Subwoofer enclosure advisory

OK, so I've finally found enough inspiration to begin a DIY subwoofer box. I want to make an identical one to this:

http://www.cardomain.com/memberpage/470207

Um... ok are you going for sound quality or just a "loud" setup?  That will be a determinging factor in ported or sealed.  The wood used for a good sub box is 3/4 mdf (medium density fiberboard).  Seal the box with silicone caulk.  Where I have boards screwed together on my box i went and got a tube of roofing caulk.  It is a tar based sealent/glue.  Once it sticks it's stuck for good.  Never leaked.  As far as running wires terminal cups are not recomended.  They are hard to seal up and if you do fiberglass it's a pain.  Just drill a small hole (just large enough for the wire to fit through) run the wire through that and put some caulk around that.  Now for the size of subs... another factor of spl (loudness) vs sq.  I'm a fan of 10" subs b/c they are clean, hit good, and normally handle bout the same amount of power (or close to) as 12".  Now a 15" will be loud but might not be as accurate as 10" or 12".  What kind of subs are you looking at?

Oh and this is your first DIY?  That box that guys got in the pic looks kinda complicated.  I would try something a little easier for a first.  Something like that takes experience to make all the right cuts and volume size correct and make sure everything is where it's suppose to be.  But if you're up to it then go for it.

the angle on the amp rack on the right is steeper than the angle on the left side..i guess thats what gives it that look

That pic bothered me fromt the start, and you just nailed why.  It does look lopsided.

You can look at the project as 3 seperate projects, the sub box intself (looks like a rectangle), the sides (one for the amp, one for the cap and conections) and the floor.  That should be easier then looking at the project as one big chunk.  To seal I use liquid nails when I assmeble.  Wood glue or caulk can be used after the assembly, but I would use a adhesive when I assembled if I where you.  A enclosure of that size needs bracing.

How much money do you have for subwoofers?  In the 200$ (us) range I could recommend Alpine Type R, JL w3v2, MTX 7500, Punch Stage 3.  Do you have the amp yet?

Also check into some Infinity Kappa Perfect 10".  They're bout the same as those that heavilymedicate mentioned (actually a little less i think).  I would do two 10" subs.  Go with about .7 cu ft for each and seal it (actually this depends on the sub but on average...).  The sealed box will give good sound quality and the subs will put off good spl.  A good 600 rms mono block amp will push any of those subs good.

Look at the sub's specifications.  It all depends on the sub.  Some have a range (ie- .6 to .9 cu ft) some have a set value to play in (ie- .75 or 1.2).  Some subs are suppose to play in a smaller box and vice versa.  If a sub ment for a small box is in a big box then it doen't have much to push against when it plays so it will not sound nearly as good or loud.  And a sub with a big volume in a small box will not be able to play as low or loud as it can because it has already compressed the air as much as it can.  Like I said check into the sub.  The .7 cu ft I previously mentioned is for an Infinity Kappa or Kappa Perfect. 

An incorrect volume (if enough) can damage a sub when it plays at higher volumes (possibly even lower).