I need assistance, and a sanity check!

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I understand all sorts of computer hardware, software, networking, systems, servers, etc. but I cannot for the life of me wrap my measly little brain around this whole car audio thing!
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I am looking at upgrading the stereo system in my Lightning, but I do not want to spend massive amounts of money (under $750- total, if possible). I am hoping to do this piecemeal, starting with front speakers and an amp, and I would like to do the install work myself or get some friends to help. Here's my thought process so far:

1. I want to keep the Ford/Visteon CD-6 headunit I have now.
2. I want to replace the front door speakers with Infinity Kappa 60.2cs components. (specs say 90W RMS)
3. I need an amp, but I don't know what specs to look for. (*see below)
4. I want to either replace the rear speakers with Infinity Kappa 572.3 coaxials or remove the rears altogether and install an MTX Thunderform instead. This will depend on whether I can get the amount of bass I want from just the components.

So the question for the moment is: what amp to get?

*After doing some naive-newbie research, I found the MTX Thunder 4244 amp. The MTX specs say this is a 45w x 4 @ 4 ohm, and 120w x 2 @ 4 ohm bridged (all at 12.5 VDC). I don't know if this is a good amp for my application, but I really liked some of the features: high-level inputs w/smart power engage, front hi-pass filter (defeatable), rear low-pass filter (defeatable).

My thoughts with this amp are that I have 4 channels to drive the 2 components and the 2 coaxials, or I can drive the components in front and bridge the rears to power the Thunderform.

So, am I off-base here, or is this doable? Is this amp going to be enough to power the speakers that I want? Please, any comments and/or assistance is well appreciated. Thank you!

 

You are on the right track. I have a similiar setup now in my truck. MTX 4160 (about the same as the 4244) driving components in the doors and a single 12"sub. If you are planning on the thunderform, I would use a 2ch sub for the front and a stronger amp for the subs. Say about 50w/ch for the doors and 400 for the subs.

 

Thanks isaiah, for the recommendation and the small 'pat on the back.' It's reassuring to know I'm not completely off track.

On a friend's recommendation and hunch, I was able to find an MTX 6304 for $250- at Good Guys. I haven't purchased it yet because I wanted to come home and do some research on it. Here are the specs on the 6304:

12V @ 4ohm -- 37.5w x 4 or 150w x 2
14V @ 4ohm -- 90w x 4 or 325w x 2

I'm starting to think at these specs and at this price, this is the way to go. The only thing I am 'worried' about is this amp seems to push the 90w RMS on the components... is this going to be okay?

What do you (or anyone else reading this!) think? Thanks!

 

Having more amp power than you need is not necessarily a bad thing. Just be careful when you max them out. If you hear any distortion turn it down a small notch and you'll stay out of trouble.

The suggestion with 50x2 up front and 400w for sub sounds right on.

For a fuller sound stage use the head unit to power the rear coaxials.

Without looking up the specs on the separates that you want to install up front, don't expect much of any bass from 5 1/4 woofers and 6 1/2 woofers aren't all that much better. Without a sub try 8inch woofers in the doors.

With a sub it doesn't matter what size the front speakers are if separates because your sub will take care of everything below 70-120hz (depending where you set your crossover). I prefer lower like 70.

If your front speakers will be run through a high-pass crossover and not have to reproduce any low bass frequencies you can probably get away with 34-40wrms per channel. Remember bass frequencies use the most power.

 

p_ferlow -- thanks for the suggestions!

The MTX 6304 amp does have a built-in hi-pass crossover, so I will be doing almost exactly as you stated.

I can't beat the price of $250- for an MTX 6304 amp, otherwise I'd consider getting a smaller amp just for the components. I am considering adding an MTX 6500D Class-D amp (250w x 1 @ 12V, 450w x 1 @ 14V) just to power the subwoofer, but at what point do I need to start looking at upgrading the battery, alternator, etc?

Thanks guys, keep the suggestions coming, please!

 

Don't worry about alternator/battery upgrades until you start eclipsing 700-800wrms. Even then I'd just add a 1 Farad stiffening capacitor. If you're on a budget shop around and get one without the fancy digital voltmeter on top. We've got a voltmeter in the dash anyhow. Shop around. You should be able to find a 1F cap for around $85 bucks. They used to be a lot cheaper years ago before the car audio guys/gals made them popular.

Don't forget to check your battery once a year, top it up with distilled water... even the "maintenance-free" batteries need looking at once in a while.

I'm not sure about the V-6 but most of the F150's if not all V-8's have 130 Amp alternators.

I was running about 500wrms in my old Ford Ranger S/C and I was able to bounce the voltmeter and turn the headlights into disco-lights. Then again... it only had a 90A alternator.

The other thing to remember is that class-D or class-T amplifiers are 75-85% efficient compared to traditional class A/B efficiency of 50% so you'll be drawing less from your electrical system for the same output power.

If you're going 300+wrms or more on the subwoofer seriously consider running a 4 gauge power wire and a 4 gauge ground wire from your amp location to the battery and put an inline fuse at the battery on the positive wire rated to 40-60 amperes. I use inexpensive brass distribution blocks at the rear where the amps are that have a single 4 gauge in and 4, 8 gauge outputs. I have dual power terminals on my Rodek amp so I run twin 8 gauge cables to it... two positives, and two negatives. Don't trust the OE ground strap from the cab to the frame and then frame to battery... always run a dedicated ground cable. It avoids noise too.

You can run the power cables through existing rubber grommets on the body underside. Drill a hole in the grommet and pull the wire through. Seal it with silicone inside and out. Tie up your wires with zap straps.

I bolted the 4 gauge power wire to a terminal under that plastic cover in the engine compartment, on the firewall close to the battery, where the 4 gauge wire comes from the alternator. Makes for a less messy install by not hooking directly to the battery. Keep in mind that your alternator sees your battery as a load when the motor is running. Adding another battery only increases playing time when the motor is off and you're parked up. While running it adds resistance and draws off the alternator.

 

Thank you! This is great information, and I'm loving this stuff!

I was already planning to run 4 gauge power wire, but I hadn't heard about running a ground wire back. Should this ground wire also be 4 gauge? Can I run the ground wire parallel to the power wire for the return? I'm assuming the ground wire should connect back to the negative battery terminal?

I have also considered replacing the stock battery with an Optima dry cell, something like the "yellow top".

The Lightning has the v8, so I think I should be good on the alternator.

Just FYI, here's my revised plan:
Phase 1: Infinity Kappa Perfect 6.1 components, MTX 6305 amp, LOCs, installation
Phase 2: MTX Thunderform subwoofer, maybe MTX 6500D amp

Now I need to find out just how to run all these wires. I can pull network cable, but I've never messed with audio stuff. Or maybe this will be a Car Toys install job...

Woohoo, spending here we come!

 

Yup... what goes in must come out so 4 gauge power and 4 gauge ground cables. Yes, ground goes to negative battery terminal.

I can't remember now but there are some cables or lines running to the rear of my supercab 98' on the passenger side. You can run your 4 gauge power cables from the battery towards the firewall, then follow the firewall down and underneath the vehicle, tying to existing cables or piping under there.

Yes, you can run both cables side by side together. It's DC so no worries. The cables have plenty of insulation on them.

Don't forget the fuse at the battery on the positive wire or by the firewall like I said is a good place to connect the positive wire. In a t-bone accident (god forbid) if you don't have a fuse on the power cable you could start a fire because if the insulation of that 4 gauge cable is broken by sharp metal it will start some serious arcing. Use a fuse all the time!

I usually recommend the slow-blo fuses at a lower amperage rating. If you think you'll draw 50 amps max then get a slow-blo 40 A for instance. It usually takes something like 100A to blow a slow 60A fuse.

Optima dry cells are nice batteries. I was considering replacing my OE battery from the get-go but decided to leave it. The main reason to change your OE battery is to avoid spilling battery fumes/acid on the metal parts of your engine compartment. As you know, most older cars have serious rust where the battery sits. The completely sealed dry cells are great to keep your new vehicle in new shape. I think they're only rated for something like 700 or 800 cranking amps though. Plenty enough but there are higher capacity batteries out there.

You can do the work yourself. Just be careful and disconnect the battery while doing electrical work. Remember, rubber grommets can be replaced, drilling through body metal can't be... not easily anyhow.

Have fun!