dillyyo

From what I have seen, the four channels are fed into the main amp and then another set of signals goes from the main amp to the small, rear deck woofer amp. The signal going to the small amp is most like processed and has a low pass put into it as the rear only plays lower frequencies.

cartman13

Doesn't the woofer amp feed the door speakers? They way I understand the system is that it's a "backwards system" with the woofers up front and only mids/and highs on the rear deck? Maybe i'm misunderstanding what is meant by rear deck?

I know, not all that useful, but just trying to alleviate my own confusion.

dillyyo

As far as I know, the small amp feeds the rear deck, which are woofers. Maybe someone can verify this, but thats how I remember the schematics. I'll have to look over again.

Yup, I just verified it. Look at page 370 of the audio video section. It clearly shows a flow diagram with the small amp sending a signal to the rear woofer, which is on the back deck.

fmrlegend

"Pull the wires from the input of the amp and solder the RCA right there, unless you need longer wire than you will have to use different wire to make it longer and then solder the RCA's to the extension. Remember, there are 8 wires coming from the HU: FL, FR, RL, RR, a positive and negative for each. If you are keeping all of your speakers and just trying to add a sub and amp, then you need to pick a pos and neg set to tap into. Realize though that you will be only taking signal from one channel, but won't really matter since sub frequencies are usually run mono."



This is a very helpful thread. If I can jump in ask if we take a signal from any speaker line for the sub-signal, would that decrease the level of power going into the speaker that was just spliced in? Or is better to take the signal from the line after the big amp but before the small amp?

Also, does any one know if the AV control unit diagram posted earlier is a good representation for a non- navigation system?

sumo8me

Okay sorry, i'm new to this stuff and i've read this thread like 4 times and im still a bit confused. So i know you dont need a DSP or anything because the signal is flat coming from the headunit to the factory amp so all you need to do is tap into the signal before the amp. Is a high/low converter still necessary? i know those things like cleansweep have a high/low converter in it, but will you still need the high/low converter by itself? Someone told me they recommended getting one to clean up the signal a little more. Just trying to get the facts straight. thanks!

fmrlegend

Same here, I read this a few times and still a bit fuzzy about where to take the signal from.

MaxToTheG37

iTrader: (3)

Use a Hi/Lo coverter until this RCA solder way is up in there air and needs to be confirmed... so just use a HI/LO for the time being if you cant wait... thats what I did....

fmrlegend

Thanks, one more question. Where should I draw the signal, HU, after the first amp before sub amp or after sub amp and where is the amp located?

Thanks

preageng

Alright I have got a problem now that I have installed my amp and sub following these instructions. I may have misunderstood something along the way.

I tapped and soldered directly into the wires 8 & 9 on connector B43 and ran this directly my amp. It works okay until I get the volume up to about half way and then the sub/amp go flat with nothing coming out. I think it is some issue with the signal coming into the amp, but I can really get my voltmeter to register. I have a JL Audio 500v2 with a 10w6v2.

I don't have a High/Low converter on it because it is the signal going into the bose amp and my amp is supposed to to be able to step down the signal when you have the signal setting on the amp set to high. I know it has to be something to do with the input side, because I can adjust the amp up and it will hit really hard when the car is set at a low volume, but even if I turn the amp all the way down and turn the car audio up it will cut the signal coming out of the amp.

Questions:

1. HELP( Really a little frustrating, because I can get my voltmeter to tell me what signal is coming into the amp.

2. Do I need to get a Hi/lo convertor, because I didn't think I would need one based on which wires I spliced into to get the signal.

3. Should I change to different wires? (Possibly lines 1&2 and lines 4&5 on connector B43?)

Any suggestions are experience on exactly what you did would be greatly appreciated.

dillyyo

First, what do you mean you tapped and soldered? Is the harness disconnected from the bose amp? I am not familar with the Jl amps, but you stated something about it was set to high. Do you mean that the amp has a switch to either take a high level signal or a low level pre-amp signal? If so, you need to have it set to low as the signal coming from the Bose HU is a low level signal. The reading on a meter would be in the mV range. Some more info would be helpful.

Did you adjust the gain structure on the JL amp? A possibility is that the main amp is sending an EQ'd signal to the small amps wires that you tapped into. This is why I didn't think you should tap from these wires. I think all of the EQ'ing is done in the main amp and as you turn the volume **** up, it starts to defeat the lower octave frequencies. Try turning your output mode to full range and turn off your infrasonic filter, bass EQ and your LP. If it doesn't cut out completely and you just lose bass response, then you can be sure that it is the AMP EQ'ing the signal that your JL amp is receiving. You would then have to tap into the one of the main signals coming into the main amp.

preageng

Thanks for the quick response.

The harness is still attached to the bose amp. I just spliced into the wiring for connectors for a connection( Wires 8&9 from the schematic provided earlier in the thread). Yes my JL Audio has a selection switch for either high level or pre-amp level inputs (This is why I don't think a high/low convertor would be needed even if I do connect to the bose amp on the output side) I have tried to set it to low but the amp just completely seems to cut out at low volume setting. I will try setting it to low tommorrow and seeing if I can get my voltmeter to read mV.

It is just weird to me how when I turn the volume on the car to certain level the sub just completely shuts off with no output at all. Then if I turn the volume down and wait a few minutes it will comeback on. It is as if a circuit is tripping within the amp at a certain input voltage. I know it is not an output issue or being loud because at a low car level volume I can turn the amp up and it will hit way harder than I would ever want, but even if I have the amp turned all the way down when I turn the car speakers up to about half way it just completely kicks off. I am guessing it is something to do with the signal coming through these particular wires. I am assuming it may be best just to connect my inputs for my amp to the outputs of the Bose sub amp. Does this sound appropriate and I am also assuming that I will not need a high/low convertor, because I believe the JL 500/v2 has one already in it.

Please let me know if this sounds correct and also if you have the amp in a G37 ( Which I know a bunch of you do ) and how you have it connected exactly and what kind of settings do you have on your amp.

I am really pretty good with wiring and electronics just never messed with car audio that much and I am trying to grasp all the settings on the AMP. Also I am guessing from some info I have read I need to get a bass test CD. Something with Sine wave signals.

dillyyo

Sounds like you are either shorting out the amp somehow and tripping the protection circuit or the signal is eliminating sub bass frequencies. I would not take the signal from the output of either amp. I would take a signal before it goes into any amp. This way you should be able to use the LOW input switch and have no issues.

First though, I would look at all of your wiring in your aftermarket amp and sub and make sure you don't have a short somewhere. If the sub is playing that loud with the volume on you HU at low then you need to set the gains properly on the amp.

AZg37

iTrader: (17)

ok, from what I understand, and please correct me if I'm wrong here, I can just tap into the sub wires to get a signal for my amp. I'm supposed to tap into the wires in the B41 connector before the amp. The shop I took my car to told me I need a 4 speaker converter and 2 sets of rca's. Is there any advantages of tapping into the wires before the bose amp and getting all four speakers vs. tapping the wires labled sub signal only??? I think they might just want more $$$ Wouldn't it work to just tap into the sub wires before the amp and run my aftermarket amp with a mono signal??

Dieseldoug22

iTrader: (27)

Yes you can tap into the wires before the sub amp. I have it that way on my car, and all that I want out of it is subs so it works great for me. If you are using a mono amp you don't need the 2 set's of RCA's. The signal coming out of the Bose amp into the sub amp I believe is crossed over already so you don't even need any real processing power. If you are running full range speakers than yes, you do need to get the signal else were.

AZg37

iTrader: (17)

Well the installer is trying to tell me that the Infinity basslink II I'm installing (only for the time being, I want a full, much better system) needs all 4 inputs to work right. He tried telling me that the sub will only get half power with just 2 rca's, but I was not buying that. I'm not stupid. The rca's supply the sound signal, and have zero to do with power to the sub. Does anyone know if there is truth to the Infinity basslink need all 4 speaker inputs to work correctly??? It is odd that the amp is a mono sub amp, but it does have 4 rca inputs?