Building a top-notch home theater system without a quality subwoofer is like building a house without a roof. A subwoofer is the heart and soul of a surround sound system, and without it, your audio experience is tinnier than a tin mine. Therefore, learning how to connect a subwoofer to an amplifier correctly will ensure a fuller and rounder sound for your system.
Although connecting your subwoofer isn’t quantum physics, there are a few things you need to know. Hooking up your subwoofer correctly is super important. So, let’s take a look at the different methods and steps you need to follow to add that final jigsaw piece to complete your home theater system.
Subwoofer Connection Methods
There are two key methods to connect a subwoofer to an amplifier. The first one is ‘Low-Level Connection,’ which is also referred to as LFE or line-level connection. The second method is ‘High-Level Connection,’ which is more commonly known as a speaker-level connection.
The type of connection you use will largely depend on your amplifier model. The decision might even depend on the type of audio you want to process.
The majority of subwoofer models offer both types of connection, although some will offer one or the other. Always check the specifications of your subwoofer to be fully aware of your connection options. Now that we’ve gone through the basics, it’s time to delve deeper into each connection type and its advantages and disadvantages.
Understanding Low-Level Subwoofer Connections
You will find the low-level connection input port at the rear of your subwoofer. Depending on your subwoofer model, this port could be denoted by either ‘LFE’ or ‘SVS,’ which is the term used for line-level. These terms are the same thing, so no need for confusion. This port is most commonly used to connect an AV receiver with a subwoofer input for multi-channel surround sound.
Most AV receivers are highly compatible with subwoofers and should have designated pre-outs that will be marked as LFE or ‘sub.’ This will allow your receiver to send low-frequency audio to your subwoofer. There are two types of low-frequency sound sent to your subwoofer, as detailed below.
LFE Track for Surround Sound
LEF is an acronym for Low-Frequency Effects, and an LFE Track will be found on a surround sound movie. When using multi-channel soundtracks on your system, they are routinely referred to as 5.1 and 7.1. The larger number denotes how many speakers you have in your surround sound system. While the ‘1’ refers to the LFE track and its low-frequency effects.
When a movie soundtrack is mixed, there is a separate channel for low-frequency sound effects that give the audio some deep rumble. This channel is usually sent to a subwoofer but can also be processed by full-range speakers that can handle LFE.
Bass management is a process that is handled by your AV receiver. This function gives you the option to send low-frequency sounds to your subwoofer and/or other surround speakers when setting up your AV receiver. This will improve the performance of your surround sound speakers by sending low-end frequencies to speakers in your system that can process low bass.
The bass management functions set a crossover frequency for each speaker in your surround system. This process will then separate frequencies below a certain level from the main speaker to your subwoofer. This is done via the low-level input. You can enable the bass management feature on your AV manually.
Configuring 2.1 Speaker Systems
This process is not limited to using surround sound for watching movies. Many people enjoy listening to music with a simple 2.1 setup with two front stereo speakers and a subwoofer. The setup is very similar, although there is no LFE channel used in music. However, the bass management function in the AV receiver is set up to send some of the low-end frequencies to your subwoofer.
Low-end sounds from bass guitars and the kick drum can be processed by the subwoofer to fill out and handle the bass. Some people like this method, while others don’t. Some users prefer to hear the natural balance of bass coming out of their standard stereo speakers, so it’s a personal preference.
Other reasons to use low-level inputs…
There are more reasons to use a low-level subwoofer connection than just for AV receivers. You can also use low-level inputs on your subwoofer if you are using a stereo amp with left and right pre-out connections. Or even if you are using a dedicated sub out. So, here are a few reasons why you would need to use this method if you are using…
- An AVR with subwoofer pre-outs.
- A stereo amp with pre-outs.
- A stereo amp with stereo pre-outs.
The main reason to use low-level subwoofer connections is to utilize the bass management functions on your AVR to get a better low-end than you’ll get on your standard surround sound speakers. So, check out these highly recommended subwoofers for low-level connections.
- ELAC Debut 2.0 400 Watt Powered Subwoofer
- SVS PB-1000 Pro Subwoofer
- SVS PB-2000 Pro 12” Ported Subwoofer
Understanding High-Level Subwoofer Connections
High-level subwoofer connections on the back of your amplifier will more often than not be speaker wire terminals. But in some cases, you might have a Neutrik Speakon connection on your amp and subwoofer.
This is a singular high-level subwoofer input connection whose key advantage is that your subwoofer and speakers receive the same audio signal. This method ensures that there are no potential phase issues between the low and mid-range frequencies.
We recommend that you use high-level subwoofer connections when your amplifier doesn’t have dedicated stereo line-outs or subwoofer outputs. This method would be ideal if you are using a stereo amplifier. But please remember that most older home theater receivers might not have subwoofer outputs, so check your model’s specifications first.
Using stereo amps and speakers…
This method is perfectly suited to anyone who has a stereo amplifier and speakers for listening to music or watching movies. You can use a high-level connection to add a subwoofer to make your system a 2.1 setup. The connection will allow you to filter the same low-end frequencies going to your speakers.
But this isn’t the only reason to use this type of connection. High-level subwoofer connections can be quite adaptable in some cases. If you are using your AVR with a sub output in bass management mode, you can use the connection to split ranges. Or you can use the low connection for watching movies and the high-level connection for playing music.
Some audiophiles swear by using high-level connections for listening to music because it reproduces a natural sound without any digital filtering.
Main Reasons for Using High-Level Subwoofer Connections
Here are two main reasons for using high-level subwoofer connections.
- If you are using a stereo amp that doesn’t have stereo pre-outs or a dedicated subwoofer.
- If you are using a stereo amp or AVR that already has a subwoofer or stereo pre-outs, but you want to listen to the music at higher quality from a high-level connection.
Using a high-level connection isn’t only reserved for listening to music. You can also watch movies with this method too, but you won’t have bass management functions or LFE channels. However, as always, there is a way around this issue. You can purchase a REL subwoofer that uses both a high-level connection and a dedicated LFE low-level input.
Connecting Your Subwoofer to Amp
We’ve been through the main subwoofer connection types, so you should now fully understand the subject. So, next, we need to discuss how to connect them properly.
Depending on which amplifier or subwoofer brands you use will have an impact on the connections and controls you need to use to set up everything. But honestly speaking, the process is similar across the board. And if you do have any issues, you will have to read the manufacturer’s instruction manual for your model.
How to Connect a Subwoofer to an Amplifier using a Low-Level Input
It’s very simple to connect a low-level subwoofer input with your AVR. You should be able to connect the two via a single RCA cable. You can purchase specifically designed subwoofer cables, but that’s not necessary for this job. But I would recommend that you buy good quality RCA cables such as any of the ones below and not the cheap and nasty types that come with DVD players.
- Amazon Basics RCA Audio Stereo Subwoofer Cable
- MonoPrice 1.5 Feet Premium RCA Cable
- Amazon Basics RCA Subwoofer Cable – 8 Feet
Some people prefer a thicker coaxial cable that has more shielding and therefore better performance due to the protection, but it’s not essential. You shouldn’t need anything more than a good quality RCA cable, so don’t get too crazy with this choice.
But do make sure you get the right length you need. If you purchase longer RCA cables, make sure you go for the more reliable and trusted brands.
Now all you need to do is connect the subwoofer pre-out on your AVR to the mono line-level input or LFE on your subwoofer. Pretty much all subwoofers have some form of low-level input. The subwoofer outputs on your receiver should be labeled clearly. And the two RCA line inputs on your sub should be labeled either LFE or ‘mono.’ But please remember that different brands and models might be labeled differently.
How to Connect a Subwoofer to an Amplifier using a High-Level Input
Using a high-level subwoofer connection is a little more complicated than a low-level connection. A high-level connection type receives the full frequency range of audio signals from your amp.
This means you should ensure that the complete audio signal is fed from the amp’s speaker connections into both the subwoofer and speakers. There are a few methods of doing this, which I have detailed below…
Connecting Subwoofers with Speaker Wires
Speaker wires are the most common high-level subwoofer connection. You will find these connections at the rear of your subwoofer. They look like standard speaker wire connectors with left and right ports that you would find on any hi-fi system.
You will need to take two pairs of speaker wires and plug them in the L and R terminals on the back of your amp. You will then plug one pair into your speakers and the second pair into the rear of your subwoofer. When you’ve connected these, you can use the subwoofer filter to match the sound with your front speakers.
Connecting Subwoofers with a Neutrik Speakon Connector
A Neutrik Speakon Connector is another common high-level connection type. This connector has one end that is a single plug that is used to connect directly into the rear of your sub. The other end of the cable has three bare wires that are used to connect to your amplifier’s speaker terminals. This is the case whether you are using a stereo amp or preamp, or even with your AV receiver.
You should place the first bare wire in the positive terminal of the right channel. The second wire is placed in the positive terminal of the left channel. The remaining wire is connected to one of the negative terminal channels, but do not connect to both negative channels.
Just make sure these color-coded wires have been connected to the correct terminals. You will now need to use the subwoofer filter to balance the sound with your front speakers.
Check out these reliable subwoofer models with high-level connections.
Need an awesome subwoofer for your car or PA?
Well, we have a nice selection of reviews to help you find exactly what you’re looking for. So check out our in-depth reviews of the Best Car Subwoofers, the Best Competition Subwoofers, the Best Under Seat Subwoofers, or the Best PA Subwoofers you can buy in 2021.
And don’t miss our helpful guides on Why Do Some Subwoofers Have Left and Right Inputs, the Difference Between and Active and Passive Subwoofer, How to Setup at-Home Surround Sound Audio, and How to Connect Speakers to your TV for more useful information.
You may also enjoy our in-depth Kef Kube 10B Subwoofer Review.
How to Connect a Subwoofer to an Amplifier – Final Thoughts
The best way to connect a subwoofer to an amplifier can involve high-level or low-level connections, or even both. But if you want to get the most from your home theater system, hooking up your subwoofer correctly is the difference between an average and a great bottom end.
First, you will need to decide whether you are using a low-level or high-level connection type. This is usually determined by the model of your amp and subwoofer, but also by what you are trying to achieve with your audio. After you’ve decided on exactly what you want to achieve sonically, connecting the cables together is the easy part.