C4ster Messages: 686 Registered: June 2001 Location: Mukwonago, WI (Milwaukee...
Senior Member
Hi Guys,
I have a K100 with a 2X12 cabinet. We played a gig in late August and after the gig I loaded the cab into the trailer and went home. I took the cab out of the trailer list last weekend and the speakers are dead/open. The cab was working on the last song we played and we shut it down normally. Has anyone else ever seen this before. I will recone the speakers soon but it is very interesting that 2 speakers would fail while sitting in a trailer. Any guesses??????
Conrad
stevem Messages: 4728 Registered: June 2004 Location: NY
Senior Member
Yup, I have seen it many times and fixed it sometimes, as what has happened is one of the voice coil wires that come up out of the voice under the dust cover to where they get soldered to the tinsel wire at the cone has simply just busted open from fatigue!
Since the speaker is dead and you would need to get it re coned away try this.
Take a new single edge blade and cut the voice coil cover off and look for the two fine wires coming up out of it and you will find one broken more than likely!
What I do when I am able to fix them is to pull up a little of the wire ,get a good hot soldering iron and head each end of the wire until it tins up and then I solder them back .
If you can not gently tug up some extra wire than just make a small jumper to bridge them back.
After you get it working again use some silicone glue to hold the wires down so they do break from extended vibration again and then you can order up a new voice coil cover , or super glue the old one back on.
NOTE that when working inside the voice coil cover be super care full to not get anything dropped down into the voice coil gap, what I do is to masking tape it off with tape that I have stuck to my pants first to kill some of the un needed stickiness off.
C4ster Messages: 686 Registered: June 2001 Location: Mukwonago, WI (Milwaukee...
Senior Member
I've reconed plenty of speakers but I guess I didn't think about fatigue. These are original C12N's and I suppose one could have been bad and then the other one failed due to DFL. I use SimplySpeakers.com for my reconing supplies. They are very helpful and fast. The only kit I had to wait for was a JBL drop-in for a 2226. I may even have a C12N with the cloth dust cover sitting in the closet. I was going to recone a working C12N just to match the dust covers. I haven't gotten to it yet. What a surprise.
Conrad
C4ster Messages: 686 Registered: June 2001 Location: Mukwonago, WI (Milwaukee...
Senior Member
No, they were 16 ohm speakers wired in parallel. They are the original C12N Jensens. I suspect one was already gone and just was going along for the ride as a passive radiator and then when that one gave out, silence. They are 40+ years old. I had things go out when I was 40, not that I want to go into detail. javascript: insertTag(document.post_form.msg_body, '', ' ');
Conrad
Kustom_Bart Messages: 601 Registered: October 2010 Location: Greenville, MichiGUN
Senior Member
No problem re=coning them, just make sure that they put the same dust covers back on them so they look the same through the grill cloth. It will take some playing to break them in and they will sound great. One thing to check that I have seen before is to make sure that the braided wire that goes from the connector (where you plug the wires on the speaker) that go to the back of the cone didn't break off. I have soldiered them back on before and had them work for a very long time. I re-done my own speakers now, it is pretty simple to do if you have just a few basic tool. Watch some videos on how to do it on You Tube and do some searching on the internet for a kit to re-cone your speakers. It is cheaper and you learn something too.
C4ster Messages: 686 Registered: June 2001 Location: Mukwonago, WI (Milwaukee...
Senior Member
Well, both speakers are done and installed. They are VERY stiff. (OK, now I believe in a break-in period) These are definitely different than JBL E series speakers. I want to use these K100's on small stages using a PA to increase the coverage while keeping stage volume lower. In that vein, I wired the 16 ohm speakers in series for a total of 32 ohms. The 60 watt @ 8ohms amp will max out at 15 watts @ 32ohms. It is very interesting how the amp breaks up when the amp starts to clip. This gives more control as the amp can be run from 10 o'clock to 12 o'clock and still not drive you out of the room. I may put a switch in one of the portholes to switch from 8 to 32 ohms easily.