Help with JBL PRX-618XLF Please!!

S

Stephen Findlay

Freshman
Aug 17, 2012
9
0
0
Sault Sainte Marie, Ontario, Canada
Good Morning All,

Would like to thank you all in advance for your help. This is my first post so here goes...I bought my 2nd 618-XLF about a month ago and hooked it up to PRX 635 tops for a wedding I am doing this weekend. This was the first time I hooked this up and my signal chain is as follows:

Mixer (basic Numark mixer with balanced outs) > 618XLF Right In (with crossover set to "IN") > Right Out to the 635

The left 618XLF/635 works fine; and the right 635 works fine. However, there is no sound coming out of the right 618XLF. I notice the signal light flashing green but the blue power light at the front is not on. Could this be a blown fuse? I live about 5 hours away from a service center so I am hoping that this could be an easy fix by replacing a fuse.

Thanks again.
 
Re: Help with JBL PRX-618XLF Please!!

First thing is check the connection of the speaker. One of mine arrived dead and I discovered the internal speaker wire was not connected to the speaker. Also, if you are sending signal from the left to right, make sure you don't have the crossover on the left cab enabled. That would mean your right stack is only recieving a signal above the crossover point(90Hz) and nothing would be comining out of the right sub.
 
Re: Help with JBL PRX-618XLF Please!!

Did you swap the tops to determine if it's the speaker or the xlr signal path? Also bypass the subs and go straight to the tops to eliminate the sub as being the culprit.
 
Re: Help with JBL PRX-618XLF Please!!

I would remove the amp module and check to see if a lead is off the speaker. This very issue popped up a few months back on a different forum. Same sub too, brand new, powered up with no sound.
 
Stephen Findlay said:
Good Morning All,

Would like to thank you all in advance for your help. This is my first post so here goes...I bought my 2nd 618-XLF about a month ago and hooked it up to PRX 635 tops for a wedding I am doing this weekend. This was the first time I hooked this up and my signal chain is as follows:

Mixer (basic Numark mixer with balanced outs) > 618XLF Right In (with crossover set to "IN") > Right Out to the 635

The left 618XLF/635 works fine; and the right 635 works fine. However, there is no sound coming out of the right 618XLF. I notice the signal light flashing green but the blue power light at the front is not on. Could this be a blown fuse? I live about 5 hours away from a service center so I am hoping that this could be an easy fix by replacing a fuse.

Thanks again.
Click to expand...

The crossover is a high pass on the output, you want it off to chain to another sub. The crossover should only be on if directly chaining to a top.

Sent from my DROID RAZR
 
Re: Help with JBL PRX-618XLF Please!!

Sounds like you have everything set up correctly. You're running a sub on each side, with a top above the sub. 2 stereo channels. It sounds as though the problem is in the new sub itself. You can verify this by swapping the sides of the subs. If the problem moves, then you know for sure that's where the problem is.

The blue LED on the front of the speaker indicates power to the amp module. Because you are not seeing that light up, that tells you for sure that something is wrong. It could be as simple as a loose connection inside the unit. Since you are seeing a signal light on the defective unit, I'm guessing it's not going to be as simple as the main fuse. The main fuse is located in the IEC connection, so it's easy to pop out and test it.

Also, I'm not sure if the crossover system is active or passive on that box. If you turn off the power switch on the sub, does sound stop coming out of the top? If so, then you can be sure power is getting to some part of the circuitry inside. Again, since you don't see the blue power light, I'm guessing the problem is more than just a loose connection on the speaker. More likely, you'll find a defective amp module. But it's easy enough to open up and look for obvious problems.
 
Brian jojade said:
Sounds like you have everything set up correctly. You're running a sub on each side, with a top above the sub. 2 stereo channels. It sounds as though the problem is in the new sub itself. You can verify this by swapping the sides of the subs. If the problem moves, then you know for sure that's where the problem is.

The blue LED on the front of the speaker indicates power to the amp module. Because you are not seeing that light up, that tells you for sure that something is wrong. It could be as simple as a loose connection inside the unit. Since you are seeing a signal light on the defective unit, I'm guessing it's not going to be as simple as the main fuse. The main fuse is located in the IEC connection, so it's easy to pop out and test it.

Also, I'm not sure if the crossover system is active or passive on that box. If you turn off the power switch on the sub, does sound stop coming out of the top? If so, then you can be sure power is getting to some part of the circuitry inside. Again, since you don't see the blue power light, I'm guessing the problem is more than just a loose connection on the speaker. More likely, you'll find a defective amp module. But it's easy enough to open up and look for obvious problems.
Click to expand...

Upon second read it sounds like you're right, the switches on those subs always confused me though.

Sent from my DROID RAZR
 
Re: Help with JBL PRX-618XLF Please!!

I wonder if the blue LED on the front and the driver connections connect to the circuit board via the same connector? The new JBL stuff has a reputation for less than secure internal wiring. If that were the case, that would explain the power light on the back, but no sound from the sub driver and no blue LED on the front.
 
Re: Help with JBL PRX-618XLF Please!!

First off. THANKS to all who responded! Nice to see that there isn't any Holier than Thou types yet lol.

So I was about to load the amp in my truck and I hear this rattling sound. I'm going to remove the module to check to see if that's the loose connection you speak of. If so, that saves me a pile of headaches and money. Little unsettling when you pay $1300 and this happens.

I'll keep you guys posted.
 
Re: Help with JBL PRX-618XLF Please!!

"Nice to see that there isn't any Holier than Thou types yet lol."

If there were it would be totally inappropriate and just plain dumb! You have a couple of quality subs. Just last night a very experienced soundman mixed on my system for the first time and had nothing but praise for my XLF's. The word "smooth" came up several times and I use no EQ on my subs. I hope you get your problem resolved quickly and easily.
 
Re: Help with JBL PRX-618XLF Please!!

Stephen Findlay said:
First off. THANKS to all who responded! Nice to see that there isn't any Holier than Thou types yet lol.
Click to expand...

Oh, sorry about that. Of course you are having problems. The subs you bought are overpriced, unreliable crap. You wasted your money. You totally should have bought the subs that I use, because what I use is automatically the best solution for every situation. But you should have already known that, and I'm annoyed that I had to tell you.

There. Now this thread seems complete.
 
Re: Help with JBL PRX-618XLF Please!!

Brian jojade said:
Oh, sorry about that. Of course you are having problems. The subs you bought are overpriced, unreliable crap. You wasted your money. You totally should have bought the subs that I use, because what I use is automatically the best solution for every situation. But you should have already known that, and I'm annoyed that I had to tell you.

There. Now this thread seems complete.
Click to expand...

LOL! @Brian Jojaede. That's more like it...I was missing being talked down to. Anyway, I am extremely happy with the one working unit and have taken the screws off the amp module of the non-working unit but cannot get the damn thing out. Anyone have experience with taking this thing out? I will keep trying but I feel like I am going to ruin the box in the process.
 
Re: Help with JBL PRX-618XLF Please!!

Update:

The subwoofer was purchased only a month ago and hooked it up the first time a week ago. Never emitted a sound. I contacted the dealer and explained they sent me a sub that was DOA. No problem - they shipped me a new one and refunded my original order and even paid return shipping. Pro AudioStar was the company - and they have never let me down.

Thanks all who tried to provide assistance.
 
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