the left, and assume one left speaker is 8 ohms. You could replace it with two 4-ohm speakers wired in series. This would (theoretically) have the same load as the one 8-ohm speaker.
If you wire speakers in series, you double the impedence. Most car speakers are 4 ohm. So if you connect the positive speaker output to the positive side of the speaker1, then the negative side of Speaker1 to the positive of Speaker2, and the negative side of Speaker2 back to the radio, you will have 8 ohms. The radio amp will see an increased load, and will not be able to play as loud. If you wire the speakers in parallel, you half the impedence. Wiring the positive side of each speaker to the positive radio output, and the negative side of each speaker to the negative radio output will present 2 ohms to the radio amp. This will allow the radio to play louder, but can damage the amp if it is not 2 ohm stable. Most modern aftermarket amps are 2 ohm stable. If you plan on running multiple speakers, get an aftermarket amp. Most come with speaker level inputs/outputs. You can avoid damage to a stock head unit that way. Or check with the head unit manufacturer, to see if it can handle 2 ohm loads.
What Larry said! If you halve the impedance by wiring them in parallel, it "asks" the amp for double the current. Most output transistors in the head amps aren't up to that. Get a better external amp to do that. In my opinion, more speakers is not necessarily a better way to go, at least if you mean more full range speakers. The most bang for the buck comes from bi/tri amping, where you use a different speaker and amplifier for different parts of the audio band. You would have a cable out from the line out on your head unit to an active crossover, which would divide the frequencies and send them to different amps which would be connected to appropriate drivers. This would give the cleanest sound with the best headroom. There are many other benefits to doing this. You don't need super power amps to benefit from this approach either. ________ Black Girl Orgasm
Why do you want more speakers? If you want them for better sound you will be soarly disappointed in the results, it will mess up the sound imaging pretty bad. That is not true for bass speakers though, their frequency is so low that it is non-directional
