JBL Premium Sound Q's Again...

Tim Groth

SCCoA Member
I've read every post on here about the JBL Premium Sound problems and I am well aware of what they are, however no one has explained what is needed when replacing the system with an aftermarket unit.

First off how the system is wired from factory the cabin speakers receive only mids and highs and then the trunk mounted sub pushes the bass...My deal is that right now I only have mids and highs for like many others the sub blew out and I removed it to get rid of the terrible shrek it made ever time a bass note cut in or out. So if I were to replace my deck so all the speakers worked at one time I would still only have just mids and highs...and when you listen to primarily Rap, R&B and Alternative...its not cool to say the least!

So with that being said, if I replace my deck is there anyway to rewire the cabin speakers so they too have some bass? I'm not much into having a "system" but I do like to hear all of the notes in a song and right now I can't. Its embarassing to say the least right now when listening to music and 50 Cent sounds like Mariah Carey!

So the question is, will I have to rewire my interior speakers with the preamp outputs on the new deck in order to receive the low notes or can I splice some wiring and get the same effect without as much work.

Thanks in advance.

-Tim
 
Wasn't exsactly what I was looking for but it did help, and I am greatful for your time and post in hopes of helping.

I guess I can either stick with the factory wiring or replace the entire system when I do my application. I'm thinking right now that is the case unless someone eles tells other wise...

Thanks again.

-Tim
 
probably the easiest way to do it is to go in the trunk where the amp is mounted and find the in and out wires. If you have a wire tester you can figure out which wire is which. If i had my car I could go look at it and find out at least the input side for you in a couple minutes. anyways.... disconnect the wiring harnesses from both sides of the amp. Once you've found the correct sets of wires, you can simply splice a short piece of speaker wire into the input and bridge it over to same speaker amp-output wire.

So essentially you're just using speaker wire to bypass the amp.

If you have questions about it feel free to e-mail me @ oxygeno2@juno.com

or IM: oxygen822


Good luck,
 
Tim,

I took out the JBL box as well. What I did was remove the entire bracket and remount the sub amp underneath the other electronics. the mounted a 10" sub freeair where the old JBL woofer was. I also replaced my head unit with an Alpine and just used the standard wiring harness from a audio store.

I felt the same way you did and this solution sound good without disturbing everyone within 1 block of you
 
Tim,
I replaced my factory unit with JVC which is CD, CDR and MP3 compatable and like I said earlier I bought it from sounddomain.com and the also sold me the correct harness which was just $4.75 compared to around $10 in walmart and my unit costed me $129 # shipping and http://shopping.com/ gives you great comparison of prices. Looks like you can get a pyle 10" sub for around $15, I bought mine from sounddomain for 28 open box the shipped me all three for one shipping price.
 
Yes you can replace the head unit with an aftermarket unit and still use the factory wiring harness.

Had the same problem as everyone else - blown factory sub. Took out the OEM box and opened it up - removed the factory sub and replaced it with a JL Audio 8" sub - sounds great. had to gring out all the extra plastic and make new mounts for the sub, but worth it.

For my head unit I installed an Alpine 7940 - this is a CD head unit with no internal amps. I bought harness' off ebay for less than $10 to mate to both the power connector and square plug for the speakers. Made my own custom harness by matching the wiring and soldering together with the Alpine connector and RCA jacks.

If you understand wiring diagrams and take your time, you can adopt almost anything.

Check out 35th Tbird Registry - he listed wiring diagrams for premium and JBL systems.

Good luck.

Mark
'93 SC
 
Head Units & Truth in Advertising

Originally posted by Tim Groth So the question is, will I have to rewire my interior speakers with the preamp outputs on the new deck
A few basics here. Preamp outputs are exactly that, PRE-AMPlifier. They are low level signals & will not drive speakers. You must connect the low level preamp signals to a power amp. The power amp then amplifies the signals enough to drive speakers.

You may select a head unit that has a power amplifier built into it. Those head units are typically in the power range of 4 x 25.

Don't believe all the fantastic power claims made by the manufacturers. They ALL play number games that make their products appear WAY more powerful than they actually are. Home stereos must (by law) be rated with both channels driven at a continuous RMS power level, at a specified distortion level. No such law exists for car stereos. Sure a car amp might put out 1000 watts of power for one thousandth of a second, @ a distortion level of 80%, but that doesn't mean it's a good amp!

Example: My home stereo amps (Yamaha MX-1000's) are rated at 330 RMS Watts per channel @ .0001% Total Harmonic Distortion, Class A. They cost about $1,000 - $1,500 (in the USA) new.

My car sub amp (Kenwood KAC-929) is rated at 1000 Watts & cost $125!!!!!!!!

If the Kenwood amp actually IS a 1000 watt amp, why isn't everybody using them for home stereos? $125 sure beats $1,000 - $1,500!!!!!!!! The reason is, that the Kenwood is actually approx. 75 RMS Watts per channel @ .1% THD at 12 volts!!!!!!

68COUGAR
 
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stereohead

have the same problem with my jbl system (omong others) anyway from what i can see the door speakers and the speakers in the back look descent but why the hell are they crossed over way to high it seems the amps jbl provided ford with are worse than a jenson 1500 watt with rms output of 2 i would start from scratch with the amps and head unit also why does everyones sub blow mines pretty much blown to either noone understands that when the speaker sounds like a fart rather than bass to turn it down or once again jbl used the bottom of the bucket amps these amps are no testament for sound quality they have no crossover control and no gain controll in my opinion jbl really lost an opertunity to make a name for themselves with wokin with ford im sure ford didnt wanna go overboard in price but im assumin when the cars were bought new this was an expensive option i have no use for jbl in the car stero world this just makes that opinion worse for me anyway eventhough the amps look nice whats undernieth the covers is junk! through them away i know its hard to do by the looks of them but trust me its a front and by the way anyone pull the foam off the top of the sub box after they got it out and se the sub somim you could get at radio shack
 
hmm whats this

i have something called "aheadX" i think it bypasses the amp somehow without me messing up the wiring.. its a little elongated box with two potentiometers on it.. anyone else heard of or seen this thing.. i never put it in there. im just trying to understand my system myself. right now only my rear speakers are workinhg.. i dont care for now cuz the door speakers are blown OEM.. so no tears.. how ever when i get new ones i hope they would work... my 5 by whatevers in the back sound ok they have a fullrange while still keeping the amp plugged in. my car is an 89 sc it just says premium sound so ithink the amp is being bypassed somehow..later
 
havent been around scs enough to really know the difference between the premium system and the jbl system but i am assumin the premium sytem doesnt have the jbl amps sounds like to me if the front speakers arent working at all that there is probably a blown cannel either in the head unit (radio) or the amp what you need to do is get a scematic from either a junk yard or a ford dealer (they should just print ya one out for free) and then unplug the amp make sure that all the speakers run throught the amp if so then use you scematic to cut the speaker wires and jump to the other 2 channels and see if your fronts start workin if you do this at the amp which is probably easier and it works then you know the head unit has a blown channel if still no fronts then the amp is bad
 
Premium vs. JBL

35th T-bird SC said:
What's the difference in the premium sound and the JBL sound.
The JBL got the subwoofer & JBL amps. Premium = w/o subwoofer. If you ordered the OEM CD player, JBL was MANDATORY.

You'll get a LOT more bass, if you replace the OEM JBL sub driver, with more robust 6.5" driver. Since a 6.5" sub isn't very big, I decided to put the best 6.5" Sub I could get in the box. I put a JL driver in my OEM sub box & got more & better bass. Because the JL driver was deeper than the OEM, I had to trim 3/8" off the legs that support the bottom of the speaker magnet. There is enough room in the enclosure that you could install a nice low pass filter in there, to cut out some of the mid-bass & midrange out of the sub.

68COUGAR
 
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68 cougar

hey if im not mistaken the amp should have a low pass filter in it and are you talkin about a low pass coil in the box or a passive radiator assumin that you are talkin about a low pass filter coil then the amp maybe doesnt have a low pass crossover in it if thats the case then the original jbl sub is not a sub but a full range woofer that would explain why they all blew up woofers that actually put out some bass never have been able to handle full range sound to much movement at one time the coils just overheat when put under pressure i would say that the jl audio sub was a good choice cause the original box is actually about the right size for the air pressure those subs are designed to run at assumin you bought a w1 that was also another reason that it works well cause those are very efficient for power and lets face it those amps aint no workhorses i can appreciate what you did there cause it kept everything nice and neat and out of the way from what i can tell by lookin at the seprates in the door the interior speakers should be capable of much more than what there runnin at crossed over the way they are stock with the four channel amp the cheap way to improve the sound a lot woulbe to buy a descent cd player or replace the 4 channel amp for the interior speakers with a descent one that had crossover controlls some of the actually most of the newer cd players got descent power in which case you can bypass the amp and get more full range sound the seprates are designed to carry some mid-bass and a capable of so much more sound than what there gettin stock im sure of it the only problem is you cant controll the gain on sub amp either so if the sub doesnt blend with the interior speakers with bass then theres nothin you can do you end up doing what i started tonight replacin everthing but the interior speakers and them to if they dont sound like i think there gonna im all about a great soundin system though im puttin 2 alpine r-12 subs and 2 keenwood kac-600 amps in the trunk tommorow if the interior speakers cant keep up then there gonna be replaced also they will be under power with an alpine v-12 amp aproximately 75 watts to each speaker with some mid bass so well see what they got ill let ya know thanks
 
heres the scoup

replaced the head unit put both subs in ran the front 2 speakers to the head unit put an amp on the back 2 speakers interior didnt keep up took1 sub out sounds descent pretty descent actually running all interior speakers full range the interior speakers do need power there good to go with about 30 watts rms a piece. is it worth spendin the money on new head units and amps for the interior speakers no cheap way to get good sound with these is to just buy a new sub and amp for it 1 10 or 1 12 the only thing you would have to do is buy an inline converter for the new amp converts speaker wire outputs to rca outputs this imput going to the original sub amp carrys the remote turn on and 1 channel of speaker output so you would also have to get 1 pair of rca splitters use the power wire for the old sub and ground it yer all set to get it really rockin i would replace everything the interior speakers dont really have the output you would need for a high end system
 
Punctuation & Complete Sentences

belucky said:
replaced the head unit put both subs in ran the front 2 speakers to the head unit put an amp on the back 2 speakers interior didnt keep up took1 sub out sounds descent pretty descent actually running all interior speakers full range the interior speakers do need power there good to go with about 30 watts rms a piece. is it worth spendin the money on new head units and amps for the interior speakers no cheap way to get good sound with these is to just buy a new sub and amp for it 1 10 or 1 12 the only thing you would have to do is buy an inline converter for the new amp converts speaker wire outputs to rca outputs this imput going to the original sub amp carrys the remote turn on and 1 channel of speaker output so you would also have to get 1 pair of rca splitters use the power wire for the old sub and ground it yer all set to get it really rockin i would replace everything the interior speakers dont really have the output you would need for a high end system
WOW! All that information, & only 2 sentences!

What do you mean, "the interior didn't keep up"? Are you attempting to say that you now need a custom acoustically designed interior?

Confused 68COUGAR
 
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nope

the interior speakers arent loud enough for the bass i added the bass was drowning out the interior speakers in short to much bass the interior speakers would need to be replaced and more power added for a high end system posibly if ya retrofit some 6by9s in the rear deck and put power to those itwould sound ok but the interior speakers would then have to keep up with them also and they wont period.
 
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