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Size 13.5" x13.5" x 19"



Featuring the Transmotional Insert

In this animated illustration, you can see the adjustable insert in three possible positions.

FREQUENCY RESPONSE OF DIFFERENT POSITIONS


This is the actual response test done on each of the three positions above.
 
 
A STUDY IN POWER HANDLING

Explains why this is the best 10 inch sub box design ever!


The Death Box was originally a study in power handling.  We studied why woofers blow up, especially in band pass boxes and in the process optimized a design to minimize the negative effects of abuse.
 
I guess you can tell we were in the car audio business! This process of seeing how far we could take a 10 inch woofer and what the causes of failure were, is how the box got it's name.
 
We built and tested over 95 revisions of the classic band pass box to improve power handling and SPL.  This lead to eliminating the typical port and replacing it with a symmetrically perfect duct system that kept internal pressure evenly distributed on the woofer cone.
 
We also found cabinet resonance would excite the woofer in negative ways and reducing it improved performance.
 
Adding a restriction to the duct assembly outlet created a duct that would now resonate across a wider frequency band (like a vero-vent) and that improved power handling again.
 
Creating a fixed symmetrical duct / baffle assembly that was transmotional allowed the circuit to be optimized for different woofers and tuned in its final destination, the room or car.
 
The resulting transmotional duct system yields symmetrically even pressures on the speaker cone, hence we named it SCD (Symmetric Compensation Design).
 
A secret to successful car audio systems is of course your subwoofer, or foundation. Understanding that a car is not a living room, but rather a box is the first step to understanding cabin gain. When you put a box in a car, you are actually putting a box inside a bigger box, thus creating additional orders. Because of this reactive capacitance all around your box, having two 12" woofers openly firing into the car is usually asking for all kinds of performance variables. This is the reason why one enclosure will sound good in one car, and terrible in another.
 
We have determined that to minimize these loading problems, and to allow an enclosure to breath freely, it must be consistent with a small box to room ratio of less than 15%. It is also desirable to control the air space in front of the woofer by removing the capacitance created by flexing metal in your trunk. This is why we chose a band pass design to begin with.
 
There are currently copies of this box being marketed that do not employ SCD technology, are not transmotional, and are not able to be tuned to your choice of subwoofer and car. Needless to say the results are inferior. DECWARE makes the only original Death Box.

Deathbox White Papers



 


COMMENTS from Users:


"This is for Steve, I called you last week about the Death box. I ended up adjusting the insert  at 2 inches from the end. Stuffed the back with polyfill, and screwed it to the floor of my trunk. !!!WOW!!!  

I have the 2 JL10W6's running Isobarically with around 300 watts rms to each one. Yikes. I can really make the earth move now. When I turn it up I wonder why I bought Bass Shakers. I was testing it out for polarity and wiring and I blew the back end of the box off. All the screws weren't in. It almost has more bass than I need. My 5-1/4 comp. set cant balance it that well. no problem though."
 

- Troy from North Dakota


"Steve,  There is only one word to describe that box  "Awwwwwesome"! It didn't seem to play as loud as my bass reflex box but when we cranked it up I was amazed in how clear it played. You could hear definition in the bass tracks that just weren't there before. I could boost the bass as much as I liked with no sign of distortion.

The one major problem with your Death Box design is once I compared it to my bass reflex I can't stand my old box anymore. It really sounds mushy and distorted in comparison to the Death Box. Any way I just though I'd let you know that we got the box built and  installed in the old Honda and we love it. My son is getting all kinds of  compliments on the sound. I appreciate all your help in this project and hope to try some more of your good stuff.  Thanks Much!"

-Larry Daube


"Steve.. Well, I built the Deathbox for a friend for his home theater, and he LOVED it!. It was built with a 10" DVC Radio Shack Subwoofer ( my friend is a little cheap) with an advertised QTS of .52 and it still gave great performance (of course, I've never heard it loaded with a driver with the proper T/S parameters). . Thanks for the great design!  Thnx, "

-Nik Martin  


"Dear Steve, Your Deathbox is slowly starting to p*ss me off. I had a box with 2x 12" 's in the trunk of my VW 16V Gti Golf and two 8" mid's on the package tray.  Worked fine, except; no bass. 
So I built the deathbox (10" version).  Got a brand new woofer; new wires and everything I needed.  I looked at the wood and the woofer for a long time; to intimidate them, like you suggested.  Then I started...

There's so much bass in the car now, that I had to install mid's in the front kick-panels (which I did a very nice job of, if I say so myself), and some tweeters in the dash, and of course everything is wired up with your phase delay wiring scheme.

So now I can make my nose-hairs itch with bass, and I've got the most incredible sound in the area.

So I just wanted to let you know, apart from the fact that I'm slightly broke at the moment, if you don't hear from me again, it's most probably because my girlfriend killed me "because I love my car more than her..."

Thanx for a great Web site and THE best designs I've ever come across.

P.S.  I'll let you know how my Housewrecker turned out."

-Piet Steyn 
Dept. Engineering 
Potch University 
South Africa 

"Steve..
thank you greatly for the plans.. I have never heard  a 10 inch woofer 'boom' as loud as now. It actually shakes the  front 2 seats! I do believe i can gain more however because i am only using a 200w amp. Finally, I would once again like to congratulate, you and your company.

From another extremely pleased customer." 

-Ryan. 

 

"Dear Mr. Deckert,

Your web page is absolutely fantastic. I read about it in  the newsgroup rec.audio.car, and decided to give it a read.  I was amazed by the fact that someone has put together the  facts and great examples that everyone who ever wanted to  upgrade their stereo system needs to read. I will recommend your web page to all of my friends interested in car audio  (almost all of them).Thank you for showing signs of  intelligent life on the web." 

-Chris Almaguer 

 

"This is a bit long-winded, but I just have to share this with everyone here. I recently built a pair of deathboxes for my Infinity Beta 10s and have been raving about them ever since. Since then I've settled on just using one of them in the hatch of my '96 Integra; with 600W it's delivering all the bass volume I need. However, I've been curious to see how it stands up in a back-to-back comparison.

Bandpass enclosures have a reputation for bad sound quality, even if it's specifically designed for the sub, so this "one-size-fits-all" approach just didn't seem right to me. I'm also considering upgrading my drivers, because the betas are severely excursion-limited when I push them hard. In my hunt for my next subs, I've been practically laughed at when I say I want a good sound quality sub to put in my BANDPASS box.

So I had something to prove. To myself, if nobody else. Skeptically equipped, I set out tonight to compare the two. One of my Betas went into the Deathbox, which I had just treated to a very thorough sealing of every seam with the ol' hot-glue gun. The other beta went into a wedge-shaped sealed box that I built to Infinity's specifications for this particular driver. I hooked up the sealed box to the bridged output of my amp and sat down for a reference listen... this is the application my subs were BUILT for.

Some may scoff, but for this comparison I popped in Rage Against The Machine. Lots of quick kick drums, low bass guitar, and some bizzare growling noises from the heavily effected lead guitar. Not my usual listening material, but this CD gives ANY sound system a good workout; and in a particularly rare example from a modern record label, it's actually well recorded to take advantage of the full dynamic range of a CD.

First impression: in the sealed box, the Beta shines... quick transients, very low extension, and pretty good SPL for a single 10" in a small sealed box application (I can thank the amplifier gods at harman/kardon for that). Yeah... this is why I bought these subs. Thoroughly impressed, I switched the leads to the Beta living in the deathbox and returned to my seat. I didn't change anything else... all volume levels, gains, etc. throughout the system are identical. Press the button to un-mute the deck and return to the same track on the CD I was listening to. Suddenly the kick drum is somewhere INSIDE my chest. The bass guitar is hitting me with this growling sound that exists in some octave below what he's playing, a sound I could never quite identify before. I can just about FEEL the guitarist's pick hitting the strings. The transients are just as fast, if not faster than before. Subjectively, I'd say SPL is up about 3-6 dB... at the exact same head and amp output. And low frequency sounds I didn't notice before are right in my face.

About this time I'm figuring that my neighbors may be getting a little annoyed, so I had to end the show and go back inside. But I just wanted to anyone who's interested know... this is good stuff. I can't tell if it's this good for any driver, but with the Betas it was incredible. And this is a 10" driver that audio magazines already compared in output and LF extension to a very good 12" driver. I've said it before, but thanks, Steve."

-David Manning


 

"151.8 dB!

Well Steve - I have some news to report to you about my 4 Decware DHM-108 subs and their corresponding deathbox's.  My system got done enough to go to Soldotna (a town 2 hours from Anchorage) yesterday with my truck for a competition.  Everything was up and running by noon in my truck - and I was at the competition around 3 pm.  I was too late to compete obviously, which is fine since MANY small details aren't done (motorization, fan system, mirrored amp rack cover, etc), but I was able to do the Outlaw SPL (just for fun). 

In case you forgot - I have four standing Db's together looking like (actually, it IS)one 20 inch tall, 52 inch wide, and 13.5 inch deep enclosure with 4 half moons at the bottom (of course).  It is directly behind the seats in the x-cab - just below the back window (even with the amp rack on top of it).

 Anyway - back to the results.  From first impressions - I realized I tuned the box a bit too high - I didn't turn up the bass at all on the  drive there, or even use the eq - I had the sub gain ALL the way down on  the amp (300hc MMATS class D amp - 1200w RMS at 90% efficiency) - the subs crossed over at 70 hz (on the amp at 24db) - the bass q turned up  just enough to allow the minimal bass.  I was expecting pretty much NO  bass (I'm used to 4 15" in my Jimmy), yet what I got was actually a bit  of punch around the 55-70 hz range.  No low end.  I was a little  worried.

 When I got there, did some tweaks, I was feeling pretty good.  I 
immediately turned the eq on and turned down the 63 and 90 hz 
frequencies down to -6 db, and turned up the 45 hz range to +3 db (my lowest frequency control).  This was a little more what I was used to.   With the gain turned up to quarter on my amp, the loud button on, and  the bass q turned up to about a third, I had a decent amount of low end  (down to about 35 hz fairly flat, peaked at 45hz(duh) - still a little  punchy at 55-70hz, but just a little.}  This was decent for me - and I'm  used to being able to play my other system at 140 db from the front seat 
at 30 hz. 

It was sounding quite good to the small crowd that was 
gathering around my truck to see where the bass was coming from.  When I rolled down the windows, the frequency response seemed to be to go down to near 25 db before it really dropped off.  So I was feeling much  better - even though I tuned the box a bit high (didn't spend near as  much time as I should have), with quick adjustments I could get the subs  to still drop pretty well, especially for tens.

I then turned the bass down and started the system for sound quality.   I was playing some cd's with my friend (he had the second highest score  overall in the competition - lost best of show and his class by two  points, just because he wasn't an IASCA member), we started talking and  let a track play that we didn't plan on listening to. It was a song that  I've listed to 100 times in my Jimmy, and it has a reoccurring bass note  at somewhere between 70 and 100 hz.  With my 15's x-over at 80 I could  get this note to play quite loud - but nothing special.

Well, we both  stopped talking because we could audibly hear the note quite well from  the subs - even though they were crossed over and tuned WAY down around that range. Right then we both got giddy - and started messing with the eq.  I tuned the eq at +6 at 63 and 90hz, turned the amp gain up to a  little over half, and turned the bass q gain to half.  I played the song 
again at a moderate volume and the bass was INCREDIBLE! 

It was BY FAR the loudest PUNCHY bass either of us have ever heard.  Even though the ports were obstructed by the seats and I wouldn't turn the volume past 20 (too loud), our shirts were puffing forward from the air flow. 

A LARGE crowd gathered around us - and our windows were UP with other  competitors playing their systems at the same time.  NO ONE believed 4  tens could hit that hard - but they could see only a 6 cubic foot box -  so they had to believe it.

To make a already much too long story short - I decided to to do 
Outlaw SPL - and lost by .1 db.  They let us put the microphone 
ANYWHERE, and with competitors with multiple subs and more power than me (one with 6 15" and 2300w RMS), putting the microphone practically in ports, I hit 151.8 db with the microphone between the seats, 6 inches from the nearest ports and about a foot and a half from the other two ports. 

I played a 70hz note five times (10 seconds), the volume at 20 
(out of 30), and all the gains a little more than half, with the mids  and tweets amp off. I was cautious - not wanting to blow a sub, and I  still hit EXTREMELY hard.  It may not drop as low, but it is  SIGNIFICANTLY louder in my Tacoma in the front seat than my Jimmy - I  probably would hit 146-148db (or more?) in the front seat in the Tacoma  if I tried - I'm just afraid to try. I need to get used to the limits  of my system before I really know where to push the limits, this was all in the first 2 hours of bass tweaking... not bad. ;)

I am already VERY happy with the enclosure - I easily have enough low  end for my sound quality, and if I ever need to I can blow peoples hair  forward if I try.  Since I was never gonna drop super low with that limited cab area - I guess it's good I tuned it a little high to wow the  crowd with SPL - 'cause it's kinda fun. I guess I meant to do that all  along.

Well, now that I've written you a complete novel - I'll go. Thanks again for your enclosure design, and I'm looking forward to my installer  getting on to his Wicked One ported into his cab. He's ecstatic about  my SPL performance - and is very impressed by everything I've shown him  of yours. I still plan on sending you pictures when I'm REALLY done.... "

-Dan (from Alaska) 





HOW TO BUILD ONE YOURSELF


  • SKILL LEVEL: This is an easy box to build provided you have a good table saw and can make accurate cuts.
  • TOOLS NEEDED: Besides a table saw (with sharp blade) you will need clamps, carpenter's wood glue, a sander (belt sanders work well) and a drill.
  • WOOD NEEDED: The box can be built from exactly 1/2 sheet of 48 x 96 inch plywood, MDF or high density particle board. Below is a cut-sheet illustration showing how each panel should be laid out for cutting:
  • TIP The trick to assembly is to construct the insert first.  Then wrap the side panels around the insert and install the bottom panel.  This way the insert will move inside the box with a perfect fit. 
  • SCREWS are typically only used to fasten the removable top (lid) so that the woofer can be accessed.  If you properly build the box with wood glue and clamps, nails are not needed as the glue becomes stronger then the wood itself.  If you have an air nailer, you can use 2 inch finish nails to hold the panels together in place of clamps while the glue dries.
  • FINISHES:  The most common way to finish this cabinet is to paint it.  There are tons of finishes available that can make the box look like anything from rock, to marble.  Also you can use real wood veneer for a completely professional look in the house. 
  • WOOFERS: Decware makes an ideal and well loved woofer for this cabinet.  However, the very design makes it compatible with 100's of different 10 inch car audio woofers that work in smaller boxes.  Even an inexpensive woofer will see double it's rated power handling in this enclosure and sound great doing it.
  • JOINERY: The quality of your cuts determines the joinery or fit of each panel.  Quality joinery is a major part of the distortion free performance of this box.  If you're into box carpet and liquid nails to hide your joinery, and demand the best performance consider purchasing one already built by Decware.  We use CNC machines and build the cabinets more perfectly then is possible to do by hand.
  • WIRING:  Since this box can be pointing in any direction other then face down, no official back or front have been defined.  We recommend soldering a pair of stranded 16 AWG copper wires to the woofer terminals and run the wire out through the port opening. Make it long enough to connect directly to your amp.  If you decide to hide the wire, you can drill a small hole through one of the sides of the box and seal the wire with caulk where it passes through the hole.  Terminal cups leak air and are not recommended.

2 BOXES CAN BE BUILT FROM 1 SHEET






DEATHBOX GRAPHIC




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