Receiver Has Single Subwoofer Output But Subwoofer Has Left and Right Inputs

Norvan Martin
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Do you have a receiver with a single subwoofer output and want to wire it to a subwoofer with both left and right inputs? Confused about how to make the connection? Don’t worry; we have prepared this article to guide you through the step-by-step process. 

You can easily connect a receiver that has a single output to a subwoofer that has left and right inputs using a Y splitter or mono. You can use an RCA Y adapter or simply connect to the input marked mono (normally L input).

Connecting receivers to subwoofers requires the right connectors. For a seamless connection, both the receiver and the subwoofer should possess ports that match a single connector type, thereby eliminating the need for an adaptor.


  • The receiver features a singular RCA jack labeled “Subwoofer”.
  • The subwoofer presents two RCA input jacks, tagged as Left and Right.
  • An accompanying single RCA cable is bundled with the subwoofer.

Quick Methods 

  1. Use A Splitter: Opt for a splitter or an RCA male-to-male Y adapter. The role of this “Y adapter” or “splitter” is to accommodate a single cable, catering to both subwoofer inputs. This method proves effective, especially when working with a processor that exhibits low output. Splitters such as the Poyiccot RCA Splitter or the FosPower RCA Y-Adapter can be acquired from online platforms like Amazon. Before purchasing, ensure that you verify the type (male/female) of inputs on your subwoofer and choose a corresponding splitter. Dive deeper to learn more about subwoofer splitters.
  2. Use Mono LFE: It’s pivotal to remember that subwoofers are fundamentally mono audio devices. Even if your subwoofer is equipped with both left and right inputs, you will typically find one of them labeled as MONO. This is the designated port for a single LFE_OUT. If such a label is missing, resort to using a Y cable, as previously described.

In the following section, we dive into the specifics of achieving this connection via a splitter.

SOLUTION 1: Using A Splitter (In Depth)

Wiring a subwoofer with left and right inputs to a receiver with a single subwoofer output is a simple process.


You need to set up the subwoofer, and receiver, and have the right RCA cables. The right RCA cable has a male plug on one end and a pair of female RCA jacks on the other end.

The female jacks should have molded connector housings together with strain-relief boots to make the connection more secure. Follow the steps below to set up the connection. 

Step 1: Position The Equipment To Make the Connection Easy

Begin by positioning your receiver on a stable place, and the subwoofer near it to make the connection easy. The subwoofer should be placed a few inches from the walls to reduce low-frequency signal absorption by the walls. 

Step 2: Connect The Male End Of The RCA Cable To The Receiver

Connect the male pin jack to the subwoofer output on the receiver. The male pin is the one appearing by itself. It should only go into the connector port on the receiver. Some receivers will have the output labeled as “subwoofer”. Insert the male jack and make sure the connection is stable. 

Step 3: Connect The Female End Of The RCA Cable To The Subwoofer (Or the Male End Depending)

Connect the two female connectors of the RCA cable to the inputs of the subwoofer. If your sub has RCA male inputs, then make sure you use a male-to-male splitter to make the connection. Be sure to match the colors so that the left and right channels are properly wired to the receiver. The connection should be secure and stable. 

Step 4: Power The Connection

Connect the receiver to the main supply. If you have an active subwoofer, connect it to the power source. A passive subwoofer, however, will not require being connected to the mains supply. You should check the type of subwoofer you are using before attempting to connect it to a power source.

Step 5: Test The Connection

At this stage, you can now test your connection. Switch on the receiver and the active subwoofer. You can then play some music on the receiver system to check if the subwoofer produces sound. Enjoy your listening! 

SOLUTION 2: Use Mono LFE (In-Depth) 

Usually, subwoofers will have both a right and left channel. They may be labeled R/L or not. However, you may get subs with a mono connector labeled either mono or LFE.  

If the ports are not labeled at all, a Y-splitter cable can be used to improve the performance of a receiver with a mono output. 

Subwoofer cables come with a standard RCA connector and are much thicker than standard RCA cables. They can be used to connect a receiver to a speaker to reproduce low-frequency sound signals.

Most subwoofers require a single long cable with an RCA connector. Where a standard RCA cable is not available, a subwoofer cable is recommended because it offers more shielding and resolution. 

What Is RCA Input In A Subwoofer?

If you have a subwoofer with both left and right inputs, then it may not have an LFE input connection. In that case, you will use the Radio Corporation of America (RCA) connection that comes with both the right and left jacks to input to your subwoofer. 

This type of connection is, however, less common and is, therefore, often less preferred. This may be because it requires two cables instead of one. It, however, works perfectly well and achieves the desired connection much faster. 

RCA cables are designed with both the left and right input side cables. Some RCA cables split the inputs with a y-cable, making it much easier and more convenient to transmit low-frequency sound signals to the left and right channels of a subwoofer.

As opposed to the LFE input cable that combines the audio signals, RCA inputs the signals in specific locations: the right and left channels of the subwoofer.

If your subwoofer has both RCA and LFE, you may be tempted to use the LFE for convenience. In this article, we focus on subwoofers with left and right inputs that are particularly compatible with RCA cables. 

Can You Wire A Subwoofer To Both Right And Left Channels?

Yes, you can wire a subwoofer to both the left and right channels. You can do this by using a Y splitter or, if connecting to powered speakers, you can use the speaker level inputs and tap the red right and white left wire. 

Why Does My Subwoofer Have Speaker Inputs?

There are many active subwoofers that have built-in crossovers.  In such cases, we feed the speaker-level signals from the receiver to the subwoofer.

The subwoofer then filters the input, using the low frequencies to drive the subwoofer, while the highs are fed out through the “speaker out” terminals to the speakers.

Why Are There Two Inputs On My Subwoofer?

The majority of subwoofer designs in production possess dual subwoofer signal input. This serves several purposes, some of which are highlighted below:

  1. For audiophiles who have only one subwoofer but have a stereo sub-signal. The dual input capabilities allow the down-mixing of stereo signals in two channels into a mono signal. The mono signal retains all the information contained in the original stereo signal.
  2. If you happen to own two subwoofers, you can use a Y-split LFE signal from the subwoofer processor output. The dual input feature on your subwoofer allows you to reproduce LFE mono + stereo audio.
  3. It is also possible to connect the sub placed on the left side to the main outleft from the processor (the output can also be used to connect an external effect block to the left front speaker).

A subwoofer possesses dual input capabilities, allowing the subwoofer to make minute, important adjustments. Under normal circumstances, it would be enough to use a mono LFE subwoofer signal from the processor.

By using both inputs with the same mono signal, we can increase the sensitivity of the subwoofer output. This means it now needs only half the signal strength to drive it to full output.

Why Do Subwoofers Have Two RCA Inputs?

Subwoofers use RCA cables with right and left inputs to digitally transfer low-end frequency audio. The audio is then split between the right and left channels of your subwoofer system.

Is A Subwoofer Mono Or Stereo?

Subwoofers are mono devices. This is why they usually use only a single Phono RCA connector connected to the LFE channel. This is the component that makes up X.1 in the naming of a 5.1 or 7.1 surround setup.

However, some subwoofers have left and right inputs, so you may think they’re stereo. However, in this case, the same mono signal is sent through both the left and right channels.

Why Use Stereo RCA Cables To Connect My Subwoofer?

These cables are used when connecting analog audio components. Most types of A/V devices use them.

Stereo RCA cables come in pairs: one for connection to the left channel, and the other for connecting to the right channel. 

What’s more, the cables are color-coded to ensure every connection is done correctly. Common color codes include black and red, white and red, and grey and red. For stereo appliances, red generally indicates the right channel. While these are the standard colors on most commercially made products, any cable with a different color can be used, as long as it’s compatible with the devices.

Why Do Some Subwoofers Have Left And Right Inputs?

Since subwoofers are mono devices, you may be wondering why some subwoofers have left and right inputs, or in other words, are stereo. It is more common for subwoofers to have a singular LFE (low-frequency effects) input that uses an LFE cable to connect with a receiver. Subwoofers Have Left And Right Inputs

However, in some cases, the subwoofer’s low-frequency signals are sent through the left and right channels using left and right RCA connectors. This type of connection sends low frequencies through both the left and right channels of the subwoofer. 


So, that’s how you can set up when your subwoofer has two inputs, but your receiver has only one output. It is a common situation that can be resolved quickly and easily, as you’ve seen, by using a Y-splitter or connecting as mono.

To learn about other ways to do this, check our article on how to connect a subwoofer to a receiver without subwoofer output.

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Norvan Martin is the founder of He is a professional Electronics Engineer and is passionate about home theater systems and AV electronics. BoomSpeaker was created as an online hub to share his knowledge and experiences as it relates to home theaters and home audio electronics. My email: [email protected]  Connect on Pinterest and Linkedin