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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: Dave Rogue on September 26, 2018, 10:25:47 pm

Title: EV Eliminator ii Crossover Issues
Post by: Dave Rogue on September 26, 2018, 10:25:47 pm
I have a pair of EV Eliminator ii dual 15 inch with horn PA speakers, and had a blown diaphragm in one of the horns. I ordered a replacement, and after putting it in there was some sound, but very little. To isolate the problem I put the horn with the new diaphragm into the known working cab and it worked perfectly. This led me to believe the crossover is bad in the originally bad speaker cab.

I have searched and searched for info, and can't find anything on this particular crossover. There is no part number, and I cannot find any wiring diagram, schematic, or layout. I can send it somewhere for repair, but being pretty handy with a soldering iron, having done lots of pot, switch, and pickup changes on electric guitars, I figured I'd see if I could fix this myself. It looks pretty straight forward, with a PCB, caps, and inductor coils, but I have no idea how to troubleshoot it without taking each component off the PCB and checking it with a DMM. If I knew what component(s) was in the circuit for the tweeter (the yellow and brown wires in pics in below link) I think I could just replace that/those components.

I am admittedly a total newb at speaker/crossover repair, but know how to read a schematic, have a great Fluke DMM, and yield a mean soldering iron. Can any of you please point me in the right direction? Thanks in advance!

Here is a link to some pictures (hopefully I followed the link posting instructions properly):
 Linky to Pics  (https://photos.app.goo.gl/PcW4PwdUQti7BjPL7)
Title: Re: EV Eliminator ii Crossover Issues
Post by: Scott Holtzman on September 26, 2018, 10:32:57 pm
I have a pair of EV Eliminator ii dual 15 inch with horn PA speakers, and had a blown diaphragm in one of the horns. I ordered a replacement, and after putting it in there was some sound, but very little. To isolate the problem I put the horn with the new diaphragm into the known working cab and it worked perfectly. This led me to believe the crossover is bad in the originally bad speaker cab.

I have searched and searched for info, and can't find anything on this particular crossover. There is no part number, and I cannot find any wiring diagram, schematic, or layout. I can send it somewhere for repair, but being pretty handy with a soldering iron, having done lots of pot, switch, and pickup changes on electric guitars, I figured I'd see if I could fix this myself. It looks pretty straight forward, with a PCB, caps, and inductor coils, but I have no idea how to troubleshoot it without taking each component off the PCB and checking it with a DMM. If I knew what component(s) was in the circuit for the tweeter (the yellow and brown wires in pics in below link) I think I could just replace that/those components.

I am admittedly a total newb at speaker/crossover repair, but know how to read a schematic, have a great Fluke DMM, and yield a mean soldering iron. Can any of you please point me in the right direction? Thanks in advance!

Here is a link to some pictures (hopefully I followed the link posting instructions properly):
 Linky to Pics  (https://photos.app.goo.gl/PcW4PwdUQti7BjPL7)

Please update your display name to your real name.  This requirement was listed when you joined.  Mods will lock the post until fulfilled.

Title: Re: EV Eliminator ii Crossover Issues
Post by: Dave Rogue on September 26, 2018, 10:52:02 pm
Please update your display name to your real name.  This requirement was listed when you joined.  Mods will lock the post until fulfilled.

Thank you! I thought I followed the instructions, but missed that one. Thanks again!
Title: Re: EV Eliminator ii Crossover Issues
Post by: Paul G. OBrien on September 26, 2018, 11:37:00 pm
Here is a link to some pictures (hopefully I followed the link posting instructions properly):
 Linky to Pics  (https://photos.app.goo.gl/PcW4PwdUQti7BjPL7)

Wow that's not much of a crossover.. 5 parts, and some muppet before you installed the components on the wrong side of the PCB. Is the crossover in the other speaker the same, if it is has it been assembled the same way? I'm looking for a view of the traces on the PCB, without that I'm guessing and that guess would be that the cap and one of the coils forms a 12dB highpass for the CD and the other coil makes a 6dB lowpass for the woofer. The big power resistor is maybe in parallel with the CD to drop it's level some, it could be in series though too. The little yellow device is a polyswitch, that is a self resetting circuit breaker of sorts. The cap and polyswitch would be the first things I'd remove to test, that is pretty much the only thing you can do if there is nothing obvious broken or blown up.

P.S. I just found a pdf that seems to indicate this was a quazi 3-way with the lower 15 lowpassed at 700hz and the upper 15 and CD are crossed at 1.6khz, that means that only the capacitor and power resistor are tied directly to the CD.
Title: Re: EV Eliminator ii Crossover Issues
Post by: Dave Rogue on September 26, 2018, 11:53:43 pm
Wow that's not much of a crossover.. 5 parts, and some muppet before you installed the components on the wrong side of the PCB. Is the crossover in the other speaker the same, if it is has it been assembled the same way? I'm looking for a view of the traces on the PCB, without that I'm guessing and that guess would be that the cap and one of the coils forms a 12dB highpass for the CD and the other coil makes a 6dB lowpass for the woofer. The big power resistor is maybe in parallel with the CD to drop it's level some, it could be in series though too. The little yellow device is a polyswitch, that is a self resetting circuit breaker of sorts. The cap and polyswitch would be the first things I'd remove to test, that is pretty much the only thing you can do if there is nothing obvious broken or blown up.
Thanks for the reply, Paul! I have not even looked at the other crossover, but I will for comparison sake. Yeah, my original hope was to follow the traces on the PCB from the yellow and brown wires to see where they went, but I couldn't find the traces to trace. I had really hoped it would lead me to that white 20w cap, as that looks real easy to replace. The resettable fuse looks like I'd have to remove other stuff to get to, which may be beyond my newb ability... without ruining the PCB. I'll look at the other crossover when I get home. Thanks again! I do appreciate the help!
Title: Re: EV Eliminator ii Crossover Issues
Post by: Paul G. OBrien on September 27, 2018, 12:38:27 am
I had really hoped it would lead me to that white 20w cap, as that looks real easy to replace.

That is a 20w 10ohm power resistor.
Title: Re: EV Eliminator ii Crossover Issues
Post by: Dave Rogue on September 27, 2018, 01:30:48 am
P.S. I just found a pdf that seems to indicate this was a quazi 3-way with the lower 15 lowpassed at 700hz and the upper 15 and CD are crossed at 1.6khz, that means that only the capacitor and power resistor are tied directly to the CD.

Man, I searched the internet for several hours over a few days, using every search words I could think of, and the only thing I could find was the EDS for the speakers (which is actually how I figured out what diaphragm I needed for the CD). What did you use for search words?

Regarding the "quazi 3-way" thing, that's funny, as I had wondered what it would be like to try something like that... not that I would have tried it, but wondered if you could cross it over like that for kind of a fake tri-amp setup, but with only one amp. Again, being totally new at this stuff, and a pretty basic sound reinforcement engineer, I thought the 1600 hz crossover, as indicated in the EDS, was pretty high. Granted, I know it's different than running a sub, but I always kind of went with 100 hz crossover for the sub. So with that said, wouldn't it give you more of the fake sub and quazi 3-way if you dropped the frequency on the bottom woofer, say to 200 hz, have the upper woofer be between 200 hz and 1.6 khz with the CD crossed at 1.6 khz? Like a broken record to repeat myself I have no idea about any of this stuff, which is why I'm so intrigued in learning.

And yes, 20w 10ohm resistor. my mistake. I may be confusing a couple of the components. When you say capacitor and power resistor you mean the white 20w 10 ohm resistor and the yellow polyswitch at R1, under the 20w resistor? I thought the polyswitch/resettable fuse was the little wafer thing at S1? So when you wrote the "little yellow device is a polyswitch" it makes me think I'm confusing the polyswitch and that yellow Chiclet  looking capacitor, or it's a polyswitch too, not a capacitor.

If that's it, and I understand what you're saying, in my layman's terms I'd replace the long white resistor (the 20w 10ohm power resistor), and the yellow Chiclet looking thing at R1 on the PCB. Is that right?

Again, you have no idea how much I appreciate your help, and understanding of my newbness and very little knowledge of what I'm doing. Thank you very much!

Oh, to add, the other crossover is identical.
Title: Re: EV Eliminator ii Crossover Issues
Post by: Chris Grimshaw on September 27, 2018, 04:02:07 am
With regards to the 2.5-way crossover, here's how it works:

You've got the HF horn running 1.6kHz and upwards (though with that crossover, it could be seeing significant energy below 1.6kHz), and then the top 15" comes in to cover 1.6kHz and all the way down.

The second woofer comes in at 700Hz, and also plays all the way down. Here's why:

When a speaker is mounted on a baffle (that's the front of the speaker), it will typically show a frequency response that has a rise through the midrange, which is related to the dimensions of the baffle (among other things). One way to fix that is using EQ, and just throw more power at it.
Another way to fix it is to bring another driver into play, which is operating in such a way as to level out that rising frequency response. It involves a lower frequency crossover, as seen here, and is known as a 2.5-way crossover, since it's effectively a 2-way design (HF and first 15"), with the 0.5-way being the second 15" covering a narrower bandwidth.

The idea is that both 15"s will work together to produce bass (ie, maximise LF output and power handling) while keeping the midrange source close to the HF unit at the crossover point.

IME, 2x15" cabs are much much better when used with a chunky 1.4" or 2" compression driver, and a horn that would support a crossover at 1kHz or lower.

Chris
Title: Re: EV Eliminator ii Crossover Issues
Post by: Mike Caldwell on September 27, 2018, 08:56:35 am
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.
Title: Re: EV Eliminator ii Crossover Issues
Post by: David Morison on September 27, 2018, 09:55:15 am
I may be confusing a couple of the components. When you say capacitor and power resistor you mean the white 20w 10 ohm resistor and the yellow polyswitch at R1, under the 20w resistor? I thought the polyswitch/resettable fuse was the little wafer thing at S1? So when you wrote the "little yellow device is a polyswitch" it makes me think I'm confusing the polyswitch and that yellow Chiclet  looking capacitor, or it's a polyswitch too, not a capacitor.

If that's it, and I understand what you're saying, in my layman's terms I'd replace the long white resistor (the 20w 10ohm power resistor), and the yellow Chiclet looking thing at R1 on the PCB. Is that right?


The component with S1 on the circuit board underneath it is the polySwitch. I don't know if this is an exact equivalent but there's a good chance it's close: https://uk.farnell.com/raychem-te-connectivity/rxef075/polyswitch-radial-0-75a/dp/1175868 (https://uk.farnell.com/raychem-te-connectivity/rxef075/polyswitch-radial-0-75a/dp/1175868)

The capacitor for the high-pass part of the circuit is the larger yellow component with "1.2J 150V" printed on it. It's probably a 1.2μF in value, from the printing, but I haven't checked to see if that's a credible value for this type of crossover.
Title: Re: EV Eliminator ii Crossover Issues
Post by: Dave Rogue on September 27, 2018, 10:35:56 am
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!
Title: Re: EV Eliminator ii Crossover Issues
Post by: Paul G. OBrien on September 27, 2018, 10:18:12 pm
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"
Title: Re: EV Eliminator ii Crossover Issues
Post by: Dave Rogue on September 27, 2018, 11:30:41 pm
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!
Title: Re: EV Eliminator ii Crossover Issues
Post by: Chris Grimshaw on September 28, 2018, 03:24:42 am
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
Title: Re: EV Eliminator ii Crossover Issues
Post by: David Morison on September 28, 2018, 03:32:15 am
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.
Title: Re: EV Eliminator ii Crossover Issues
Post by: Chris Grimshaw on September 28, 2018, 04:51:00 am
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
Title: Re: EV Eliminator ii Crossover Issues
Post by: Mike Christy on September 28, 2018, 04:56:57 am
Check for cold/loose/broken solder joints and fractured traces on the PCB, especially where the wire is connected. - Mike
Title: Re: EV Eliminator ii Crossover Issues
Post by: Dave Rogue on September 28, 2018, 03:17:02 pm
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!
Title: Re: EV Eliminator ii Crossover Issues
Post by: Scott Holtzman on September 28, 2018, 04:42:32 pm
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.

Title: Re: EV Eliminator ii Crossover Issues
Post by: Dave Rogue on September 28, 2018, 05:24:10 pm
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.
Title: Re: EV Eliminator ii Crossover Issues
Post by: Dave Rogue on September 28, 2018, 08:27:59 pm
I reconnected to crossover and jumped the resettable fuse/polyswitch and the horn still didn't work. As previously mentioned, I've tried the horn in both speaker cabs and it works in one, but not in the cab with the crossover in question. I was really hoping that would isolate the polyswitch as the problem. Oh well. At minimum I'd have to remove the power resistor to get to the polyswitch solder joints anyway, so I guess I'll remove the reisistor, capacitor, and polyswitch and test their values with my multimeter.
Title: Re: EV Eliminator ii Crossover Issues
Post by: Rob Spence on September 28, 2018, 09:48:40 pm
I reconnected to crossover and jumped the resettable fuse/polyswitch and the horn still didn't work. As previously mentioned, I've tried the horn in both speaker cabs and it works in one, but not in the cab with the crossover in question. I was really hoping that would isolate the polyswitch as the problem. Oh well. At minimum I'd have to remove the power resistor to get to the polyswitch solder joints anyway, so I guess I'll remove the reisistor, capacitor, and polyswitch and test their values with my multimeter.

You donít have to remove them, just on lead on each. Makes it easier to put back if good.


Sent from my iPad using Tapatalk Pro
Title: Re: EV Eliminator ii Crossover Issues
Post by: Dave Rogue on September 28, 2018, 10:39:59 pm
You donít have to remove them, just on lead on each. Makes it easier to put back if good.


Sent from my iPad using Tapatalk Pro

Thanks Rob! I had been told about only lifting one lead, but I figured I'd go for the gusto, thinking that the resistor, cap, and polyswitch probably all need to be replaced. Well, chalk it up as part of my learning experience, as it looks like all 3 components may be okay.

Not that I wasn't already at a loss, but the 20w 10 ohm resister read 10.3 ohm, which I would think is within tolerance. The capacitor read 1.24 microFarad, which I also think is in spec, and I didn't really know what to do with the polyswitch, other to check for continuity, and megged out at 0.4 ohm, which would make me think it's okay too.

The board doesn't really show any easily traced traces, at least that I can see, so I don't know what to do there, as I suspect there might be an open or bad bad connection somewhere, and there's still the 2 inductors, but I'm pretty sure you guys figured those are for the two woofers (a wiring diagram sure would be nice!).

Here are some pictures from my readings. Any other suggestions, or should I send it off to a pro? I just hate thinking about spending the estimated $40.00 - $70.00 for someone to replace a few bucks in parts, but there is definitely a value to the expertise they posses that I do not.

 Pics of readings  (https://photos.app.goo.gl/KFU3WV6bEcj1HpHk6)
Title: Re: EV Eliminator ii Crossover Issues
Post by: Paul G. OBrien on September 28, 2018, 10:47:05 pm
Time to fully disassemble that cab I think, maybe there is something else patched into the wires going to the CD that you can't see. These wires should be a dead short measured end to end of course.
Title: Re: EV Eliminator ii Crossover Issues
Post by: Dave Rogue on September 28, 2018, 11:06:47 pm
Time to fully disassemble that cab I think, maybe there is something else patched into the wires going to the CD that you can't see. These wires should be a dead short measured end to end of course.

I'm not sure I follow you, Paul. The crossover has all of the speaker wires connected to it, and both woofers worked perfectly, and it sounds like there is a very faint sound coming out of the horn. The original horn that was in that cab had the diaphragm replaced, and is now in the other cab working perfectly. The horn that was in the good cab worked fine before I took it out, and for good measure I hooked it up to some speaker wire connected to my garage stereo and it works fine.

So yes, I guess I will test each speaker wire individually and see what I can find. However, a visual inspection, and feeling for any kinks in the wire, all seem okay. If everything test out okay, and I can't see anything funky on the circuit board, maybe for funsies I'll put the parts back on the board and see if maybe there was a bad solder joint on one of 3 parts.
Title: Re: EV Eliminator ii Crossover Issues
Post by: David Morison on September 29, 2018, 02:32:44 pm
I'm not sure I follow you, Paul. The crossover has all of the speaker wires connected to it, and both woofers worked perfectly, and it sounds like there is a very faint sound coming out of the horn.

He means the fault could be in the wiring (inc its joints) from the crossover to the HF driver, ie after the crossover - hence your testing to date not showing anything obvious.
For example, if that wire was secured against vibration by attaching it to a brace somewhere between the crossover and driver, perhaps the method of retention has created wear on the insulation to the point of creating a near-short circuit that you might not have seen yet.
Title: Re: EV Eliminator ii Crossover Issues
Post by: Ike Zimbel on September 29, 2018, 06:12:48 pm
He means the fault could be in the wiring (inc its joints) from the crossover to the HF driver, ie after the crossover - hence your testing to date not showing anything obvious.
For example, if that wire was secured against vibration by attaching it to a brace somewhere between the crossover and driver, perhaps the method of retention has created wear on the insulation to the point of creating a near-short circuit that you might not have seen yet.
Yes, or if there are crimped connections on the driver end, those can go bad. When you eliminate all of the smart things, it's going to turn out to be something stupid! :-[
Title: Re: EV Eliminator ii Crossover Issues
Post by: Dave Rogue on September 29, 2018, 06:57:02 pm
Yes, or if there are crimped connections on the driver end, those can go bad. When you eliminate all of the smart things, it's going to turn out to be something stupid! :-[

Yes, I agree. I'm thinking (hoping) that when I put it all back together that it's going to work, but probably not. I did check each wire, and they did test okay, but I will look at the crimps if if doesn't work. At this point I fear that the problem is with the PCB, and there's nothing I can do to fix it. We'll see when I button her all back up.
Title: Re: EV Eliminator ii Crossover Issues
Post by: Scott Holtzman on September 29, 2018, 07:05:28 pm
Sure you can fix the pcb with a wire.  Should be simple enough to follow traces,

Sent from my VS996 using Tapatalk

Title: Re: EV Eliminator ii Crossover Issues
Post by: Mike Caldwell on September 29, 2018, 07:20:50 pm
Sure you can fix the pcb with a wire.  Should be simple enough to follow traces,

Sent from my VS996 using Tapatalk

Yep, if it is a cracked PCB those big wide traces would be easy to bridge the crack with a piece of wire. You do need to clean off the green varnish coating to get some clean copper to solder to.

I just fixed a cracked PCB in a keyboard a couple weeks ago, those traces were not nearly as big as those on your crossover!


Have you tried swapping drivers with your working speaker.
Sorry if you did that already and I missed reading it.
Title: Re: EV Eliminator ii Crossover Issues
Post by: Dave Rogue on September 29, 2018, 11:09:30 pm
Sure you can fix the pcb with a wire.  Should be simple enough to follow traces,

Sent from my VS996 using Tapatalk

I guess my lack of experience makes me have a hard time seeing the traces. There are lines, which must be them, but some of the components don't seem to cross them. I'll take a better look.
Title: Re: EV Eliminator ii Crossover Issues
Post by: Dave Rogue on September 29, 2018, 11:16:06 pm
Yep, if it is a cracked PCB those big wide traces would be easy to bridge the crack with a piece of wire. You do need to clean off the green varnish coating to get some clean copper to solder to.

I just fixed a cracked PCB in a keyboard a couple weeks ago, those traces were not nearly as big as those on your crossover!


Have you tried swapping drivers with your working speaker.
Sorry if you did that already and I missed reading it.

How would I clean off the varnish? It almost seems like it's layered laminated plasticky stuff. In the pictures I posted can you see the traces? It just seems like the lines I see are more lines, not copper traces. I will take a real good look at it in the morning.

Regarding testing the speaker, yes I have. When I got the speakers I was told of the blown diaphragm, which it was. I replaced it and a little more sound than before came out of the horn, but very little, and nothing like the other (properly working) speaker. So, to troubleshoot I put the horn I just replaced the diaphragm in in the other cab, and it worked perfectly. Thanks what lead me to the crossover.

Title: Re: EV Eliminator ii Crossover Issues
Post by: Paul G. OBrien on September 30, 2018, 12:18:56 am
How would I clean off the varnish? It almost seems like it's layered laminated plasticky stuff. In the pictures I posted can you see the traces? It just seems like the lines I see are more lines, not copper traces. I will take a real good look at it in the morning.
Can you post up some pics of the circuit board after the parts were removed?
Title: Re: EV Eliminator ii Crossover Issues
Post by: Jean-Pierre Coetzee on September 30, 2018, 03:34:21 am
Might be easier to see the traces with a light behind the PCB as well. Stick it on an old school overhead projector or otherwise just put it in front of a light and you should be able to see what's going on a lot better.
Title: Re: EV Eliminator ii Crossover Issues
Post by: David Morison on September 30, 2018, 09:47:56 am
I guess my lack of experience makes me have a hard time seeing the traces. There are lines, which must be them, but some of the components don't seem to cross them. I'll take a better look.

On a loudspeaker crossover, the traces handle a bit more current than say a line level device, so they're quite big.
This leads to the outcome of the traces actually taking up most of the surface of the board - the lines you see are actually the gaps between adjacent traces.
Title: Re: EV Eliminator ii Crossover Issues
Post by: Ivan Beaver on September 30, 2018, 10:30:32 am
How would I clean off the varnish?
A flat head screwdriver will scrape it off easily.

Just get it mostly off.  Then add some solder with a HOT iron and the rest should flow off easily
Title: Re: EV Eliminator ii Crossover Issues
Post by: Dave Rogue on October 08, 2018, 04:33:48 pm
Thanks again for all of your help! I soldered the capacitor, resistor, and polyswitch, back on the board and the CD is still very weak. So, I'm throwing in the towel and am going to bring the crossover, with the speaker cab, to a pro to see what they can do. While I didn't fix the problem I definitely learned a little something, thanks to you guys, so not a complete loss. Thanks again! Cheers!
Title: Re: EV Eliminator ii Crossover Issues
Post by: Mike Caldwell on October 08, 2018, 04:44:19 pm
Thanks again for all of your help! I soldered the capacitor, resistor, and polyswitch, back on the board and the CD is still very weak. So, I'm throwing in the towel and am going to bring the crossover, with the speaker cab, to a pro to see what they can do. While I didn't fix the problem I definitely learned a little something, thanks to you guys, so not a complete loss. Thanks again! Cheers!

We're are you located?
Title: Re: EV Eliminator ii Crossover Issues
Post by: Dave Rogue on October 19, 2018, 02:12:05 pm
We're are you located?

Mike, sorry for the delay in my reply. I live in the SF Bay Area. I got a call from the shop today, and it turns out one of the inductors was shorted, so he replaced it. I'll pick it up later today. I'll let you guys know how it sounds. Thanks!
Title: Re: EV Eliminator ii Crossover Issues
Post by: Ivan Beaver on October 19, 2018, 04:40:32 pm
Mike, sorry for the delay in my reply. I live in the SF Bay Area. I got a call from the shop today, and it turns out one of the inductors was shorted, so he replaced it. I'll pick it up later today. I'll let you guys know how it sounds. Thanks!
A shorted inductor is very very rare, unless it is obviously burnt or has gotten really hot (it would show signs of that).  that would require the insulation to be scraped off of two spots in the coil that just happen to be touching.

I have seen it, but only once in all of my years in this business, that non abused inductor/coil was shorted.
Title: Re: EV Eliminator ii Crossover Issues
Post by: Mike Caldwell on October 19, 2018, 07:50:33 pm
Mike, sorry for the delay in my reply. I live in the SF Bay Area. I got a call from the shop today, and it turns out one of the inductors was shorted, so he replaced it. I'll pick it up later today. I'll let you guys know how it sounds. Thanks!

Shorted does sound strange, open maybe.
Your average size inductors will measure less than one ohm DC, even large ones will only measure an ohm or two.
I wonder how they determined it was shorted.
Title: Re: EV Eliminator ii Crossover Issues
Post by: Chris Grimshaw on October 20, 2018, 05:46:00 am
Shorted does sound strange, open maybe.
Your average size inductors will measure less than one ohm DC, even large ones will only measure an ohm or two.
I wonder how they determined it was shorted.

Just a quick FWIW, I'd want all inductors (especially the big ones, since they're usually feeding straight into a woofer) to be much less than 1ohm at DC. Preferably less than 0.5ohm.
The only exception would be as part of a highpass filter, where it can be useful for the inductor across the driver to have a little series resistance, as that will give a slightly softer knee around the crossover frequency. Good for tweaking phase alignment.

Chris
Title: Re: EV Eliminator ii Crossover Issues
Post by: Ivan Beaver on October 20, 2018, 11:11:29 am
Shorted does sound strange, open maybe.

Many people use the term "shorted" to simply mean broken.

Completely different though.

Kinda of like phase and polarity-------
Title: Re: EV Eliminator ii Crossover Issues
Post by: Chris Hindle on October 22, 2018, 08:08:51 am
Many people use the term "shorted" to simply mean broken.

Completely different though.

Kinda of like phase and polarity-------
Agreed. Only real possibility for a short would be manufacturer defect in the coating/winding. (I would imagine)
I've sen them burnt with WAY excessive power, but never shorted.
Chris.
Title: Re: EV Eliminator ii Crossover Issues
Post by: Dave Rogue on December 21, 2018, 03:00:27 pm
Hey guys, thanks for the continued comments on this. I may have used incorrect verbiage, or did a poor job translating what I thought the repair guy said to me. All I know is they replaced 1 inductor, and the speaker sounds great!

However, I just noticed that the other speaker seems to lack some of the low-end that the speaker with the repaired crossover has. This was originally masked by playing both speakers side by side, and not differentiating what is coming our of each individual speaker. It wasn't until I panned all the way left and then all the way right before I noticed. All 3 speakers make sound, so I will open it up and check connections, and then will troubleshoot from there. Since these older EV crossovers seem hard to find, I'd love to build two new 2.5 way crossovers for these speakers, but then we're back to the newb factor. If I had a design with the values, and where to solder things (basically if I was spoon fed what to do), I could make them... but I don't, and still don't really know what I'm doing. Lol!
Title: Re: EV Eliminator ii Crossover Issues
Post by: Paul G. OBrien on December 22, 2018, 03:20:50 pm

However, I just noticed that the other speaker seems to lack some of the low-end that the speaker with the repaired crossover has.
This simply could be that the woofers are connected out of polarity with each other in this box, the 9v battery test will show which one it is pretty clearly.
Title: Re: EV Eliminator ii Crossover Issues
Post by: Dave Rogue on January 07, 2019, 06:35:36 pm
This simply could be that the woofers are connected out of polarity with each other in this box, the 9v battery test will show which one it is pretty clearly.

Thanks, I will give that a try tonight. In my troubleshooting of the original problem I did remove the crossovers for both speakers, so maybe I reconnected the speaker wires incorrectly.