How To Connect Passive Subwoofers To 2 Channel Stereo Amplifiers
(Last Updated On: September 2, 2020)

If you are you looking to connect passive subwoofers to your existing home theater setup, then we have all the detailed instructions for you. As most audiophiles will tell you, passive subwoofers do not contain amplifiers and so must be connected to an external amplifier to get the proper performance by your subwoofer.

To connect a passive subwoofer to your amplifier, you can use RCA cables to connect the amplifier’s output to the sub’s input. We explain more below.

But first, let’s help you understand what a passive subwoofer is.

What’s a Passive Subwoofer?

Passive subwoofers are subs that need to pair with an external amplifier like traditional loudspeakers. A powered subwoofer on the other has a self-contained amplifier.What is a Passive Subwoofer

As you might have guessed, powered subs come with an inbuilt amplifier as opposed to passive ones.

As such, the actual integration of the two subwoofers with your home audio system is quite different depending on the type of subwoofer that you’ve chosen.


What’s a 2-Channel Stereo?

A surround sound system is what you need to enjoy the best audio performance when watching a movie.

A 2-channel system is the simplest stereo system that doesn’t offer the surround sound but attempts to provide a better experience than a single speaker.

What is a 2-Channel Stereo

That’s because a two-channel system delivers the sound in multiple directions, attempting to replicate the way a stereo sound operates.

In a 2-channel system, the main components include two speakers (right and left), an amplifier, and the audio source (this could be a receiver).

That makes it ideal for connecting with a passive subwoofer as your receiver comes with an inbuilt amp (although some setups may have an additional amplifier). Here are some pointers to help you choose your gear for setting up your home audio system:

  • Speakers – You’ll want speakers with a high power handling capability, low distortion, and a balanced sound. It’s advisable to use wide-dispersion speakers to easily move them around without changes in audio quality or volume.
  • Amplifier/ Receiver – When choosing a receiver/amp, you’ll want one with dedicated stereo settings and a high power rating. The right receiver will allow you to play your music without any distortion at high volumes, especially on the high notes.
  • Cables – In a 2-channel stereo system, every component, including the speaker cables, have to be of the highest quality. That ensures the signals reaching your subwoofer and speakers are as clean as possible.


How to Connect Your Passive Subwoofer To Your 2-Channel Stereo: Step By Step

As mentioned earlier, passive subwoofers must be hooked up to an external amplifier as they don’t feature any internal amps.

Here are the steps to follow when connecting your subwoofer with a 2 channel stereo amplifier.

1. Ensure Everything Is Off

Before connecting your system components, ensure the sub and the amp are both disconnected from the power and turned off.

2. Properly Connect the Subwoofer to an External Amplifier

Before starting the set-up process, you need to decide where your subwoofer will stand. Fortunately, the sub doesn’t require a lot of directional pushing, though proper subwoofer positioning is paramount to get the best audio performance from your system.

Connect the Subwoofer to an External Amplifier

To start the actual hook-up, connect the subwoofer to your external amplifier using RCA cables. However, you’ll need to use two sets of cables if you want to get a stereo set-up. Good thing most RCA cables come in pairs like the Monoprice 1.5ft Premium 2 RCA Plug. Essentially, the set-up process involves connecting your amplifier’s output to your subwoofer’s input. On your amplifier, the jack might be labeled “subwoofer output.” If your receiver doesn’t have a sub out, note that there are many other ways to connect your subwoofer to an amplifier that doesn’t have sub out.

3. Check your subwoofer

If you have any issues, you need to check the sub. This step requires some understanding of your subwoofer.

The subwoofer may be using a single voice coil system, which means it will have a negative and positive terminal. Alternatively, it might be using a dual voice coil system, meaning it will come with two negative and two positive terminals.

Dual voice coil subwoofers are highly flexible compared to single voice coil subs, as they have multiple wiring options. However, you may need to check your subwoofer manual for more specifics if you’re not sure.

3. Connect your Amplifier and Stereo Receiver

Given that modern receivers are essentially tuners with inbuilt amps, the functions of a receiver and an external amplifier might overlap.

However, an audio-visual receiver functions as an audio distribution center, allowing you to match the sound from your TV with the output from your home audio system.

To connect your amplifier with the stereo receiver, you’ll need to connect cables from your receiver to the amplifier to synchronize the sound from your entire system.

In this step, you’ll need to connect a cable from the receiver’s pre-out socket and link the other end with the input jack of your external amplifier.

4. Connect the Speakers To The Receiver or Amp

Connecting your two-way receiver with your speakers should be your last step to enjoy an audiophile-quality audio performance.

Connect the Speakers to the receiver or amp

Fortunately, that’s pretty easy to do, as your receiver will have output ports labeled either front or main. That’s where the speaker wires go.

When connecting the speakers, ensure that the right and left speakers are connected appropriately. Additionally, you must ensure the positive terminal from your receiver goes to the positive terminal of your subwoofer to avoid polarity issues. For more detailed instructions, here is how you can connect up to four speakers to a two channel amp.

Hooking up your speakers should complete the connectivity. After that, you can fine-tune the performance of your using the controls on your receiver. You can then switch on your receiver’s power supply and start enjoying your audio performance.


Passive Subwoofer and Amplifier Power

The critical thing to remember when pairing a passive subwoofer with your stereo receiver or amplifier is that it needs to output enough power to sustain its bass effects.

As such, you’ll need to ensure that your subwoofer’s bass won’t drain the receiver’s power supply when connected.

The amount of power required to run such a system depends on your media room’s size and the requirements of your subwoofer.

However, connecting your passive subwoofer to your 2-channel stereo amp isn’t a complicated process, similar to connecting a traditional loudspeaker to an amplifier. Nonetheless, you must understand that pairing a passive subwoofer to your amp is quite different from pairing a powered sub.


Bottom Line

When it comes to getting the best audio performance from your home audio system, pairing a passive subwoofer with your amplifier is easy and simple. All you need to do is to connect with an RCA cable and then connect the rest of the devices.

However, many audiophiles will tell you that a little experimentation is necessary when setting up your system, to ensure that the subwoofer positioning allows you to get the best audio performance.