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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Lounge => Topic started by: skip grumblis on February 25, 2014, 05:47:40 PM
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i keep smoking capacitors in the internal crossovers of these enclosures. any suggestions?
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i keep smoking capacitors in the internal crossovers of these enclosures. any suggestions?
Sounds like you may be under powered. What amplifire are you using?
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Sounds like you may be under powered. What amplifire are you using?
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I'm using a crown ca9. 600w/chan
Cabinets are rated @ 375 . I'd like more headroom, but I'm good there.
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Sounds like you may be under powered. What amplifire are you using?
What makes you think he's underpowered? He could just as easily be overpowering and getting into deep power compression where more signal equals no more acoustic output.
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I'm using a crown ca9. 600w/chan
Cabinets are rated @ 375 . I'd like more headroom, but I'm good there.
If you're burning up crossovers I think you don't have Enough Rig for the GigŪ. You need louder speakers or more speakers (dependent on the coverage geometry).
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Blown components = overpowered.. period. The only question remaining is how was that accomplished.
Assuming the replacement caps were the correct voltage rating and the overall design isn't somewhat flawed to begin with(it's EAW not Cerwin Vega), there isn't much left besides user error. Was the amp driven hard into a limiter or into clipping? Both of those actions could create a situation where an otherwise well matched amp is overpowering the speaker system.
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I'm not flogging anything. Gain structure is solid from channel to amp. system comp/limit is a dbx 160a with the threshold set so only the occasional red light of reduction happens. The enclosures sound good when working. i may have exaggerated the frequency of the failures though, it's happened twice in the last 5 years
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What value are the caps that are blowing?
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What value are the caps that are blowing?
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Last caps I replaced were bought from eaw, so I'm assuming all the values were correct for that crossover. I will check the values as soon as I pull the x-overs out this time. Thanks for your time and input. I normally run all my amps with any onboard limiting disengaged, relying on input level to keep stuff in a safe range. I will check those switches though. You know, because shit happens.
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Post of a pic of the crossover as well. Are any of the drivers damaged when the caps blow?
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What value are the caps that are blowing?
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Last caps I replaced were bought from eaw, so I'm assuming all the values were correct for that crossover. I will check the values as soon as I pull the x-overs out this time. Thanks for your time and input. I normally run all my amps with any onboard limiting disengaged, relying on input level to keep stuff in a safe range. I will check those switches though. You know, because shit happens.
Skip, is there anything different about the shows you do leading up to the caps blowing?
It sounds like the rig is being run near the edge of its capability, and if there is nothing special or different about the gigs where the failure occurs, it's probably a cumulative fail. Every 5 years doesn't sound too bad, actually, but I know it's embarrassing and repairs are no fun...
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Why would over-powering lead to the crossover failing rather than the driver itself?
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Post of a pic of the crossover as well. Are any of the drivers damaged when the caps blow?
the first time it happened there was no apparent damage to the drivers. i replaced the caps and used the cabinets until this last outage. i threw a wedge on top and got thru the show. only the 7" driver and tweet shut down. the 15" wasn't affected either time. it's been too cold to dig them out of the truck and dig into them. I'll post a picture of the crossover when i get them opened up.
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Skip, is there anything different about the shows you do leading up to the caps blowing?
It sounds like the rig is being run near the edge of its capability, and if there is nothing special or different about the gigs where the failure occurs, it's probably a cumulative fail. Every 5 years doesn't sound too bad, actually, but I know it's embarrassing and repairs are no fun...
yea i hate looking bad. this was a rock show, as compared to the country i've been doing lately. but i'm not real loud, believing that a band can sound big and fat without being loud. these cabinets have been modified before i got them and by modified i mean screwed up. tweeter attenuator and fuse no longer wired in. i can't find a schematic to restore the wiring to factory and eaw's a little stingy when it comes to schematics. a link to a schematic would be helpful. i'm not really much of a technician, but a big oozing cap is not hard to diagnose. i'm running these as top boxes over a pair of sb180's on each side so it's not like i'm trying to get these boxes to thump a little. i have two mccauley 622-2 i could use, but kinda like the smaller footprint and ease of handling of the fr153's in smaller rooms
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Why would over-powering lead to the crossover failing rather than the driver itself?
just guessing but the crossover is next in line after the amps, before the drivers. weakest link kinda thing.
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these cabinets have been modified before i got them and by modified i mean screwed up. tweeter attenuator and fuse no longer wired in.
That is telling. I found these things on ebay http://www.ebay.ca/itm/EAW-FR153E-HI-Frequency-Crossover-Network-/271218639817, does that look like what's inside your cabs? To me that looks pretty shade tree for a production cab but who knows.
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That is telling. I found these things on ebay http://www.ebay.ca/itm/EAW-FR153E-HI-Frequency-Crossover-Network-/271218639817, does that look like what's inside your cabs? To me that looks pretty shade tree for a production cab but who knows.
That looks like an EAW crossover to me-at least the ones I've seen.
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That is telling. I found these things on ebay http://www.ebay.ca/itm/EAW-FR153E-HI-Frequency-Crossover-Network-/271218639817, does that look like what's inside your cabs? To me that looks pretty shade tree for a production cab but who knows.
Bingo. that's it exactly. it's on a 3/4 in piece of plwood. at least it's easy to solder
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Bingo. that's it exactly. it's on a 3/4 in piece of plwood. at least it's easy to solder
OK.. So what caps are blowing and what parts are missing. If your copies are in bad shape then jump on these and snap them up. Oh.. nevermind looks like these are long gone.
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What value are the caps that are blowing?
the caps i'm blowing are 30 uf 100v
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the caps i'm blowing are 30 uf 100v
Replace them with 30uF 250v.
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Replace them with 30uF 250v.
And use a poly cap instead of electrolytic (they age much better, electrolytics don't age well).
HTH,
Jeff Robinson
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the caps i'm blowing are 30 uf 100v
I have heard of this issue with the OEM 100Volt caps
Simple fix.
Use the same value cap and go with a 400volt-600volt
Example
Current Cap = 18mfd/100volt
Replace with = 18mfd/400volt
You can do the same with inductors
Same value inductor at a lower gauge wire/winding.
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I have heard of this issue with the OEM 100Volt caps
Simple fix.
Use the same value cap and go with a 400volt-600volt
Example
Current Cap = 18mfd/100volt
Replace with = 18mfd/400volt
You can do the same with inductors
Same value inductor at a lower gauge wire/winding.
Thanks fellas. All pretty straight forward and budget friendly solutions/suggestions.