#142155  by claytushaywood
 
:cry:

i got a cab on ebay with two jbl e120's for a very nice price. I've been playing it out of low volume amps for a couple months and now I finally had a chance to crank it up with a twin and I believe I'm getting cone cry. Well... if what i'm hearing is cone cry... Certain notes kinda like squeal and make a terrible noise like something isnt vibrating properly.

the front loading clips that came with the cab look like they might be the cause of this sound (in which case I know it wouldnt be cone cry) but what do you guys think about these pics? The clips are pushing the cork somewhat into the outer layer of the surround.

Unforunately I dont have an amp loud enough to do a video clip of this clean- i can push my amp to distort and get some examples of this nasty sound

any input is appreciated- do you think these speaker clips could be the source of my sound problems with these jbl's?

Also- how difficult is replacing the dust caps on these?

THANKS!!
 #142158  by hippieguy1954
 
The term "cone cry" means different things to different folks. Hearing an audio recording would really help a lot.
Does it only happen with certain notes, high or low strings? At what volume on the Twin did it start?
 #142160  by TI4-1009
 
claytushaywood wrote:tried to attach pictures and it says the board attachment quota has been reached
forum/viewtopic.php?f=359&t=12940
 #142161  by tatittle
 
The cone cry I have experienced came on a speaker with no dope...and doping it removed the issue I think (though I sold it soon after).

I have had less obvious high freq noise on JBL's before which seem to be related to a dented dustcap, especially if it has been pulled back out with tape etc. I am not aware of any real cure for this issue though, other than a recone. There is an original JBL 12" recone kit on ebay now for an inflated $150.
 #142200  by claytushaywood
 
i do have a dented dust cap- i thought you could replace the dust cap alone for a lot less. is a full recone an easy job? i was under the impression that it was not.
ill try to make an audio recording. i wish i had an sm58 right now so i could isolate to see if it is one speaker or both.

the squeal comes on certain notes. i feel like it is getting worse because it is happening at lower volumes and on notes in the first 5 frets when i turn up a little. it seems to be happening on certain notes. on the twin it got real bad at like 4... but now im running an ampeg reverberocket ii through it and it's happening at pretty low volumes. lower than band situation practice volumes.

so i have a feeling it might have something to do with these speaker clips. Can we not post pictures on here anymore?
 #142201  by hippieguy1954
 
Image

Sure can post pics from photobucket.

To rule out the clips, lay the cab on its back with a block or something under each end (so you have enough space to plug it in) and take the speaker clips off and try it.
To see if it's coming from both speakers, try each speaker separately.
I've never re-conned a speaker, so I don't know how difficult it is, but people charge between $150 and $300 to do it including the re-cone kit which is around $100. So, like everything else, it's probably not that difficult IF you have had a few to practice on and have some experience etc.
 #142206  by tatittle
 
The problem with reconing an old JBL is JBL has gone all NAFTA/corporate/Wall St. on us and they no longer make recone kits because the ones they made in Mexico were a failure. People have varying opinions on various recipes and reconers recapturing the JBL intricacies; there has certainly been a lot of effort into reproducing the original JBL tone. My experience isn't too broad, but I am yet too hear any recone that quite gets the whole JBL experience, and many aren't even close (Weber comes to mind). But a speaker that squeals and shrills isn't usable anyway, so the question becomes obtaining another original JBL speaker entirely or repairing yours so you know it will serve you reliably for some time (if not with the same exact tone).

There are so many variables that it is difficult to diagnose the problem even in person, much less over the internet. I don't think the dented dustcap in itself causes sever problems, but it can be a symptom of trauma that has messed up the VERY tight tolerances around the voicecoil etc. When it is pulled back out it may weaken the cap at creases so that some extraneous freq's are produced though.

Your issues are typical when trying to use 40 yr. old speakers that are quite valuable (thus every single one gets sold), and likely have been driven hard at some point (since they are pro audio and the high price tag was paid for a reason). Sometimes you can find an older guy whose band never got out of the occasional small gigs whose wife is forcing him to sell his JBL's he bought new e.g.; but it is tougher to find perfect JBL's everyday.

I have never replaced a dustcap myself. I heard that they are mounted directly on the voicecoil which would make removal/installation delicate. Some folks use a wider dustcap that attaches to the paper cone, and these never seem to sound the same to me.
One can get too crazy with all this stuff though, if your playing amazes it will do so with or without a perfect JBL, and most folks cant tell the difference or wont care cause the playing is more important.
 #142207  by TI4-1009
 
TI4-1009 wrote:
claytushaywood wrote:tried to attach pictures and it says the board attachment quota has been reached
forum/viewtopic.php?f=359&t=12940
claytushaywood wrote: Can we not post pictures on here anymore?
"You can lead a horse to water....."

Read.
 #142218  by claytushaywood
 
I guess the question for me is how much is it gonna cost to get a decent sounding speaker- do speakers that exhibit problems like this but arent obviously damaged (the cone isnt damaged in any way) need a full recone? I know the cone material is one thing that is not being reproduced like the originals, so is keeping the cone an option if the voice coil needs to be replaced. can it be done part by part? I'm just wondering if i'm gonna be able to get away with this with a decent speaker cheaper than watching ebay and grabbing a deal when it happens. i promise I would just take this to a speaker repair shop if i knew of one around here. but i might have to travel to nashville form what ive heard so far.

Anyone have experience with these guys?
http://www.soundspeakerrepair.com/mm5/m ... de=KIT-JBL

unfortunately my JBL is an e120-16 or a 16ohm speaker. I believe the cone is what determines the impedance though right? so I could use this kit and they would just become 8ohm speakers?

anyways- i was thinking maybe the pictures below could illustrate a potential problem with the speaker clips causing the cork gasket to infringe upon the surround. Let me know what yall think! Appreciate the input so far!


Image

Image
 #142219  by tatittle
 
The voice-coil is what determines the impedance of a speaker, not the cone. No, you generally cannot replace the voicecoil while keeping the original cone. It may be theoretically possible, but it is so unreliable that it isn't done I believe.

One thing you might consider is something may have fallen into the voicecoil gap thru the hole in the middle of the magnet. You could try trying to shake it out, or VERY gently moving the cone around while trying to careful dislodge any foreign material. You would need to be VERY gentle...and yet knock whatever may be in there off of the magnet.
 #142225  by hippieguy1954
 
I agree with everything tatittle said. Good info!

Also, get these: http://www.ebay.com/itm/Modern-Style-Tr ... 27e70d155e

I have a shit load of speakers, so if all else fails I have two extra 8 ohm E120's with original cones that are in excellent condition with NO issues that I would be willing to part with for a RUKIND member for $200 each paypaled including shipping.

I also have two extra (two year old/never gigged or left the house) Beyma Liberty Eight's (JBL E120 clones) in like new condition that I would be willing to part with for the same price for an RUKIND member.
http://www.usspeaker.com/beyma%20liberty-1.htm

Hope it works out for ya one way or the other :smile:
 #142233  by NSP
 
I've had a speaker redone by Orange County and they did a fantastic job - http://www.speakerrepair.com/

They used the aftermarket kit and comparing it to my original E120 there is not a significant difference. Been gigging with it for about two years without issue.
 #142234  by TI4-1009
 
The pics help. Yeah, I can see where the clips are pushing the cork into the cone ridges. I wouldn't like that, but I'm not sure it would cause the symptoms you're describing? Seems like it would be a deeper rubbing or vibrating sound? Do you need the cork on there if you have them front-mounted? Maybe at least cut off the cork right in the clip area?

Good suggestions about making sure there's nothing rubbing in the coil tube. I've reconed a few stereo speakers, and in the kit they give you these very thin plastic shims that you stick down around the coil to keep it perfectly centered while you glue the new cone to it. If it's off more than a few thousandths it can rub. If almost anything gets down in between the coil and the tube it will interfere with the coil moving up and down, and it moves so fast that who knows what kind of noise it could make? If you lay the speaker on its back and very gently push down near the center you should be able to feel- or even hear- if something is rubbing down there.
 #142242  by claytushaywood
 
so yeh I couldnt keep the original cone and replace the other parts that are problematic? and if i get a full recone is it possible to change these to 8ohm? it seems some places only have 8ohm kits? I'll try to see if i can shake anything loose.

if that doesnt work i can make a video if anyone would be willing to listen to it and tell me if i just need to throw down some dough and get recones or new speakers.

hippieguy i bet you would love to part with e120's for $200 a piece haha. while that would be better than paying OC speaker a ton of money for a recone with non original cones its not a reasonable price. they dont go for that much on ebay to the buyer and the seller doesnt take home the shipping or 10% ebay and paypal fees. I'd say $275 would be more than what youd profit on ebay and would be a good price to me too. Plus, I would have been covered on this ebay purchase if I just wouldnt have been an idiot and tried out the cabinet sooner with a louder amp.