starbai

Hey everyone.

I have a Shaker 500 in my 2011 GT. I want to leave all the connections alone in the car if possible. I'm replacing all the speakers with alpine Type r 5x7's which is simple enough but beyond that I dont want to touch the 8" subs nor do I want to figure out a way to amplify the 5x7s I'm putting in.

What I AM trying to do is add an Mono Subwoofer Amplifier and a Subwoofer to my trunk.

I know that the J4 Connector of the headunit, will give me the subwoofer output that I need.

What I need help with is a clear understanding of how to get that signal, into my amplifier, without affecting the factory amps and the factory door mid bass drivers.

I'm still a bit confused based on some information I'm hearing from some of the other forums.

To make what I'm doing possible, and doing it in the simplest and cheapest way, can I just use a very basic LOC that I would wire into this setup by just using T-TAPS on those 3 wires I need from connector J4? AUX +, AUX -, and Enable (for remote turn on)

My confusion is on whether or not an LOC is going to cause the signal being sent to the two factory AMPs to be distorted and therefore screw with the way the two Factory 8" MID BASS drivers sound. Distorted because the LOC will be pulling too much voltage from this line from the factory head unit to the factory amps???

Okay assuming it is, What are my options? Just cut out the two factory amps and subs altogether and rely on just my Trunk sub?

Assuming it isn't, and I CAN just tap these 3 lines for my amp, Can I just use any old LOC converter without issue? Should I be looking for something in particular?

2nd issue:

I've been told that I need to make sure my amp has a differential balanced input. I have no idea if it does or not, and I'm inclined to believe it doesn't as its an old Kenwood amp:

http://www.sonicelectronix.com/item_...KAC-8101D.html

Because I'll be using an LOC will this really be an issue? I was briefly under the impression that its only an issue if you try to connect a wire directly to an RCA Connector, without any kind of LOC in between.

I have no idea what a differential balanced input is, but I will read up on it.

If it will be a problem, what are my other options? Is getting a new amp my only choice?

Please help, I'm struggling here to understand and figure everything out. Every time I feel like I've got a good grasp on this, I take two steps back unsure of whether or not I'm understanding.

Thanks in advance everyone.

A few people on the forum has been helping me via PMing but I figured I'd open this question out to the general public for more advice.

wayne613

Tapping them to use another amp isn't really an issue voltage/draw wise for the factory's. It's just matching the impedance. Not totally sure after reading that what the one you plan on adding is Ohm wise. In any case you want to not drop or raise the impedance value on the line(s). This will obviously (if lowered) cause a higher input to the factory amps, distorting it more than likely. Higher and the factory will not put out as much and still be possibly distorted as the factory amp isn't exactly awesome.

Someone that's a bit more of an expert at the actual sound aspect can explain further for options, and hopefully give you an answer to your second problem, as that one I really can't give squat for input for. I think you may have the 2 issue split, when they're actually the same thing.

starbai

Thanks for the reply man.

So Impedance is what I need to be concerned with on my "New Amp"

But beacuse this line will be going to an LOC before it hits the amp, do I need to be concerned with the impedance of the amp? or the LOC?

Does anyone know what the impedance of the factory amp(s) are so that I know what parameters I have to work within, in order to not fudge up the signal going to the factory amps?

starbai

Specs on the amp if it can help anyone help me:

http://india.kenwood.com/products/ca...101d/spec.html

wayne613

Impedance is just another term (simplistically speaking) for resistance. The Ohms of the speaker(s) used is at issue here.

See here for more info. I "think" the factory subs are 4ohm a piece. So if you use a 4ohm sub for the right channel, both speakers will be doing half that, or 2ohms, and thus over-driving the right side factory amp. The kenwood from the brief look I had can do 2ohms, but will of course push out 400watts instead of 200.

starbai

400 Watts should be fine with the Alpine Type R (I think)--

I've been following this guy's article, and seems like its right up my Alley. I wonder if the Soungate LOCB.2 fixes some of the issues we're describing somehow?

This is the piece he's using though its for some reason discontinued or backordered:
http://www.logjamelectronics.com/sounlocbosli.html - I wonder if it actually will fix the issues I'm running into here, or if its just another LOC.

Here is the link to the article I'm quoting below:
http://savkomedia.com/kevin/Index2.asp

wayne613

Upon looking at this further, Iīm unsure how:
I think he just hooked it up and prayed, same as most do. An active LOC might remove the connected components rating from the equation of the original line, but Iīd ask someone at a reputable audio shop(crutchfield) or wait for another to comment, as I do not really know for sure.

Iīve never actually tried to do exactly what you are doing, however, from what Iīve read so far I donīt think youīll have much to worry about unless you get a 2ohm sub with an active LOC. Iīd inquire about the below linked LOC from crutchfield and ask to speak with one of their audio techs about impedance matching. He should know by experience, I really donīt in this case.

Here's an overkill active LOC. The one review on this one is great, and it was for another 2011 mustang, go figure.. At $100 though for an active LOC, itīd better be IMO.

Iskwezm

The problem with forums is you can ask 5 guys and get 10 different answers.They will all conflict but get the same result.

wayne613

Does using an active LOC remove the original lineīs impedance value from the equation from your perspective though? I simply donīt know, as Iīve never tried to skirt around it before.

Iskwezm

I havent had any issues weather is a Bose,SYNC,Sony,Pioneer or the Shaker system. I have never measured the change if any because there was no reason to.