JBL amp disassembly?

Could you disassemble the JBL amp to the point where the internal circuitboard is exposed?

Reason I ask is because if that so is the case I will tear it all apart and modify it's internal crossovers to work with the ones that I had to remove off of my Polk DB6501 speakers

 

I've had mine apart, just a few TQ scews. I took mine apart because it had some rattles coming from it, put some high temp trv around it on a few spots and all is quiet.

But im not following you on why you have to modify it to work with your crossovers , cant you just put the crossovers after the amp ?

 

That's a negative. The crossovers are built within the amp internally, not externally. That being said the crossovers rock for the stock speakers but when it comes to upgrading to a nice higher then stock quality aftermarket speaker they make the tweeters sound like crap. Changing out the crossovers within the amp would be the best option here. First I would have to locate the circuits within the board, desolder the old crossovers then resolder the new ones. Should be an easy enough task!

 

Gotchya , I normally just put component speakers and cross overs after the factory amp in previous installs .
let us know how you make out .
The one thing I'm not certain of that might give your trouble is if the sub has it's own crossover , or if it's the same cross over that filters all the rear speakers . Cause on the headunit there's no separate sub control just front and rear left and right .

 

Shit.You are right.. I'm sure the sub has it's own independent channel and set of crossovers. It should ideally. I guess I'll be finding out soon enough . I'm going to give it a stab tomorrow. I'll let you guys know what happens!

 

Also the thing is that I tried doing that as well but the speakers sounded like utter garbage. The crossovers built into the jbl amp doesn't like anything else inserted after it but before the speaker.

 

Ya let me know how you make out , i think you can at least do the fronts . Which would be a upgrade .

Other option would be to add a separate amp for your highs . It's not optimal to take a amplified sound , knock it down just to amplify it again .
Though I'm doing it for my jl 10" sub and it hits pretty good .

 

Yeah I mean I really REALLY do not want to go that route. I really enjoy the sound that the stock stuff has the voice portion just doesn't sound great with aftermarket tweets on the stock amp. That's where I want to correct the issue and if I have to do circuit board modifications then so be it you know? I'll let you know later today!

 

Are you high on drugs? The JBL setup (which I had) is flat and sounds like shit.

Do yourself a favor and ditch the JBL, its not worth keeping.

 

I have great news. The amp circuit board is modifiable and I have located the capacitors responsible for the system sounding like crap with aftermarket speakers. I will take some pictures of the circuit board and which pieces need to be removed and modified in order to fix the issue.

 

Great news, is the sub separate ? looking forward to the pics


I like my JBL headunit, its the speakers that suck. I added a sub to my setup and am pretty happy with it. Will upgrade the highs some day .
So nice to have factory steering wheel controls, reverse camera etc.

I would not have bought the JBL thinking back now, but cant justify wasting the money to switch to aftermarket aftermarket.

 

The sub?? I never looked into it. I believe so. Either way I have plenty of pictures to document all the circuitry and where it flows. After swapping out the capacitors I determined a couple of things:

There are (2) 220pF (picofarad labeled 1L-104) ceramic capacitors which look like resistors in place of where the tweeters circuitry runs throughout the pc board. After swapping them out to the ones which came with my Polk DB6501's (They were 35uF Sounder capacitors) the audio out of the tweeters has smoothed over quite a bit. There is much more room to play with the equalizer after swapping them out. Volume required to get into the louder ranges has dropped as well.

For the woofers themselves I left in place the 4.7uF capacitor (microfarad) capacitors that were along the circuit. Thinking about it in retrospect I probably should had replaced them as well with the ones that came with my speakers too. It might have really smoothed out audio some more.

EDIT: To answer your question, YES the factory sub has it's own channel green/yellow and green/white pins 5 and 12 ||||||| blue/black and blue/red pins 4 and 10 at the same white 12 pin plug the speakers run off of. Why did you want to know about the sub?

 

After using this modded amp for close to about a week or so now. I am pleased to report that I have surprisingly lost A LOT (I'd probably have to say about 98.5%) of the digital noise and random popping that used to come out of the audio when I would play music in the USB mode of the JBL head unit. The audio sounds a lot cleaner now, a lot louder at lower volumes, but most importantly the tracks sound much more cleaned up playing now vs. before when the amp was untouched there were just certain tracks that sounded like absolute shit because there was so much random popping.

Someone I talked to reffered to it as "digital noise." He nearly condemned the head unit and was thinking that was the problem I was having. I'm more then pleased to say that I am much MUCH happier with it now! I may crack it open and play with upgrading some more of the capacitors for maybe the woofers or even the subwoofer portion but all in good time.

If anyone would like to see some pictures of what the amp circuit board looks like let me know and I will post up. I only touched certain areas of the board so all I took was some focused pictures but there is a picture where I have the entire board in the shot and if you zoom you could actually see the voltages and uF ratings of the larger caps. The small orange reddish ones are 220pF (104 labeled) caps. (Just a FYI) Thanks all for your time.

 

Yes, post the pics. I dont know how similar the older JBL amps are? Mine is a 2006 model and I've read that from 2009 and up toyota changed the connectors of the amp but not sure of the internals.

 

Okay, sorry for the delayed response. I didn't realize someone wrote back. I will post them up shortly.

 

In this picture you are going to want to swap the red capacitor labeled 104 somewhere on it which is semi covered in glue. The one that is in between the two large blue (or black) capacitors. The top of the capacitor needing replacement is marked in black. Beware because I marked three of them but only two need swapping. If you cannot understand these instructions I will provide you a picture with an arrow of which one needs swapping!

If if helps at all, you are going to want to ignore the red capacitor which I accidentally marked black at the further bottom left of the board. Ignore it, leave it alone, don't touch it! Lol



You want that 104 labeled red looking resistor that is right in the middle of the picture. Swap that out with the one which typically comes with your aftermarket speaker.

Again, it's the one in the middle, it too just like the first one I marked has black ink on the top of it indicating it is the one that I want to pull out.

 

Did you just run an additional amp and added another sub to the JBL sounds system? Im interested in adding a better sub, but not sure how I would go about it with the JBL system installed... noob at car stereos

 

Ya Im running a high level output converter off the stock jbl amp, to another amp which powers my sub.

more details here
http://www.tacomaworld.com/forum/audio-video/291173-10-jl-w0-double-cab.html

 

Are you still running the stock sub TRD Toy?

Edit, NVM, all it took to find out was one click.

 

you the man, thanks!