How to Connect a Subwoofer to an Amplifier

The most important things with speakers are the crossover, the amplifier, and the subwoofer. They are what are known as “the main parts” of a speaker system. The crossover is the dividing line between where different frequencies meet in a speaker’s frequency response.

The amplifier increases an electrical signal that flows into it, which is then sent to power either by your computer or through an amplifier into your speakers. This signal can’t pass through the subwoofer without an additional amplifier, which is what the subwoofer is. The subwoofer amplifies (and reduces) bass frequencies.

The subwoofer should be wired to an amplifier with a sub-out connector, which means it’s plugged into the sub-output of the amplifier. And this is how you connect it to your amp – with a set of cables (called “cable sets”).

The subwoofer is the low-frequency driver in a home audio system. It is housed in a separate enclosure, and is able to reproduce deep, accurate bass. The subwoofer turns the low frequencies of the preamp signal into audible sound.

Subwoofer used to be known as “the cabinet” or “the front end”. While it’s not much bigger than an average speaker, it’s capable of producing much deeper and stronger bass than the average speaker. Some models use an external amplifier but most come with their own amp and crossover network.

Types of Subwoofer:

The subwoofer can be found in four types:

  • Active Subwoofer
  • Passive Subwoofer
  • Integrated Subwoofer
  • Portable Subwoofer

What is an Amplifier:

Amplifier is a device that increases the power of a signal. Amplifiers are usually found in on car stereo systems, home stereo systems, and theater systems. These devices can be powered by AC or DC electricity, depending on the type.

Table of Contents

Choosing a Suitable Amplifier for Subwoofer:

For home audio systems, you can use a receiver or a separate amplifier for the subwoofer. The receiver is the best choice if you’re building a home theater system. For a stereo system, a separate amplifier will provide more control and cooler operation.

You need to have the following things before you can connect a subwoofer to an amplifier or any other speakers –

  • Subwoofer
  • Amplifier
  • Speaker Cables
  • Wire Cutter
  • Screw Driver
  • Audio RCA Cable
  • RCA Converter
  • Power Cord
  • Power Strip
  • Power Splitter
  • Ground Loop Isolator

Steps to Connect a Subwoofer to an Amplifier:

Step 1: Connection

First, you need to connect the amplifier output to the subwoofer. Usually, the subwoofer will have a connector which is called “sub-out” and is connected to an audio input of the amplifier.

Step 2: Cables

Next, you need to connect your speaker cables from your amp into the subwoofer enclosure. You can use speaker cables that are usually used for speakers, but most people use RCA cables, which are typically used for connecting audio equipment such as TVs and home theater systems.

Step 3: Channels

Now you need to connect your left channel (L) one end of the RCA cable into L port on L-Stereo input on your amp. Then connect your right channel (R) one end of the RCA cable into R port on R-Stereo input on your amp.

Step 4: Subwoofer to Amp

Next, connect the speaker cables from the subwoofer into the amp. Connect one end of the speaker cables into the main speaker output on your amp. Then connect other end of them to L and R inputs of your subwoofer.

If there is a subwoofer pre-out connector, plug it into the subwoofer’s pre-out connector and then plug in audio cables from your audio source equipment (e.g., DVD player or computer) to the pre-out port on your amplifier for playing back music and movies through those sources.

Step 5: Isolator

Finally, connect the Ground Loop isolator. For this, you need to disconnect the speaker and subwoofer cables and remove the screws on the ground terminal plate of your amp.

This plate isolates your amp from its enclosure, which can cause interference during playback of low-frequency signals. Then simply place the Ground Loop isolator over it and tighten it with screws once again.

Things to Remember:

There may be a reverse polarity switch on some amps that must be switched before connecting them to a subwoofer or speaker system.

A switch of this type is normally inside the speaker output connectors and may be operated by sliding a lever or similar mechanism in either direction (see illustration).


If you follow the steps described above, you will be able to connect your subwoofer to an amplifier. But if you are not sure, you can always search the internet for the step by step guides. You can also come up with different home audio system designs using these methods.


Q: How to match a subwoofer and amplifier?

A: How much power? Find out the “watts RMS” rating of the sub Then,multiply the number of subs you have by the RMS rating of each,to get … What impedance? The results of combining coils and subs Figure out the possible total impedance (s) that the subs can be wired together to form. … Pick an amp that can do both — X watts at Y ohms

Q: What is the best way to connect a subwoofer?

A: The best way to connect the sub is to get a subwoofer with a high level input and then run a set of speaker cables from the output of your receiver or power amplifier to those inputs. Subs today are generally powered so no need to get a passive one and I’d recommend against that.

Q: How to tune a subwoofer amplifier?

A: Before turning on your system,make sure your amplifier’s gains are set to their minimums,their high- and low-pass filters are off (set to “all pass” or flat),and that … Turn on all the units of your system. … Play your test music. … Set the receiver’s fade control all the way to the front speakers.

Q: How do you hook up a subwoofer?

A: Connect Using Stereo RCA or Speaker Level Outputs . Sometimes a receiver or amplifier does not have the LFE subwoofer output, and sometimes the subwoofer doesn’t have the LFE input. Instead, the subwoofer might have right and left (R and L) stereo RCA connectors or spring clips like you see on the back of standard speakers.