An aftermarket sound system can go a long way in adding quality to your listening experience, but the large number of parts must be connected correctly. A bad connection job can lead to a blown subwoofer, a burned out amplifier, or in some cases, even a car on fire. If you plan to install your own subwoofers, make sure you understand the basic circuitry of the job.
Method 1 of 3: Understand the Basics of Connection
Step 1. Know the difference between series and parallel connection
There are two ways to connect cables and the choice of each is important. You must connect in series whenever you want to increase the impedance of the system and, in parallel, when you want to reduce it.
- Series connection means that you start by connecting the positive output terminal of the amplifier to the positive wire of speaker A. Then, you have to connect the negative wire of speaker A to the positive wire of speaker B. Finally, the circuit is completed when you connect the wire. negative of speaker B to the negative output terminal of the amplifier. This can be done for any number of speakers as long as you follow the pattern (amp + + speaker- + speaker- + speaker- + speaker- ……… + speaker- -amplifier).
- Parallel connection means that you are connecting the positive output terminal of the amplifier to the positive wire of all the speakers in the system. Next, you would have to connect the negative output terminal of the amplifier to the negative wire of all the speakers.
Step 2. Understand the different effect the connection has on power
The two connection schemes have radically different effects on the impedance and power of the system.
- Connecting in series increases the impedance of the system, which decreases the amount of power that each speaker receives. Likewise, each added speaker will also increase the impedance of the system.
- Connecting in parallel lowers the impedance of the system. In other words, more power will be transferred to each speaker because adding speakers to the circuit will lower the impedance of the system.
Step 3. Try to identify the parts of the system and their functions
The stereo head functions as the control panel of the system and sends signals to the amplifier. The amplifier amplifies the signal from the stereo head and sends it to the speakers, which produce the sound. Subwoofers are the speakers responsible for producing sounds at a very low frequency.
Method 2 of 3: Make a connection diagram
Step 1. Locate the system specification labels
The amplifier should have a label near the speaker output connector that indicates the power (measured in watts) and the minimum impedance (measured in ohms). Subwoofers should also be labeled with an impedance value (in ohms) and a value indicating the maximum power they can handle (in watts).
Step 2. Record these values
You must have at least four different values noted.
- Amplifier output power
- Minimum amplifier impedance
- Speaker rated power
- Speaker impedance
Step 3. Calculate the total impedance of all the speakers
To do this, you have to add the speaker impedance number of all the speakers. The impedance must be at least equal to the minimum impedance value of the amplifier on each channel, but not exceed 16 ohms, unless your amplifier is specifically rated for impedance values greater than that value.
- The formula to find the total impedance of speakers connected in series is Z1 + Z2 + Z3…. = Ztotal, where Z is the impedance of a given speaker.
- For example, if you have three speakers with impedance values of 4 ohms, 6 ohms, and 8 ohms, the total impedance connected in series would be 18 ohms (4 + 6 + 8 = 18).
- The formula to find the total impedance of speakers connected in parallel is a bit more difficult: (Z1 x Z2 x Z3…) / (Z1 + Z2 + Z3…) = Ztotal.
- Let's assume you have two speakers with impedances of 6 ohms and 8 ohms. In this case, it would be like this: 1) Multiply the values. 6 x 8 = 48 ohms 2) Add the values together. 6 + 8 = 14 ohms 3) Divide the top by the bottom to find the total impedance. 48/14 = 3.43 ohms (rounded).
- You can also use an impedance calculator like this
Step 4. Calculate the power each speaker will receive
This will be based on the total impedance and power of the amplifier. You can use variations of Ohm's law to do the calculations yourself, or you can refer to the online calculator mentioned above.
Method 3 of 3: Connect the system
Step 1. Disconnect the battery terminals
The system cannot have power while you are making connections, so turn off the vehicle and disconnect the battery cables.
Step 2. Connect the amplifier to the first speaker
Connect the positive output wire to the positive wire of the first speaker. This may mean joining the two wires together, but more often than not, the amplifier is made so that the speaker wire is inserted into an output jack. This step will be the same regardless of whether you are going to make a serial or parallel connection.
Step 3. Connect the remaining speakers
Each of the speakers that you are going to connect in series will be connected to the other and can be done by joining the cables together. Each of the speakers that you are going to connect in parallel will be connected to the output connector of the amplifier.
You can connect several speakers in series and some in parallel within the same system to achieve the desired impedance and power values
Step 4. Close the loop
This will be done by making the final connection and creating a loop. Connect the negative cable from the last speaker in any series, and the negative cables from all the speakers in parallel, to the negative port of the amplifier's output connector.
Step 5. Connect the battery cable
Now you can connect the battery ground wire and restore power to the vehicle.
Step 6. Turn on the music
This is the step that is all about. Enjoy your music and make sure others do too!
Drawing a connection diagram can help you decide the best way to connect the system
- Overloading the amplifier can cause it to melt and may even burn out.
- Do not connect the system with the battery connected.