DeeCee

Resin is used to smooth out the interior of the box for air flow but fibreglass inside a box doesn't work as bracing. With a box that big, you would be better off chucking in some bracing.

Someone asked me the reason that I was going to this level.. well... The reason for going to this level was that I was having trouble sorting out the pressure zones and reflection inside a box i'm about to hack up. Basically the last big box was a big failure, only pulling me around 144db with an 18" sub and 4kw. As a result of that experiment, I didn't want to repeat those mistakes in the physical world, taking up time, money and resources. Since I was looking at a lot of this back in 2k6 with an extreme build, I thought it might be a good time to try and figure out the programme again and see what I can do. I'll break it down. The current box has to be decreased in height to fit under window line for St C. That means that my MT18 has to be top mounted with a port somewhere else on the box. Now I have successfully used corner loading within street vehicles a lot, so I thought that a port on the drivers side would be more beneficial than a port on top or firing back, where there isn't much space. The area of concern was the sub position on the top face This is an issue as there is the creation of a dead pressure zone beside the port. Subequently, I was trying to figure out a lot of the reflection paths and pressure areas in my head and really I needed to apply what I had researched before into a theoretical model and seeing it on a screen. I'll play with sub positions and figure out where I need to mount the sub now As for the potential.. I am still learning the programme and how to fully capitalise on the CFD features, so who knows what may come of it, or if I'll just leave it alone. Sometimes the fun is in the mystery. Also, I would say straight up, that the what the programme does is basic in terms of what is out there to calculate the minuite details of fluid dynamics. So I'm not sure if it would be right for various applications in the SPL world. I thought it was just a cool picture

No lol. I'm thinking I'll just keep this advantage to myself

Do it!!!!! Currently the computer is churning away doing some pressure calculations. Maybe I will, maybe I won't. I do know that I won't be doing this for anyone else haha. It takes too long to do all this stuff!

hahahahahaha

Geez Duran.. do you ever sleep hahahaha. I always see you on! I was thinking about using this programme in 2006 when I was about to take on an extreme build. As I was trying to figure out something in my head recently with a new box for the forester, I decided that it would be better to apply better models to what we do instead of best pracitce and thus I went to the trouble of making the box and testing it. This is just the first model, but yeah, I'm sure that I will benefit I wonder if those kerfs and angles work inside boxes........

use the BTL18 specs as a guide only.

bigger box = higher efficiency = more output for the power you have available

Fantastic results

Haven't tested yet. Won't be able to test until tomorrow evening (its 2am now) Currently it is sealed enclosure with removable port. Once I find the res freq of the car, then I can make the port so basically I'll be building up until the show on Saturday. Theoretically, it should be able to push 147ish *fingers crossed

I wonder what is happening...

Yay - its alive! Ended up borrowing a 4kw off a friend who is currently in Canada. Batteries are now in series/parallel providing a solid 12V system as I don't want to blow his amp. I got the batteries off an old competitor. Only cost me $250NZ for all 6 batteries. I get to travel to the show with my creative zen and some headphones hahahahaha

was already going to do 16v - 2 banks of 4V + the 12V batt = 16v

I'm working on build for competition.. i got no time for interweb

MIA - missing in action. Basically the amp was picked up from the client last friday and was scheduled to arrive in my locale yesterday. Unfortuantely, the amp is lost somwhere in between, so the logistics company is busy trying to trace it. Oh well.. time to move some batteries

Crisis.. amp has gone MIA in transit. I'm rather fux0red at the mo and I leave for a 9 hour car journey tomorrow Time to take out the battery bank i think. I'll just have to run a small mono now *cries

Who wants a build log, I've got one sitting here with some tasty sundown amps powering the system :bigclap:

They are just stinger PRO3 RCAs

Not too bad aye Note, C10 rating so that is a 10 hour mark instead of the normal 20 hour mark (i think thats right..) I picked up the 6x 2V forklift cells for $250NZ off another competitor. Cheap as chips and the condition is excellent Just add to 1x Kinetik 2000 I have floating around and voila - juice for a 3000D

Charged up the 2V forklift batteries last night.. holding 12.9V in series The 2V cells are these little beasties: http://www.sonnenschein.org/A600.htm The are rated at 200AH C10 rating so should last for a show without having to recharge

cool trick

Possible solution in large L brackets. I used Bowmac reinforcement joiners on my removable wall http://www.mii.com/site/frameset.aspx?site...sp%3Fpid%3D1493 if you could find something similiar then I'm sure that it wouldn't be a problem. Put a couple of M12's bolts in and I'm sure it wouldn't move lol Even some long tek screws would do it.

Impressive! Are you guys strapping the beast down or letting gravity take its natural course?

Of course Jacob We have the second round of the local series which has a special "monster class" using 1x 18 Blaupunkt sub as specified by the monster class rules. Competitors must compete in a minimum of two of the three events in the series, so I have to make this one and the one in January to qualify. Amp is, of course a sundown - 3000D specifically One of the customers who bought two changed up jobs and is finding a bit of a stretch getting paid monthly, and he offered me the BNIB 3000D back to me so i bought it. I'll be running the 1x18 Blaupunkt VPW460 competition sub and the Sundown 3000D for the competition. I'm not sure I'll have time to set it up, but i do have 6x 2V forklift batteries in the garage, so I am hoping I'll have time to setup a 16V system for this comp. Box is 25mm / 1" mdf with a 36mm triboard layer on the bottom left over from my Krazy8s bandpass box. The box is also designed for my MT18s as well, so i will be making an interchangable top plate with threaded wood inserts. The port will also be interchangeable (hence why it is so big), again using threaded wood inserts to attach the port to the box. Box size is around 8 cu ft - this time no resin or 45 degree fillets which are my standard SPL additions. I'll be playing around to see what I can manage first and then play around later before round three of the series to see what gains I can make. I'll also have to make up my pods for my dual midbass ID components and maybe some dash pods for my morel supremos, but I don't think I'll have time for the dash pods. Car is a stock 1998 Subaru forester, so I will have to test the resonant frequency to determine the peak of the car. I am undecided whether to go for the peak or the second peak which is usually higher at the expense of no cabin gain. Oh the joy of playing with transfer functions. So yeah.. a bit of work ahead, but the box is pretty much done so that is the hard part out of the way I'm hoping to crack a 150 as there is a special prize for the first person to crack a 150 in the monster class Oh.. and the box will stick around.. I'm thinking I may use it as my daily unless it becomes too much of a burden on the ol' wallet with petrol costs and shoulder wear on the tyres More tomorrow.. that is the only pic so far.. more interesting pics tomorrow Dave