My new fluorescent lamps are NOISY! at DVinfo.net

Jack Kelly · July 5th, 2009, 03:00 AM

Hi folks,

I just bought a 4x55w fluorescent lamp fixture. It's not a Kino Flo, it's a cheaper make and model. My unit was an ex-display unit. The dimmable ballast is built into the lamp fixture.

The problem is that the lamp is really noisy! It sounds like a distorted mains hum. The sound varies depending on the setting of the dimmer. In general, the noise gets more intense the dimmer the lamp is. I've tried re-seating the tubes and I've also tried gently knocking the lamp fixture (!) but the noise wont go away. I've also tried leaving the lamp to fully warm up but that doesn't help.

I'm just wondering if anyone else has experienced this problem? Is there an easy fix? (Like perhaps the tubes are old and need to be replaced?)

In the past, I have experimented with building my own fluorescent lamp fixtures. I found that some ballasts are noisy and some ballasts are silent. I will phone the company who sold the lamp to me on Monday to ask if they'll replace the lamp. But I'm also considering opening the unit up, removing the existing ballast and installing a couple of dimmable Philips ballasts which I know are silent-running. Even after buying the new ballasts, the lamp will still have cost me less than half the price of an equivalent Kino Flo!

Daniel Epstein · July 5th, 2009, 09:00 AM

Call the company first because you will not get any help from them if you modify the unit before they have a chance to fix or comment on the problem

Jack Kelly · July 5th, 2009, 09:04 AM

sure thing.

Bill Pryor · July 5th, 2009, 12:55 PM

If it's a professional fluorescent light, ie., one designed for shooting, it will have a silent electronic ballast. The ones you buy for household lighting may have electronic ballasts but in most cases they make some noise. One reason professional ones cost more. I've never used lights with dimmers, but I guess it could be the dimmer as well. Or even a defective lamp. Probably the easiest thing to do would be to take out one lamp at a time, then put each one back in one at a time, ie., check out each one to see if there's one that doesn't hum. If so, that might tell you if the lamp is the problem. Or buy a new lamp and try it out and if it hums, then it's probably the ballast or the dimmer. But if you just bought the light, the above comment is best--call the company first. If it's making noise they should replace it.

Andrew Dean · July 5th, 2009, 10:39 PM

Hmm. i thought the hum from fluoros was always the ballast. Not sure where i heard that, but come to think of it we had humming fixtures at my old work that changing the bulbs out did nothing... which I *think* validates the theory.

Bill Pryor · July 7th, 2009, 08:17 AM

It's almost always the ballast, but I remember on some house lights in a studio there was a humming bulb that was about ready to die. I took it out and the hum stopped. It's different from the ballast noise. Supposedly electronic ballasts don't make noise, but that's not always true for non-movie lights.

Richard Andrewski · July 7th, 2009, 03:15 PM

A defective (or cheap for that matter) electronic fluorescent ballast can indeed make a hum. It all has to do with the grade of transformer they used inside the ballast. Its pretty rare on ones that are selected for studio/pro lighting fixtures but could happen if the transformer inside the ballast developed a problem of some sort or the transformer was just super cheap. I would think if the model in question is still in warranty, you should be able to get it replaced. That should be a simple ballast swap.

July 5th, 2009, 03:00 AM	#1
Jack Kelly Major Player Join Date: Oct 2004 Location: London, UK Posts: 243	My new fluorescent lamps are NOISY! Hi folks, I just bought a 4x55w fluorescent lamp fixture. It's not a Kino Flo, it's a cheaper make and model. My unit was an ex-display unit. The dimmable ballast is built into the lamp fixture. The problem is that the lamp is really noisy! It sounds like a distorted mains hum. The sound varies depending on the setting of the dimmer. In general, the noise gets more intense the dimmer the lamp is. I've tried re-seating the tubes and I've also tried gently knocking the lamp fixture (!) but the noise wont go away. I've also tried leaving the lamp to fully warm up but that doesn't help. I'm just wondering if anyone else has experienced this problem? Is there an easy fix? (Like perhaps the tubes are old and need to be replaced?) In the past, I have experimented with building my own fluorescent lamp fixtures. I found that some ballasts are noisy and some ballasts are silent. I will phone the company who sold the lamp to me on Monday to ask if they'll replace the lamp. But I'm also considering opening the unit up, removing the existing ballast and installing a couple of dimmable Philips ballasts which I know are silent-running. Even after buying the new ballasts, the lamp will still have cost me less than half the price of an equivalent Kino Flo! __________________ Jack Kelly's filmmaking website AfterCarbon.org

July 5th, 2009, 09:04 AM	#3
Jack Kelly Major Player Join Date: Oct 2004 Location: London, UK Posts: 243	sure thing. __________________ Jack Kelly's filmmaking website AfterCarbon.org

July 7th, 2009, 03:15 PM	#7
Richard Andrewski Major Player Join Date: Jun 2006 Location: Shenzhen, China Posts: 781	A defective (or cheap for that matter) electronic fluorescent ballast can indeed make a hum. It all has to do with the grade of transformer they used inside the ballast. Its pretty rare on ones that are selected for studio/pro lighting fixtures but could happen if the transformer inside the ballast developed a problem of some sort or the transformer was just super cheap. I would think if the model in question is still in warranty, you should be able to get it replaced. That should be a simple ballast swap. __________________ Richard Andrewski - Cool Lights USA - RED #114 http://www.coollights.biz

July 5th, 2009, 09:00 AM	#2
Daniel Epstein Trustee Join Date: Jan 2006 Location: New York, NY Posts: 1,267	Call the company first because you will not get any help from them if you modify the unit before they have a chance to fix or comment on the problem

July 5th, 2009, 12:55 PM	#4
Bill Pryor Contributor Join Date: Jan 2003 Location: Kansas City, MO Posts: 4,449	If it's a professional fluorescent light, ie., one designed for shooting, it will have a silent electronic ballast. The ones you buy for household lighting may have electronic ballasts but in most cases they make some noise. One reason professional ones cost more. I've never used lights with dimmers, but I guess it could be the dimmer as well. Or even a defective lamp. Probably the easiest thing to do would be to take out one lamp at a time, then put each one back in one at a time, ie., check out each one to see if there's one that doesn't hum. If so, that might tell you if the lamp is the problem. Or buy a new lamp and try it out and if it hums, then it's probably the ballast or the dimmer. But if you just bought the light, the above comment is best--call the company first. If it's making noise they should replace it.

July 5th, 2009, 10:39 PM	#5
Andrew Dean Major Player Join Date: Dec 2005 Location: Motukarara, New Zealand Posts: 475	Hmm. i thought the hum from fluoros was always the ballast. Not sure where i heard that, but come to think of it we had humming fixtures at my old work that changing the bulbs out did nothing... which I think validates the theory.

July 7th, 2009, 08:17 AM	#6
Bill Pryor Contributor Join Date: Jan 2003 Location: Kansas City, MO Posts: 4,449	It's almost always the ballast, but I remember on some house lights in a studio there was a humming bulb that was about ready to die. I took it out and the hum stopped. It's different from the ballast noise. Supposedly electronic ballasts don't make noise, but that's not always true for non-movie lights.