Simple audio question:

HMGanja

NAXJA Forum User
Location
N.C.
So do you have to install a aftermarket head unit to run an amp/subs? Or can you wire the amp to the stock cd-player? BTW: '99 Limited w/factory amp Excuse my lack of electrical knowlegde...
 
You can use the stock radio. Here's one way to do it:
a) cut the speaker wires from the harness that plugs into the amp under the rear seat. You will need to cut 8 pairs of wires: 4 pairs incoming into the original amp; 4 pairs from the original amp to the speakers.
b) install speaker level to RCA converters on the wires that went into the original amp (or buy an amp with speaker level inputs).
c) plug the RCA connectors into the amp.
d) run speaker wires from the amp to the wire speaker output of the original amp under the seat.
e) run power wires to the amp.

I don't have the wire colors for the connector into the original amp on hand but can get them for you if you need them.
 
LOL, you lost me at "b)". Let me tell you what I got. I have a Rockford Fosgate P3001 amp mated to 2 Kenwood 12's. They were originaly in my 88 GT that I just sold. Unfortunately I didnt get to keep the power wires. Anyway, what do you mean by speaker level inputs? Sorry for the ingnorence.
 
Nah I think you should just send me your CD player before you let all the magic smoke out of it.:looney: Then get yourself an aftermarket one lol. Sorry couldn't help myself.
 
HMGanja said:
LOL, you lost me at "b)". Let me tell you what I got. I have a Rockford Fosgate P3001 amp mated to 2 Kenwood 12's. They were originaly in my 88 GT that I just sold. Unfortunately I didnt get to keep the power wires. Anyway, what do you mean by speaker level inputs? Sorry for the ingnorence.

There are 2 types of inputs into an amplifier: RCA inputs (the round connectors) and speaker level inputs (the wires from the back of the stereo). Look at the input on your amp - does it require the RCA connectors or can you use the speaker wires as inputs? If your amp does not allow speaker wire inputs - then you have to get the line level converter to change from speaker wires to RCA inputs.
 
True, you can make do with a line level converter but the sound quality is not going to be the best. But then again if you are running a factory head unit, sound quality is probably not priority. Also, you will need to splice into the existing rear speakers which means that any time you adjust the rear speakers you adjust the signal going to the amp. Not ideal
 
Wow, it does sounds like its not going to be ideal. The only reason I even ask is because I like the way the stock unit looks. I hate the way a aftermarket cd-player just jumps out at you. But I dont want to damage the stock unit. So it sounds like im biting the bullet on this one. Theres another $250...
 
you could also get an amp that will take line level input, it has been a while since i used to install these on a regular basis but we used to have amps that took line level input, I dont know if they are still available. I am seeing that suggestion was made (i should read all the posts)

google is your friend

http://www.abtelectronics.com/product/22169.html

the speaker level inputs allow you use your speaker output from the factory head unit and redirect it back into your pseakers with much better sound quality and power. you can the hook up your sub to the sub output.

i am not as young as you guys are so its been a while since i bombed a sound system. I prefer my power under the hood but this setup should allow you use your factory sound sytem fairly easily.

on that note i have an apine head unit i would mind trading for the factory system from a 98 in anyone wants and upgrade for their system. i too like the factory unit better, the alpine came with the xj it is xm ready
 
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Well, the basic question has already been answered--no, you don't need an aftermarket head unit to run amps and subs. Would it behoove you to do so? Of course. With the stock head unit, all you're doing is amplifying the crappy O.E.M. sound, and you'll be doing it at the speaker level, which is noisier than line-level outputs, especially today's higher-voltage outputs. If you decide to look at aftermarket head units, look into the line-output voltage--essentially, the higher the better (expressed in actual volts, NOT millitvolts). Decent ones have outputs in the 2 volt range, with the good ones at 4 volts.
EDIT: It just occurred to me to let you know that car audio watts aren't legally regulated the same way, nor as strictly, as those for home-audio systems. Beware unusually high wattage claims from unusually small packages.
 
Man, you guys are full of knowledge! I never even knew they made such a thing. I think I may try it after all. I mean, all I want is a little bass. Im only going to use 1 of the 12's anyway. Thanks again.
 
HMGanja said:
LOL, you lost me at "b)". Let me tell you what I got. I have a Rockford Fosgate P3001 amp mated to 2 Kenwood 12's. They were originaly in my 88 GT that I just sold. Unfortunately I didnt get to keep the power wires. Anyway, what do you mean by speaker level inputs? Sorry for the ingnorence.

There are two versions of amplifier audio input (referred to as "outputs" from the head unit also - so it gets a bit dicey sometimes...)

"Speaker-level input" - this input will accept a direct audio input from a speaker signal output without letting the blue smoke out of something (a Bad Thing (tm).) Speaker-level signals are higher voltage/current than "line-level" or "pre-amp" signals. A "speaker-level" input will allow you to use the speaker lines to feed your amplifier, as mentioned.

"Pre-amp" or "line-level" input (also called "preamp output" on the head unit.) These are signal lines that have a bit lower voltage and current than speaker-level signals, and are usually a bit "cleaner" (in an electrical sense) than the speaker signals. These are usually indicated by seeing RCA jacks on the back of the head unit, but may also take the form of a terminal strip. Pre-amp signals will always be labelled as "Amplifier Feed" or "Amplifier Output" or something like that, as they cannot be used for speakers (they don't have enough signal to drive the coils in the speaker.)

Check your amplifier - if you have speaker-level inputs, they'll be labelled as such. If you do not, and you do not have pre-amp outputs on the back of your head unit, you're not done yet...

You can get what's called a "line converter," which will take the speaker-level signals and step it down to a "pre-amp" level - which will allow you to connect your amplifier without blowing out something important. Here are some examples:

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=302-307

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=265-025

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=265-026

This should give you a better idea of what you're dealing with. If you're not sure, you're probably better off getting a line converter and using it to convert your speaker lines to a line-level signal, and using that to drive your amplifier.

If you're going to use your amp to drive subwoofer drivers, you'll want a crossover (low-pass filter, cuts off high-frequency signals, and cleans up your bass) to filter the signal going to your amp. If your amp is set up to drive subs, the crossover should be built in to the line-level input section - but I'm not sure about the speaker-level section, if any...
 
Thanks bud. What I got is a "Install Edge.com" IEC AULOC Adjustable line output converter. 2-60watts. It seems to be well made and compact, and by Rockford Fosgate. Could you maybe explain excactly how to hook this up to my factory amp? It has 2 gray wires, 2 white wires, and 2 little brown wires. Could you tell me which color wires on my amp to hook these to? It is highly appreciated!
 
HMGanja said:
Thanks bud. What I got is a "Install Edge.com" IEC AULOC Adjustable line output converter. 2-60watts. It seems to be well made and compact, and by Rockford Fosgate. Could you maybe explain excactly how to hook this up to my factory amp? It has 2 gray wires, 2 white wires, and 2 little brown wires. Could you tell me which color wires on my amp to hook these to? It is highly appreciated!

Did you not get rules with the thing? If not, give with an actual model number (should be on the case somewhere...) and we'll see what we can dig up. I just don't want to guess - and end up with you connecting the thing backwards or somesuch...
 
not to be a smartass or anything but it might be adviseable to go to circuit city or best buy and maybe ask one of those guys if they could do after work on the side so as not to blow up your unit cause than your back to square one but the good news is if you do blow it and have to buy another one i belive the install is free good luck is it possible that your name has anything to do with why your having so much trouble lol sorry man im kidding i just couldnt resist i was also a long time student of the ganja
 
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why would you be installing an amp is sound quality isnt that important? if you dont like the way most aftermarket HU's look browse through the crutchfield catalog. im sure you will find one that will match your interior. you also get an instruction manual with it.
 
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