SO I guess I may as well start with hello, this is my first post, and I'll throw some pics of my truck up here later...


Heres the specs:
05 Dakota
Factory Head unit (REF?)(single disc)
6 3/4 Infinity front speakers (aftermarket)
6 3/4 Infinity rear speakers (aftermarket)

Problem:
I want to add a Sub. But not sure how to wire off the factory head unit. Theres no factory RCA outs, so I'm not sure which direction to go. Should I splice a line level converter off the rear speakers? I'm not thrilled with splicing/cutting on the factory harness, but I am comfortable with it if its the only way.

With a line level converter,My main concern would be if I would be changing the ohm load to the rear speakers (in esence lowering it) I don't want to overtax the factory head unit, and at the same point, I'm running the same infinitys front and rear, and if I change the ohms of the rear speakers their output would be louder then the fronts. (yes, I know I can fade front/rear)

I found a PAC wiring setup (AOEM-CHR2) but it really gives no specs on what it does except 2pr rca outs and a trigger wire. It makes no reference if its in addition to the factory speakers, or if it disconnects them and just turns them into RCA's

As far as what sub/amp/box combination I'll be going with, I'm still deciding, but its a moot point until I can figure out how to get power (rca's) off the head unit with the least amount of intrusion to the factory wiring or the output of my speakers.

If splicing IS necessary, is there a place that sells a factory harness extension (maybe a few inches) so I can just splice into that instead of compromising the factory wiring.

Sorry for the length of the post, but I wanted to make sure I had all the details covered as to get the right answer with the least amount of random variables for missing information.

Any help would be greatly appreciated...

-Ueland

 

ok.. answered my own question.. the PAC wiring leaves the stock speakers functioning.

 

LOC's are pretty much the only way to go if you want decent quality sound from the factory head unit. No worries about changing the ohm load, since the load of the speakers will be presented to the amp, not the factory head.

 

ok.. ya lost me on that one about the ohm load being presented to the amp and not the head unit. I thought the head unit would see the variant ohm load and adjust output accordingly.

Examplefaking the ohm load for the loc cause I have no idea)
Standard Headunit-factory speakers(4ohm)=4ohm load
w/LOC Headunit-factory speakers(4ohm)/LOC(4ohm)=2ohm load

So why would the head unit not see the LOC as part of the ohm load it was powering?? and if it DOES see the ohm load, wouldnt the result be higher output on the speaker set that the LOC is actually wired to (ie: rear speakers) So if the front speakers(4ohm) generate lets say 1db at volume setting 4, wouldn't the rear speakers/loc(2ohm load) generate 1db at volume setting 2 or 3 ????

Granted all the numbers I listed are for ease of use and generic, but I thought thats how the ohm load worked etc etc.

I'm not doubting what your saying, but I'm very interested in understanding the "why" behind it. also on a side note, i did pic up the PAC wiring assembly which has a front and rear LOC, so if I use just the rear LOC, would the front still be visible to the ohm load or would it be stagnent cause its more of a deadhead then a pass through.



Again, Sorry for the long post, but I'm interested and want to learn

 

The LOC will present a small amount of resistance to the channel that you're using it on, but it will be a very very small amount and shouldn't be noticable. The reason that it won't present the load is because it's using the electrical signals coming through the speaker leads as just that, electrical (or audio) signal. There's no driver directly connected to the LOC, therefore no additional load on the radio's built in amp. The subwoofers are being powered through an external amplifier that sees the load of the speaker (like you said, 2 4ohm drivers in parallel equaling a 2ohm load, wired in series 8ohms, etc). The amplifier is using the LOC and its connections as a signal input rather than using it to actually drive the woofer, and that is why there is no adverse effect from the using the LOC on a factory head unit.

And as far as the resistance goes in terms of volume, you've got a pretty good basic understanding of how it works. Doubling the resistance halfs the power, halfing the resitance doubles. That's why you'll see on many aftermarket amplifiers more than one RMS power rating. They'll say 225w rms@ 4ohms, 450w rms@ 2ohms, 900w rms @ 1ohm. If you want to understand the mathematics behind this, check out Ohms and Kerchoff's Laws, check out some of the MECP basic training stuff if you're really really interested.

 

ok.. now that makes sence.. I never really messed with LOC's so I wasn't sure the operation etc behind the consumption/rating of the actual line effect.

As for the ohms law, I'm farmilliar with most of that stuff, and have used theile small equation on seveal occasions to make sure I got everything right.


So any suggestions/fedback on the sub I'm considering.. was lookin at the shallowmount pioneer/premier stuff. from what I've seen it looks like the only thing with a small enough footprint to be able to fit in a gen3 dak without causing interference with the rear seat flip and fold.


Also, on a side note, any opinion on running lets say 4- 5 1/2 drivers in an enclosure as opposed to one larger speaker? I've seen it done long ago, but wasn't sure if I would get enough volume or response out of a setup like that.

 

It'll give you volume, but that's about it, but it's not going to give you any bottom end at all. It's simple physics, a driver that size cannot effectivley reproduce bass and mid-bass frequencies without distorting the audio and destroying the driver. Adding such a set up to your truck would also destroy your sound stage.

PS-Pioneer Premiere is pretty good quality stuff, so they've got my recomendation if you're looking at them as a potential solution.

 

My problem is I just installed some Infinity 6 1/2 (6032si) speakers in all 4 doors. The sound quality is great, and after breaking them in a bit the bass response has filled in a little, howeverI'm still lacking a nice solid bass line.

The infinitys are actually producing less bass then the factory speakers, but the mids and highs are 100% better (crisp clean and clear)

So my goal is not to blow the windows out, but just to get a decent/reasonable amount of bass.

As far as music styles, I play about everything, from jazz-techno-rap-country-pop-rock.


So do you have a better idea??
I'm open to suggestion, but I'd like to keep the price "somewhat" reasonable.

 

I think you're on the right track, and the Infinities (or any other quality aftermarket 6.5" speaker for that matter) are not designed to handle the full spectrum of sound that is begin generated through music. Like you said, mids and highs are crystal clear, and that's what they're designed to do, reproduce crisp clean mid and high frequencies and leave the bass and mid bass to other drivers. If you're listening to a little bit of everything, you can go either 10" or 12", though I'd probably reccomend a 10" just because from your description of what you want, you're concerened more with sound quality rather than overall SPL, and a 10" woofer will have a better tighter sound than a 12", although it is at the expense of some overall volume. So, a 10" slim fit sub in a sealed enclosure with an amp that will drive it would be pretty much perfect.

I'm actually getting ready to do something very similar in my Dak. I did have 2 10" Alpine Typer R's in a custom built ported box, and it sounded amazing and was rediculously loud, but I'm kinda wanting to have a back seat again. I'm looking at installing a 10" woofer (haven't picked a model yet) into a custom fiberglass enclosure under the passenger side rear seat, and having two amps (one for the sub, one for the component and coaxials speakers) sit into an amp rack under the drivers rear seat. It won't be anywhere near as powereful as my previous set up, but the sound quality will be tremendous and I'll actually be able to store things or take people in the back of my truck again.

 

sounds pretty good.. you gonna share some pics and install notes from your system??

years back I did a 4th order bandpass in a jeep where the sealed chamber was behind the rear seat and the ported side was under the seat. it sounded amazing with the top on, but with the top off and the turbulence it lost about 60% of volume while moving...

I'm very interested in what you come up with... so do you just do your own stuff now or still custom work for people.. depending on what you come up with, and that you have the same platform, would you possibly build a second box off your design if it comes out right? (for the right price of course)

If its a possibility maybe hit me with a PM and we can swap contact info