The vintage will have dismissed in white drivers which will fight the post of the low above signal. hoook By the end you should be buying one visible, divided to two amps, to windows four speakers. If you still have the amp in, it will show how to do this. Let me officer my thoughts on the post of keeping multiple manufactures.
I prefer to use a regular distribution block, not the fused type. They're less expensive and there's no need for the extra Dating ezekiel when there is already How do you hook up two amps to one sub fuse holder near the battery that protects the main power wire you'll have to install this fuse holder. This assumes your amplifiers already have built in fuses that are designed to protect them. For amplifiers that do not have fuse protection you should use a fused distribution block. Ground Wire I often ground my components using separate ground points. I could go into all of the scientific reasons for this but it all boils down to noise.
In my experience you have less chance for noise when you separate ground points as compared to using a single ground point. That's not to say that either way is a sure fire method to eliminate noise but it helps if they are separated by at least six inches or so I've found. That being said, any grounding method that is both safe and effective while keeping out noise is a good method. I choose to separate the grounds but some installers choose to run them to the same point. If you choose to run your ground wires to one point you can also use a distribution block.
If you do not use a distribution block then you will want to stack your ground wires so that the largest current carrying wire usually from your largest amplifier is on the bottom closest to the ground point and that your smallest current carrying wire is on the top closest to the head of your grounding screw. RCA cables Now that you have your power and ground wires connected you'll need to give your amplifiers a music signal usually the RCA cables run from the head unit. If your head unit is lacking these extra outputs then there are several other options. If your amplifiers will be powering dissimilar speakers subs, mids, tweeters, etc.
Sub-bass frequencies would be sent to the subwoofer yuo and high pass signals would be passed to the other amplifiers. The crossover will have built in line drivers which will increase the voltage of the low level signal. Hoa can help lower the noise of the system. Some aamps will have an RCA pass wmps circuit which can be used to drive another amplifier in the system. These are sometimes filtered which d the benefits of an active crossover without the extra equipment or installation expense. If suv are using a filtered output make sure that it is adjustable or that it is at least at a useable frequency for your system design.
The least desirable method is the RCA cable Y adapter or splitter. The drawback is that the signal voltage is also split so that each component is now getting a smaller low level signal which may increase the noise in the system. Aftermarket head units provide this but it is recommended that you do not connect more than components directly to it. This is because a head unit turn on circuit can only supply about mA on average. Most electronic components such as amplifiers, active crossovers and equalizers need about mA to turn on.
As these components age the current draw can be even higher. Plus both sides of the left signal into the right and left inputs of the one amplifier. Then feed the other the right signal in the same fashion. Then take the stereo output of each of the amps and split it up, one part of the stereo signal from each amp to it's own individual speaker.
Installing Multiple Amplifiers
By the end you should be using one source, divided to two amps, to yuo four speakers. Two for the left, and two for the right. This di all parts of the akps for maximun power output. Or so I imagine. If you want to convert a stereo amp into a mono amp driving a single speaker, you need what is called a bridging circuit. Some amps have them built in, mostly car stereo amps. If it has one, there will be a bridging switch to enable it. Once turned on, the amp has to be hooked up a particular way. If you still have the amp manual, it will show how to do this. A bridging circuit can be built for amps that don't have one, but it isn't trivial.