Check the connections for the Logic subs. Also check to make sure you have output from the alpine amp to the Logic subs. Eliminate each piece as a possible problem.

 

The connections from the amp had to be working since it worked on my mtx's. Then it still worked in my dads suburban after we took them out, and wired them back up.

 

How are you hooking the subs up to the amp? Parallel? Series? What ohm rating are the subs? etc

 

only reason this would matter is if they were both 2 ohm subs connected in parallel and the amp was not 1 ohm stable. Even in that case i was work for a while before the amp got overloaded and overheated.

most likely it is a bad remote wire or ground connection. Check amp gain to see it is not turned all the way down on the amp, remote knob if there is one, and the head unit.

 

Well the alpine is a mono, and I was running the subs parallel I believe, right? Fosgate is a two channel. Each Sub has its own box with separate wiring, including the mtx's. I tried the Logics, which I believe are 4ohms, whereas the mtx's are both 2. The fosgate is olldddd, works good enough for the mtx's though. I have a Clarion deck to and RCA's running straight into the amp. I have a good, solid ground, car has the high output alternator in it, and battery terminals are good. Amp will push the mtx's just not the logic's.

 

ohms shouldn't be an issue here. nor should anything else. your issue is some sort of wiring issue. You need to check all your grounds, i would even go as far as rewiring the subs in the box etc or even possibly rewiring your whole system. if your really into top quality sound you could even upgrade your components and wires.

 

ahh posted twice sorry.

 

You must have missed something, even if you have the sumbs wired incorrectly they should still work. Look for a wiring diagram on how to wire 4ohms subs into 2ohms. With a mono amp, to get the most out of it I believe you wan't something around 2ohms or 1ohm and you should have it wired so only 1 speaker line is connected into the amp, a positive and negative. Here is a wiring site http://www.crutchfield.com/S-mCmfLYTgKep/learn/learningcenter/car/subwoofers_wiring.html

Are the subs single or dual voice coil? Also check the alpine site to see what ohms the amp is, if it runs the MTX 2ohm subs it might be 1ohm mono.

I'm guessing single coil so it should look something like this, http://a248.e.akamai.net/pix.crutch.../pix.crutchfield.com/ca/learningcenter/car/subwoofer_wiring/2SVC_4-ohm_mono.jpg

 

Retrace and rewire making sure your grounds are good. Take one of the subs out and hook them up one at a time to make sure they are working. If they work, reinstall them and plug back into the box. If the don't work, rewire the box. Repeat this step to your amps, then your head unit. good luck.

 

For the rockford 2 channel you cannot run it parallel because it is probably not mono or crossover capable, sometimes you can but you need to check the rockford website for you specific amp and make sure the amp is set up correctly and your wiring on it is correct. The more I think about this the more I think it is how you have the lines connected into the amp and the amp settings. 2channel amps suck for subs, mono amps are the only way to go when you wan't bass and power.

 

if there in a sub box pull them out and see if there hooked up to the connector and if you still dont get any noise they could be blow.. blown subs get very lose or they get hard and you could feel it when you push the cone...

 

Like I said guys, the subs were hooked back up into the suburban after trying this in my car. Both worked and I know my grounds and positives are all fine since the Fosgate is pushing both of the mtx's as we speak. It is a two channel and there is a crossover hooked up. The fosgate is olllddd and it only has 150 total power. I made double sure everything was hooked up correctly when the alpine and logics were in there. I even unhooked my fosgate and put the alpine in and wired the mtx's to it. The only thing that is not working in the car is the Logic subs, however, in the suburban they hit fine. I was reading across another thread and they guy seemed to have bridged a connection between the + and - on his subs and they worked. Should I give that a try?

 

I would say it is an ohm issue. I know someone up there said ohm shouldnt cause it not to work blah blah but yeah ohm loads can cause lots of problems. If it is too low it will keep your amp in protect, too high and it will barely have any power going to the sub and it will seem as if they arent working.

Bad grounds or anything else in yor car wouldnt cause one set of subs to work and another set not work, and since you have tested the subs in the burban and they do work then it isent the subs either. Which only leaves the subs themselves being wired differently between the two vechicles. You said the subs you had working in the car may have been 2 ohm whereas the logics ou thought were 4's. Also are these Dual Voice Coil subs you are working with or Single? That will drop or raise your ohm load as well depending on that and how they are wired up if they are dual voice coil.

Thats where I would start. Check and see if they are 2's or 4's, and if they are Dual voice Coil or not.

 

I believe the logics are 4 ohms they are competition subs so they might be dual voice coil. But still if they are working in the burban and hooked up exactly the same way in both vehicles then why wouldn't it work in my car? There's a ton of adjustments I can make on the amp though but it really shouldn't matter if they work in both even if the subs and amp are disconnected and reconnected in the other vehicle. Idk I might have to change up the RCA's or look up on my deck or something.

 

Ah ok, I didnt realize that you were putting the same amp in the burban too. I thought there was a seperate amp in the burban. Now that really doesnt make sense, I mean you have power, ground, remote, and rca signal obviously since your other amp works with the other subs. If you are taking it straight out of one into the other wired exactly the same then there isent a ohm issue either. So everything is good on the Sub/amp side.

The power, ground, rca, remote wires dont discriminate and work for one amp but not the other, they should work with both setups or not at all. Which means if they work for one amp then they are "technically" working correctly. In theory meaning everything is good on the vechile side as well.


Then again DSM's have minds of their own with themselves and anything put into them. Maybe your subs hate DSM's? or your DSM hates those subs =p.

 

Yeah I don't fucking know. Today I tried starting my car and all my power was going to my subs and they car wouldn't start. At first it scared the shit outta me haha. Anyway I found out that the subs are single voice coil. Tonight I'm going to try rewiring the car and fix the ghetto-ness of how my dad did it. I really am going to be pissed if it doesn't work, but at least it will look better. I might need to pull the subs out of their boxes anyway to see how he wired them in there. Wish me luckkk.

 

Ok well I rewired it and the heavy gauge wiring doesn't help, and the alpine powers down if I'm hitting to hard on the mtx's. It goes into safe mode and I have to restart my deck. Seriously does anyone have an idea?

 

I would imagine the alpine is 2ohm stable if it's a monoblock amp. How do you have the subs wired?

 

Well since its a mono I have both connections from each sub screwed into the pos and neg parts of the amp. I believe the mtx's are not meant for what that amp has to put out. Therefore the amp is going into safe mode. I want the damn logics to work, but neither of them do. I know a sound technician that could help me but seriously? What else can you do?

 

The subs will work regardless. The amp would only go into safe mode if it's NOT intended for a 2ohm load (assuming the subs are 4ohm). I can't imagine the subs being a 2ohm SVC.

 

My other amp is a 150 watt 2 channel rockford fosgate and it runs both of those subs (mtx's) until I can hear my car 4 blocks away. But the alpine hits a lot harder, just in a different way.

 

lol @ when people rate their bass on how many blocks away it can be heard

 

If your amp is going into safe mode then it is clipping. If the subs are playing and then when it hits hard it stops playing then starts again in a couple of seconds (or even stops playing until you turn off and back on to reset the power to it) then it is clipping most common reason for clipping is due to being wired at the wrong ohms. Either way you are having clipping issues and it may be the way it is wired, may have something crossed, or it may be like I said just dropped in ohms too low and causing it to clip at high volumes.

 

It cant be wired wrong. I have a lead coming from my battery thats 4g and a ground to the frame that is 4g. The Logics finally work but they dont hit as hard as they should. I need to adjust some settings. The connections in the subs were loose. I don't understand how they were because all I did was move them around. Anyway the mtx's still hit harder. I'm going to try using a cap to see if that helps. I don't get light dim or anything so I don't understand why the amp is shutting off. The Logics don't pull more than 1.0 amp when the deck is turned up all the way.

 

Don't get a cap it will not help. Honestly, it sounds like a loose or bad ground connection to me. It pretty common if the metals not perfectly bare or the connection just isn't tight enough. That would make it go in and out too.

 

I actually think the voice coils in the logics are screwed. You can push on the sub and it'll hit for a couple seconds. I already have the cap though. Usually to kick them off I have to have the thing turned all the way up which is wayyy to loud for me. The amp goes into safe mode and has to be reset by turning the deck off then on.

 

I'm also thinking the subs are causing the alpine to kick off. They are only rated for like 100 rms or something. Is that a possibility?

 

How did you set your gain? Most people think the gain is a volume knob... It is not. If your amp can put out an RMS of 1000watts at 2ohms, and you have 2 4ohm single voice coil subs wires in parallel, you can have 500watts rms per sub. If you try turning the gain up to where the signal would require more than 1000watts to produce, then the signal peaks, and flatlines or "clips" until the signal comes back into range, and that is brutal on your amp and subs. Also, you can clip the signal coming from the deck if you turn your deck settings up too high.

Do you understand RMS values? They are a lot more important than "MAX" ratings.

And I have to also suggest you check your electrical connections throughout your system. ALL of them. Make sure there is nothing that is questionable. A simple loose ground can cause all sorts of hell. Make sure it's clean and tight.