The half circle is wrong, it should only be part of a half circle.
Check the plans.

Bart

I did play with the setting depth of the insert.    it is just about 1/8" above the cut out.
it sounded best there.     my db is 25.5" tall.   so I have a bit more lenght up top than most.
maby thats why it sounds best ( to my ears ) at the height its at now.
I then marked its position,   and banged it up in the box an inch,   cauked all around it,   and fliped it back over and droped it on the floor a fiew times to get the insert back down to where I marked it.
and then re caulked it in its final position. ( so it basicly has 2 rows of caulk going around it )    and then I screwed it to death!!hahaha     its never going to move.

I played with the position of it in my car,   I like the way it sounds best with the port facing rear wards,  about 5 inches away from the back,   at a slight angle.    gets the feeling of deep bass deep in my chest that way.    I like.

it sounds great up to a certan point.     im not shure if its my highs,  or lows that are breaking up at super loud levels.     its hard to tell in my car.   the inside is so small its silly.

my amp is a 4 channel 350w.    im running 2ch bridged to the db.  manufacture rated its watt at 175.  do you think thats not enough to give me the punch I want at crazy loud levels of sound?

maby ill try and hook up my 600w ( bridged ) amp to power the db and see what it sounds like.

and about my port shape,  its most likely wrong.    im 75% shure.     but it sounds ok to me.
I traced a little shorter than 1/2 of a taco bell lid for the cut.  hahaahahhahahahah.
I guess that solidifys my "newb" status.   hahahahahahaha

wow that was a good thread about tuning the db and the affects that alter its sound output.

I am quite happy with mine right now.   mostly because there is no way in hell I will ever get that speaker cradel to move anywhere.   haha,   I guess I did it in general over kill fashon.
its cool.
altho -
I am probly going to take the lid off it,   and round out the circle port ( half moon or what ever )
and your saying I should round the edges of the baffle piece that is on the speaker cradel?    im not shure how I would go about making it a 45deg angle since its already installed.   and never coming out.    haha.  do you think smoothing the harsh edges off will help?

my current plans are for a mini wicked one - around 32" by 18or20"
im going to use a pair of 8" drivers
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&sspagename=STRK%3AMEBTO...
I got on ebay for super cheap.   less than $50 for the pair shipped.
hope they will do something in a wicked one.    on a plus note for them their magnets are rated at 60  wich is pretty big for a little 8" sub.     generaly bigger magnets are good in small enclosures right?

I also hooked up my db in my car ( what a tiny little thing it is inside ) to my 600w bridged amp.   so there is now 600w pushing my db10"  it sounds real good.  ( my 600w amp has more tuning options,  and I finaly got it to sound "crisper" )  nice bass  and a pretty big spectrum of sounds it produces.   but like before,    some songs I listen to it just pounds like crazy.
and on some other songs it sounds muffled  and or muddy.  ( not many songs like that but a fiew )
there are 2 main bass line songs ive been tuning it to,

whoop that trick - from the hustle and flow sound track, - highly recomended bass track -
aint nuthin but a g thing - from dr dre and snoop,
that and a variety of realley hard house / rave music.

so some time before the new year,  I plan to have my wicked one built,   so I can give a head to head test from my current db,  and the wo,  to see who will win in sound quality,  and wich box will stay in my car.