Smart dimmer that doesn't hum with LEDs on a pre-wired 3-way?

I'm about to close up my walls and I have one lingering problem that's keeping me up at night: I've got a pre-wired 3-way circuit with LED recessed lights, and every dimmer I've tested so far hums like a angry bee. Not loudly – but once you hear it, you can't unhear it. And in a quiet living room, it's all I'll be able to think about.

Here's the setup: 1970s ranch, full gut renovation. I ran 14-3 to both switch locations – power comes into the first switch box, 14-3 travelers to the second, and the load (six 4-inch LED wafer lights) is at the end of the run. The LEDs are from a reputable brand (not the cheapest on Amazon), they're dimmable, and they're on a dedicated 15-amp circuit.

I've tried three different dimmers so far:

1. Lutron Caséta (with neutral) – hummed at mid-range dimming. Not terrible, but noticeable.

2. A basic Leviton dumb dimmer – hummed louder, especially at lower brightness.

3. An off-brand "universal" dimmer – hummed AND flickered. That one went back same day.

I haven't tried Inovelli or Zooz yet, but before I start buying more switches and playing "swap and pray," I want to understand what's actually causing this – and how to fix it permanently.

Why do LEDs hum with dimmers in the first place?

I did some digging, and here's the short version (because I'm not an electrical engineer, but I play one on forums):

LEDs don't dim the same way incandescent bulbs do. Incandescent dimmers work by chopping the AC waveform – they literally turn the power on and off rapidly (the technical term is "leading-edge" or "trailing-edge" phase control). An incandescent bulb doesn't care – it just gets less power and glows less.

LEDs, on the other hand, have a driver (the little power supply built into the bulb or fixture) that converts AC to DC. When you chop the waveform, you're sending a "dirty" power signal to that driver. The driver tries to regulate it, but the uneven power causes the internal components to vibrate at a frequency we can hear – that's the hum.

So the humming isn't actually the LED bulb – it's the driver inside the fixture vibrating. And the dimmer itself can also hum if its internal components (like the inductor) aren't matched to the load.

Why does it seem worse on 3-way circuits?

This is where it gets interesting – and where my pre-wired 3-way setup might be making things worse.

In a standard 3-way circuit, the dimmer is usually placed at one location, and the secondary switch is a simple (non-dimming) switch that just toggles the circuit. The dimmer is the only device that actually modulates the power.

But here's the thing: some dimmers are designed specifically for 3-way use, and they handle the traveler wiring differently. The traveler wire carries the dimmed signal from one switch to the other. If that traveler isn't properly shielded, or if the dimmer's internal electronics create noise on that wire, it can interact with the LED driver in unexpected ways – leading to more hum.

I've also read that some electricians recommend using a "dummy" or "companion" dimmer at the secondary location – but that only works with certain brands (like Lutron's accessory dimmers), and you're back to compatibility concerns.

My attempted fixes so far (and why they didn't work)

1. Bought a more expensive LED. I swapped one of the wafer lights for a premium brand (Sylvania, not the no-name ones). No improvement.

2. Added a "load resistor" or "decoupling device." Some people recommend adding a LUT-MLC (Lutron's minimum load capacitor) across the load to fix LED flicker. I tried a generic one – it reduced flicker but didn't help the hum.

3. Moved the dimmer to the other switch location. In a 3-way, the dimmer can be at either end. I swapped the dimmer and the secondary switch. Hum persisted.

4. Replaced the traveler wires with a shielded cable. I don't have shielded 14/3, but I separated the travelers from other cables in the box. No change.

What I think the problem actually is

After reading a bunch of threads (many from the Crash Archive, ironically), I've come to a few conclusions:

• Not all "dimmable" LEDs are equally dimmable. Some brands are more tolerant of phase-cut dimming than others. The hum might be a driver compatibility issue that no dimmer can fully fix – I may need to swap the fixtures themselves.

• The dimmer brand matters more than the switch type. Some brands (like Lutron Caséta) are known to be less prone to hum, but even their compatibility list is not 100%. Others (like Leviton, GE, or TP-Link) vary widely.

• Trailing-edge dimmers (also called "reverse phase" dimmers) tend to be quieter. Leading-edge dimmers (the older, cheaper ones) are more likely to cause hum because they chop the beginning of the waveform. Trailing-edge dimmers chop the end of the waveform, which is gentler on LED drivers.

• The minimum load matters. Some dimmers require a minimum wattage to work properly. If your LED load is too low (say, under 25 watts), the dimmer may not have enough load to regulate properly, causing hum. I have six 10-watt LEDs = 60 watts, so that's not the issue.

So what's the solution for a pre-wired 3-way?

Based on what I've learned, I'm considering these options:

Option 1: Try a trailing-edge (reverse phase) dimmer

• Lutron Caséta PRO (the version that supports reverse phase)

• Inovelli Blue Series (supports both leading and trailing edge via configuration)

• Zooz ZEN77 (800-series, also supports reverse phase)

These should be gentler on the LED driver. But I need to verify they work in a 3-way configuration with my existing wiring.

Option 2: Use an ELV (electronic low voltage) dimmer

ELV dimmers are designed for electronic transformers and are often more compatible with LEDs. They're more expensive, but they're known to be quieter. Lutron makes an ELV dimmer (the MA-ELV), but it requires a neutral.

Option 3: Replace the LED fixtures with a different brand

I found a few threads where people switched from cheap wafer lights to Philips or Cree and had zero hum. It might be cheaper to replace the fixtures than keep testing dimmers.

Option 4: Use a dimmer that specifically advertises "no hum" technology

Some newer dimmers (like the Shelly Dimmer 2) claim to use a different dimming algorithm that reduces hum. I haven't tested it yet, but it's on my list.

My specific questions for the forum

1. If you've got a pre-wired 3-way with LEDs and zero hum, what exact dimmer and LED fixture combination are you using? I need specific model numbers – not just "I use Lutron."

2. Has anyone successfully used a trailing-edge dimmer in a 3-way setup with existing travelers? Does it require any special wiring beyond what's already in place?

3. Is there a way to test for hum before closing up the walls? I have access to the fixture boxes right now – I could install a test dimmer and leave it running for a few days to see if it hums. But I don't want to do that with 10 different dimmers.

4. What's the single most hum-free combination you've found for LED wafer lights on a 3-way circuit?

What I'm leaning toward

After all this research, my current plan is:

1. Order an Inovelli Blue Series dimmer (supports both phase modes) and test it with my existing LEDs.

2. If it hums, swap to a Philips Hue or Cree LED wafer (I've heard good things).

3. If that still hums, bite the bullet and get a Lutron Caséta PRO with an ELV dimmer – even if I have to change the wiring slightly.

I'll document the whole process in this thread, with photos and results. But before I spend any more money, I need your collective wisdom.