How to Set Up a Subwoofer with a Soundbar

Ryan Smith

Soundbars and subwoofers are increasingly common pairings. Whether you have a soundbar that came with a wireless sub or you’re trying to add an aftermarket sub to an existing soundbar, here’s how to get it working properly.

Option 1: Soundbar with Dedicated Wireless Sub (Easiest)

Most mid-to-high-end soundbars come with a dedicated wireless subwoofer. Setup is typically automatic:

1. Power on the soundbar and sub — they usually auto-pair within 30 seconds
2. If auto-pairing fails: hold the pairing button on the sub (check your manual for location), then confirm pairing on the soundbar
3. Place the sub in the front half of the room near the TV wall
4. Adjust the sub level using the soundbar remote or its app

No crossover settings to configure, no phase adjustment — the factory calibration handles it. This is the most convenient option for a reason.

Option 2: Adding an Aftermarket Sub to a Soundbar

This is more complicated because most soundbars are designed as closed systems. Check whether your soundbar has any of these:

Dedicated Subwoofer Output (RCA or 3.5mm)

Some soundbars have a dedicated “SUB OUT” jack. If yours does: run an RCA cable from this to the sub’s LFE input. Set the sub’s crossover to 100-120Hz (higher than the 80Hz standard — soundbars roll off earlier than full speakers). Adjust the gain to blend.

Headphone/Line Output

Some soundbars have a 3.5mm output. With a 3.5mm-to-RCA adapter, connect to the sub’s line input. The sub receives full-range audio — its internal crossover filters out the high frequencies. Set crossover at 100-120Hz on the sub.

No Usable Output

Many basic soundbars have no external audio output at all. Options in this case: connect the TV’s subwoofer output (if it has one) to the sub, connect both soundbar and sub to the TV’s audio output system, or accept that your particular soundbar doesn’t support external subs.

Setting the Sub Level for Soundbar Use

Soundbars have limited bass output themselves. It’s tempting to set the sub level high to compensate. Resist this — it usually results in boomy, disconnected bass that clearly comes from a different direction than the soundbar’s audio. Start low (sub gain at 8-9 o’clock) and increase gradually until the bass feels like a natural extension of the soundbar’s sound, not an addition to it.

Recommended Subs for Soundbar Pairing

Compact, sealed designs work best. The controlled bass character integrates more naturally with a soundbar’s limited midrange than a large ported design:

• Sonos Sub — if you have a Sonos soundbar, this is the right choice
• Bose Bass Module 500 — for Bose soundbar owners
• Audioengine S8 — universal, compact, musical bass
• Polk PSW10 — affordable, neutral, easy to integrate