Question on stock bose HU + aftermarket sub/amp setup

[5][Spyder]

Currently I am using a speaker level->RCA converter to convert the leads going to the stock sub into one mono channel then to a PPI 200x2 RMS amp/ 2 rockford s1 subs. Everything works as expected but I do not feel that the subs are responding to low frequencies very well. Is the stock bose sub crossed over on the low end as well as the high end? I mean does it have a crossover on the lowend bumping it up to say 50hz and then a high end crossover killing the highs like normal as well?

Is this the recommended method to do this or is there a better way? It seems the lineout converter is also killing alot of the gain, these subs are not hitting near as hard as the should with the RMS wattage I am putting to them, and if I crank up the lineout convertor near 100% it starts distorting fast. All wiring used is high quality and dedicated 8ga power to the amp, and the amp/subs/sealed box sound amazing when plugged directly up to other equipment(alpine crossover+ipod).

Any advice without replacing the stock HU?

 

[ejh]

Can you take the signal from the speakers or direct from the HU and not use the factory sub output?

 

[5][Spyder]

I wish I knew how to get sub out from the HU that would be amazing but I doubt it is possible, is it? If I were to take the inputs from the front or rear door speakers those would already be crossed over by the factory bose xovers which are removing the super low frequencies from the door speakers and those are the frequencies I want for the aftermarket sub, so that wouldn't work =(.

 

[aceblaster]

I wish I knew how to get sub out from the HU that would be amazing but I doubt it is possible, is it? If I were to take the inputs from the front or rear door speakers those would already be crossed over by the factory bose xovers which are removing the super low frequencies from the door speakers and those are the frequencies I want for the aftermarket sub, so that wouldn't work =(.

Just tap straight into the door speaker wires with no filter. (splice them in)
Use your Amp that is connected to your aftermarket sub to control the frequencies... Hook up your Amps signal wire to the 12Volt Accessory wire on the HU.
This is what I've done with my car for my aftermarket sub. I don't even turn the amp up all the way because it's too loud. So it is possible.

 

[kvndoom]

You picked the absolute worst place to tap into a signal. Any signal post-blose amp is going to be garbage. You want to get your signal to your amps before the blose rapes it into oblivion.

Find the diagram for the cable from the HU, splice from the line-level outputs (front or rear) directly into your amps, then set your lo-pass at the amp itself.

 

[halo0]

What kvndoom said. Should be real easy to pick one of the 4 matched pairs of speaker wires coming out of the stock HU, even without a wiring diagram. I forget all the colors but I'm pretty sure one of the pairs is gray/gray with white or black stripe.

 

[aceblaster]

You picked the absolute worst place to tap into a signal. Any signal post-blose amp is going to be garbage. You want to get your signal to your amps before the blose rapes it into oblivion.

Find the diagram for the cable from the HU, splice from the line-level outputs (front or rear) directly into your amps, then set your lo-pass at the amp itself.

Sorry I made that sound so horrible. haha. I meant to tap straight into the speaker wires in the harness... If you did tap into the wire after it would sound horrible.

 

[kvndoom]

Sorry I made that sound so horrible. haha. I meant to tap straight into the speaker wires in the harness... If you did tap into the wire after it would sound horrible.

You really want the line out from the HU and not the speaker out from the amp. It's all in the same harness though.

 

[5][Spyder]

You really want the line out from the HU and not the speaker out from the amp. It's all in the same harness though.

OK so the HU has a line out, which wires, what colors and where to get that? I assume this is coming from the HU and is a clean preamplified signal that is not crossed over yet?

 

[aceblaster]

OK so the HU has a line out, which wires, what colors and where to get that? I assume this is coming from the HU and is a clean preamplified signal that is not crossed over yet?

Ya, when you hook it up don't use a LOC. Most of the LOC's will act as a filter as well, I would just tap straight into the wires if I were you.

 

[5][Spyder]

Ya, when you hook it up don't use a LOC. Most of the LOC's will act as a filter as well, I would just tap straight into the wires if I were you.

I understand that would be preferable but what wires? Do you have any documentation anywhere that show which wires(where? what colors? etc) that I need to use to get a clean preamp output from the headunit?

 

[kvndoom]

I understand that would be preferable but what wires? Do you have any documentation anywhere that show which wires(where? what colors? etc) that I need to use to get a clean preamp output from the headunit?

I'll PM you a link. It's from another forum. We have it here somewhere, but I just went with the first good result from google. (google)

 

[Kain]

Just my opinion, but if you're tapping into the stock HU, chances are you're not putting in a system to really maximize the difference between a direct signal and using a LOC.

That being said, I've done both: spliced into the pre-amp signal underneath the driver seat (PITA with my bad back), which worked fine. I then wanted a cleaner, easier, plug n' play solution and got the PAC LOC for later Mazdas. It has a wiring harness that attaches to the back of the stock HU. No fuss, no muss, and no discernable difference in sound.