Anyone running an upgraded sub off the stock amp?

[Swerny]

Hey Guys,
I read in the FAQ that running a 4 ohm sub off the stock inverted amp wasn't the best idea.
Has anyone upgraded their sub to a 10 or 12 inch that is using the stock Kenwood amp to power it?
I am looking to add a 12 inch Infinity 1230W in a sealed enclosure, and would like to keep the stock amp to start.
Thanks!

 

[dynastims]

i have a 12in sony explode sub in a ported box with the factory kenwood amp. that amp is actually pretty good for what it is. the sub i have isn't all that but i think it hits good and so does everyone that hears it. the only problem i have is that i have the gain up all the way and if i drive a long trip and it is hot out the amp will get hot and shut off, but that is a good thing since it saves your amp from blowing up. as soon as i fold the seat down air hits the amp and withing 3 minutes it is cooled off and starts working again. so if you don't have 300 to spend on an amp the factory will work fine

 

[Swerny]

Cool, thanks for the info dynastims.
I had to do the same thing with the system in my old car, the amp would overheat after really long drives.
Anyone else?

 

[DSMConvert]

mspeed#267(david) is running a 12 fosgate I believe...sealed box off the stock amp...damn thing bassey as hell makes my eyeballs hurt...he also went ahead and installed 6x9s in the back "fake" grills when he removed teh stock sub enclosure...hopefully he'll come across this thread and respond...

 

[Riles]

I am running an Audiobahn 12" high travel (big foam surround) on the stock amp. It really sounds great- not overly loud, but loud enough to make all of the music sound good. I take it out every now and then for the track, though, cus its big in it's box.

I just have to be careful to turn the non-fading output down to -9 or -11 on the headunit in order not to blow fuses in the amp (found that one out the hard way... many times)

 

[Swerny]

Thanks for the info guys, i'm going to run that setup myself for the time being.
I don't have the $ right now for amp (s).
I will look at adding amp (s) when i upgrade my front speakers down the road.
I just hate the stock 8 inch sub.
This way, when i need the trunk space, i can just yank out the box with the 12 and use just the stock 8 inch.
Anyone else?

 

[mspeed101]

I have a 12in. sub also hooked up to my stock amp. It sounds really good I have only had it shut off a couple of times on me but thats because I have the bass very high.

 

[Swerny]

Now have you guys left the stock amp in the stock position (inverted) or have you moved it to a better location cooling wise??

 

[Swerny]

How big a box are you guys running in cubic feet?
I dropped buy Best Buy to take a look at enclosures, and they had a deal on one of the pre-made, Q-Logic boxes.
It was on sale for $79, and was the exact size i needed for the Infinity sub i'm getting , 1.25 cubic feet.
The damn thing won't fit in my trunk!
How are people running 12 inch subs back there?
I guess i need a sub that can run in a smaller box?
I had hoped to put the new box under the amp, but there's hardly any room there at all.

 

[Riles]

You should just get a smaller box and stuff it. Also, 80 bucks is way too much to pay for a box for a single sub! My recommendation- get a walmart box, seal it yourself with caulk, and stuff it a bit. I'm running a little over 1 cubic foot, and it just fits perfectly- another centimeter either way and it wouldnt fit. It is a very tight squeeze.

Also, you could always remove the amp rack if you really wanted more room for the sub, but this would take away the ability to easily remove the 12 when you need space.

 

[Swerny]

It was a Q-Logic box, regular price was $130 Canadian, on sale for $80 Cdn.
The area under the stock amp is 15 inches tall, 15 inches wide.
Is that where you guys have your 12's sitting?
The parameters for the sub were 1.25 cubic feet with poly fill.
I could go slightly smaller I guess, but even then, using 3/4 inch MDF + a 11.25 inch cutout for the sub, = 12.75 inches. Not much margin for error.
I want to keep the rack there so i can go bck to the 8 when the box is out.
I might just get a new Fosgate or JL 4 ohm 8 inch and drop it in the stock enclosure.
Thanks guys!

 

[_Sloteg_]

mspeed#267(david) is running a 12 fosgate I believe...sealed box off the stock amp...damn thing bassey as hell makes my eyeballs hurt...he also went ahead and installed 6x9s in the back "fake" grills when he removed teh stock sub enclosure...hopefully he'll come across this thread and respond...

John when you heard my sub all of my setting's in the head unit had been reset the battery must have died again i guess.you should hear it now it sound's ten time's better now!

I'm running a 12" Rockford Fosgate Punch Z sub on the stock amp in, a sealed box that i made myself.it sound's so much better then the stock system now, all i need now is a amp for my 6x9's.......(lol2)

Also, i do not have the gain turned up on my amp very much,maybe 1/2 way up. it took me a little while to get the head unit setting's just right with the new sub.

Good luck with it!

 

[Swerny]

Well, i just bought a RF Punch Stage 1 12 inch. I'm building the box as we speak out of 3/4 MDF.
The external dimensions of the box are 14 x 14 x 14, so it will slide into the space beneath the stock amp.
I'll keep everyone posted as to my progress.
Thanks for the help.

 

[MazdaSpeeder00]

Ive been running two 12's off the stock amp for 10 months. I havent had any problems with it shutting off or getting to hot. It hits hard and sounds good. I mounted the amp to the back of box. Ive thought about running a new amp and wires but i dont find it necessarry.

 

[Swerny]

Wow! How did you fit 2 12's in the MSP trunk? Did you pull out the rack?
Thanks!

 

[1sty]

Wow! How did you fit 2 12's in the MSP trunk? Did you pull out the rack?
Thanks!

If neccissary you could fit 4 12"s in an MSP truck. (thumb)

like the others have said the factory amp is a decent little amp, on a lesser sub anyways. The point of relocation is to aviod the termal protect, which is not a good thing to hit. Its best aviod especialy on kenwood amps which don't have the most fail safe protection circuits. To maintain the logevity of the amp I would suggest its relocation and if your going to a 4 ohm sub, I would also highly reccomend running a new power and ground wire of 8 AWG instead of the stock wiring that goes through that clip connector.

Also don't make the box 14"x14"x14"... thats a big car audio no-no as it can creat standing waves in the enclosure. Make it longer and less deep.
perhaps 14" x 17.5" x 11.5"

 

[Swerny]

1sty, thanks for the info.
I'm sure 4 12's would fit with the stock rack gone.
My box is done, so too late I guess. I just have the final putty and sanding to do then paint.
Funny thing is, the shop i bought the sub from called Fosgate in front of me and those were the specs they gave him.
It gives an internal volume of 1.13 cubic feet.
Tat way, it fits right under the stock amp, and in between the trunk hinge and the stock enclosure.
As for the wiring, i'll take your advice sooner rather than later.
Thanks again.

 

[1sty]

1sty, thanks for the info.
I'm sure 4 12's would fit with the stock rack gone.
My box is done, so too late I guess. I just have the final putty and sanding to do then paint.
Funny thing is, the shop i bought the sub from called Fosgate in front of me and those were the specs they gave him.
It gives an internal volume of 1.13 cubic feet.
Tat way, it fits right under the stock amp, and in between the trunk hinge and the stock enclosure.
As for the wiring, i'll take your advice sooner rather than later.
Thanks again.

Use polyfill then and you should be ok.

Why are you sanding and painting an MDF box? Why not just carpet it?

 

[MazdaSpeeder00]

Wow! How did you fit 2 12's in the MSP trunk? Did you pull out the rack?
Thanks!

LOL.. yeah i took out the rack. It took me about 20 minutes and then another 5 to figure out how in the hell to fit that box in the trunk. Finally i wiggled it in there.

 

[Swerny]

Use polyfill then and you should be ok.

Why are you sanding and painting an MDF box? Why not just carpet it?

Yeah, i was wondering about polyfill. It cheats the woofer into thinking the box is bigger than it is right?
As for sand and paint, i didn't want carpet, so i'm doing a gloss black with orange speckle paint job, just for fun.