So I'm looking at headunits. Before I buy one, I have one question. To bypass, or not to bypass the JBL Amp? The stock sub in my system is blown, rattles whenever there's a hint of bass, and i'm not sure if I should keep it or not. I want to keep the car as stock as possible, but I also like my sound. I've never liked subwoofers, I want bass to come out of the speakers equally, not from one big box in the trunk. But there's where the issue comes in. If I bypass the amp, and disconnect the sub, will I have ANY bass out of the main speakers? Down the line, I might replace the speakers, but I'm not sure if I want to yet, just out of keeping it stock. But I'm just asking this because I'm not sure what to buy (adapter, and headunit wise). In your opinion, in this car, should I bypass, or keep the JBL amp in use?
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- Thread starter Roboplex
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TBirdJKC
Registered User
The JBL speaker amp has a crossover built into it. You will not get any bass from that amp regardless of weather or not the sub amp is hooked up. If you want full range to your speakers, and still retain a stock appearance, the "Premium Audio" amp is your only choice.
That being said, I wouldn't run full range through those JBL 2 Ways anyway. They're only good down to maybe 100hz. So if you turned it up even slightly they will distort trying to produce any kind of mild bass.
Personally I'm not a fan of the amp bypass harness to run speaker power from an aftermarket head unit. Just because I don't like pushing actual current though those super thin audio input wires that run to the amp. I have used the amp bypass to avoid cutting up the factory harness to run an aftermarket 4 channel amp. I cut the bypass harness in half and ran the wiring to the corresponding inputs/outputs om my aftermarket amp. That seemed to work out well.
That being said, I wouldn't run full range through those JBL 2 Ways anyway. They're only good down to maybe 100hz. So if you turned it up even slightly they will distort trying to produce any kind of mild bass.
Personally I'm not a fan of the amp bypass harness to run speaker power from an aftermarket head unit. Just because I don't like pushing actual current though those super thin audio input wires that run to the amp. I have used the amp bypass to avoid cutting up the factory harness to run an aftermarket 4 channel amp. I cut the bypass harness in half and ran the wiring to the corresponding inputs/outputs om my aftermarket amp. That seemed to work out well.
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OldZofTorC
Registered User
My 2 cents
The JBL system was designed to work in each individual model of car.
If you would be satisfied with the power of the factory system then it would be hard to beat.
With that in mind it sounds like you need to re-edge the subwoofer. That will involve splitting the enclosure to get to the speaker.
Orange County Speaker sells kits to re-edge.
You would also want to look for the factory cd receiver or run line level from an after market head unit.
I am in the same boat and will help you locate the kit and modify the wiring harness for after market.
It would be less technically difficult to go after market head amp and speakers.
However i would want to use a sub woofer because once you get rolling the road noise buries the low frequencies.
The JBL system was designed to work in each individual model of car.
If you would be satisfied with the power of the factory system then it would be hard to beat.
With that in mind it sounds like you need to re-edge the subwoofer. That will involve splitting the enclosure to get to the speaker.
Orange County Speaker sells kits to re-edge.
You would also want to look for the factory cd receiver or run line level from an after market head unit.
I am in the same boat and will help you locate the kit and modify the wiring harness for after market.
It would be less technically difficult to go after market head amp and speakers.
However i would want to use a sub woofer because once you get rolling the road noise buries the low frequencies.
TBirdJKC
Registered User
That's what Ford claimed, but Lincoln's were really the only vehicles that got their own system per model. My moms old 94 Crown Vic and my girlfriends explorer all have the same part number on both JBL amps and the speakers as my 95 Thunderbird. The sub enclosure and speaker location are the only things that differ.
Is it true that the JBL systems would automatically tweak loudness based on road speed/noise?
TBirdJKC
Registered User
I should correct myself here. I'm referring to Ford JBL systems 95 and older. Ford started making some changes to the systems starting in 96. Mostly cost cutting decisions.
You're right. I think I'm going to keep it stock for now (except the head unit), and just get the adapter for converting the amp plug to RCA. So what I'm understanding is that I should buy a headunit with 4 or 6 channel preamp outputs, and then just attach the adapter. TBH, I'm not even sure I'm comfortable with doing much else at the moment (like speakers). I just don't want to screw anything up. Maybe I'll try fixing the amp since it's already pretty screwed up xD.
Here's the head unit I'm looking at:
http://www.crutchfield.com/p_613HD262U/Kenwood-KDC-HD262U.html?cc=01&tp=5684
And the adapter:
http://www.crutchfield.com/p_120705510/Metra-70-5510-Receiver-Wiring-Harness.html?tp=2977
SuperCoupeDave
Registered User
I tried the JBL amp bypass, and it did not sound good at all. Also had to turn the volume way up to get good sound out of it. So I hooked it back up to the JBL amp, and it is much much better. The stock Sub sucks though. Zero bass.
Ill see if I can save up for a new sub then. If it doesn't sound good fixed, then I shouldn't try to repair it. I should be able to just connect a new one without replacing anything else, correct?
90tbird4.7l
Registered User
just go to the junkyard and pull the stock premium amp out of an LX. i swapped one into my SC and it sounds great
I've already got the premium amp xD. I must've forgot to mention it.
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