factory amp for aftermarket subwoofer?

[03EXPO4x4]

I want to just replace my 2003 factory 8" with another one.
Will I need a 4 ohm single or dual voice coil to work with the factory amp?

 

[Skauber]

Ford has used many different setups, so you will need to check yours. I do suspect it's a dual voice coil though

 

[Lostneye]

Ford has used many different setups, so you will need to check yours. I do suspect it's a dual voice coil though

This

 

[03EXPO4x4]

Also i read somewhere else that the factory amps only give 15-25 to the sub. Can you still use a subwoofer that needs a minimum of 50?

 

[Lostneye]

I have no idea what the factory rating is and there are multiple setups used so you will have a hard time knowing for sure. I wouldn't go with a lower impedance than the factory sub as it may overheat the factory amp. As far as too low power it won't hurt anything on it's on, however if you push the amp to hard and it clips that can damage the sub and the amp. It also might not be as loud as the factory sub.

Is your sub blown or are you just looking to upgrade?

 

[03EXPO4x4]

I'm just looking for an upgrade its an 2003 ford eddie bauer expedition

 

[Lostneye]

Also don't expect a night and day difference. These are still large trucks with a lot of interior air volume to move. I have a 500W amp and Polk MM 8" in the factory THX box. It's noticeably better than stock in sound quality and I can turn the whole system up louder now without distortion but one 8" isn't going to set off car alarms or give you double bass hits you can feel in your kidneys.

 

[03EXPO4x4]

yeah, i expect it not to be real loud, but it has got to be better than the one i have now. so much distortion. haha

 

[johnboneske]

I plan on using my enclosure as a template for a new one. I am gonna mock up a cardboard box for the outside of it, and then build a new enclosure out of fiberglass and enlarge it where I can so i can fit a 10" in it. First I am gonna try and use the factory amp with my 4ohm DVC sub. When I get to it and build it I will follow up with pics so you see how it turned out...

 

[Lostneye]

yeah, i expect it not to be real loud, but it has got to be better than the one i have now. so much distortion. haha

I accomplished this. There were different systems so yours may be different however the Lincoln THX sub(which is stamped Ford DVC 2ohms 50W each) has a bolt through the back of the enclosure into the back to the sub. You will have to take the box out to get to it. And you will most likely need a spacer fit an aftermarket sub as it is pretty shallow. Also plan on sound deadening. There was plenty of rattling after the install and I had to take the panel back out and used sound deadener on the panels and closed cell foam weather stripping tape around the edge of the sub to seal it against the panel so it would vibrate less and push more air through the grill.

It went from distortion at half volume on most source material to pushing past 75% without issue.

I will eventually upgrade to at least a single 12 but will keep this setup as well to use when I need the room and remove the larger box.

I plan on using my enclosure as a template for a new one. I am gonna mock up a cardboard box for the outside of it, and then build a new enclosure out of fiberglass and enlarge it where I can so i can fit a 10" in it. First I am gonna try and use the factory amp with my 4ohm DVC sub. When I get to it and build it I will follow up with pics so you see how it turned out...

The JL Stealthbox uses a 10 and is noticeably larger than the factory boxes so that shouldn't be an issue. If you're going through the work I highly suggest you A. upgrade the amp and B. cut out the panel and add a larger grill as the JL setup does to get the extra air moved by the 10 out from behind the panel. And don't forget to sound deaden.

You don't need to go crazy with sound deadener for decent results. Going all out is expensive and will add a decent amount of weight to the vehicle. Using a small amount of dampener tiles i.e. Roadkill or Stinger. I've been using Stinger Roadkill Expert only because I got a deal on them. You are looking to add mass to cut vibration so focusing on problem areas goes a long way. You don't need to fully cover a panel or multiple layers for results.