If you want deeper bass from a Sonos Arc, adding a Sonos Sub can transform your home theater setup.
This guide explains how to add Sonos Sub to Arc, plus the placement and tuning details that make the biggest difference.
What You Need Before You Start
Before pairing the two speakers, make sure your system is ready for the Sonos app-based setup process.
The Sonos Arc and Sonos Sub must be connected to the same Sonos account and configured in the same home theater room.
- Sonos Arc already set up in the Sonos app
- Sonos Sub or Sonos Sub Mini, depending on your system
- Sonos app installed on iOS or Android
- Wi-Fi network with stable connectivity
- TV connected to the Arc through HDMI eARC or ARC
If you have not finished the Arc setup yet, complete that first.
The app will handle the Sub pairing only after the Arc is recognized as a living room or home theater component.
How to Add Sonos Sub to Arc
Adding a Sonos Sub to Arc is done inside the Sonos app.
The process is straightforward, but the app needs both products online and on the same system.
- Open the Sonos app.
- Go to the room where your Sonos Arc is already assigned.
- Select Settings, then choose System.
- Tap the room name for the Arc.
- Select Add Sub or Add Surrounds if prompted within the room setup flow.
- Follow the on-screen instructions to connect the Sub.
- Wait for the app to confirm that the Sub has been added successfully.
Once paired, the Sonos app routes bass frequencies away from the Arc and sends them to the Sub.
This creates cleaner midrange sound and fuller low-end response, especially for movies, music, and gaming.
Why Pairing a Sonos Sub with Arc Matters
The Sonos Arc is designed as a premium soundbar with strong clarity and virtual surround capabilities, but a standalone soundbar still has physical limits when it comes to bass output.
A Sonos Sub adds dedicated low-frequency reproduction, which improves impact without overworking the soundbar.
- Better bass extension: Explosions, drums, and sound effects feel more physical.
- Cleaner dialogue: The Arc can focus more on voices and midrange detail.
- Reduced distortion: Bass-heavy scenes are handled by the Sub instead of the soundbar.
- Improved room balance: Low frequencies are distributed more evenly when placement is correct.
This pairing is especially useful in larger rooms or open-plan spaces where a single soundbar can sound thin at higher volumes.
Best Placement for Sonos Sub with Arc
Sonos Sub placement has a major impact on performance, and unlike many speakers, the Sub does not need to sit directly in front of the TV.
Sonos recommends flexible placement because the Sub uses wireless communication and is designed to fill the room with low frequencies.
Placement basics
- Place the Sub on the floor, not on a shelf or elevated stand.
- Keep it plugged into power and connected wirelessly to the Sonos system.
- Avoid placing it inside a closed cabinet.
- Try different locations along the front or side wall for the smoothest bass.
Common placement options
- Near the Arc: Convenient and often good for balanced home theater layouts.
- Along a side wall: Can help bass spread more evenly through the room.
- Behind the seating area: Sometimes produces stronger perceived bass, depending on room acoustics.
If the bass sounds boomy or muddy, move the Sub a few feet at a time and test again.
Small changes in position can significantly affect how the low end interacts with walls, furniture, and flooring.
How to Tune the System After Adding the Sub
After pairing the Sub with Arc, take time to tune the sound using Sonos features such as Trueplay and the room’s audio settings.
These adjustments help the system adapt to your room’s acoustics.
Run Trueplay if your device supports it
Trueplay measures how sound reflects off surfaces in the room and adjusts the speaker response accordingly.
If you use an iPhone or compatible iPad, this tuning step can improve bass integration and overall clarity.
Adjust sub volume in the Sonos app
Go to the room’s sound settings and change the Sub level if the bass feels too strong or too weak.
Start with the default setting, then make small changes while testing with a movie scene or a track you know well.
Check loudness and night mode
If you watch content late at night, Sonos Night Sound can reduce dynamic peaks while preserving dialogue.
Loudness settings can also affect how full the system sounds at lower volume levels.
Common Problems When Adding a Sonos Sub to Arc
Even simple Sonos setups can fail for a few predictable reasons.
Most pairing problems come down to network issues, outdated software, or a mismatch between room assignments.
The Sub does not appear in the app
Make sure the Sub is powered on and connected to the same Wi-Fi network as the Arc.
If the app still does not detect it, restart the router, Sonos Arc, and Sonos Sub, then try again.
The Sub is added to the wrong room
In the Sonos app, verify that both devices are listed under the same room.
If the Sub is attached to a different room, remove it and reassign it to the Arc’s room.
There is no bass change after pairing
Confirm that the Sub level is not set too low in the app.
Also check whether you are playing content with limited low-frequency output, since speech-only content will not highlight the difference as much as music or action scenes.
The system sounds unbalanced
Run Trueplay again, then test the Sub in another location.
Room acoustics, nearby walls, and furniture placement can create uneven bass response even when the pairing is correct.
Sonos Sub vs Sonos Sub Mini for Arc
Choosing between a Sonos Sub and Sonos Sub Mini depends on room size, listening habits, and budget.
Both can work with the Arc, but they serve different needs.
- Sonos Sub: Best for larger rooms, stronger bass output, and full-scale home theater setups.
- Sonos Sub Mini: Better for smaller rooms or users who want added bass in a more compact form factor.
If your goal is cinema-like impact with the Arc, the full Sonos Sub usually delivers more headroom and deeper extension.
If you mainly want to improve sound over the Arc alone without adding a large bass module, the Sub Mini can be a practical alternative.
Tips for Getting the Most from Arc and Sub
Once the system is paired, a few habits can help keep performance consistent over time.
- Keep the Sonos app updated.
- Update firmware for both the Arc and Sub when prompted.
- Re-run Trueplay after moving furniture or changing the room layout.
- Test bass levels with familiar content, not just one scene or track.
- Use the same room name consistently to avoid setup confusion.
For movie watchers, the Arc and Sub combination is often the core of a larger Sonos home theater system, and it can later be expanded with Sonos Era or other compatible surround speakers if desired.