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M16 vs. GU10 lights?

Posted by juliew_austin (My Page) on
Sat, Mar 3, 07 at 9:45

Ack! Our builder wants to switch out our mini directional (gimbaled) reseccesd MR16 fixtures with fixtures that take a GU10 bulb. The specific fixture he wants to use is Commercial Electric hbr 303. He says they are the just about the same thing as the lights we picked out. I know that the ones we had specified were low voltage and the ones he wants to use are not, the ones he wants to use are less expensive.

Can anyone tell me the difference between the the quality, intensity, type of light from these different lights? Any Pros or Cons would be helpful.


Follow-Up Postings:

RE: M16 vs. GU10 lights?

Julie, you might want to peruse this thread...

Here is a link that might be useful: line vs. low voltage

RE: M16 vs. GU10 lights?

Thanks for the pointer. That thread was helpful! We have decided to push the issue with our builder and keep the MR16 fixtures as planned. I think that since the GU10 bulbs are only floods and the beams can't be concentrated as the MR16, we'd loose the effect we hope to achieve.


RE: M16 vs. GU10 lights?

Julie, check out or any other online light bulb store. GU10 bulbs are available in all the same beams as MR16s. They can be spotlights, floodlights, narrow floodlights, you name it. I had the same dilemma and went with the GU10 bulbs for 1 reason...buzzing. Line voltage lights don't buzz when dimmed. Even with the right dimmers low voltage fixtures can buzz. Not always, not every one but we put 16 in one room and 22 in another room and I didn't want to gamble that any would buzz when dimmed. You can get narrow spotlight GU10s.

RE: M16 vs. GU10 lights?

Thanks for the information xtenson. We are building in SW Austin and dh went to Lowes, HD, and Texas Light Bulb (a specialty lighting store) and could only find the GU10 bulbs in floods. I think I'd rather stick with bulbs we can get locally. We are only using four of these fixtures in the room. Two centered in front of the fireplace and two on a wall. I've had mr16 fixtures before with no buzzing. They were connected to a Lutron Grafix Eye as these will be, do you think that makes a difference with the buzzing?

RE: M16 vs. GU10 lights?

I am in the same gray area as the OP... can someone tell me if I have this right.

MR16 (Low V halogen)
pros - could be better/more light... bulbs are easy to find in many types eg spots, floods etc
cons - more expensive... more heat output than GU10... could buzz when on a dimmer.

GU10 (line V halogen)
pros - cheaper... no dimmer buzzing... cooler running that MR16s... no buzzing on a dimmer...
cons - harder to find bulbs... light might not be as strong...

And now the third which I know nothing about

Do I have the right idea of the pros/cons for each bulb? or could you help correct me if I'm wrong... FYI these recessed lights are for accent and art lighting... I am going to save some $ are use 5" line voltage cans for the rest of my lighting.

thanks Mark

RE: M16 vs. GU10 lights?

Both lamps are designated as MR16's (Multifaceted Reflector 16/8" diameter) but they can have the same or different bases. The low voltage MR16 usually has a GU 5.3 base and the line voltage MR16 usually has a GU 10 base.

Both lamps should be available in beam spreads from 7 to 60 degrees although not all types are made by all manufacturers.

Here are some typical beam spread designations:
* VNSP (Very narrow spot): less than 8 degrees
* NSP (Narrow spot): 8-15 degrees
* SP (Spot): 8-20 degrees
* NFL (Narrow flood): 24-30 degrees
* FL (Flood): 35-40 degrees
* WFL (Wide flood): 55-60 degrees
* VWFL (Very wide flood): 60 degrees or more

Not all of these lamps are designed or constructed the same. I recommend buying Westinghouse from an electrical supply house and avoiding online or bargain outlets. They last a long time so it's well worth paying a premium price for the good ones.

Don't touch these lamps with your skin or shake them. They should always be covered and the ones that are made with a cover are best.

RE: M16 vs. GU10 lights?

Good quality MR16 lamps have longer lasting reflectors. Less expensive lamps may keep burning but the reflector degrades and you get color shifts and light output loss over the life of the filament. Different manufacturers call their better reflector coating technology different names. GE is the market leader with their "Constant Color". Most lighting designers spec this line of lamp. Having a local source of inexpensive lamps is not a good strategy for choosing lamps or fixtures. Order extra better quality lamps and keep some on the shelf.

Better quality LV fixtures shouldn't hum. Cheap offshore produced fixtures have poorer manufacturing specs with cheap transformers on them that can hum. The "best" quality LV fixtures (Iris, Aculux) do not hum. They have expensive top quality transformers.

Philips seems to have the lead now with a new more efficient IRC lamp design. They are available in MR16 and Par lamps.

The link is for the MR16 version. The Par version has a better explanation but you can Google it.

Here is a link that might be useful: Philips IRC

RE: M16 vs. GU10 lights?

Trying to make this same decision. If I could find wide flood gu10 bulbs I would probably use these since the fixtures are around $15 ea as opposed to $40-70 each for LV. I need 9 of them for recessing in a two vanity crowns. I have searched quite a bit and found one source for a 50 degree gu10 beam bulb. Could not find a 60 degree one, though. Anyone know where I could find it? I think I will likely go with LV because the bulbs are so much easier to find.

RE: M16 vs. GU10 lights?

Hi folks. New homeowner here and I'm doing a build out of a closet into a wine cellar. Googled this conversation and found it very helpful. Was wondering though if you guys had thoughts on which way to go for a wine cellar. Racking will be on one facing wall and the track lighting will cover racks left to right top to bottom. I read in another conversation that low voltage might be better for 'cabinets' that get closed and opened all the time...insert 'cellar doors' for 'cabinets' in my case because the bulbs are more compact and sturdier. But the heat of the low v is a concern for extended time in the cellar. Dimmers will not be used so potential buzzing is not an issue. Any thoughts appreciated.


RE: M16 vs. GU10 lights?

LEDs would be great. Zero heat and will last practically forever. They're also very, very small for in cabinet use.

Not the least expensive way to go, but definitely worth it.

RE: M16 vs. GU10 lights?

I have a 3x5' tapestry. It hangs 2' from ceiling about my staircase. I want to accent it but am told I can only use 'cans' placed two feet away. I don't understand the degrees part of the other posts; can someone put that into english for me or tell me what I can get for this purpose. I really don't want to use track lighting. I'd like to get the 'cans' more than 2' out from the wall; maybe more like 42" or so. Is that possible and yet have this tapestry accented? Than you.

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