How To Connect A Subwoofer To An Old Amplifier? Top Full Guide

How To Connect A Subwoofer To An Old Amplifier? Top Full Guide

One of the most common questions we get here at the office is how to connect a subwoofer to an old amplifier. The short answer is that you can do it, but you’ll need to wire the subwoofer to the amplifier. The long answer is a little more complicated, but we’ll try to break it down.

Stereo Subwoofer Types

Stereo Subwoofer Types

When it comes to home audio subwoofers, they may be powered/active or non-powered/passive. A low signal is amplified by a built-in speaker amplifier, power supply, and crossover in powered subs.

They are one of the most regularly used and connect to the receiver through an RCA-type input connection. On the other hand, passive subs are just subwoofer speakers housed inside the bass enclosure. This is directly connected to the speakers or an internal bass crossover. These are uncommon.

Subwoofers may be front-firing (the primary driver faces forward) or down-firing (the driver is located on the bottom of the subwoofer). It performs best when the front-firing subwoofer is situated closer to the primary speakers.

A stereo sound system must have speed, clarity, and exact intonation of individual tones. Forward-firing engines create significantly more of them than down-firing engines. As a consequence, the bass will sound quick and forceful.

Ported subwoofers are those that have ports that go directly to the interior. Subwoofers with no ports are referred to as sealed subwoofers. The most often utilized subwoofers are sealed because they are less expensive than ported subwoofers.

Aside from pricing, the difference between them is in sound quality. Sealed subwoofers provide an even, controlled sound, but ported subwoofers may produce more volume. Sealed subwoofers are ideal for home theaters because they improve sound quality in a smaller area.

Most subwoofers will need a direct connection to a wall outlet for electricity and an RCA wire to your amplifier to receive sound. Wireless subwoofers are far more costly and often only function with sound systems from the same manufacturer. Subwoofers may also vary in overall sound quality, power (wattage), frequency range, equalization, and connection.

If you’re in the market for a new subwoofer, several excellent options are available for around $1,000. If you’re on a tighter budget, try for the best subwoofers under $500 since you may still find some great offers here.

How Do They Work?

How Do They Work

A subwoofer is a loudspeaker that generates low-frequency sounds, such as bass and sub-bass. Subwoofers are made up of one or more woofers housed in an enclosure constructed of high-quality wood that can endure pressure and resist deformation.

Subwoofers may pick up frequencies inaudible to the human ear, unlike normal speakers, which can reproduce a broad range of frequencies but lack bass.

High-quality subwoofers may reach as low as 15-16 Hz, although humans can only hear at 20 Hz. Subwoofers are never utilized on their own since their function is to broaden the range of loudspeakers that cover higher frequency bands.

Subwoofers are linked to a receiver or amplifier. The receiver transfers low-frequency signals to the subwoofer through an electrical current. This frequency varies between 20 and 100 Hz, and the lower your sub descends, the stronger the bass sound effects will be heard.

The current is then amplified and converted to a sound frequency by the subwoofer through a magnetic coil, causing the driver to vibrate. This vibration causes the right sound waves to exit the driver through its output.

Because these low bass or sub-bass impulses are not directional, users may position the subwoofer anywhere they wish. The sound works best with a subwoofer when it deflects off anything. When the sub is turned on, you won’t be able to identify where it is or where the bass is coming from. You may move your subwoofer around until you find the perfect place for your desired sound quality.

A crossover in the signal channel filters the bass out of the signals driving the main speakers in passive subs. Subwoofers that extend bass without filtering will not increase the power of the main speakers. The powered subwoofers already include a built-in crossover that is adjustable to allow you to set the frequency. This simplifies interaction with the primary speakers and automates line-level output filtering.

Low, mid, and high frequencies are the three levels of sound. A bass guitar or drum, for example, generates a low-frequency bass note, while the intermediate frequencies are commonly produced by a singer’s voice or a guitar, and the higher frequency sounds like other instruments with a ringing or clashing sound. Subwoofers assist in decluttering the speaker by isolating low-frequency sounds from mid-and high-frequency sounds.

If you’re looking for a wonderful example of a high-quality subwoofer, go beyond the SVS PB-1000, which hits the right blend of quality, longevity, and price. Several excellent subwoofers are available that may significantly improve your home theater experience.

Old Amps vs. Modern Receivers

If you’re thinking about utilizing a subwoofer with an amplifier, you probably wonder if it works better with an older amp or a newer technology. The solution isn’t entirely straightforward. Several things determine the sound quality produced by a subwoofer with an amplifier.

For example, if you already have an old, working receiver, you will likely wish to make it work again. You should be able to connect it to the subwoofer. However, the sound quality may be lesser than desired.

You may also purchase new or antique amplifiers. The older ones will surely be less expensive since you can get them at any thrift shop or yard sale. Connecting a subwoofer to a vintage amp also evokes feelings of nostalgia.

However, when purchasing any used goods, there is always the possibility of a problem. This is more likely to happen with older amplifiers, so verify the amp before purchasing. If there is a problem, ensure sure it is repairable. While contemporary receivers are ten times more expensive, the odds of prior damage are far lower, and they often come with a manufacturer’s guarantee.

Vintage amplifiers outlast newer ones in terms of longevity and service. A vintage amplifier may be serviced or repaired by replacing components such as capacitors, resistors, diodes, transistors, or broken circuits.

Vintage receivers seldom need maintenance since they were built to endure a long period. This is not the case with most current receivers unless they are quite expensive. When a modern amplifier fails, you will almost certainly need to replace it rather than fixing it.

The decision between old and new may also be influenced by how you want to utilize the amplifier. Most older amplifiers feature tuner, tape deck, aux, and phono inputs. The first three are line-level inputs for CD players or MP3 players.

The phono output is only available on older versions since it was formerly utilized for turntables. Because it does not have a line-level output, the cartridge signal must be boosted and lined via a phono preamp. With the rising usage of CD players, current amplifier manufacturers seldom include a phono preamp.

How to Connect a Subwoofer to an Old Amplifier

How to Connect a Subwoofer to an Old Amplifier

There are a few things you should look at before connecting our subwoofer to the old amplifier. To begin, make sure your subwoofer includes high-level inputs and standard RCA connections.

Also, ensure that your receiver can play both the main and remote/speakers A and B outputs simultaneously. All of them have benefits after you’ve completed the setup procedure. Here’s how to connect your old amplifier to your subwoofer.

How To Hook An Active Subwoofer To An Old Amplifier

Some older amplifiers will provide different outputs than newer ones. Many will have a straightforward mono output. Locate the corresponding port on your subwoofer and utilize it as the signal source from the sub to the amp. It’s a nice old feature that works with subwoofers without a hitch.

However, some older amplifiers do not have such ports, so you may need to improvise a bit. To begin, your amplifier requires a few components.

To play sets A and B simultaneously, it will need two speaker outputs. In contrast, an active subwoofer requires a high-level input option.

If your amp and sub have all of these features, you’re good to go. Set the amplifier to A to connect to your standard speakers. The B line should be linked to the high-level input of your subwoofer. When you play them both simultaneously, you should notice an increase in bass.

Most amplifiers even include indicators for where you should connect your subwoofer. The B line is often labeled “subwoofer output.”

It’s even simple to turn off. Turn off the B channel on your amplifier.

How To Hook a Passive Subwoofer To An Old Amplifier

Passive subwoofers are significantly easier to connect to older amplifiers. Passive subwoofers include pass-through connections that enable you to connect the subwoofers before the speakers.

Connecting the passive subwoofer to the amp is as simple as treating it like a loudspeaker and plugging it straight into the speaker connections.

How To Connect Your Stereo System to A Subwoofer

If you accomplish this properly, you will be able to improve the sound of your complete speaker system. A subwoofer may enhance the sound of a stereo system in ways other than just increasing the bass levels. It will make the system sound more pronounced and complex. However, the actual task of linking the two differs somewhat.

To build this connection, there are no bass management options. The high-input connector on the subwoofer will be utilized for this. Connect the speaker outputs from your sub to your stereo using the output connectors. This doubles the connection and gives your system the full subwoofer impact. This comprises the bass, middle, and treble ranges.

Connecting a Subwoofer to a Vintage Amplifier Without an Out

Some antique amplifiers may not have a subwoofer output. It is still feasible to connect your subwoofer and amplifier in situations like these. Depending on the manufacturer, the amplifier should feature a preamp or pre-out labeled “Preamp” or “pre-out.” A Y adapter is required for subwoofers with just one RCA input.

If your amp lacks an output designated, you may still utilize your subwoofer as if it were another speaker. Connect the subwoofer to the speaker output using speaker cords. You’ll have to connect the front-right and front-left speakers to your sub.

What The High-Level Signals Do To Your Connection

When linked through its high-level signals, the subwoofer will view the same signal as the other receiver. There is no latency. The sub-signal may not be as tightly synched when you connect it through an RCA output connection. Therefore you may have some time lag.

The tiny drop in hearing quality is virtually inaudible to most people, but it may be very annoying to individuals with training in the subject. Even inexperienced listeners would perceive a change if the identical sounds were repeated back-to-back.

However, in terms of damping and tonal balance, when you connect your subwoofer to your speakers, they receive the signal at a relatively comparable frequency. Consequently, the bass is emitted simultaneously by both objects, masking any latency to the human ear. This is particularly significant if you’re making music in a studio, where synching is crucial.

You should now be able to get the required sound quality by plugging your subwoofer into a vintage amplifier or receiver. Vintage amplifiers have a unique place in my heart for nostalgia, and music is frequently the catalyst for that trance.

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How do I connect my subwoofer to my stereo amp?

Connect a pair of speaker wires from the positive and negative terminals of the right-side output of speaker B on the rear of your two-channel stereo amplifier receiver to the positive and negative terminals of your powered subwoofer’s right side high-level input.

Can RCA cable be used for the subwoofer?

Any single standard RCA or subwoofer cable will suffice. However, if the RCA/sub connection is causing hum in the sub, you should consider using a “shielded” subwoofer cable. One subwoofer/RCA cable end should be hooked into your receiver’s Subwoofer Output.

How do you hook up an amp without an RCA jack?

There are almost three ways to connect your amplifier without utilizing any RCA connectors.

  • Join the speaker wire to the RCA adapter.
  • Using High-Level Amp Inputs, install.
  • Connecting an Amplifier Using a Line Output Converter (LOC)

Why do subwoofers have left and right inputs?

Consider it analogous to employing a Y splitter to separate two distinct pathways but in reverse. This is accomplished inside the receiver. The proper sound may now be routed to the subwoofer since the left, and right signals have been merged into a single channel.


One way to improve the sound quality of your music is to connect a subwoofer to an old amplifier. This can boost the bass frequencies, making for a fuller, richer sound. Thanks for reading!

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