OFFICIAL WEB SITE
click video to pause
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
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
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
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
DBK-10 Exploded Views
COMMENTS from Users:
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!!!
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
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!"
"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, "
|"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
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."
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
From another extremely pleased customer."
"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."
|"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
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
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
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
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
2 BOXES CAN BE BUILT FROM 1 SHEET
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