#115615  by cmc64
 
I just received a JBL K-110 from ebay today and I think I may have a problem. I checked the speaker for cone rub and didn't hear anything - the cone pushed in very easily and pushed back out very smoothly. And it does sound great. But.... I am getting some "crackling" type sounds through the speaker. Regardless if I am playing through the amp of if I just have it on there are these little crackling type noises coming through the speaker. Is it toast or am I having some other issue? The speaker has a 14 day return so I am wondering if I should just send it back. What's the word guys?


Thanks as always!!
 #115616  by playingdead
 
That sounds like an amp problem, not a speaker problem. Try the amp with another speaker (or cabinet) and see if you are still getting the noise.

Don't forget that on a K-110 the black and red terminals are reversed from what they are on most speakers, so you may have your phase backwards. That would not, however, cause the problem you are describing.
 #115634  by cmc64
 
playingdead wrote:That sounds like an amp problem, not a speaker problem. Try the amp with another speaker (or cabinet) and see if you are still getting the noise.

Don't forget that on a K-110 the black and red terminals are reversed from what they are on most speakers, so you may have your phase backwards. That would not, however, cause the problem you are describing.
Thank you very much for your input!! :thumbs up:

Ok, so if I have this straight, on a K-110 red is actually black and black is red. Yes/no? Anyway, when I first hooked it up I thought is sounded rather anemic so I reversed the wires and the sound radically improved. So I do believe I have the polarity correct. The amp was purchased new about six months ago and while I did recently change the tubes there was no crackle noise with the stock Fender speaker. I even gave the amp a full run through before I changed the speaker out, so I believe the issue is related to this speaker because it did not happen with the stock speaker.

Is it possible that the stock speaker was crappy enough that the crackling was not evident and the JBL is revealing enough that the problem is now audible whereas it was not before?

Also, the cable that came with the amp that goes from the speaker out to the the speaker (1/4" connector to +/- termination) is comprised of a very low quality molded 1/4" connector and very high gauge copper wire that is essentially lamp cord - could that be causing the problem? The cable was originally terminated with female F (or T1) push-on connectors that connected to the male F( T1) blade-style connectors on the speaker. I snipped the F connectors off, stripped a bit of the insulation from the wires and inserted the ends into the spring-loaded connectors on the JBL.

So, whaddya think? New speaker cable? Amp issue that was masked by a crappy speaker? I don't have a power conditioner so potential RFI/EMI interference?

As a final note, while the K-110 fits into the cabinet, it is a "fits like a glove" type of fit. At the very center point of the chassis is a small silver colored box that hangs down.It is obviously some part of the amp circuitry but I have no idea what. Anyway, the basket of the speaker clears it, but it JUST BARELY clears it. The two are not touching but the clearance is literally the width of two medium guitar pics. If the basket was about 2mm higher it would not have cleared the chassis. Could the extremely close proximity of the two be causing the crackle? Also, the back panel strip that I had to remove to ch

playingdead, thanks again for your quick reply.
 #115642  by cmc64
 
mkaufman wrote:Sometimes the vibrations caused by the speaker making sound can cause loose amp components to rattle or weak soldier joints to move and introduce noise into the circuit.

mk
I considered that but I ruled it out because the crackle was happening when I wasn't playing. Everything plugged in and on, but the guitar on the stand. Crackle crackle.

But check this out:
I have had the amp on for a few hours today and I put a small cardboard box under the front of the amp (which I often do) so it is angled upwards just a bit and the crackle seems to be gone. Now the ambient noise level in the room is a bit high as I have the ceiling fan and TV on, so I need to shut everything off and quiet the place down to confirm, but at this moment it seems to be gone. But I have to confirm.

I also need to have a new speaker cable made. The stock Fender cable is a POS.
 #115643  by JonnyBoy
 
It can be the ground loops in the house wiring, or appliances that give you noise, I have a ceiling fan that causes issues with my tube amp. Try it in different rooms, different times of the day, maybe even a different house/building all together. I would make sure you know its not the speaker before the 14 days! Good luck!!!!
 #115644  by Poor Peter
 
I had a problem like the one you are describing on a super reverb. Finally narrowed it down to a dimmer switch that I had on over the drum kit.
 #115645  by cmc64
 
Well, I have been using the same power outlet for this amp,I know I have somewhat "dirty" power, lots of devices around the house that have introduced noise into other audio circuits - I have some work/research to do.

Thanks for all of the suggestions guys! This place has helped me immeasurably. I'll report back after trying a few things out.

You guys rock!!! :smile: :cool: :cool: :smile: :-) :-) :cheers:
 #115667  by cmc64
 
Well for the time being the crackling seems to have stopped. I still have to do some testing - different outlets and rooms, a power conditioner (high on the list) and so on.... But for some reason angling the amp about 15 -> 20 degrees upwards has stopped it. I have no idea why but as I usually prop my amp up like that I'll take it.

Although I do want to know why it was (or is) happening at all. Hmmm.........

I need more cash. For some reason I have a feeling that a Mesa Mark II Head or an SMS -> McIntosh combo should clear this right up. :smile:

Well not really, because if it is an artifact from dirty power or something in that realm it will rear its ugly head everywhere, although it does seem to be particularly fond of this K-110 (not the prior speaker in the amp, not in my stereo system (which is is the same room as the amp).

I'll report back as needed.

Cheers
 #115754  by cmc64
 
playingdead wrote: Don't forget that on a K-110 the black and red terminals are reversed from what they are on most speakers, so you may have your phase backwards. That would not, however, cause the problem you are describing.
I am going to pick up a new 1/4" speaker out jack -> speaker cable (because the stock one sucks) and just so I have this straight:

RE: The above quote - so on the JBL K-110 the terminals are reversed, so I would want the red(+) cable to go to the black(-) terminal on the speaker and the black(-) cable to go to the red(+) terminal on the speaker. Yes? No?

When I swapped out my speaker and trimmed the F-style connectors off the cable I forgot to mark the cable as to which one was red(+) and which one was black(-). I went with the general standard that the lead with the white stamped lettering is the positive and hooked it up like that. It didn't sound right so I switched it and the speaker then sounded MUCH better so I am guessing I got it right but I want to be sure and since the stock cable is a high gauge lamp cord I am going to replace it with something a little better. Just want to get it right.

Thanks (I'm a dumb-ass, I know :-) )
 #115759  by playingdead
 
Connect a speaker wire to each terminal on the JBL. Touch the individual ends to the positive and negative terminals of a 1.5 volt AAA battery. The cone will move out if you have the positive wire touching the + terminal on the battery. If the cone moves in, the phase is reversed.
 #115791  by cmc64
 
playingdead wrote:Connect a speaker wire to each terminal on the JBL. Touch the individual ends to the positive and negative terminals of a 1.5 volt AAA battery. The cone will move out if you have the positive wire touching the + terminal on the battery. If the cone moves in, the phase is reversed.
Thanks for the reply!!

I know of this test but I am not quite sure how to implement it.

The speaker out on my amp is a female 1/4" jack. So my cable has a two leads connected to a male 1/4" connector. The only thing I can think of is to get a piece of speaker wire and touch one lead to the tip, wrap the other lead around the ring (of the 1/4" connector) and touch the opposite ends to the battery. Would that work? But then, I do not know if the + or - lead of the molded cable is connected to the tip or the ring.

Not quite sure what to do here.
 #115797  by playingdead
 
Tip and ring would be a TRS cable ... You are dealing with a tip (hot) and sleeve (ground) ...but yes, you can connect the speaker cable to the K-110 and then touch wires to the negative terminal of the battery and to the sleeve of the plug, and the positive to the tip and see if the speaker moves in or out.