JBL STX Problem

K

Kevin Spencer

Freshman
Jun 28, 2013
22
0
0
I just added 2 JBL STX 828s cabs to my inventory. Running them each on a crown XTi 6002 however output isn't right. When I have everything rigged, The tops work perfectly as usual, however the subs are inaudible in comparison (I have SRX 828 cabs too so I know how loud they should be). My signal chain is clean, crossover settings are spot on, etc. Ive tried everything. I'm powering it at 4200 watts program but the mixer level clips before i even get anywhere close to full volume, or even half volume for that matter. Is it that the signal strength is decaying? I have no idea what is wrong.
 
Re: JBL STX Problem

Sounds like a polarity issue. Check all your cabling for polarity. What happens when you just have one cab running?

Also you may want to change your name to your full name. They're required for this forum.
 
Re: JBL STX Problem

Unfortunately it's not the polarity. I've switched the polarity of each individual driver and took took one step further and independently powered each driver with no luck. Same weak output.
 
Re: JBL STX Problem

Its funny you mention that because I had divided feelings wether or not it could be the XTi preset. I definitely thought it was possible because i haven't enabled a preset yet (I only had a Mac computer on me and you need Windows to update the XTi with the STX 828 preset package) but to compensate I just used a driverack I had with me and input all the speaker information manually in a custom preset. I was thinking this could be the cause of the problem however i couldn't help thinking that it's too simple Could it really be just the lack of the preset being enabled thats putting such a damper on output?

And I've tried eliminating different pieces in the signal chain with no success. I was thinking it could be a problem with the cabs but I bought them 2 days ago from 2 different dealers.
 
Re: JBL STX Problem

Tim McCulloch said:
What device file/preset are you using for the XTi?
Click to expand...

Actually I just checked and Crown doesn't appeal to have the presets for the STX 800 series. The do have them for the PRX 400 series which is odd to me considering it's a younger model than the STX 800 series...
 
Re: JBL STX Problem

Try another amp. The XTI series isn't the best amp for subwoofers as is. I recently just set up a friend's rig. He has the STX subs, SRX tops and itech 8k's for power. I manually made the sub & top presets, and I was very impressed with the sub's output.




Evan
 
Re: JBL STX Problem


[TD="colspan: 5"] Subwoofers
[/TD]

[TD="width: 20%"] STX818S 812M LT 80
[/TD]
[TD="width: 20%"] 20
[/TD]
[TD="width: 20%"][FONT=Arial,Arial] [FONT=Arial,Arial]STX818S Stereo 80Hz LPF - use with STX812M[/FONT] [/FONT]
[/TD]
[TD="width: 20%"][FONT=Arial,Arial] [FONT=Arial,Arial]STX818S[/FONT] [/FONT]
[/TD]
[TD="width: 20%"][FONT=Arial,Arial] [FONT=Arial,Arial]STX818S[/FONT] [/FONT]
[/TD]

[TD="width: 20%"] STX818S 815M LT 80
[/TD]
[TD="width: 20%"] 21
[/TD]
[TD="width: 20%"][FONT=Arial,Arial] [FONT=Arial,Arial]STX818S Stereo 80Hz LPF - use with STX815M[/FONT] [/FONT]
[/TD]
[TD="width: 20%"][FONT=Arial,Arial] [FONT=Arial,Arial]STX818S[/FONT] [/FONT]
[/TD]
[TD="width: 20%"][FONT=Arial,Arial] [FONT=Arial,Arial]STX818S[/FONT] [/FONT]
[/TD]

[TD="width: 20%"] STX818S 825 LT 80
[/TD]
[TD="width: 20%"] 22
[/TD]
[TD="width: 20%"][FONT=Arial,Arial] [FONT=Arial,Arial]STX818S Stereo 80Hz LPF - use with STX825[/FONT] [/FONT]
[/TD]
[TD="width: 20%"][FONT=Arial,Arial] [FONT=Arial,Arial]STX818S[/FONT] [/FONT]
[/TD]
[TD="width: 20%"][FONT=Arial,Arial] [FONT=Arial,Arial]STX818S[/FONT] [/FONT]
[/TD]

[TD="width: 20%"] STX818S 835 LT 80
[/TD]
[TD="width: 20%"] 23
[/TD]
[TD="width: 20%"][FONT=Arial,Arial] [FONT=Arial,Arial]STX818S Stereo 80Hz LPF - use with STX835[/FONT] [/FONT]
[/TD]
[TD="width: 20%"][FONT=Arial,Arial] [FONT=Arial,Arial]STX818S[/FONT] [/FONT]
[/TD]
[TD="width: 20%"][FONT=Arial,Arial] [FONT=Arial,Arial]STX818S[/FONT] [/FONT]
[/TD]

[TD="width: 20%"] STX828S 825 LT 80
[/TD]
[TD="width: 20%"] 24
[/TD]
[TD="width: 20%"][FONT=Arial,Arial] [FONT=Arial,Arial]STX828S Stereo 80Hz LPF - use with STX825[/FONT] [/FONT]
[/TD]
[TD="width: 20%"][FONT=Arial,Arial] [FONT=Arial,Arial]STX828S[/FONT] [/FONT]
[/TD]
[TD="width: 20%"][FONT=Arial,Arial] [FONT=Arial,Arial]STX828S[/FONT] [/FONT]
[/TD]

[TD="width: 20%"] STX828S 835 LT 80
[/TD]
[TD="width: 20%"] 25
[/TD]
[TD="width: 20%"][FONT=Arial,Arial] [FONT=Arial,Arial]STX828S Stereo 80Hz LPF - use with STX835[/FONT] [/FONT]
[/TD]
[TD="width: 20%"][FONT=Arial,Arial] [FONT=Arial,Arial]STX828S[/FONT] [/FONT]
[/TD]
[TD="width: 20%"][FONT=Arial,Arial] [FONT=Arial,Arial]STX828S[/FONT] [/FONT]
[/TD]
 
Re: JBL STX Problem

Now another problem. I havent used system architect in awhile and the UI is completely different after updating it. I software wont recognize my amps. Instead of reading into it can someone just explain how to push the preset packages to the the amps. It getting very frustrating just clicking around the software
 
Re: JBL STX Problem

Harman has tutorials on the HiQNet website. System Architect is a very powerful tool that can have a steep learning curve to use to the fullest extent, but fear not.

When your amp appears in the Venue workspace, right click on the amp icon and choose "Open Device File" from the context menu. If the Open File dialog box doesn't take you directly to the Device Files & Presets folder, the default location is My Documents/Harman Pro/Device Files.../Portable PA/STX8000 Crown XTi2V4/ Select the most appropriate file click on the Open button. The device file will be sent to your amp. You can double click on the amp icon and a control panel will appear.
 
Re: JBL STX Problem

As Aaron said - divide and conquer:
- Use a 9v battery on the speaker terminals to ensure that both drivers move the same way. Do this on both your cabs to make sure both speakers have the same polarity.
- Verify your speakon cables are wired correctly - no polarity reversals.
- Skip the amp presets, try the amp flat. With the speakers unplugged, use a signal generator or a sine wave file as input and make sure you can get the amp to go to full output. Measure with a volt meter to be sure.
- Start putting things back together slowly and see what affects things - plug one sub into one channel of the amp, use your signal generator carefully and see if you get the output you expect (be careful of driver excursion and use 80Hz to do this - not 30Hz).
 
Re: JBL STX Problem

So at this point I'm fairly confident it is a preset issue. I have checked all driver polarity, all cables are wired correctly, and individually removed every single piece in the signal chain. The only problem now is audio architect is not recognizing the XTi 6002s and they are just showing up as unknown USB devises on my computer. Apparently when I initially plugged it in the driver installed, however, upon restarting the computer and starting up audio architect there is no connection. Can I just download the driver somewhere and redo it; or is there something simple I have bypassed that I'm missing?
 
Re: JBL STX Problem

Kevin Spencer said:
So at this point I'm fairly confident it is a preset issue. I have checked all driver polarity, all cables are wired correctly, and individually removed every single piece in the signal chain. The only problem now is audio architect is not recognizing the XTi 6002s and they are just showing up as unknown USB devises on my computer. Apparently when I initially plugged it in the driver installed, however, upon restarting the computer and starting up audio architect there is no connection. Can I just download the driver somewhere and redo it; or is there something simple I have bypassed that I'm missing?
Click to expand...

Disregard my last comment. I figured out the problem. Now to test everything
 
Re: JBL STX Problem

Kevin Spencer said:
So at this point I'm fairly confident it is a preset issue. I have checked all driver polarity, all cables are wired correctly, and individually removed every single piece in the signal chain. The only problem now is audio architect is not recognizing the XTi 6002s and they are just showing up as unknown USB devises on my computer. Apparently when I initially plugged it in the driver installed, however, upon restarting the computer and starting up audio architect there is no connection. Can I just download the driver somewhere and redo it; or is there something simple I have bypassed that I'm missing?
Click to expand...

Kevin, the connectivity issue sounds like a Windows thing. Did you use the same USB port on your computer each time? For some reason Windows wants each port to have its own driver.

Also consider a switch to Band Manager instead of Audio Architect. Smaller, faster, lighter.
 
Re: JBL STX Problem

Tim McCulloch said:
Kevin, the connectivity issue sounds like a Windows thing. Did you use the same USB port on your computer each time? For some reason Windows wants each port to have its own driver.

Also consider a switch to Band Manager instead of Audio Architect. Smaller, faster, lighter.
Click to expand...

Yes, I actually just looked into band manager and it definitely looks like a simpler alternative to audio architect. After applying the appropriate presets everything is running perfectly. They put out a lot of pressure. I'm have to get two more
 
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