About a week after I put in the RF separates in my doors (5 1/4" and a tweeter) the tweeter hasn't worked on the drivers door. So, now that I've had my door panels off for the past three months (Shaving door handles, putting on SS mirrors, going to paint next weekend) I finally looked into what might be wrong. All the wires were still attached, tested the tweeter by connecting it to the pass. side x-over (These are the x-overs that come with the speakers) and it worked fine! I took the cross over apart expecting to see abunch of caps and maybe a coil, sure enough those were there, but there was also what looked like a dome light! The filament wasn't connected inside, so I made a jumper wire and now the tweeter works! So, what's the deal with putting a light bulb in there? Is it supposed to work like a fuse to protect the tweeter? There wasn't a bulb "number" on it to replace it with, so I just left the jumper wire in there. Any body have any ideas?
What's the deal with a light bulb in the x-over?
- Thread starter Roc87
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Stealthfxxr
New Member
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light bulb
That light bulb is used to absorb power to protect the tweeter, kinda like a fuse.
Dale
That light bulb is used to absorb power to protect the tweeter, kinda like a fuse.
Dale
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Put the replacement bulb back in! 
You can get a replacement from an RF dealer.
Its to protect the tweeter from a melt down (blown tweeter). It uses an incandescent lamp to divert power from the tweeter at excessive input levels. Because the lamp's empedance increases with heat, as the power to the tweeter increases the circuit absorbs more power continually protecting the tweeter from damage.
You can get a replacement from an RF dealer.Its to protect the tweeter from a melt down (blown tweeter). It uses an incandescent lamp to divert power from the tweeter at excessive input levels. Because the lamp's empedance increases with heat, as the power to the tweeter increases the circuit absorbs more power continually protecting the tweeter from damage.
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Originally posted by roc87
Thanks! After 3 Semesters at DeVry, the Jumper Wire didn't seem to good of an Idea!!
I'm glad that you "See the light" (I know...its a bad pun!)
D
Datsunboy
Guest
If you have ever seen a lightbulb in action on an xover, youll see it light up at different intensiteis. Generally speaking, the lighbulb is used to remove DC current (IE distortion) from the signal path. Back in the day pyramid made speakers that lit up due to this phenomenon... the dirtier the power, the brighter they got!
Evan
Evan
salvageV6
Daily Driver
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Bulbs work quite well with A/C voltage and current as well. 
Just a power absorber and cheap insurance.
Wonder what the inductance of the lamp does to the crossover point?
Just a power absorber and cheap insurance.
Wonder what the inductance of the lamp does to the crossover point?
