[Dave-ROR]

Originally Posted by Sony

HID's (Xenon's, Heavy Metal Halides, HMI's and MSR's) are the only types of lamp that REQUIRE a projector housing, both Halogen's and LED's can use plain reflector only type housings but HID's require condenser optics for focused and controlled light output.

That, like his post, is completely wrong. There are two standard automotive HID bulb types, S and R (D1S/D1R/D2S/D2R/D4S at least as different models of those types). Would you like to guess why the R is called a D1R/D2R? It's for relfector housings.

This is a D2R bulb (assuming the site it's hosting on allows linking):


Some older Acuras, Mercedes, Nissans, etc used them. Almost everyone uses projectors now as they are far superior but reflector based HIDs absolutely exist.

you also cannot restrike a lamp within 10 or fifteen minutes of turning the lamp off...the lamp MUST cool to a certain temperature before it can be re-struck, unless you have what is called a "hot re-strike ballast" which is more expensive and seldom used in cars.

This means having two separate HID projector housings, one for highs and one for lows is not feasible, as the constant re-striking of the high beams would kill their lamp life as well as not being able to turn your high beams back on for 15 minutes after turning them off would not be a good thing. This is why on production cars with HID's the high beams are created by ether physically moving the lamp within the projector housing to change the lights focal point OR having a second high wattage Halogen housing mounted NEXT to the HID housing. You will notice in cars with the latter option, the high beams only add the Halogen's to the HID's and do not turn the HID's off due to the previously mentioned hot re-strike complication.

Oh and BTW you can have auto HIDs running for HOURS and turn them off and back on 1 second later. I've had HIDs in cars for 8 years and have never had to let them cool to reignite them. Yes, it's not good for bulb life but it's not an issue either. Lights are a safety item, they would NEVER make it into a car if you couldn't use them because you turned them off pulling up to someones house to avoid lighting up the neighbors (of their) house, etc.

As for the rest, you can run halogens as highs as you said, or bixenon (no point in the expense of second set of housings, balasts, bulbs etc to run two seperate units one for low and one for high) and for bixenon a flap moves out of the way allowing light to bounce off the bottom of the projector making it a high beam, the bulb never moves.

Obviously this is different from entertainment systems, but please don't spread misinformation.