How To Connect A Subwoofer To An Old Amplifier

Have you come here to know if there is any possibility of connecting a subwoofer to your old amplifier. If I say yes you can,  probably the following question from your side will be how? Well, I’ve got answers to all these questions, for which you need to read this article. So without further delay, let’s get started.

Is there really a chance to connect a bass system to an old amplifier?

The answer is Yes. There are many ways to get this done. And, surprisingly, it won’t cost much, either! Without taking much of your time, let me briefly explain the methods to achieve this.

how to connect a subwoofer to an old amplifier


Before getting to know the connection procedure, you need to really understand what kind of subwoofer you’re using.

Basically, there are two kinds of home-stereo subwoofers, namely powered (“active”) and non-powered (“passive”).

Active speaker - how to connect a subwoofer to an old amplifier


Suppose your woofer system has an internal amplifier, RCA inputs, speaker inputs and digital audio inputs. Then it will come under this category. This type of stereo system uses a low signal which in turn is boosted using the amplifier.

passive speaker - how to connect a subwoofer to an old amplifier


Suppose you see your subwoofer speaker inside the bass enclosure and directly wired to the speaker terminals. Then your speaker will be called a passive subwoofer. These have become rare nowadays.

Effective methods to connect your vintage amplifier to a powered subwoofer (active type)?

METHOD 1: Connect a subwoofer to your old amplifier using High-level Subwoofer inputs

A subwoofer with speaker-level inputs allows easy connection to your older amplifier or receiver. If your woofer does not have this provision, simply connect the speaker outputs to the matching inputs on the subwoofer using speaker wires. 

Before starting the procedure, first, make sure you’re using an amplifier/receiver that can play both speakers A(front) and B(rear) together. Next, make sure your subwoofer has high-level inputs.

high level - how to connect a subwoofer to an old amplifier

Why are high-level subwoofer inputs preferred to RCA inputs?

RCAs are good for home theatre effects, but vintage amplifiers don’t come with RCA inputs. Adding to it, you need to balance the gain on the subwoofer for perfect loud volumes. Unfortunately, vintage amplifiers don’t give you this ease.

If you intensify the amplifier’s signal, the subwoofer might get damaged. And even if you wish to get bass effects, it will sound unpleasant. RCA inputs also tend to pick up AC noise from wall outlets which you don’t want. This is the reason behind using high-level subwoofer inputs rather than RCA inputs.

So what’s the solution?. No worry, you can enable a physical connection between your amplifier and subwoofer by following the given steps.

  • Hook up any unused speaker outputs of the amplifier to the woofer’s high-level input using any speaker wire (copper wires preferred).
  • Now the subwoofer will take signals from the left and right high-level inputs, sum them together such that you get a clear mono signal.
  • Switch on the power of the amplifier and speaker.
  • The connection between your vintage amplifier and subwoofer is now established. You can now adjust the volume settings, gain controls on the sub-woofer to get that bassy effect.

You can expect pretty good sound quality as the signal used is just divided and isn't changed. Because the subwoofer level inputs have a very high input impedance (total input resistance), so you don't have to worry about the subwoofer getting damaged even if you power it to a high wattage channel. 


This is the second method to achieve the connection between your subwoofer and the old amplifier you own. If you have a recent technology woofer system, it will definitely have output slots. But, if your woofer system doesn’t ensure this, you can still connect your vintage amplifier to your subwoofer using the preamp output.

If your old amplifier has an output slot, get a pair of interconnects and pass them from the PreOut of that amplifier into your subwoofer.

Note: Preamp outputs are labeled as “Pre Out” on some amplifiers. In case if your old amplifier doesn’t have a preamp output, you need to consider your subwoofer as a normal speaker, and the rest becomes easy. 

1. Connect the front right speaker and the front left speaker terminal of the amplifier to your subwoofer’s speaker-level terminal. 

2Plug the amplifier and subwoofer into a power source and switch them on.


In this article, I have stressed how to connect your old amplifier to a subwoofer with a mindset that most of you will be using only powered subwoofers. However, if you want to know how to connect a non-powered subwoofer to your old amplifier, please let me know in the comment section. I will be glad to share my knowledge on your queries. Thank you for reading!

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