Audiosavings Guide to understanding car subs and amps..
This guide is being written by Charlie from ebay user ID AudioSavings.
This guide is intended to teach you how to match up the proper car subwoofers and car amplifiers.
Lets get started...
There are basically (2) things you need to worry about when matching up subwoofers and amplifiers. The main thing is to match up the sub and amp with the right amount of power which we will talk about in detail shortly. The second thing is to match up the proper impedance (ohms).
The most common mistake people make is that they look at the peak watts. When you are matching up your subs and amps ignore any peak, max, or dynamic power ratings. They are bogus ratings which mean nothing these days. Only worry about the RMS ratings. If a sub or amp does not have an RMS rating then we recommend you stay away from buying it.
The most common question we get from customers is asking us should the sub be more or less powerful than the amp ? Or should they be the same amount of power ? The answer to this is that you want the amp to have slightly more power than the amp. This is called having top power. The reason you want top power, and why you want your amp to be a bit more powerful than your subs is simple. When you turn the volume (or gain) on your amp up more than 85-90 % to the max the amplifier will struggle a little and distort slightly. Also, when you push your amp that hard you will shorten the life of the amp tremendously. Getting back to the topic at hand, if your amp has 15 % more power than your sub(s), you can have the gain up to about 70 % to the max and fully maximize the potential of your subwoofer, while getting the cleanest possible sound.
OK, now is the more complicated task of matching the impedance of your subs and amp.
(Please note we have a simple to use wiring wizard in our ebay store. Click the below link, and scroll down to where it says
"Click here to view Car Subwoofer Wiring Diagrams").
Subwoofers come in different configurations. They come in single voice coil and dual voice coil. (We will not get into quad voice coil for now b/c it's uncommon). You can also have single or dual voice coil 4 ohm, 2 ohm. (we will not talk about uncommon configurations like 6 ohm, and 8 ohm for now). Without getting into scientific theories, we will explain how to match up the ohms of your subs to the amp. We will do this buy giving examples of different possible configurations.
The most simple configuration is (1) single voice coil subwoofer. For this example we will make pretend we have a 4 ohm SVC subwoofer. We will also make pretend the subwoofer has 200 watts RMS. For this set-up, the proper amplifier should be running approximately 200-225 watts RMS @ 4 ohms. It happens to be that all 2 channel car amplifiers on the market will run at 4 ohms when bridged to mono mode. So for this set-up we recommend you go with a 2 channel amplifier.
The next configuration we will discuss is (2) single voice coil subwoofers. This set-up is the same as running (1) dual voice coil 4 ohm subwoofer. More on that later.. For this set-up there are actually 2 ways you can wire it. With any (2) sub single voice coil set-up you can wire the (2) subs together to run at half or double the original impedance. In this same example of having (2) 4 ohm single voice coil subs you can wire them either to 8 ohms or 2 ohms. Since no car audio amplifiers are built to run at 8 ohms, you will always want to wire them down to a 2 ohm load. To do this you wire the positive to positive, and negative to negative on each sub. The proper amplifier would be a mono amplifier that pushes 400-450 watts RMS @ a 2 ohm load. (Assuming each sub is 200w RMS).
Now to the fun stuff. Dual voice coil subs. A dual voice coil sub is like having 2 subs that are single voice coil in terms of configurations. So with (1) dual voice coil subwoofer you can wire it to half or double the amount of ohms, just like you do with (2) single voice coil subs. If you have (1) dual voice coil sub that is 2 ohms, then you can wire it to 4 ohms or 1 ohm. Both good options. You can wire the positive to negative on each side and run the sub up to 4 ohms and use a 2 channel amp bridged to mono mode. The other option is to wire the subs coils positiv to positive and negative to negative. This will make the sub run at a 1 ohm load. You will need a 1 ohm stable mono amp for this set-up.
The next and last configuration we will discuss for today is (2) dual voice coil subs. For this example we will use (2) dual voice coil subs that are each 4 ohm. Now with (2) dual voice coil subs you can either wire the subs to the same impedance (in this case a final 4 ohm impedance), or you can wire the subs down to 1/4 of the original impedance (in this case 1 ohm).
We hope this guide is helpful. Email audiosavings on ebay with any questions. Our audio engineers are here to answer your questions.
Again, if you want to view the wiring diagrams and more info on matching up your subs and amps, then Click the below link, and scroll down to where it says "Click here to view Car Subwoofer Wiring Diagrams").