Preamp signal from Stock headunit

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Old 06-03-2004, 08:41 AM
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Preamp signal from Stock headunit

Has anyone used this from the stock radio to feed an amp? I'm not talking about the speaker level outputs, i'm talking about the wires that go to the bose EQ. I know some people have tapped these wire for the preamp signal.

My question is, there is just two wires, "left" and "right", which would be the positive wire for each speaker (left and right). What do you use for a negative for each speaker?

I'm working on this today, so if anyone can reply today that would be great.

thanks..
Old 06-03-2004, 11:42 AM
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anyone?
Old 06-03-2004, 01:24 PM
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i had done it on mine, but i found the signal strength to be weak. when i replaced the stock deck with my alpine all was well. but if you must keep the stock deck, the wiring diagrams are here:

http://users.adelphia.net/~krisnlore...o/schframe.htm

you will want to use the blue/green and orange/blue wires coming out of the EQ box. if you don't know, the amp is behind the back seat. easy to get to, just have to be patient. like i said i found the signal to be weak. maybe i should have taken it from the deck *before* the EQ instead. or right from the rear speaker signals. that's probably your best bet because it will generate a signal more proportional to the interior volume of the car. just follow the diagrams and you should be ok. let us know if you need anything else.

SSTS
Old 06-03-2004, 01:40 PM
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SatinSilver,

Where did the schematics come from? I wonder if they will be available for the '04 soon?

If I'm reading it right, it looks like there is no need open anything up. Just intercept the signal between the head unit and equalizer. That daynamic equalization can drive you batty.

As far as the weak signal, there is always the line driver option.
Old 06-03-2004, 02:13 PM
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i plan on tapping the blue/green and orange/blue wires for my install. what would cause the signal to be weak? how much will it affect the performance of the sub?

what is the line driver option?
Old 06-03-2004, 02:53 PM
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Originally Posted by 999999
SatinSilver,

Where did the schematics come from? I wonder if they will be available for the '04 soon?

If I'm reading it right, it looks like there is no need open anything up. Just intercept the signal between the head unit and equalizer. That daynamic equalization can drive you batty.

As far as the weak signal, there is always the line driver option.
the schematics were graciously posted here by another member. i am not sure who though.

i did have a Line Out Converter cranked all the way up on it but i still don't know why the signal was weak. as far as a line 'driver' is concerned, i did not try one. (Vtec11, you will need a line out converter for hooking a set of RCA cables up. you can get it in circuit city/best buy)

the downside to the weak signal (to answer your question vtec11) is that the sub did not pound very hard. it was there, just not booming like when it's hooked up to my alpine. and im running a 350W (@4ohms) mono amp on it. so it's not like it was power starved. like i said before though and as steveinathens said, get the signal *before* the equalizer. it may be stronger and sound clearer. i should have done this in the first place i guess. good luck!

SSTS
Old 06-03-2004, 03:39 PM
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Steve,

With the amp and sub you have, you probably will be fine unless this signal is REALLY weak.

A line driver takes a weak signal and boosts it significantly. RCA in and RCA out. It sends a stronger signal to your amp. Aside from more signal to work with, it sometimes helps to cut down on noise becasue noise picked up along the way is a smaller % of the total signal. In your case, noise is probably not important because most noise is at a high frequency and you will be filtering that out with your low pass anyway.

Personally, I would try it without and add a line driver later, if necessary.

Here is an example of one on ebay http://cgi.ebay.com/ws/eBayISAPI.dll...702644036&rd=1

Here is David Navone's site. He is somewhat of an automotive electronics cult figure and sells LOCs, line drivers, etc that he develops. I have heard that the Soundgate LOCs are his. http://www.davidnavone.com/linedrivers.html
Old 06-03-2004, 04:17 PM
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that sounds fair enough 9'er, i could always try it first and then if i was unhappy with the results I could add the LOC later. i want to keep the number of times i do this to a minimum... hehe

what worries me is that SilverSatin said he had a LOC in the mix and still was unhappy with the strength of the signal. i THINK was SilverSatin was saying was that he wasn't 100% happy with it until he replaced the stock HU...
Old 06-03-2004, 05:06 PM
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Steve,

The LOC just takes the speaker level and converts it to a pre-amp like level. You will be starting with the preamp signal, I think. Definitely get the signal before it gets to the equalizer. A line driver is a different animal from a LOC.
Old 06-03-2004, 05:44 PM
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i gotcha....

my biggest problem now is that i wanted to pull this off without having to break open the center console. if i have to do that, i'm just going to pay somebody to do it cause i'm not THAT comfortable with my skills...
Old 06-06-2004, 11:20 AM
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finished the install yesterday, here it is:





install went pretty well. sensitivity is not even turned up half way on the amp, so i'm happy with the signal i'm getting from the headunit.

thanks for all the help
Old 06-06-2004, 11:55 AM
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Acura Bose EQ

Does anyone have a stock EQ for an 2000 Acura 3.2 TL that they are not using and are willing to sell?
Old 06-07-2004, 11:29 AM
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steveinathens, congrats on the awesome install! im thinking about going back to the stock HU with a blitzsafe for my CD changer and using a line driver for the sub amp. i just get paranoid about theft when i have goodies in the car. i dunno. so the sensitivity is halfway up and it still slams? what lines did you tap into?

SSTS
Old 06-07-2004, 11:32 AM
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Originally Posted by steveinathens
that sounds fair enough 9'er, i could always try it first and then if i was unhappy with the results I could add the LOC later. i want to keep the number of times i do this to a minimum... hehe

what worries me is that SilverSatin said he had a LOC in the mix and still was unhappy with the strength of the signal. i THINK was SilverSatin was saying was that he wasn't 100% happy with it until he replaced the stock HU...
this is true, but there seriously was no signal when i tapped it. but i am still willing to think i just tapped the wrong lines.
Old 06-07-2004, 11:36 AM
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Steve. it looks good. How does it sound?

On mine, I'm goiing to build a sub box to fit where your amp is.
Old 06-07-2004, 05:37 PM
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SatinSilver,

I tapped the BLU/GRN (+) and ORN/BLU (-) wires that go into the stock amp. they are in the brown sheath. i just took a long RCA cable, pulled it apart into two wires, then cut the tip off one. fit to length, then spliced the above wires to the proper wires of the rca cable. ran the rca cable into a Y splitter then into my amp. the signal seems fine to me, honestly, considering what i'm doing with it and all. the input sens on my amp is up about 40% of the way, i.e. not even halfway up, so i definately have room to go up, but i find its not nessessary. even at 40% it may be a bit much depending on the music. as far as does it slam? well, that all depends on your def of "slam". i'd say it hits very very good at certain frequencies, and not as strong on others, which i suppose is normal for a box like that.

9'er,

thanks for the help. i'm very happy with the results. considering what i did, which was just replace the stock sub, it sounds great. i can definately tell a difference. the infinity 10 hits MUCH deeper, cleaner and stronger than the stock amp, however i can tell that there is a "dead spot" in the midbass area of the spectrum compared to the stock sub. maybe dead spot is a bad term, i just mean that there seems to be a dull spot between what the sub hits hard on and where the stock door speakers take over. i'm sure the stock sub was eq'ed just right, so i think this dull spot will go away once i replace everything else. on the other hand, i feel that the new sub seemed to "clean up" the highs and mids. perhaps because of that dull spot in the midbass, the highs and mids are a bit more pronounced. there is absolutely no noise in the system so i was very happy about that.
Old 06-07-2004, 05:50 PM
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Steve,

I'm not sure where you have that sub crossed over, but you might sneak up to 120 or so to help out. You may not be able to help the midbass much without more power. However, it would be cheap to find out. The Infinity Refernce 6.5 componenets and coaxials go pretty cheap used on Ebay. Wouldn't cost mcuh to buy some, try them and re-Ebay them if it doesn't help. If you do that, try to get the ones with silk tweets.
Old 06-07-2004, 06:04 PM
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sub is crossed over at 200 ( the max ), basically getting the full signal from the stock EQ. the JL does allow for a variable boost at 48hz, which i've played with, and definately helped, gave kick drums more punch

i agree that i may not be able to help out the situation until i replace the door speakers. and i'm fine with that for the time being...
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