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XTi 2000 source input issues


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#1 BaldGuyBrit

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Posted 28 September 2012 - 11:03 AM

Hello. First off I've been a Crown fan for many years & have never had any problems with the amps or blown speakers ( I have knocked the power out at a few venues with the older models!). I have a XTI2000 and have now replaced two cones - one on an EAW250 & a JBL JRX100. I'm currently running the amp with 2 JRX100 subs. The problem I'm having - It always takes a while for a signal to display on the amp. I'm running 2 QSC 12 powered for the high freq' & run a signal via a zone to the Crown amp. When I do get the signal & the bass bins push air - it may be a few minutes or a hour or so & no bass. There are no error messages on the amp ( which is still powered up). Last night, it happened again, and out of frustartion I tapped the amp near the input & it came on. I'm thinking this is an issue with the inputs - anyone else had a similar situation or is there some other setting I should be checking ? I'm very careful about my levels & always use limiting, but of course, still managed to blow 2 cones ( probably when the sub came back online). Any suggestions or help would be greatly appreciated. Steve

#2 BaldGuyBrit

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Posted 28 September 2012 - 11:04 AM

Forgot to mention. I've tried many different cables for the input. Also tried different config settings.

#3 bobbysdad

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Posted 28 September 2012 - 11:46 AM

The problem with 'later' models is that they're capable of delivering a lot more power than the 'older' models, and therefore create so much more heat regardless of how many fans you may have running trying to keep them cool.
What generally happens is that the boards containing the output stages are very prone to problems with the soLder joints expanding and contracting which eventually results in intermittent faults similar to what you describe.
There are no short cuts or magic bullets that can fix the problem you describe other than pulling the amp and throwing it on the work bench, stripping off the covers and visually inspecting all the soLder joints and possibly going over some of the suspect ones with a soLdering iron. (excuse me while I have a bit of a giggle right now, as I know Americans can't pronounce the word "soLdering".... sorry)
This would best be done at your local tech's as at least he'll have the tools, instruments, and the knowledge necessary for such a job.

Let us know how you go, and good luck.  :)


ooops! just noticed you said Inputs, which I mistook as output.
it's 'cause I'm in Australia, and we get everything upside down here.
.... but I'm still thinking dry joint tho'.
I might be deaf, but I can still hear the bells......

#4 BaldGuyBrit

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Posted 28 September 2012 - 12:11 PM

I appreciate your very fast response "down under". I have just updated firmware & installed band manager which is showing everything is ok. At the moment my one bass bin is working as it should now I'm configuring for the second. I think it may be something inside. I have to use them this wk d & for a big function next wk d ( I'm bringing backup powered subs) and then if the problem persists I'm dropping them off at my local Crown center. How are those Shelia's there mate. My dad served in Australia during WW2 as a pilot on the Lancasters.

#5 bobbysdad

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Posted 28 September 2012 - 12:40 PM

Lancasters???
My all time fave WWII bomber. Awesome and fantastic looking aeroplane. .... and not only one Merlin like the Spitfire, but FOUR! What a sound.....

Posted Image

They have one left here in Oz and that's at the war museum. I will get around to seeing it one day....
The 'sheilas' here are just like anywhere else.... They change their minds constantly and expect us mere males to understand.
I gave up after I lost the last house, and the car, and my bank account.....
Nothing unusual.
Anyway, back on topic, I hope you get your amp sorted soon.
Nothin' worse than not having the 'full' PA up and running.

;)
I might be deaf, but I can still hear the bells......

#6 dakos

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Posted 28 September 2012 - 03:07 PM

Hello Steve,
The sound not reaching the amp problem, it does sound like bad soldering joints...

As for the reconing problem, then you say you use limiters all the time, but if you operate your rig at power levels that force your limiter to engage, this actually allows more average power to reach the speakers so that could be your problem.

What EAW250 sub do you have? What JBL JRX100 do you have? What processing and which amps do you have and how does it all connect?

I suggest you read this:
http://www.bennettpr...undamentals.pdf
It contains detailed explanation about why speakers fail.

Reconing damage comes from over excursion, You avoid the over excurtion and overheat damage by:
1. limiting the amp to the specified speaker long term power specs and many times allot less then the continuous spec (to avoid power compression).
2. Use a HPF to filter out the unreproducable frequencies that create huge cone movement, usually a 24dB/octave (IIRC Butterworth) at the -3dB point of the speaker.
3. Never clip anything on the signal chain!!!
4. Keep your ears open for destortion and back off a bit when it happends.

#7 joust

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Posted 09 October 2012 - 10:09 AM

Perhaps, you may still have a display board issue. :unsure:
Verify the display board for the version number. The recent and most stable board version (!) is the 138911-5 version. If the version number is lower, then I would suggest to get the display board verified and replaced, if necessary.
If you have the latest firmware, it may take up to ten seconds for the Ready lights to come on, after the last double click of relays. You should have signal then.

Alain