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Discussion Starter #1
well as some of u know, i had my system stolen outta my car a few weeks ago. well ive been in the process of replacing all of my stuff. i went a couple days ago and got an amp. its a mtx tc4001 class d amp. 400 rms watts. well i hook everything up and i get nothing. i take it up to circuit city and ask the guy to help me out and he tells me to get new rc cables and if its not that then the amp has a blown channel and to return the amp. well i went and got new rc cables and still got nothing, so i exchanged the amp. well i had to go to a different circuit city cause the one didnt have it. so i go and exchange the amp and just get them to hook everything up. the guy calls me and says he has my amp hooked up but my subs are blown. well wierd thing is is when i asked the other guy for help at the other circuit city, he took the subs outta my car and hooked them up and both of them were hitting. i told the guy this and he said he tested them out and said they were only reading 48 ohms. since i dont know to much about car audio, i took his word for it and i went and got 2 new mtx 4500 subs. hooked them up and still nothing. now im very frustrated and just spent a lot of money to get this crap working and its still not. if i turn the gain all the way up, the subs buzz and if i turn it down then it stops. now im thinking its a ground wire. what do u guys think??
 

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noise is generally from a bad ground...

I never let people install stuff in my car.
talk to the head guy in charge and tell them what's up.
have them re-do everything from square 1.

seriously, hooking up a system is not that difficult in my opinion.
Those guys are slackers and there's something that's being over-looked.

simple: make sure that the amp has 100% continuity. 1 wire greater than 8AWG, needs to connect to the battery, with a fused rated at 40-60 amps. (60-120amps if using 4/1/0 gauge).

The ground needs to have metal-to-metal contact. wire-brush the paint off, and sand it down. Instead of drilling a hole, I'll use a hole puncher. It just looks like a tiny ice-pick... hit that with a hammer in the middle of the scoured paint and attach your ground cable.

The remote power wire, I would tap from the HU (or ignition column).

that solves your power issues, now you know the only problem lies with the RCA (low-level input) If you are using an aftermarket radio, it's a piece of cake, just route the cables to the amp input. If using the stock radio, wire up a LOC, then plug in the RCAs.
 

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Discussion Starter #3
well the amp is getting power. i know that. its just if i turn the gain all the way up, the subs buzz and then when i turn it down, they dont hit or anything. when i was reading the instructions, it said that the amp needed a 4 gauge ground. i dont think the ground wire is a 4 gauge. but would that cause the subs to not hit at all and then buzz when the gain is turned up??
 

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I had the same problem. I was getting pissed off because I couldnt find the problem. I replaced grounds, replaced power....everything. I finally picked up a ground loop isolator and that fixed the problem. It is a little box that you put in between the amp and the head unit (rca). It killed all my alternator whine.
 

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first thing I'd do is take that equipment back, get a refund, and tell CC where to shove it.

they are ripping you off and taking advantage of you

Are you using the stock HU, or an aftermarket HU?
What are the exact wires being ran, and what size for each?
Are the subs dual or single voice coil?
How are they wired to each other and to the amp?
Where is the X-over set on the amp?
If you have an aftermarket HU, is the sub level turned on, and at what level?
If LOC, is there a gain pot?
 

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Discussion Starter #7
i have an aftermarket headunit.
the wires are all rockford fosgaste wires. 8 gauge ground and power wires, 16awg speaker wires.
subs are single voice coil
they are wired with one wire coming from the negative side of speaker one and the other wire coming from the positive side from speaker two.
i dunno
the sub level is turned all the way up to 10 and im barely gettin anything outta the subs.
what is loc??

i took my car up to best buy and asked the guy that worked there and he said its a bad ground or the amp is bad. there is no way that amp is bad. its the second one. i came home and tried to make a better connection on the ground and still nothin. id do this all myself but i dont really know anything about car audio. i had to go and look at my boxes and wires out in my car just to try and answer ur questions the best i could.
 

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1) What exact HU do you have?
Does your HU have any crossover features?
If so, what is the sub Low Pass set to?

2) An LOC is if you were using a stock HU.

3) Are your subs single 2 or single 4 ohm?
Wired + from one sub, then - from the other, then the remaining - and + should be wired to each other from one sub to the next. Is this correct? If they are single 2 ohm, then that Series wiring will creat a 4 ohm final load, of which you'll only get 200w total max RMS.

If they are single 4 ohm, and wired for 8 ohm, then they are not getting enough power.

If they are single 4 ohm, they need to be wired in Parallel. Each pos to the amp pos, and each neg to the amp neg. This will be a final 2 ohm load for a total of 400w RMS max.

4) What is the amp LP (low pass) crossover set at? The dial ranges from 40 to 200Hz, so set it at what you'd guess to be 80Hz. Switch the subsonic filter on as well.

5) Where is the amp Gain set at? I'm gonna guess it should be set about 1/3 the way up.

6) Turn the Thunder EQ down all the way or off.

7) Make sure the amp ground is connected to the body of the car with the paint sanded down to bare metal. This is key.
 

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Discussion Starter #9
ok well i got the problem fixed. took it back up to circuit city and told em to fix it. turned out the subs were outta phase and the rca cables were bad. so i had to buy new rca cables. he showed me that they were bad. the guy who hooked up my subs hooked em up wrong. im just glad its fixed.
 

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awesome....i guess that is why I always install my own stuff....i hear too many horror stories about other people installing it.
 

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to sum up the disaster of your circuit city install...

they ruined your RCA cables, damaged the amp and subs? Were those purchased from CC? Why isn't CC covering the damaged equipment?
 

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Discussion Starter #12 (Edited)
no they werent damaged. he told me they were damaged but they werent. im kinda upset cause he said my old subs were blown so i went and got new ones. tried hooking everything up myself and still the new subs didnt work. its just they didnt wanna take the time and look at my car and tell me what was wrong with it. when i took it back, this guy was much nicer and let me see the problem and explained everything to me. i would have redone everything myself but i dont know much about car audio so i wanted someone else to do it. he said he was sorry for the inconvience and apologized. the only thing that was ruined were the rca cables. subs(new and old subs) and amp are fine and they hit hard as hell now. MUCH harder than my previous system. im keeping the new mtx subs and selling my old fosgate punch subs. thank u to everyone who tried to help me out.[thumb]
 
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