View Full Version : Lightbulbs on Germanium crossovers

07-25-2006, 11:17 AM
Quick question here. Are the lightbulbs supposed to kinda flash with the music, or is this a sign that there's a problem? Never had a crossover with a lightbulb in 'em . . . my g/f was driving last night and said she started to notice a burning smell . . . turned down the gain this morning and I don't notice anything, but the crossovers are mounted in the trunk and I noticed the bulbs on both of 'em are pulsing with the music. Is this an urgent situation or normal operation?

07-25-2006, 11:20 AM
They're there for tweeter protection, IIRC...so what you're describing is exactly what they should be doing.

You aren't sending the amplifier into clipping, are you? :)

07-25-2006, 12:01 PM
The bulbs on my germaniums pulse with the music at medium/high volumes. I asked about this when i first got them and was informed that this is normal.

07-25-2006, 12:56 PM
It protects the tweeter by attenuating it at high volume. The light comes on and its resistance increases as the filiment heats up. Acts as a variable resistor.

07-25-2006, 03:14 PM
That was the only thing that I found that my Rainbows were lacking in... The tweeter protection seemed to kick in at moderate volumes and cut the tweeters out... But
I have sense fixed that...

07-25-2006, 03:18 PM
Hmm. The lightbulb doesn't really cut the tweets out...at least, they keep getting louder when turned up, even when the bulb is glowing some. The bulb glows slightly brighter too, but the volume does increase. I always considered the lightbulb a glowing fuse.

07-25-2006, 10:47 PM
I gotta pair of SLC's that use the lightbulb too as tweeter protection. I was talkin to a guy at a local stereo shop the other day and showed him my SLCS (haven't installed them yet). He looked at the bulb and said that whiel they were probably good crossovers, the bulb is the weak point of the system as all the voltage was running through the tiny filament in the bulb. Anyone care to comment on this? Also, are there any alternatives that may increase performance?

07-26-2006, 12:22 AM
The germanium manual states that 'audiphiles may wish to replace the bulb with a silver wire/jumper'...it also states that doing so eliminates your tweeter protection....

07-26-2006, 01:01 PM
I have the Germs and it is for protection. They should not flicker to music. I have mine biamped and I have never had the light come on. I am running mine off of an Arc Audio xxk 4150

07-26-2006, 02:53 PM
That happened with my friends Apline Type X components, and turns out it was a short :( Fixed it, and a couple of months later he noticed it was occuring @ high volumes. He called Alpine and they said it's a result of either too little or too much wattage.

07-26-2006, 05:36 PM
The germanium manual states that 'audiphiles may wish to replace the bulb with a silver wire/jumper'...it also states that doing so eliminates your tweeter protection....

That is exactly what I did with my profi's

07-27-2006, 01:28 AM
The light bulb flashing is fine, although it is a sign of overpowering. It is simply converting that extra power into light and heat. Not an issue as its designed to protect and will not cause damage until you see it constantly lit, then it goes to the second order of protection via the PTC on the board. Wehn your bulb is staying solid its a sure sign to reduce power, if it stays lit obviously it will be hot and begin to melt the board/cover of the crossover. For long periods of time the current *could* eventually meet and overheat your tweeter coil.