Denon Receiver Subwoofer Not Working? (Quick Fix Guide)

If your Denon receiver subwoofer not working, and you’re wondering why continue reading!

Whether you’re using the default subwoofer from Denon or a third-party unit, issues often arise due to different factors.

Some of them include the cable connection, frequency adjustment, or the power supply, so in this quick guide, we will walk you through the complete solution list.

Here are the most effective solutions when your AVR’s subwoofer is not working:

Keep reading for a full debrief of the solutions above!

Denon Receiver Subwoofer Not Working – 6 Working Solutions!

Tip: Have you checked if the subwoofer and receiver are both turned on?

1. Use the Correct Subwoofer Input

Well, many users may confuse the “Audio In” inputs of the Denon receiver with the jacks for the external subwoofer and connect the device incorrectly.

That’s why the first step is to ensure that the subwoofer’s 3.5 mm RCA or XLR cable is connected to the correct inputs on your receiver.

1.1 How to Identify the Subwoofer’s Inputs?

Similar to standard home theater receivers, the Denon unit has both “Left” and “Right” PHONO inputs for the subwoofer.

The ports can be found in the upper-right corner of the receiver’s rear panel and are colored in white and red respectively.

Note: The cable that must be used with the subwoofer is a 1-to-2 jack 3.5 mm RCA cable that uses a PHONO channel.

1.2 How to Correctly Connect the Subwoofer?

To ensure the cable installation does not have any flaws, connect the single jack of your audio cable to the 3.5 mm output on the subwoofer and the split end into the “L” and “R” Denon ports.

If the audio cable is not colored, there will be an “L” and “R” imprint on one of the 3.5 mm jacks.

Note: Some Denon or custom subwoofers may also be compatible with an XLR connection, so check if your Denon receiver model has an “XLR” line-in input.

1.3 How to Identify a Defective Audio Jack?

If you’re certain that the audio cable has been seated properly, but the receiver doesn’t seem to recognize the subwoofer, there’s a possibility that the audio cable is defective. 

There are two ways to identify a defective cable:

• Test the audio cable on a different device that uses the same input port.
• Search for signs of physical damage on the cable (rips, cuts, bent spots).

Reminder: Even if the cable is faulty, the subwoofer may still work, but at a reduced capacity, that includes consistent disruptions.

2. Set the Speakers Channel to “Small”

Well, the Denon speakers’ “Small” and “Large” functions refer to the bass management of your devices.

So, based on the connected subwoofer type, it’s always preferable to set the speakers to “Small” for a consistent output and frequency of the bass.

Here’s how to manually set the speakers to “Small” in Denon’s settings:

1. Access the system settings of the Denon receiver.
2. Navigate to the “Speaker Configuration” category.
3. Individually adjust all connected speakers to “Small.”
4. Exit the menu of the receiver and test the bass level.

Determining whether to set the speakers to “Small” or “Large” typically solely depends on your subwoofer’s type and application.

If you are using one of Denon’s models, the “Small” setting should perform the best, as it significantly enhances the audio strength at the low frequencies.

Note: Configuring this setting requires accessing the system settings of the Denon receiver through the connected TV.

3. Power Cycle Denon and the Subwoofer

A primary cause when the subwoofer not working Denon receiver is because of a failure with the power supply.

Fortunately, you can address any type of power issue with the subwoofer or the receiver by conducting a power cycle.

Let’s begin with a power cycle on the Denon receiver!

3.1 How to Power Cycle Denon Receiver?

1. Press “Power” on the remote to power off the receiver.
2. Disconnect the power cable from the receiver’s back.
3. Next, unplug the other end from your electrical outlet.
4. Wait for 60 seconds until the residue power drains fully.
5. Reseat the power cable of the Denon unit on both ends.

3.2 How to Power Cycle the Subwoofer?

1. Optional: Check if your subwoofer has a “Power” button.
2. Optional: Press the “Power” button to power off the unit.
3. Disconnect the power adapter from the subwoofer’s rear.
4. Wait 60 seconds until the device drains the residue power.
5. Reconnect the power cable and press the “Power” button.

If you’re noticing unusual behavior in the receiver or subwoofer, check if there’s damage to the power cord and try switching the electrical outlet of both devices.

Additionally, refrain from using third-party power equipment such as power strips, dividers, or power cord extenders and plugs.

4. Adjust the Subwoofer Output Interface

There’s a strong possibility that the fault isn’t with the Denon receiver, but with the frequency and volume adjustments of the subwoofer.

4.1 How to Adjust Individual Subwoofer Settings?

Most high-end Denon or third-party subwoofers tend to have the following adjustments:

• “Crossover” knob – This is the frequency at which your subwoofer activates with bass notes and LEFs. We recommend setting the crossover frequency to between 70 Hz and 80 Hz. 
• “Phase” knob – This is the timing difference between the high and low frequencies of the audio output. Set the phase to either 0 degrees or adjust it to anywhere between -40 and -50.
• “Level” knob – This knob increases or decreases all of the bass’s frequencies that are sent to the amplifier. We recommend setting the level of the soundbar at -6dB or all the way to +6 dB.

4.2 How to Adjust “Speakers/Crossover”?

So, the “Speakers/Crossover” menu is the interface through which you can assign a custom frequency setting for all of the receiver’s connected speakers.

The menu is accessible through the homepage of the receiver’s system settings.

First, ensure “Speaker Selection” is set to “All” and pick a setting between “70Hz” and “80Hz” for optimal audio performance.

Of course, this setting can be adjusted according to preference.

5. Change the Subwoofer Mode in the Settings

While it may seem that the Denon receiver subwoofer output not working, the fault could simply be caused by the subwoofer mode in the Denon receiver’s settings.

The “Subwoofer Mode” menu of the receiver can be set to either of these values:

• LFE (Low-Frequency Effect) – Enables discrete content from the DTS or Dolby-encoded audio track if the subwoofer supports it. The “LFE” is also the “.1” (10%) of a track that supports the surround sound format.
• LFE + Main – This regulates all of the subwoofer’s low frequencies, regardless of the speaker’s channel settings. This mode does not influence the “Small” and “Large” speaker settings we’ve discussed earlier in the guide.

How to Configure Subwoofer Mode?

To adjust this feature, navigate to Denon Receiver Menu → “Bass” → “Subwoofer Mode.”

There should be a drop-down menu, allowing you to select any of the settings.

We recommend setting the receiver to “LFE + Main” if it was set to “LFE” or vice versa, and then test the output.

6. Factory Reset the Receiver and Subwoofer

If the Denon receiver subwoofer not working problem is still there, it’s time for a full factory reset on both of the Denon devices.

Keep in mind that if you are using a third-party subwoofer with Denon, the factory reset instructions may vary, so consult with your device’s user manual.

Alert: All of your Denon receiver and subwoofer’s settings will be erased!

6.1 How to Factory Reset a Denon Subwoofer?

1. Ensure your subwoofer is plugged in and turned on.
2. Press the “RESET” button on the rear for 5 seconds.
3. Next, wait until the LED’s status changes to amber.

6.2 How to Factory Reset the Denon Receiver?

Based on your AVR’s type, the reset instructions vary:

• If your model has a digital interface, go to “Home” → “General” → “Factory Reset” and follow the steps to erase all saved settings.

• If your model doesn’t have a digital interface, press the “SLEEP” and “INFO” buttons simultaneously for roughly 10 seconds to initiate the reset.

Note: Once the reset starts on either of the devices, stop all interactions for several minutes and wait until the process is complete.