It's 10 PM. Your kick drum is booming. You measured a 12 dB peak at 100 Hz last week. And now you're wondering: did I just wake up my neighbors?

I got an email from a subscriber recently that captures this exact anxiety perfectly:

"I live in an apartment, third floor. I'm standing in my room, and at that place there's a boost of 6 dB at 100 Hz. Will that volume go through the ceiling, floor, wall to the neighbors, or is it only this loud in my room?"

It sounds logical, right? If it's loud here, surely it's loud there.

The short answer: no.

And understanding why might save you a lot of unnecessary guilt (and prevent you from wasting money on the wrong solution).

The Misconception That Won't Die

Forums love to suggest that bass traps in your room can reduce noise transmitted to your neighbors.

The problem? This advice treats two completely different acoustic problems as one.

Room modes and sound transmission are not the same thing. And mixing them up leads to confusion, wasted effort, and solutions that don't actually solve your problem.

Room Modes Are Local to Your Room

That 6 dB or 12 dB boost you're measuring? It's a resonance effect created by sound waves bouncing between the surfaces in your space.

When a wavelength fits between two parallel walls, the wave going one direction interferes with the wave coming back. That folding-in-on-itself creates the peaks and dips you experience in the low end.

Here's the key: this effect is local to your room. It's even local to your exact position in the room.

You've probably noticed this yourself. Walk around your studio while music plays and the bass changes. Move a foot to the left and that boomy kick suddenly sounds different. That's room modes at work.

The dimensions of your room and the reflective surfaces create this behavior. It exists only inside your space, determined by your specific walls, floor, and ceiling.

Sound Transmission Is a Different Animal

For sound to reach your neighbors, energy has to transfer into the wall material itself. The wall then vibrates, and that energy exits on the other side into the adjacent room.

Think of it like an aquarium with a cardboard barrier in the middle.

Stir up the water on one side. Waves hit the cardboard. Some energy transmits through (making the cardboard vibrate and creating small waves on the other side). Some energy reflects back and stays on your side.

The ratio of reflected to transmitted energy depends entirely on what that barrier is made of. How thick. How dense. How rigid.

Put thin cardboard in the aquarium? Lots of energy gets through. Put thick drywall or concrete? Much less energy transmits.

Your walls work the same way.

The Critical Distinction

Any energy that gets reflected stays inside your room. Only reflected energy can cause room modes.

Any energy that gets transmitted goes through the wall. Only transmitted energy reaches your neighbors.

These are two separate pools of energy doing two different things.

So that 12 dB peak you're measuring at your listening position? That's reflected energy bouncing around inside your room. It's not the same energy that's transmitting through your walls.

Your neighbors are experiencing whatever portion of energy made it through the wall structure, which then creates its own acoustic behavior in their space. They're not experiencing your room modes.

Why Bass Traps Won't Help With Transmission

Back to the aquarium analogy.

Imagine you put sponges along the edges of one side to calm the splashing. Sure, it helps with the wave behavior on your side. But those sponges don't stop energy from hitting the barrier and transmitting through.

Bass traps and acoustic treatment improve the sound inside your room. They damp the resonant behavior. They tame the peaks and dips.

They do not stop sound from going through your walls.

That's a question of wall construction. Thickness. Mass. Materials. The structure itself.

What Actually Reduces Transmission

For low frequencies, there are no simple solutions.

Real isolation requires proper decoupling, significant mass, and often a room-in-room construction to stop that energy from coupling through the structure into adjacent spaces.

That's a much bigger undertaking than acoustic treatment. Different problem, different solution.

The practical takeaway? Lowering your monitoring volume is the simplest way to reduce what your neighbors hear. Less energy hitting the walls means less energy available to transmit through.

The Bottom Line

Room modes are local. What you hear at your position is not what your neighbor hears at theirs.

Bass traps fix sound inside your room. They don't fix sound going through your walls.

If you're worried about neighbors, the answer isn't more treatment. It's either lower volume, or (if you're serious) actual structural isolation.

And if you've been feeling guilty about that boomy kick drum at 10 PM? You can probably relax a bit. That peak is yours alone.

P.S. If you want to get that low end under control inside your room (so you can actually trust what you're hearing), check out Build A Better Bass Trap. It's my step-by-step program for building bass traps that tackle room modes without killing the vibe or wasting money on solutions that don't work. Learn more here.