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  Top » Catalog » Chevrolet / GMC Sub Boxes » CHD-210

01-06 GM HD Crew Cab Dual Downfire Box *Best Seller*

Availability: In Stock


01-06 GM HD Crew Cab Dual Downfire Box *Best Seller*

Fits: 01-06 and 07 Classic GM Heavy Duty Crew Cabs
Approx. Empty Weight: 27 lbs
MDF Construction
Installs under the rear seat
Must swing jack out of the way
No other modifications required
Does not affect rear seat latching
Forward folding function slightly affected
Fits 8" round or square and 10" round subs
Cutout Size: 8"=7-1/8", 10"=9-1/8"
Mounting Depth: 6-1/8"
Based on 5.75" dia. magnet
Volume: .55 cu.ft per chamber
Sealed Box, separated chambers
Finish: Carpet
Terminals: Installed
Subwoofers Sold Separately
Customer Video:

We have been asked over and over again if we had anything for the GM full size crew cab HD trucks.  So we went to work on a radical new sub box design for this truck.  The result: a dowfire box that fits neatly under the rear seat and packs one heck of a wallup.  This box hits so hard you will not believe it.  Hands down, this is easiest and simplest way to get big sound in your HD crew. 

As you can see from the photos our box is designed to fit both the the bench seat rear and the 60/40 split rear seat.  You've probably noticed that there aren't a lot of boxes out there for this particular truck.  And nobody does one for the newer style split seats without major modifications required to the truck.  Many of the boxes out there are quite generic-looking or don't fit too good.  Not to mention that when they say you must remove this bracket or that bracket, they actually mean that you have to "cut" the bracket out of the truck.  Not with our box.  Our box requires no modifications to the truck whatsoever. The box fits great and sounds even better.  It molds around every part of the under seat area, including all the tricky seat bracing and supports for an authentic-custom look.  You don't even have to take out the jack.  One of our customers suggested that you can drill another hole in the bass plate of the jack so it can simply be rotated out of the way and re-positioned.  Other than that, just drop the box into place and start. thumpin'.  

This is a two-chamber sealed box with .55 cu.ft. of air space per chamber. It is meant for two 10s or two 8s only.  There is no way to fit 12s in this box so please do not ask.  Two 10s were a challenge and pound quite nicely.  Standard mounting depth is now 6-1/8", and is even expandable to 6-5/8" if you add a 1/2 spacer.  There is no other crew cab box anywhere with a mounting depth that deep.  There are a few knock-off imitations out there but don't fall prey to their gimmicks.  

This box is a must-have if you like your bass low and loud in your HD crew cab.  With out a doubt, this is the loudest best sounding style box you can put in your crew cab, making this box our best selling box for this truck.  Don't settle for anything less than a quality  crew cab box from Subthump.  If some other imitation looks 'cheap', it probably is just that.  Our box is the real deal.  Get yours today, they are going faster than ever! 


Recently purchased your dual down fire box for 06 hd crew cab. Put two kicker comp rt 10" and kicker 800.1 amp for power. My neighbor who lives 9 houses down was watching a game (he's deaf and screams at the tv) came out from his BASEMENT to see what was going on. I've had two 15" jbl's not sound this loud. Very impressed. p.martin



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by David Gonzales Date Added: Wednesday 26 January, 2011
Every else one told me my 2 Alpine Swr-1043d could not fit in my 2007 classic crew cab. After a few E-mails to sub thump we found a solution 1/2" spacers. Put them in last night. They fit like a Glove. I am a very happy customer. Product shipped fast at a great price. Thanks subthump!! I will return. David Salt Lake City Ut...

Rating: 5 of 5 Stars [5 of 5 Stars]
by aaron loudermilk Date Added: Tuesday 02 October, 2012
Very well built box. fits exactly as described. You loose a little bit of softness in the rear seats but hey it sounds very good with my r f p2 10's. 1/2 inch space left on depth. Snug cut out for subs (in a good way) air soace just right for these subs. Im pushing 800w rms @ 4 ohms total and still holding together..

Rating: 5 of 5 Stars [5 of 5 Stars]
by Payton Cook Date Added: Monday 03 January, 2011
Great Sub box, I have two 10" w3's on a Treo amp in my 05 HD crew cab. Sounds great, built strong and right and Hits like heck. I will be buying from Subthump again! A++++..

Rating: 5 of 5 Stars [5 of 5 Stars]
by Howard Young Date Added: Wednesday 07 July, 2010
I own a 2004 Chevy 2500HD I looked high and low for a downfire box that was deep enough to allow som JL Audio w3v3. This is the only sub box that has the depth to do that and still fit correctly under the seat. Order from these guys and you will not be disappointed. Its light weight but built very well. It was delivered fast and the product was custom built to fit my truck interior. There is no box out there for 10 inch subs that is better than this. My subs hit hard. I might even order the behind the seat box from these guys just because they make a great box and I know I am getting quality. I am a real consumer that is very picky and they exceeded my expectations. Thanks guys..

Rating: 5 of 5 Stars [5 of 5 Stars]
by Rikki Martinez Date Added: Monday 11 March, 2013
i got this box cause i could not find a good box for my duramax crew cab. every box i found was cheap and or had bad reviews. i have been looking on subthump for awhile and finally took the chance to buy one and i am really happy with the box!! i got it fast in like 4 days from when they shipped it to me here in idaho. i only got one 10 inch alpine 10d2 and this thing hit hard with my 900 max watt amp (500 wat rms. now im just waiting for my second sub to get here! just make sure u get a sub with the right cubic inches to really bump. the alpine type s are a perfect sized sub. thanks for the box!!..

Rating: 5 of 5 Stars [5 of 5 Stars]

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01-06 GM HD Crew Cab Dual Downfire Box *Best Seller*
Great Sub box, I have two 10" w3's on a Treo amp in my 05 HD ..
5 of 5 Stars!
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