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[Dave Rogue]

Chris, Mike, David, and Paul from last night, thank you for looking at this and explaining the way the this crossover works. I appreciate you taking the time to help me figure this out, as I know in some boards, like guitar tube amplifier repair boards, the experts prefer insulting the newbie instead of sharing their knowledge, or helping someone else learn about it.

Regarding what is likely needed to be replaced, do you think it would be the long white 20w 10ohm power resistor and the yellow 1.2J 150v high-pass capacitor on R1? And/or would you replace, or at least remove from the circuit and test, the polyswitch at S1? I think it is doable for me to replace those 3 components, as once I remove the 20w 10ohm resistor I will get better access to the joints for the S1 polyswitch, and the high-pass cap at R1 will be a breeze.

You guys are great! Thanks again for you help and lesson on crossover operation and functionality! I'm excited to confirm what should be replaced, and look forward to heating up the soldering iron and whipping out the solder sucker!

[Paul G. OBrien]

My bet would be the polyswitch followed by the cap, the resistor could be visibly burnt and still work but then you never know what you will find when you start taking things off, maybe a lead is broken off of something and you just can't see it.
BTW.. the cap is the only part mounted on the correct side of the PCB so it will be covering it's designation which should be C1. R1 is the big white resistor, L1 and L2 are the inductors.

P.S. I found the pdf for what I think is this box here.. http://pdf.textfiles.com/manuals/STARINMANUALS/Bosch%20-%20EV/Eliminator%20Double.pdf

And I simply searched for "EV eliminator dual 15"

[Dave Rogue]

simply searched for "EV eliminator dual 15"

Thanks Paul! I had done that search as well and downloaded a newer version of that EDS, but for Eliminator ii Dual 15, which is the one I have, so I thought that was the more current one. However, the one I downloaded was a 2-sheet and wasn't as detailed regarding the crossover as your was, and only has "Crossover frequency LF/HF: ...... 1600 Hz" not showing anything about the quazi 3-way you described, as your pdf did.

Regardless, You've helped tremendously, and I appreciate it. I'm hopefully going to make it to the parts store tomorrow, and make the repair over the weekend. I'll let you know how it goes. Thanks again for your help!

[Chris Grimshaw]

Being that it's a quazi 3-way design and from the components on the crossover the top 15 must just be running all the way out with no low pass.

JBL did the same thing in their gray carpet series SRX double 12 and 15 boxes when operated in the passive crossover mode. Maybe they carried that on it to some of the later ones as well.

Look again. There are two inductors. One for the top woofer, one for the bottom woofer, rolling it off lower. With two drivers covering a bandwidth together, I think 2.5-way is the best description of this crossover topology.

Chris

[David Morison]

Look again. There are two inductors. One for the top woofer, one for the bottom woofer, rolling it off lower. With two drivers covering a bandwidth together, I think 2.5-way is the best description of this crossover topology.

Chris

The other possibility is a 12dB high pass for the HF (presumably using the air core inductor), the upper woofer run full range as Mike alluded to and the remaining iron core inductor being the low pass for the lower 15".

Given there's only a 1" HF, this may be better than using both inductors for the 15's leaving only a 6dB HPF for the HF.

FWIW,
David.

[Chris Grimshaw]

The other possibility is a 12dB high pass for the HF (presumably using the air core inductor), the upper woofer run full range as Mike alluded to and the remaining iron core inductor being the low pass for the lower 15".

Given there's only a 1" HF, this may be better than using both inductors for the 15's leaving only a 6dB HPF for the HF.

FWIW,
David.

Yeah, fair point. We'd need a schematic to find out for sure either way.
I think if I was given a pair of these boxes to work on, I'd immediately move to a 1.4" exit (3" diaphragm) HF driver.

Chris

[Mike Christy]

Check for cold/loose/broken solder joints and fractured traces on the PCB, especially where the wire is connected. - Mike

[Dave Rogue]

Man, I wish there was a "like" function, or similar, for each comment. You guys know your stuff, and I appreciate all of your help!

While I am a total newb with this stuff, I think if I could have found a wiring diagram, schematic, or even a simple layout of the crossover I may have been able to get a little closer to figuring it out... or at least know the values of each component, mostly the inductors, which scare me the most (not knowing what I'm doing).

Based on the comments and expertise from you guys I am going to replace the resistor, cap, and polyswitch, and if that doesn't fix it I may send it to someone who knows what they're doing... which obviously I do not.

My 19 year old son has started doing live performances with his emo/rap/hip hop music (like guys like that L'l Peep did), and I wanted him to perform away, but not use one of my PA gear. So, I thought I'd help him in putting something together. While I got these speakers for cheap ($200.00 for the pair), with it known that one of the diaphragms was blown, and maybe a crossover issue, I figured I'd dive in. I'm not too discouraged about the bad crossover, but the size of these behemoths does kind of make me regret getting them. Maybe they'll end up becoming my garage PA speakers... if I ever get this one speaker to work, and let him use a couple of my Club V's. Live and learn!

Thanks again for all of the comments, and patience with my lack of knowledge with this stuff! You guys are the best!

[Scott Holtzman]

Man, I wish there was a "like" function, or similar, for each comment. You guys know your stuff, and I appreciate all of your help!

While I am a total newb with this stuff, I think if I could have found a wiring diagram, schematic, or even a simple layout of the crossover I may have been able to get a little closer to figuring it out... or at least know the values of each component, mostly the inductors, which scare me the most (not knowing what I'm doing).

Based on the comments and expertise from you guys I am going to replace the resistor, cap, and polyswitch, and if that doesn't fix it I may send it to someone who knows what they're doing... which obviously I do not.

My 19 year old son has started doing live performances with his emo/rap/hip hop music (like guys like that L'l Peep did), and I wanted him to perform away, but not use one of my PA gear. So, I thought I'd help him in putting something together. While I got these speakers for cheap ($200.00 for the pair), with it known that one of the diaphragms was blown, and maybe a crossover issue, I figured I'd dive in. I'm not too discouraged about the bad crossover, but the size of these behemoths does kind of make me regret getting them. Maybe they'll end up becoming my garage PA speakers... if I ever get this one speaker to work, and let him use a couple of my Club V's. Live and learn!

Thanks again for all of the comments, and patience with my lack of knowledge with this stuff! You guys are the best!

I would use this at least to step up your electronics knowledge.  Don't shotgun the repair.

Lift each side of the resistors and cap and measure.  The cap is non-polarized so any 4-10v a/c signal will pass if it is good.

Resistors are measured on ohms mode on a multimeter.

[Dave Rogue]

I would use this at least to step up your electronics knowledge.  Don't shotgun the repair.

Lift each side of the resistors and cap and measure.  The cap is non-polarized so any 4-10v a/c signal will pass if it is good.

Resistors are measured on ohms mode on a multimeter.

That's kind of what I'm thinking. I showed the crossover to a guy at some electronic parts store, and just by quick visual inspection he doubted the cap and resistor was bad, and suggested I jump the polyswitch and see if the horn works. So, I'm going to try that tonight.

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