Bass travels through buildings far more easily than any other sound, which is why subwoofers cause more neighbour complaints than anything else in a home cinema. You can’t fully soundproof against bass without construction work, but you can cut transmission a lot. Here’s what works, roughly in order of effectiveness.
1. Lower the volume (and the deepest bass)
Unsurprisingly, the biggest single factor. Every 6 dB reduction halves the sound pressure. The deepest notes (below about 40 Hz) travel furthest, so reducing those specifically, via EQ or a higher crossover, helps more than a general volume cut.
2. Decouple the sub from the floor
Much of what neighbours hear is structure-borne: the sub vibrates the floor, which vibrates the building. A dense, heavy platform (a paving slab or thick MDF on a layer of resilient material, or a purpose-made isolation riser) reduces this, especially on suspended wooden floors.
3. Move it away from shared walls
Corners and walls boost bass and couple it into the structure. Moving the sub away from a party wall and out of corners reduces both the boost and the transmission.
4. Choose a sealed sub
Sealed subs roll off more gently and tend to produce less energy in the very lowest octave than ported designs tuned low. See ported vs sealed and apartment subwoofers.
5. Raise the crossover slightly and EQ peaks
If one note booms (a room mode), it’s also the note most likely to travel. Cutting it with EQ lets you lower the overall level. See how to EQ a subwoofer.
6. Use night mode
Dynamic range compression (Night Mode, Dynamic Volume, DRC) on receivers and soundbars reduces the loudest peaks while keeping dialogue clear.
What doesn’t work (much)
- Foam panels and egg crates: they absorb treble, not bass.
- Rugs and curtains: good for echo, minimal effect on bass transmission.
- Putting the sub in a cabinet: often makes rattles worse. See why.
Talk to your neighbours
Ask them to tell you what they can hear at a specific volume and time. It’s quicker than guessing and usually goes down well. And if you’re on the other side of the wall, see dealing with neighbours who have subwoofers.