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I think I blew both of my PRX518S !!


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Never said the studio environment caused anything, just recommended a more practical "tool". As mentioned before, I agree something is wrong in the signal path, most likely this mentioned "recording unit".

{ducking and running away} also

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Hey guys, looks like everyone's almost as baffled as I am:confused:. I was using a presonus firestudio tube for the recording device. In addition, yes I was using the PA as monitors because I just dropped 4.3K on it and can't afford studio monitors.

 

As for using the 1/4 in. outs, I don't have the 1/4 in to XLR cables but I guess that's an easy buy. Does a 1/4 in. to XLR cable convert the signal from line level to mic level? Or do you have to use DI boxes? Noob question I know....

 

I'm pretty positive the subs are blown. I took a direct out from my bass amp to each sub seperately, and they still sound blown. Should I try a different power outlet? I'm grabbing for straws here.

 

Here's the only thing I can think of that could have gone wrong. The stereo output from my program (cubase) was clipping during playback. That's it though. I had no clipping of the mixer or the subs (I didn't check the sub overload lights, but I was at low studio levels....) I had the system running for about 7 hours straight, could it have overheated? And what's this about underpowering?

 

Even if we don't know why they blew, does anyone have any idea as to what actually blew? I'm still getting sound, it's just quiet and distorted....

 

I called JBL. Looks like my next step is to drive 4 hours to a service center just to find out it my subs are covered under warranty...... I just can't believe this. I dropped 4K on powered speakers so I wouldn't blow my PA, and they're telling me it probably won't be covered under warranty. What the hell is covered under warranty?

 

sorry for the rant, but I think you can all understand my frustration....

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I can understand you being frustrated but why should a mfg have to make good on a product that appears to be damaged by user error?

 

 

I think there's still a question as to what the user error might be. Sounds like the OP was just running a line out of his mixer to the speakers at a relatively low level. The only issues that have been identified are some clipping before the mixer, and running one sub off the other's HPF. Personally, I think both of those are red herrings...

 

I can't fathom how either of those issues might have blown the PAIR of speakers.

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Gotta interject here that it doesn't sound like the OP did anything wrong. Even if he cranked the !@#$ out of them the internal protection should have kept them thumping. IMNSHO any powered speaker that lets itself go louder than the drivers can stand is a POS - even if it says JBL on it :mad:. Now, if he fried the inputs that's another story but I doubt that's the case. It will be interesting to see if JBL stands behind their engineering or not :p.

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I Am wondering if the inputs have been destroyed some how.

 

soem things to ask/try.

1) . at any point did you put a POWERED level in to then speaker, (ie soemthing out of an amp). When you say direct out of your bass amp, please confirm this is line level direct out, not "direct out to a speaker".

 

2) how loud did you ahve them play .. was it "stuipd loud" , like you would expect them to act in a club?

 

3) is there a change that your SOUCE is all distored, can you try direct form your sound card to teh speaker? still distored? ... how about no sound card, and jsut mic to mixer to speaker?

 

are we all 100% sure that the speaker is haveing issues and it is not really the mic/ cable/ mixer/sound card ect?

 

 

Just tossing soem ideas out there.

 

 

Kev.

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You think they'll let the user error slide on two subs at once? I guess I'll just have to suck it up and call....

The only other thing wrong was that my brother accidently hit the HPF and reversed the polarity on the 1st sub in chain. But that shouldn't blow them.


?

 

 

how long where they running with 1 subs poraity reversed, and were the subs close together (maybe side by side).

 

I am wondering if they were working realy realy hard, but canceling each other out?

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I think for this user, following the warranty process (without attitude) will result in getting the problem resolved, even if it's due to something else.

 

 

His attitude or any other subjective aspect shouldn't have any influence on the outcome of this if JBL was smart enough to understand that a thread about failure of their products on a forum like this really hurts their business. Claiming user error on a powered speaker failure won't help either. People make mistakes every day, but I can't remember last time anyone reported a powered Yorkville or EV failure.

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Sure people make mistakes, but let me tell you from the perspective of a pro audio service shop that when somebody come in with big atttitude, is rude and nasty, I will do the bare minimum to get them out of the shop before they cause more disruption and inconvenience to getting my good customer's work completed. In fact, I will flat out not do any out of warranty work for folks like this and depending on my warranty contract, most allow me to send a disruptive customer elsewhere or to the factory depot.

 

On the other hand, for a customer who approaches us even the most difficult issue, one that may cost more than anything we could possibly charge, but is nice, respectful and really wants/needs the help will get treated better, and with any ambiguous issues settled in their favor.

 

It's the classic "treat others as you would like to be treated" scenario.

 

Regarding powered speaker failures, we don't know for sure that there really is a failure, and I have seen failures in every single brand of powred speaker I am familiar with. The fact that JBL may sell 10x (could easily be higher than this too) as many as those you mention would indicate that it would be expected that they see 10x the number of failed units for an identical failure rate.

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You might want to try to take other items out of the signal path and go with a CD player or iPod into the AH MixWiz. Take the Main L/R outputs to your crossover and then to the subs. Make sure your gain levels are set well below max everywhere. Trim pot, channel fader, main output, crossover. Start with the gain on the sub very low. (All the way down). With the CD player/iPod playing, bring the sub volume up. If it still distorts at lower volumes, you've got issues. If not, continue to bring the volume levels up. Making sure not to peak any of the levels anywhere in your signal path.

 

Once you've tested this, then, add the other pieces of the puzzle back into the mix. Continue to make sure your gain levels are set correctly everywhere in the signal chain.

 

Johny

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They were running for probably 7 hours with polarity reversed about 3 feet away from eachother. However, I was also running 2 KSC HPR122i tops, and they were quiet (and didn't get blown). I keep the sub and top levels even, so the subs wouldn't have been overpowered.

 

Kevin, Johnny, I feel like no one believes me that the subs are blown. My tops sound fine coming from the same mixer, but my subs, which are hooked up on an aux out like always, are farting at low levels. If there was a problem with the source and not the subs, wouldn't the tops sound distorted as well? I was playing at very low studio monitoring levels. In addition, I took a line level Direct Out from a bass amp straight to a sub, and it sounds the same. They're blown.

 

Could it have anything to do with a power surge or a bad outlet?

 

I'm at a loss, I'm just gonna have to make the drive and get a tech to look at them. I'll be sure to keep everyone updated.

 

thanks all

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Kevin, Johnny, I feel like no one believes me that the subs are blown. My tops sound fine coming from the same mixer, but my subs, which are hooked up on an aux out like always, are farting at low levels. If there was a problem with the source and not the subs, wouldn't the tops sound distorted as well? I was playing at very low studio monitoring levels. In addition, I took a line level Direct Out from a bass amp straight to a sub, and it sounds the same. They're blown.


Could it have anything to do with a power surge or a bad outlet?


I'm at a loss, I'm just gonna have to make the drive and get a tech to look at them. I'll be sure to keep everyone updated.


thanks all

 

 

 

Just trying to be sure you aren't missing something obvious.

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I, like many others here have been suspicious about the assertion that the subs are blown, because of the low mxing level claimed. But, if the speakers are indeed fried, I'm wondering how "quiet" is quiet. I mean, I've done a fair bit of marathon recording and mixing, and have never had a problem with speaker/amp failure.

 

How low did your recorded material go. A sub 40hz drone frequency for seven hours would make any sub unhappy, if the levels were fairly loud.

 

Digital clipping is a complete no no, so is not noticing that one sub is only getting "high" end. So... not to be unkind, but maybe there was another egregious error made that you weren't aware of. Maybe something else your brother did - who really knows.

 

Nonetheless, I do feel your pain. Just can't think of a good reason why those subs blew. I would plead ignorance, and just say you were using them for low level mixdown and the subs blew for no good reason - which on the face of it is true.

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I pretty sure he said the speaker cones were fried. The tech I took it to was really nice, and he said that technically both subs were my fault because there was no factory problem and they were burned up. So he said there was no way he fudge it to get JBL to cover both of them, because then they'd get suspicious and ask him to send the parts in, and they'd realize they were just burned up. So he managed to get them to cover one of them. End the end I'll only be paying for a recone cit (~150), shipping, and tech work, which will total to about 230. Not bad, but I still really want to know what I did to blow them so it won't happen again! Digital clipping is the only thing I know for sure was happening. The kick drum was causing the stereo output from cubase to clip. Are ya'll saying that this would not have blown them?

 

And yes, they were at low levels. Not even close to what we use to play live.

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Be thankful you found a tech that was willing to help you out the best he could.

 

Power problems such as on open neutral on a 120/240 pair of circuits can cause all kinds of fatal problems for amps. Large voltage spikes, high line conditions etc. can also cause amps to fail.

 

Sounds like you just overdrove your speakers hard enough and long enough for the speakers to fail. Ifthe digital clipping was bad enough, it will skew the limiter RMS integrator and the limiters may effectively have their thresholds shifted by as much as 3dB the wrong direction for survival.

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