What You Should Know About Connecting A Subwoofer To An Amplifier

Adding a subwoofer to your home audio system is a great way to increase its bass output. Attaching a subwoofer to an amplifier, on the other hand, may be challenging if you are new to audio equipment. We’ll go over everything you need to know about Connecting A Subwoofer To An Amplifier in this post, including subwoofer types, amplifier compatibility, and step-by-step instructions for connecting and setting up your audio system.

1. Types of subwoofers

A subwoofer is a loudspeaker that reproduces low-frequency sounds such as bass and sub-bass. In contrast to ordinary speakers, which are designed to produce a wide range of frequencies, subwoofers are specifically designed to handle the lowest frequencies, frequently ranging from 20Hz to 200Hz or below.

Subwoofers are available in a number of sizes and types, ranging from small and portable units for use with computers and home theatre systems to larger, more powerful models for use in concert halls and professional sound systems. They can be used alone or in conjunction with other speakers to enhance overall sound quality and provide a more immersive listening experience.

Yamaha SW218V Club Series V Subwoofer

The different types of subwoofers available

Subwoofers come in a variety of styles, each with its own set of traits and advantages. The following is a breakdown of each type:

  • Active subwoofers have their own amplifiers built-in, making them simple to set up and use. They are an excellent choice for smaller spaces or when space is limited. They are also more efficient than passive subwoofers, so they can produce more bass with less power.
  • Passive subwoofers: These subwoofers do not have their own amplifiers and are driven by your audio system’s amplifier. They may be more difficult to set up, but they offer more customization options. Passive subwoofers are an excellent choice if you have a high-quality amplifier and want to tailor your system to your specific needs.
  • Sealed subwoofers have an airtight enclosure that keeps air out, resulting in tighter, more accurate bass sounds. They’re a great option for music that requires precise bass, but they may not be as loud as other types of subwoofers. Sealed subwoofers are also more compact than other types, making them a viable option if space is limited.
  • A vent or port on ported subwoofers allows air to escape from the enclosure, resulting in a louder, boomier bass sound. They’re a great option for movies and games that require a lot of basses, but they may not be as accurate as sealed subwoofers. Ported subwoofers are larger than sealed subwoofers and may not be the ideal solution if space is limited.

How to choose the right subwoofer for your amp and speakers

Choosing the right subwoofer for your amplifier is crucial to getting the best sound quality. Consider the following crucial variables:

  • Power Handling: Ensure that the subwoofer can control the power output of the amplifier. Look for a subwoofer with a power handling rating equal to or greater than the output of your amplifier. If you have any questions concerning the power output of your amplifier, consult the user manual or contact the manufacturer.
  • Impedance: Make sure the impedance of the subwoofer matches the output impedance of your amplifier. Most subwoofers have an impedance of 4 or 8 ohms, whereas amplifiers can have a range of output impedance values. Using an impedance-incorrect subwoofer may result in poor sound quality or possibly equipment damage.
  • Size and kind: Consider what size and type of subwoofer will work best with your amplifier and listening environment. In a small space, a smaller subwoofer may suffice, whereas a larger subwoofer may be necessary for outstanding sound in a larger room. Consider the type of music and audio you’ll be listening to; certain subwoofers (such as sealed, ported, or bandpass) may be better suited to different sorts of audio.
  • Frequency Response: Look for a subwoofer that complements your speakers by filling in lower frequencies that your speakers may be unable to reproduce. A subwoofer with a frequency response of at least 20Hz is suitable for producing the deepest bass sounds.
  • Choose a subwoofer from the same manufacturer as your amplifier or speakers, as they may have been designed to work well together. However, you may mix and match brands as long as you do your research and ensure that the equipment is appropriate.

2. Amplifier compatibility

An amplifier, often known as an amp, is a piece of electrical equipment that is used to increase the amplitude (or intensity) of an audio signal. Amplifiers are commonly used in audio systems to enhance the signal from a source such as a CD player or turntable and to generate enough power to drive speakers or other output devices.

The fundamental function of an amplifier is to increase the voltage or power of a low-level signal so that it can drive a speaker or other load. This is performed by amplifying the electrical signal with electronic components such as transistors, tubes, or integrated circuits.

Amply Boston Acoustics BA150 300W

Based on their application, amplifiers are categorised into five types:

  • A pre-amplifier is a device that processes and fine-tunes signals from an input source to create an amplified amplifier without the amplification function.
  • Amplifier (Power-amplifier): This device amplifies the signal before it is sent to the output source.
  • An integrated amp (Integrated-amplifier) is the synthesis of a pre-amplifier and an amplifier.
  • Symmetrical integrated amplifier (Dual mono amp): An integrated amplifier having symmetrically designed insides to split the left and right channels, with each channel supported by a separate amplifier.
  • A monoblock amplifier is comparable to a symmetrical integrated amplifier, but it has two unique situations.

We will use amps that are appropriate for the sound system. A 2-channel amplifier is usually an integrated amplifier.

BIK amplifier provide a good sound quality

How to check if your amp is compatible with a subwoofer

When deciding whether your amplifier is compatible with a subwoofer, there are several factors to consider:

  • Power output: Examine your amplifier’s power output to ensure it has enough power to power your subwoofer. Subwoofers often require more power than ordinary speakers to deliver low-frequency sounds. Check the RMS power rating of your subwoofer and confirm that your amplifier can produce at least the minimum required power.
  • To ensure compatibility, check the impedance of your amplifier and subwoofer. Impedance is commonly measured in ohms and is used to match the electrical resistance of the amplifier to that of the subwoofer. If the impedance of the subwoofer is too low or too high, the amplifier may be damaged.
  • Determine whether your amplifier has a built-in crossover or if an external crossover is necessary. A crossover is a device that filters an audio signal and routes it to the appropriate speakers. In a subwoofer, a low-pass filter is frequently employed to exclude high-frequency noises and reproduce only low-frequency sounds. If your amplifier does not have a built-in crossover, you will need to use an external one to correctly connect your subwoofer.
  • Check the connections on your amplifier to ensure they are compatible with your subwoofer. Most subwoofers have a single RCA input, however, some amplifiers feature a separate subwoofer output. Check that your amplifier and subwoofer have the same connectors and that you have the correct cords.
Check if your amp is compatible with a subwoofer

3. Connecting the subwoofer to a 2-channel amplifier

Before connecting

There are a few things you need to perform before attaching a subwoofer to a 2-channel amplifier:

Check that the subwoofer and amplifier are both switched off and disconnected from the power supply.

Determine whether your amplifier has a dedicated subwoofer output.

To guarantee compatibility, check the specs of both the subwoofer and the amplifier.

Choose a location for the subwoofer in your listening environment to maximise sound quality.

  • Place in front of the audience: This is a straightforward placement that helps to blend the sound from the speakers.
  • Place in the room’s corner: This position keeps the bass from colliding with sound suppression or “dead spots” in the room, resulting in better sound quality.

The size or configuration of your space will also heavily influence the placement of the subwoofer, so be willing to experiment with different positions until you find the best sound quality. Additionally, keep your subwoofer at least 10-15cm away from a wall.

Prepare the cables and wires needed for the connection.

Steps to connect a subwoofer to a 2-channel amplifier


Here’s how you connect a 2-channel amplifier to a subwoofer. The article made use of the Boston Acoustics BA300 Karaoke Amplifier and the Klipsch SUB100-BK Subwoofer.

Step 1: Determine the output type of your amplifier.
Check to see whether your amplifier has a separate subwoofer output. If it does, connect the subwoofer’s RCA input to the amplifier’s subwoofer output via an RCA wire. If your amplifier does not have a dedicated subwoofer output, you can use speaker wire to link the amplifier’s speaker outputs to the subwoofer’s speaker-level inputs.

Look for the OUTPUT port on the amplifier and SUB LINE below it.

Look for the OUTPUT port on the amplifier

Look for the subwoofer’s input ports:  LINE IN port or which are usually labeled as “subwoofer input,” “LFE input,” or “low-level input”.

Look for the subwoofer's input ports  LINE IN port

Step 2: Connect the subwoofer to a two-channel amplifier.
You connect a sufficient length of 2-ended RCA cable like follows:

The amp’s white port is connected to match the subwoofer’s white port.
The red wire links the amp’s red port to the subwoofer’s red port.

Step 3: Test the system
Turn on the amplifier and subwoofer and put the system through its paces by playing bass-heavy music or watching a movie. To check that the subwoofer is working properly, listen for a clean and deep bass sound. Make any necessary changes to achieve the desired sound.

Tips for ensuring a secure and proper connection

  • Remember to switch off all electronics before you begin.
  • The power of the subwoofer should be less than or equal to the power of the amp to ensure reliable operation.
  • If connecting is difficult or you are doubtful, get the help of a technician to avoid damaging the item.


To connect a subwoofer to an amplifier, use an RCA connector to connect the subwoofer’s input to the amplifier’s subwoofer output. You will also need to adjust the amplifier settings to ensure that the subwoofer is properly integrated into your audio system.

Use a high-quality RCA cable designed for audio purposes. Look for cables with gold-plated connections and insulated construction to reduce interference and ensure the best possible sound quality.

To completely integrate the subwoofer into your music system, adjust the crossover frequency and volume on your amplifier. The crossover frequency determines the frequency range that the subwoofer can handle, whilst the level setting controls the volume level of the subwoofer with respect to the rest of your speakers.

Yes, you can connect multiple subwoofers to your amplifier; however, you must ensure that your amplifier is capable of driving multiple subwoofers and that you have the necessary space and power.

If your subwoofer isn’t creating any sound, check that all connections are secure and that the amplifier settings are correct. Check the power source to ensure the subwoofer is receiving power. If you continue to have issues, consult the user manuals for your specific subwoofer and amplifier models, or contact the manufacturer.

Above, Casual Living USA assisted you in Connecting A Subwoofer To An Amplifier to enhance your sound system. We wish you a fun and meaningful entertainment experience!

Vincent Mason

Vincent Mason sells speaker and audio devices for home and small civil works and has 15 years of experience. He is a US-based expert. Vincent is a well-groomed, early-forties man. His warm, approachable nature helps him connect with consumers and develop enduring connections. Vincent is a good salesman who knows his products and consumers. He's good at matching products to customers' needs and budgets. Vincent spends his free time researching audio technologies and market trends. He loves music and attends concerts and festivals whenever possible.

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