Wiring 2 Subs to Mono Amp

Can You Really Connect 2 Subs to a Mono Amp?

So, let’s begin by eliminating the myth “You can’t connect two subs to a mono amplifier.” Yes, you can connect two subs to a mono amp

As mentioned above, you need a car stereo system that can provide double the amount of power compared to what single subwoofer needs.

That’s because the amplifier sends out equal power output on both “channels” or sides, even though it is only one channel (mono), ensuring that each sub gets the same signal and produces sound at the same level as its counterpart.

Furthermore, that depends on what kind of connection you choose between the parallel, bridge, or series for your subs and mono amps. 

Difference Between Parallel, Bridge, and Series Connection:

Now that we know about the connections types that can successfully run two subs on your mono amp let’s differentiate them before we follow those steps:

1. Parallel Connection:

This connection means you have to connect the positive terminals of both subwoofers with the positive terminal of your mono amp and the negative terminals of both subwoofers with the negative terminal of the amplifier, respectively.

With this type of configuration, you will not only balance the impedance load on the single subwoofer, but also you will get a better power handling option. 

2. Bridge Connection:

The bridge connection is much similar to the parallel one, as you have to maintain the connections like the positive terminal with the positive terminal and the negative terminal with the negative terminal.

However, in a bridge configuration, you’ll have to connect the positive terminal of one subwoofer to the positive terminal of another subwoofer while the negative terminal of one subwoofer to the negative terminal of another subwoofer.

Once done, you have to connect the remaining positive and negative terminals of the subwoofers to the positive and negative terminals of the mono amp, respectively.

3. Series Connection:

Series connection is different and slightly more tricky than the other two connection types. In a series configuration, you have to connect the positive terminal of one subwoofer to the positive terminal of the mono amp and the negative terminal of the same subwoofer to the positive terminal of another subwoofer.

Once you do it, you’ll need to connect the negative terminal of that subwoofer (second sub) to the negative terminal of the mono amp to complete the circuit.

This connection can increase the mono amplifier’s impedance load, improving the overall impedance level if you have a weaker amp.

1. Making a Parallel Connection:

Let’s begin with step by step guide to making the parallel connection between two subs and a mono amplifier below:

Step 1. Determine the Impedance of Subwoofers:

Before you begin, let’s make sure you’re using the consistent total impedance level of the two subs with the amplifier. You can use the multimeter to measure the subwoofer’s impedance level. However, you should determine it in the Ohm rating. Let’s suppose both your subwoofers have a 4-ohm impedance level ⁽¹⁾.

Step 2. Cut the Wire:

Place your subwoofers at your desired destination near the mono amp. Arrange the speaker wire and calculate the total distance between the subwoofers and the amplifier. After measuring the length, cut the wire while making sure the speaker wires don’t get short when you begin the next step.

Step 3. Strip off the Wire:

Once you have followed the above methods, let’s move to the next one. Here you will need to strip ¹/² inch of the speaker wire at each end to provide the exposed area for a reliable connection. Ensure you don’t strip the wires more than the optimum length to avoid any damage to your stereo system.

Step 4. Make the Parallel Connection With Mono Amp:

In this step, you will need to connect the positive terminals of both your subwoofers to the positive terminal of the mono amp and the negative terminals of both subs with the negative terminal of the mono amp using the stripped wires as mentioned above. Hurrah! You successfully executed the method.

Note: You will get a 2-ohm load by making the parallel connection of these two 4-ohm subwoofers. In such a case, ensure your mono amp (wiring) can handle a 2-ohm load on it.

2. Making a Bridge Connection:

Now let’s move forward with the two subs and mono amp bridge connection. Follow these steps:

Step 1. Cute the Speaker Wire:

Before you do anything:

1. Ensure you place your subwoofers in a suitable location.
2. After putting the two subs, measure the distance between the subwoofers and the monoblock amp.
3. Cut the speaker wire to the desired length while ensuring it won’t get short when you start making the bridge connection.

Step 2. Strip the Wires:

Now, it’s time to strip off the ¹/² inch of speaker wire at each end to expose the area. Keep the inches in such a way that you won’t strip off too much and too less to avoid any disruption to your connection.

Step 3. Start Making the Bridge Connection:

After you follow the above steps, connect the positive terminal of subwoofer-one to the positive terminal of subwoofer-two and the negative terminal of subwoofer-one to the negative terminal of subwoofer-two.

Once you do it, connect the rest positive and negative terminals of the subwoofer-one (also associated with the subwoofer-two positive and negative terminals) to the mono amp’s positive and negative speaker terminals, respectively, without making improper polarity.

Step 4. Test the Subwoofers:

Hurrah! You’ve built the bridge connection successfully. Now, it’s time to test whether your subwoofers are producing any sound. Double-check the connections and adjust the bass and treble. Play a song! You must hear the clear sound coming from the subwoofers.

3. Making a Series Connection:

As mentioned above, it’s a kind of technical but effective way to connect your two subwoofers with the mono amp. Follow these steps:

Step 1. Place Your Subs and Cut the Speaker Wires:

Put your subwoofers in a position where they won’t get any disruption when making connections with each other and the amplifier. Once you place them, take a tape to measure the distance between the mono amp and the two subwoofers. Cut the speaker wire to the required length while making sure the wire won’t get short throughout the process.

Step 2. Connect Subwoofers With Each Other:

As mentioned above, you must connect the positive terminal of subwoofer-one to the negative terminal of subwoofer-two using the speaker wire. Ensure you strip off the speaker wires to expose the areas lengthening ¹/² inch.

Step 3. Connect the Subwoofers With Mono Amplifier:

After connecting the subwoofers, it’s time to hook those subs with the mono amp to perform a successful series connection. For this, you’ll have to connect the negative terminal of subwoofer-one with the negative terminal of the mono amp and the positive terminal of subwoofer-two with the mono amplifier’s positive terminal, respectively.

Step 4. Enjoy the Music:

Hurrah! We’ve made the series connection too. Now, it’s time to turn on your stereo system and enjoy the music at total volume while we can. If you find any trouble, double-check the connection carefully before you go for any troubleshooting.

Note: You will get an 8 Ohm load by a series connection of two 4-ohm subwoofers. Ensure your mono amp is compatible with the series to prevent any damage to your stereo system.

What if You Have Two SVC 4 Ohm Subs?

You can wire two single-voice 4-ohm subs to the mono amp in either a series or parallel configuration. When wiring your subwoofers in series, the total impedance will double (2×4=8 Ohms). When wiring them in parallel, the total impedance will halve (4/2=2 Ohms).

When wiring your subwoofers in series, you will get more power output from the amplifier than from wiring them in parallel. However, this could result in too much strain on the mono amp, and it might not be able to handle the higher load.

Therefore, ensuring that the mono amp has sufficient power output to drive both subs in series is essential.