2.1 System with Subwoofer

Hello Linux community,

I recently made the switch to Linux and am facing challenges configuring my 2.1 audio setup with a subwoofer. On Windows, I used Equalizer APO to channel copy L+R to LFE, giving me separate EQ settings for my speakers and sub.

However, on Linux using Analog Stereo Output, I encounter issues with excessive gain sent to my speakers, leading to clipping even at low subwoofer volumes. Despite spending hours tweaking PulseAudio settings, I haven’t found a solution.

Has anyone successfully set up a 2.1 system with a subwoofer on Linux? I’m seeking guidance on achieving a setup where my monitors and sub have separate EQs. Additionally, I’ve noticed that on Linux, 50 percent volume seems equivalent to 100 percent on Windows. I want to avoid accidentally maxing out the volume and risking damage to my subwoofer.

Any advice or insights would be highly appreciated. If you guys think this isn’t a possible setup than it was nice meeting you all anyway and I really did enjoy using linux.

Thanks in advance!


Preamp: -5 dB
Filter: ON LPQ Fc 60 Hz Q 0.707
Channel:L R
Preamp: -3.5 dB

Filter:ON HPQ Fc20Hz Q0.707

GraphicEQ: 20 0; 25 0; 31.5 0; 40 0; 50 0; 63 0; 80 0; 100 0; 125 0; 160 0; 200 0; 250 0; 315 0; 400 0; 500 0; 630 0; 800 0; 1000 0; 1250 -3.99; 1600 -3.99; 2000 -4; 2500 -3.99; 3150 -2.19; 4000 0; 5000 0; 6300 -4.9; 8000 -4.9; 10000 0; 12500 0; 16000 0; 20000 0

Peak Filters
Filter 1: ON PK Fc 79 Hz Gain +1.82 dB Q 1.13
Filter: ON PK Fc 79 Hz Gain 2.57 dB Q 1.2
Filter: ON PK Fc 3110 Hz Gain 2.78 dB Q 2.99
Filter: ON PK Fc 7173 Hz Gain 2.48 dB Q 0.58
Filter: ON PK Fc 8199 Hz Gain -2.39 dB Q 2.24
Filter 6: ON PK Fc 11843 Hz Gain -2.53 dB Q 2.08
Filter 7: ON PK Fc 13997 Hz Gain -2.35 dB Q 1.04

Hello and welcome to the Linux community!

Configuring a 2.1 audio setup in Linux can be a bit tricky, especially when you’re used to the tools available on Windows. Let’s try to address your issues step by step.

1.	Separate EQ for Speakers and Subwoofer:

Linux doesn’t have a direct equivalent to Equalizer APO, but you can achieve similar results with a combination of PulseAudio and ALSA or by using JACK audio connection kit.
• PulseEffects: It’s an advanced equalizer and audio effects program that works with PulseAudio. You can install it via your package manager. It allows you to apply effects and EQs to different output streams, which could help you manage separate settings for your speakers and subwoofer.
• JACK Audio Connection Kit: This is a more complex, professional audio server and routing system. It’s very powerful but has a steeper learning curve. You can route audio from any source to any destination and apply various effects and adjustments.
2. Excessive Gain and Clipping Issue:
This can be a result of improper configuration in PulseAudio.
• You might want to create a custom profile for your sound card that correctly defines the subwoofer. This involves editing ALSA configuration files.
• Also, try adjusting the output levels using alsamixer from the terminal. It gives you more granular control over each channel.
3. Volume Differences Between Linux and Windows:
The perceived volume difference is often due to how the audio subsystems are implemented in both OSes. In Linux, you can adjust the system volume curve to better suit your needs.
• Explore pactl and pacmd list commands to view and change various settings in PulseAudio.
• You can also look into paprefs for additional configuration options.
4. Setting Up Your EQ:
Translating your APO config to Linux might need some trial and error. PulseEffects or JACK with appropriate plugins can be used to recreate your EQ and filter settings.
5. Preventing Accidental Volume Maxing:
You can set soft volume limits in PulseAudio to avoid accidentally setting the volume too high.
6. Additional Considerations:
• Ensure your audio drivers are up to date.
• If you’re using a USB DAC or a similar device, make sure it’s properly recognized and configured in Linux.
• Experiment with different sample rates and bit depths in the audio settings.

Since you’re new to Linux, some of these tasks might seem daunting, but the Linux community is here to help. Don’t hesitate to ask for more detailed guidance on forums or relevant community groups.

Remember, the flexibility of Linux means that virtually anything is possible – it might just take a bit of time to get everything set up to your liking. Good luck, and I hope you continue to enjoy your Linux journey!


Thank You! This is just what I was looking for. I’m glad to be here and you guys are amazing! I managed to get everything worked out.

Also PulseEffects is just what I needed ! I feel right at home

Edit - Thanks to AlsaMixer I found the issue, The Center and LFE were both receiving the same input which basically doubled the volume but now it works as expected. Thank you very much!


For Anyone else who has a 2.1 System and wants to use the subwoofer for music this PulseAudio config worked for me

enable-remixing = yes
remixing-use-all-sink-channels = yes
remixing-produce-lfe = yes
remixing-consume-lfe = yes
lfe-crossover-freq = 80

I used Alsamixer to adjust the Volume like Admin stated and now everything works smooth after muting the center channel (No more clipping yay and regular volume)


Awesome glad you got it figured out

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