So I've been looking more into designing my own enclosures and learning about them. I know the general rules of port/cube, aero, slot, etc. I'm not chasing any 4th/6th orders/walls. Just a plain old aero box.
Still learning to use sketchup so I don't actually have an image yet but it should be pretty easy to follow.
IA 21" at .5 nominal off a 2K. [sq2200, ia 20.1, ect ect.]
My dimensions are 41W x 22T x 23D. 2 6" ports, 12" long.
~28-31hz tuning, ~8.4-9 cubes net. .25 for woofer displacement, and an estimated .5 ft^3 for bracing. 1" dowel rods, top to bottom and front to back. Double baffled naturally. [net enclosure varies based on which calculator I used. They are all pretty close to each other though)
On paper, the port to cube is abysmal (6 inches/cube). After modeling with Win ISD and Bassbox, they're both showing pretty similar results with a peak port velocity of 26 M/S, which is within the "no port chuff" general guidelines.
I am also finally using the metal flares I got from chauncey forever ago. IIRC, they add about 1" to port length, not that 2" is going to drastically change anything. I thought it would help with the airflow really [and I have them/6" PVC laying around].
My goals are wide bandwidth and authority in the subsonic region. I've never been down there much, and am interested to see the general output of extending my bandwidth. I do not want to worry about unloading, etc etc. If any of you read my posts, you've probably seen this 100 times by now.
I've been told that I should build a larger box, with a smaller port, and mediocre power if I want to get where I'm heading.
I've also plugged in 2 8" ports @ 20" long for a ~32-34hz tuning with 11" port/cube. Obviously the smarter choice for general guidelines, but I'm looking to play down to at least 25 hz, hoping for 20. That much port has me thinking it would unload pretty quick. Would bring box down to ~8 cubes.
Either way I think I will incorporate a swappable port piece on it to play with things a bit more.
As far as orientation goes, would I be better off with ports towards the corners, or centered next to the sub on either side? As far as I know I don't want it directly underneath the sub due to loading/phasing issues. Shouldn't it be as far away from the sub as possible?
Any insight and opinions welcomed.
I'm trying to start simple without building 10,000 boxes.. subs supposed to ship on the 25th. I want to get an idea on what I should be looking at here. Sub up, port back in a 96 Jeep Cherokee [box] loading off the [soon to be reinforced] hatch.