Kobold hmi buzzing

[sam caravana]

i have a pair of kobold hmi (400w) that are buzzing even after warm up. The buzz is coming from the head/bulb and not the ballast. Is that normal?

[Bob Gundu]

Yes some brands of HMI bulbs are louder than others. Perhaps ask the manufacturer what they recommend.

[RobMNeilson]

Yeah probably, does it buzz louder when it starts up before the bulb gets up to temperature?

[Bob Gundu]

Yeah probably, does it buzz louder when it starts up before the bulb gets up to temperature?

That’s usually the case with most HMI bulbs.

[sam caravana]

Yeah probably, does it buzz louder when it starts up before the bulb gets up to temperature?

It does start louder and then gets quieter once it’s warm. I had a chance to compare to a friends with the same model and mine is noticeably louder. Will probably try a new bulb and see what happens