What Hz should a subwoofer be set to?

The short answer is 80 Hz for most systems. But the “Hz” people ask about is the crossover — the frequency where your main speakers hand bass over to the sub — and knowing what that number does (and what it doesn't) is the difference between bass that blends and bass that booms or disappears.

The quick answer

• Most speakers → 80 Hz. The THX reference and the right starting point for standard bookshelf and mid-size speakers.
• Small satellites → 100–120 Hz. Tiny speakers can't reach low, so the sub takes over sooner.
• Full-range towers → 40–60 Hz (or LFE only). Capable mains can run lower before the sub fills the true bottom octave.

For a value matched to your exact speakers, run the crossover calculator, or see the full table by speaker size in the crossover, phase & gain guide.

What the Hz number actually is

The adjustable “Hz” on a subwoofer or receiver is the crossover (a low-pass filter): the frequency below which the subwoofer plays and above which your main speakers carry on. Set it at 80 Hz and everything under 80 Hz goes to the sub, everything above stays with the speakers. It follows your main speakers' capability — a speaker handed notes below its reach doesn't play them quietly, it distorts — so the number is about the speakers, not the sub.

The “lower Hz = deeper bass” myth

This trips up almost everyone. Lowering the crossover Hz does not make your subwoofer dig deeper. How low a sub can go is fixed by its design — its rated extension, the spec that says “20 Hz” or “25 Hz” — and no setting changes that. Turning the crossover down just hands more of the upper-bass back to your main speakers; it doesn't unlock output the sub doesn't have. If you want deeper reach, that's a bigger or ported subwoofer, not a lower knob.

Two different Hz numbers

Because of that, it helps to separate the two “Hz” figures people mix up:

• Crossover Hz (~80): a setting — where speakers hand off to the sub. This is what “what Hz to set” means.
• Extension Hz (e.g. 20–25): a fixed spec — the deepest note the sub can reproduce. This is what “how low it goes” means, and it's on the review page, not a dial.

Setting it right

With an AV receiver: set every speaker to “Small,” set the crossover Hz in the receiver menu, and turn the subwoofer's own Hz knob to maximum (or LFE/bypass) so the two filters don't stack into a dip. With a plain stereo amp (no bass management): use the sub's own Hz knob, starting at 80 Hz and adjusting by ear. Either way, set it, then tune the rest — the full order is in the crossover, phase & gain guide.

What about a car?

In a car the same 80 Hz low-pass is a good default, often nudged to 80–100 Hz so there's no gap above small factory door speakers. The cabin already boosts the deepest bass for free, so you don't need to chase a very low number — set the low-pass so the sub blends with the doors. More on car tuning in the car subwoofer size & enclosure guide and the car wiring guide.

The bottom line

Set the crossover to 80 Hz and adjust from there for your speakers — higher for tiny ones, lower for full-range towers. Don't expect the Hz knob to add depth; that's the sub's job, not the setting's. To dial in the whole system, use the crossover calculator or the three-dial setup guide.