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View Full Version : Can 030 system blow a channel on amp?



EddieJ
03-30-2009, 07:22 PM
I recently hooked up an 030 system to an Onkyo Integra A-809 amp and it sounded great for a few days, then suddenly the right channel on the amp became extremely weak. With headphones the right channel was also extremely weak. I doubled-checked that the speaker wires were properly connected, and they were.

The N2600 xovers are original and have not been recapped.
As you can probably surmise, I am not handy with electronics.

Did I do something stupid?
Or could it just be coincidence?
Any suggestions?

Mr. Widget
03-30-2009, 10:39 PM
Did I do something stupid?
Or could it just be coincidence?
Any suggestions?
I'd put my money on coincidence... doesn't rule out doing something stupid :D, but that amp should have no trouble with the load an 030 system would present.


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robertbartsch
03-31-2009, 06:33 AM
Is this the Onkyo receiver with 7.1 channels at 130 WPC?

If yes, I own one and it is NOT a steller performer. One of many annoying traits of this unit that is well documented on the Net includes a popping noise when used with multiple sourses including cable boxes, DVDs, etc.

The amp section is NOT conservatively rated and I have several 80 WPC untis that outperform the Onkyo.

With respect to your immediate issue, there are calibration controls that allow you to adjust the volume on each channel, so try that first. I have seven speakers all with the same sensativity ratings and I need to make radical changes to get a balance sound.

EddieJ
03-31-2009, 08:05 AM
The Onkyo is a 2-channel amp.

What's strange is I just attached the 030s to a vintage Kenwood receiver with 80 wpc, and the right channel on the Kenwood also suddenly got weak. I guess I'm having a bad day.

So I detached the 030s and hooked up a different set of speakers to the receiver and now all channels sound fine.

Any ideas what could be causing this?
Could there be a lose wire on the 030s?
Or something screwy in the xover?
Or is the moon aligned with Venus?

Mr. Widget
03-31-2009, 08:15 AM
Could there be a lose wire on the 030s?
Or something screwy in the xcover?Possibly and possibly.... what do you mean by weak?

A partial short could cause the output to become almost nil...

You only have a single 030 speaker?



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EddieJ
03-31-2009, 09:03 AM
I have a pair of 030s (15" D130, 075, N2600) in C38 cabinets.

The weak right channel started when I connected the 030s.

Volume on right channel is extremely faint. Even when volume is turned to 0, there is extremely faint audio on right channel. When the balance is turned all the way to the left there is still extremely faint audio on the right channel. When I plug in headphones, I'm having the same issue.

I used Deoxit on the controls of the amp and it seemed to fix the weak right channel problem for a few minutes, then the right channel became extremely weak again.

Would it be a good idea to open up right C38 and re-connect wires to the woofer and tweeter? Or could it be a lose wire in the xover?

Is there some type of meter I can get at Radio Shack to connect to the 030s that might isolate the problem?

I have several 2-channel amps and receivers that I can try hooking up to the 030s, but I'm afraid to connect the 030s until I hear from you. I'm learning as I go. You're the JBL experts.

Thanks for all your help and suggestions!!! When both 030s were working, they sounded great.

Mr. Widget
03-31-2009, 09:06 AM
I have a pair of 030s (15" D130, 075, N2600) in C38 cabinets.

The weak right channel started when I connected the 030s.The first thing to do is switch channels... I assume the problem will be with the left speaker then... at that point you know either a woofer or more likely the wiring or a network is not quite right.


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EddieJ
03-31-2009, 11:16 AM
If the problem is bad wiring in the 030s, could it damage an amp or receiver?

jcrobso
03-31-2009, 01:30 PM
Try swapping the speaker to the other channel (as the other post suggested), slowly turn up the volume, listen for any signs of shorted wiring. John

EddieJ
03-31-2009, 02:03 PM
Thank you Mr. Widget and jcrobso. I will follow your advice and report back later tonight or tomorrow.

Before I start, I will light a candle and say a prayer to the lord of JBL.

As always, you guys are great!!!

EddieJ
03-31-2009, 09:56 PM
I hooked up the 030s (as you suggested) to an 80 wpc Kenwood KR-7600 receiver and the 030s sound great. Both channels work properly.:applaud:

It might have been a coincidence that the Onkyo A-809 amp had a problem with the right channel at the same time that I hooked up the 030s.

I assume if/when I recap the N2600s the sound might improve.
The circa 1960 xovers are original. And the 030s might sound better with a different amp/receiver. (My 15 wpc Marantz receiver and 22 wpc Pioneer receiver might be too small; and my 200 wpc amp way too large.)
Those issues should probably be posted in a different JBL forum.

I want to thank all of you for your patience and wise advice.
Finally, I can enjoy my first set of JBLs.

LE15-Thumper
04-01-2009, 08:52 AM
If you have a multimeter, check the drivers for DC resistance value. They should both be within roughly 10% of each other. As for the actual resistance, I am not sure of the value. I would imagine it should be more than 5-6 ohms.

You guys out there know the DCR of a D130 off hand ?

Also, check your wiring, I once had a rouge single strand of my cable touching the other terminal. It was maybe only 30awg, but it was enough to give my amp a hard time.

robertbartsch
04-03-2009, 10:06 AM
...so you are having the same weak signal issue with the headphones too?

EddieJ
04-10-2009, 06:13 PM
Mr. Widget was correct when he said "I'd put my money on coincidence."

It seems the amp had a couple of dirty switches (balance and input selector); I cleaned all switches with DeOxit and it seemed to fixed the weak right channel. Now the 030s are up and running. These old JBLs sound GREAT!!!

I am completed amazed at the sound quality of these speakers; they are about 50 years old and 100% original.

I did an A/B test with my current non-JBL speakers; it was no contest.
The JBLs blew those other speakers away.

Once again, I sincerely thank you for all your help.

Mr. Widget
04-10-2009, 11:14 PM
I am completed amazed at the sound quality of these speakers; they are about 50 years old and 100% original.

I did an A/B test with my current non-JBL speakers; it was no contest.
The JBLs blew those other speakers away.Another one is born. :applaud:

Enjoy them... that's what it's all about!


Widget