Gadgetory

am CNET's right Chris today we're taking a look at dimmable LEDs and testing out some of the concerns that people have about them now what we've got here is our light bulb testing rig that's set up with a couple of common wall switch dimmers we've got a Lutron model a Leviton model there in the middle and then a cheap $5 rotary dimmer that's supposed to work only with incandescent now one of the chief concerns people have about dimmable LEDs is the fact that they might buzz but that's not a problem that is unique to LEDs take a look at this incandescent bulb it's been buzzing the whole time I've been talking and you can't hear it that's what it sounds like the reason it's buzzing is because of the dimmer the dimmer is cutting the power back and forth from full to low strength as you dim it up and down so it's not actually halfway it's actually just approximating it by alternating and that causes electromagnetic resistance which makes the filament vibrating Wiggles around in there you can kind of see it almost if you look close with LEDs you get the same problem there's no filament but there are still parts in there that'll move around in that electromagnetic resistance that's it now let's look at this Cree 60 watt replacement LED as you can see it dims fine it goes up and down and it's definitely dimmable like they say but there's still that buzz and I take my microphone off again you can definitely hear it but now take a look at this probably the most interesting result we've got in our testing was this philips LED this is the standard Philips 60 watt replacement LED not the slim style flat bulb we'll get to that one but this is just a normal LED that they sell and you can see even on this incandescent only cheap rotary model it dims just fine and there's also no buzzing if I hold my microphone right up to the bulb you might be able to hear a little bit of buzzing but to the naked ear just about a foot away I can't hear any buzzing none of us can and that's the same on all three of these dimmers so that's a fantastic result for Philips that said remember that slim style model that I mentioned well this is it right here and as you can see it works with dimmers but as you can hear buzz is pretty badly it was one of the worst performers in our dimming test in that regard it also flickers a bit at low light levels which I don't like either one last thing we want to point out if you're thinking about going with smart LEDs that dim on their own they have built-in dimming capabilities you're not going to want to use them with a built-in wall dimmer this is the connected by TCP bulb one of my favorite smart LEDs and it works well when you dim it on its own but when you use it with a wall dimmer like this one you get really really bad performance but he use this bulb in a lamp or any overhead light that doesn't have a built-in wall dimmer it'll dim on its own with the built-in remote or through the app and there won't be any buzzing there will be any flickering and that's across the board for life X Philips you any smart bulb that dims on its own moving forward we'll be testing out a lot more dimmers and a lot more bulbs looking for things like buzzing and flickering in the dimmable range how low those bulbs can go before they cut out and all that's going to lead up to our big series of LED reviews we'll be reviewing every bulb that we test in full and recommending our favorites all to help you make better bulb buying decisions for CNET appliances I'm red Chris