2nd gen sub upgrade using OEM enclosure

[Mesozoic]

My '00 Mounty came with the Mach audio system, but the PO had replaced the head unit with a Sony CDX-M8800. The unit itself seems to be quite capable and the sub amp is wired to the unit's sub output via RCAs. The front and rear speakers appear to be the stock Mach pieces. The steering wheel controls are not attached.

I want to perform a mild upgrade, so I ordered a set of 4 Pioneer TS-A6885R for the front and rear doors, along with a Pioneer TW-SW2002D2 sub to replace the stock unit in the stock enclosure.

I'm concerned with the new sub being powered by the stock sub amp since the new sub calls for 150W RMS, 600W peak with dual 2 ohm coils. I haven't torn into the truck yet, so I don't know what kind of space I'm limited to. I've read 3"x7"x1" for stock amp dimensions on another forum post here, but would like to know if I could accomodate a RF amp with the dimensions: 1.53" x 4.25" x 8.2" in the same area as the OEM amp. Thanks in advance!

 

[DjDom]

Hide the amp for the subwoofer under the rear passenger seat. I did this and the seat still folds down all the way and I don't have any problems.

 

[chefduane]

I made use of the stock amp with a K'wood KFC-XW800F sub: 8" 4-ohm shallow-mount, 2-3/4" to 3" max depth, power range 50-150 watts RMS, peak power 600 watts, frequency response 40-500 Hz, sensitivity 78 dB. Direct replacement, sounds great (to me, at least) and be aware that the OEM sub enclosure will only accept a shallow mount sub. Also, stuff the OEM box with new polyfill and use some adhesive rubber backing for the inside of the quarter panel for better isolation.

 

[Mesozoic]

Pulled it all apart yesterday and discovered the OEM sub amp is actually quite large. It would be pretty straightforward to stuff a much larger amp into that space.

I installed the Pioneer 8" sub, wired the dual voice coils to 4 ohms since the OEM woofer measured out to be a 4 ohm load and I have no idea whether the OEM amp can drive a 1 ohm load. I'm not very happy with the results at all. The sub is definitely noticeable, but it doesn't hit like I would like it to. I wonder if replacing the amp with a higher output unit to match the sub's power capability would be worthwhile.

 

[97exploder19]

I replaced my stock sub with an older NOS Clarion single 4 ohm sub and at first I was really disappointed with the output. After a little while though, the sub started to get louder and now Im pretty happy with it. Maybe yours just needs to break in too.

 

[Mesozoic]

I replaced my stock sub with an older NOS Clarion single 4 ohm sub and at first I was really disappointed with the output. After a little while though, the sub started to get louder and now Im pretty happy with it. Maybe yours just needs to break in too.

Yeah, I've probably not given it enough time to break in, for sure.

I'm not sure the amp is up to the task, though, still. The sub calls for 150W RMS and 600W peak. Maybe I should upgrade the amp?

 

[Big_Pezzy]

I'm sure you'll need to upgrade your amp. Being that you have a DVC, each at 2 ohms, I would recommend wiring it in "series" so the final impedance is 4 ohms. Find an amp that can produce 150-200 watts with a 4 ohm load

 

[Mesozoic]

I'm sure you'll need to upgrade your amp. Being that you have a DVC, each at 2 ohms, I would recommend wiring it in "series" so the final impedance is 4 ohms. Find an amp that can produce 150-200 watts with a 4 ohm load

This looks like it would fit the bill quite nicely: http://www.rockfordfosgate.com/products/details/pbr500x1

Seeing that the sub's maximum power handling is 600W, wouldn't running the amp at 500W into 1 ohm be better than running it at 4 ohms (175W)?

 

[DjDom]

Factory amp puts out somewhere near 75 watts peak. Not even. So there's your problem.

Swap it out for something better and you'll love it. And like someone recommended, stuff the box with polyfill and put a noise isolater behind the box. Dynomat would be perfect.

 

[Big_Pezzy]

When it comes to car audio, focus on RMS power. Match the RMS rating of the woofer to an amp with a similar RMS output (doesn't need to be exact. A little more is ok). I say to wire the woofer at 4 ohms because your only other option is to wire it at 1 ohm. Most amps can't handle a 1 ohm load safely. That series of amplifiers from Rockford is stable with that low impedance however. If you choose to wire the woofer in parallel to achieve a 1 ohm load, I would suggest a smaller amp. hhttp://www.sonicelectronix.com/item_34758_Rockford-Fosgate-Punch-PBR300X4.html

this one is rated at 300 watts RMS. Another thing to consider, amps will get hot if the load is very low. I assume you will use the stock location which is not very well ventilated. I say get the amp you suggested earlier but still wire the woofer to 4 ohms. Safer and only a $10 difference between the amps.
http://www.sonicelectronix.com/item_43423_Rockford-Fosgate-Punch-PBR500X1.html

 

[chefduane]

... and put a noise isolater behind the box. Dynomat would be perfect.

Dynomat! That's it. I couldn't think of the name of it. Available at Home Depot IIRC.

 

[Mesozoic]

When it comes to car audio, focus on RMS power. Match the RMS rating of the woofer to an amp with a similar RMS output (doesn't need to be exact. A little more is ok). I say to wire the woofer at 4 ohms because your only other option is to wire it at 1 ohm. Most amps can't handle a 1 ohm load safely. That series of amplifiers from Rockford is stable with that low impedance however. If you choose to wire the woofer in parallel to achieve a 1 ohm load, I would suggest a smaller amp. hhttp://www.sonicelectronix.com/item_34758_Rockford-Fosgate-Punch-PBR300X4.html

this one is rated at 300 watts RMS. Another thing to consider, amps will get hot if the load is very low. I assume you will use the stock location which is not very well ventilated. I say get the amp you suggested earlier but still wire the woofer to 4 ohms. Safer and only a $10 difference between the amps.
http://www.sonicelectronix.com/item_43423_Rockford-Fosgate-Punch-PBR500X1.html

Ok, that's what I wasn't sure of... whether to run it at 4 ohms or 1 ohm. The PBR500X1 amp is actually smaller than the OEM amp, but packs quite a bit more power! Is there a difference in sound quality when running a sub at 1 ohm vs 4 ohms? My understanding of these Boosted Rail technology amps was that they do not run hot due to their design, so running it at 4 ohms or 1 ohm shouldn't make much of a difference.

 

[Big_Pezzy]

how you wire a sub makes no difference it's performance. It's the amp and enclosure that will ultimately determine the way the woofer plays. To be honest, the setup you're describing wouldn't exactly be a "sound quality" setup. It'll be a great improvement from stock and I'm sure you'll have a smile on your face but don't expect a revelation or something haha.
It sounds like your main concern is keeping it "stock" so just slap the woofer in there (after reinforcing the enclosure as stated in another post) and wire the amp. I believe the amp is supposed to take a 10 gauage power and ground, but you can squeeze 8 gauge in there

 

[Mesozoic]

Ok, thanks so much for all the input. I'll get 'er wired up for 4 ohms and report.

 

[toypaseo]

Dynomat! That's it. I couldn't think of the name of it. Available at Home Depot IIRC.

Dynamat is not available at Home Depot. A product used in a similar fashion as Dynamat might be available at Home Depot. You can Google "Dynamat Home Depot", or similar terms, for more info.

 

[chefduane]

Yeah, its kind of a thick rubberized product with adhesive on one side. Peel off the backing and stick it on the inside of the quarterpanel. I can't for sure say it was called dynamat but I did get it at Home Depot. Pretty good sound deadener.

 

[Anticitizen1]

How did the final product turn out? I have a 1998 XLT with pretty much a fully stock sound system, not mach or premium, and I would like to do some modest upgrades like good 6.5" door speakers, 2 or 4 tweeters mounted up high, and a decent subwoofer utilizing the stock cover and location as it currently does not have one. I don't know much about audio electronics as of yet, still self educating at the moment. I appreciate the help guys.

 

[Mesozoic]

I used a couple of Rockford Fosgate Punch amps, one dedicated to the sub and a 4-channel for the front and rear door speakers. For speakers I used all Pioneer stuff, including the sub. Sounds great!