wiring suggestion

Once again, limited information.  All I found out was that you have a 5.25" round coaxial speaker.  It did not mention if it had a separate crossover, but I do not believe it does.  No wattage listing either.  But it should be fine on the Alpine amp's output wattage.  Just don't drive it into distortion.  All the website had was the "new for 2005 version" and it said it was reworked for 2005 so you may not have the exact same thing I was looking at. 

Is 5 1/4" the actual size that the 2002 Trailblazer takes in the rear(no puns intended......seriously)??  So you have 6.5's in the front and 5.25's in the back.

No I don't know about tapping that ignition wire.  Why do you need to relocate the factory stereo??  Is it something to do with not losing other things like door chimes or alarm or something??  Also, are the speaker adapters to mate with factory wiring?? 

Also, there is now a new and very important issue with the sub and amp that we have to look at.  If you have a 4 ohm DVC, then it's going to be difficult to work with and get enough out of it.  In a nut shell, if the coils are wired parallel, then it will be a 2 ohm load total.  You cannot bridge this to an amp only stable at 4 ohms bridged.  That's exactly what your amps are, 4 ohm stable bridged, 2 ohm stable stereo. 

So, you need another sub just like the one you have, or another amp, a mono amp that can handle 2 ohms. 

Otherwise, you can wire series, for 8 ohms, but that will cut bridged power in half and would only be 100 watts.  This is where it comes in whether that Kicker amp is rated RMS or PEAK(remember me saying that before?0.  If it's RMS, then that's ok, but still kinda weak considering that the other speakers will get 55 watts RMS each.  IF it's PEAK, then that just plain sucks.  I don't know which it is.

Still, you can wire one coil per channel and that will be a 4 ohm load stereo, and that will still only be 100 watts total cause we said it would be 50 x 2 @ 4 ohms before.  That would be the same as bridging it 8 ohm wired though.  No way of doing it to get the 200 x 1 @ 4 ohms.  And before you ask, I don't recommend using only one coil unless you know that it is rated to handle the 200 watts by itself and know for sure which the amp is pushing RMS or PEAK.

Well, this is a snag, but don't be discouraged.  You can still come out of this ok.  Even if you ran it stereo at 4 ohms, it will still be bassy, but maybe not as bassy as you would want.  Good thing it's a SUV and the sub will be inside with you instead of a trunk.  That will help some if you decide to only use this one sub. 

Thanks again! Relocating the factory stereo would be for the chimes, but I do not care about losing those so he told me to tap a brown wire under the steering wheel with the red ignition wire on the head unit. He said that this would work, and I would not have to relocate.  I am starting to get confused about the sub. I have the manual for the amp and it states: RMS POWER in watts all channels driven     4 ohm stereo 70 x 2 , 2 ohm stereo 100 x 2, 4 ohm mono 200.  Also states Low impedance operation stable in 2 ohm stereo or 4 ohm mono loads.  If this is a snag could I wire the sub to the alpine amp and use the kicker for the back door speakers or would it be cheaper to get a 2 ohm sub and get rid of the one I have?

Alright, now we have some actual owner's manual amp specs to work with here. 

OK, wait a minute.   No matter which amp you run the sub on, you will still have the same problem.  Both amps are only stable at 4 ohms bridged.  This means that they can handle a minimum load of 4 ohms when they are bridged.  Bridged is when you wire two of the amp's channels together to create one channel.  So when you bridge your amp, you have to make sure that the subwoofer is no less than 4 ohms.  They can take more ohms, like 8, but not less than 4.  Get it??

So if you did run one coil per channel, then you will get 70 watts RMS per channel, which will be 140 watts RMS going into your sub.  This is not bad.  Yeah, the amp could do a little better if you had an actual 4 ohm subwoofer that was not a DVC.  Then it would put out 200 watts RMS, but with your sub, you just can't do that.  You could get another subwoofer just like the one you have and run two of them in parallel and get a 4 ohm load that way.  You'd get 100 watts per sub.  That would be a little better, but you'd have to decide if it was within your budget. 

It's just a situation where your sub and your amp are not ideally suited for each other.  If you wire it up the way I said in stereo though it will be OK.  Or you can also wire it in series(8 ohms, remember??) and bridge the amp and get 1/2 of the 200 watts, which would only be 100 watts.  That way it's less and I don't recommend this.  But those are your two options with that amp and that subwoofer.

When you say get rid of your sub and get a 2 ohm sub, I think you are confused.  You might get rid of it and get a 4 ohm sub and do better, but a 2 ohm sub would make it worse.  You'd need two of those to do any better.

See, what it is is that the amp can only take certain ohm loads as a minimum depending on the way it's used, either bridged, or two channel stereo.  Your amp's manual is showing you that.  It also tells you the power outputs you will get with the possible ways of wiring it to different ohm loads.  That's what all those numbers are. 

You have to make the speaker and amp match.  With your sub and amp, it's hard to do cause of the DVC 4 ohm part.  Understand??  I hope I'm making this clear enough. 

As for the brown wire tapping and all, you're on your own there.  I don't know how to do what it is that they are saying.  I've never dealt with that issue before.  Sorry.

Your idea of getting a DVC 2 ohm sub instead of the DVC 4 ohm is correct when you are using a two channel amp.  You'll then be able to achieve a total 4 ohm load.  It would have been helpful for the dealer in question to get you the proper sub to begin with.

But a couple of points to clarify here:  " Bridged is when you wire two of the amp's channels together to create one channel."   You can't create a channel.  You are connecting two channels into one load, so the load (the subwoofer) gets half its power from one channel and half from the other channel.  The load impedance goes half to one channel and half to the other.

On wiring coils independently:  Yes, only one coil can be used and the other left unused without harm done (as long as the power handling capability of one coil is not exceeded).  There is rarely a reason to do this, and there is no reason to consider this in your case.  A change in equipment is called for.

...have the manual for the amp and it states: RMS POWER in watts all channels driven     4 ohm stereo 70 x 2 , 2 ohm stereo 100 x 2, 4 ohm mono 200.

The spec here indicates that this is an amp suitable for a pair of components but not for subwoofer use.  Notice how the wattage is not doubled when it goes from 4 ohm to 2 ohm?  It's just a little higher.  That means the amplifier is not built to handle the full current at a low 2 ohm impedance (4 ohm bridged).  But it should work fine as a coaxial or component amp at the rated 4 ohm impedance.

You should do an exchange at the dealer unless you have some closeouts or something and got a great deal on them.  But if you want to use that sub, you should have a D class mono amp capable of powering it to at least half its RMS capability.  A mono amp is one channel and therefore rated to deliver at 2 ohms.

or is it better to get 4 ohm DVC?

You already have one of those.  And as far as that amp goes, use it for a pair of component speakers and it will work out fine.  But not for the sub.  You would have to replace the sub to use that amp.  One or the other.