I’d like to start off and thank Neo Dan on his thread “IXL 18 meets the ‘Easy Button’ "
. This feed one of my objectives which are mentioned below and was my inspiration for this project.. After talking to SteveCallas further I was convinced this would be a perfect little project with some minor modifications to suit my requirements for the build.
As much as Neo Dan’s design is “simple” I wanted to refine it even further, making it even simpler. Less cutting, etc.
My second objective was cost. I wanted to get into the LLT game without spending a fortune. SteveCallas helped me solidify this decision. Thanks.
My last objective was around mobility of materials for construction. As I don’t have a truck or access to anyone with a minivan I wanted to be able to haul all parts/materials with my car.
1 18” Mach5Audio IXL18.4
: Currently one of the best bang of the buck subs available. This facilitated the cost objective. Although there are better drivers, very few are close to this price tag [$235 shipped] and deliver similar performance with as much displacement.
Leaning on NEO Dan’s design I liked the use of MDF over a SonoTube for 1 reason only. Mobility. Back to objective #3. I can transport planks of MDF easily within my car, putting the seats down. A 24” sonotube unfortunately wouldn’t fit.
.: Design :.
Back to the whole “make it easier” objective. My local Home Depot sells pre-cut 48x24 [Actually 49.5x24] sheets of ¾” MDF. Although I own a table saw, having the wood precut with precise measurements IMHO is a head start. Less work of me having to cut them precisely myself + no MDF dust cleanup. Bonus..
So if I use 4 of these sheets for the outer sides I’m going to need 2 additional 24”x22.5” planks for the end pieces. I choose to buy 1 additional precut 48x24 sheet and had Home Depot cut this 49.5” long plank twice yielding 2 22.5x24” end pieces. In and out of Home Depot in 10 mins. Piece of cake, no cutting, no having the wife complain about asking her to “hold the MDF” as I run it through the table saw.. You get the gist..
So to recap, I purchased 5 precut 48x24 [Really 49.5x24”] sheets and used 1 of the 5 sheets utilizing Home Depots saw to cut 2, 24x22.5” end caps.
.:Primitive Paper Design:.
I've spent some time taking the Google SketchUp tutorials but still don't posess the necessary skills that others have. My replacement is pen and paper:
So without displacement of bracing, ports and driver, internal volume is 424.8 liters or 15 cu feet.
After discussion with Steve Callas he recommended an enclosure size of around 400 liters with 3 4” 34” ports tuned to 14hz.
So adding the displacement of the driver and these 3 ports the internal volume Vb
stands at 391 liters. (I have still yet to add some bracing which I will equate later)
As for the finish, I really liked tregarza’s final product
using a ¼” round over bit and black Dura Color bedliner spray for the final finish. I’ve completed many car audio enclosures using speaker carpet which looks great in an automotive environment but I really seem to think the bedliner spray suits a home theater sub. Regardless of the outer finish, I think it’s going to be hard to disguise a 15 cu foot enclosure.
Here's a pic of Tregarza’s final product using dura color bedliner spray:
I’m planning on powering this sub with an EP2500. This should be ample power with room for growth if I plan to add another one. Where's the best deal going these days for a brand new EP2500?
1) Where can I find black PVC pipe? My local Home Depot seems to only sell the white stuff. Also, will they cut it to size for me? I've also seen much mention in some threads about Schedule 40 PVC Pipe or "Quick Pipe"? What is this?
2) Which type of liquid nails is everyone using? In my past car audio projects I’ve always used the “Interior Projects” type. Wasn’t sure if there was better stuff more suited for MDF and PVC.
3) As I am planning on purchasing the EP2500, will I need an EQ? Anyone running a Panasonic XR55? Does it have enough preout voltage to feed the EP2500 pro amp? Any suggestions on how to feed the EP2500 from the receiver?
4) T-Nuts or Hurricane nuts or Plain old 1-5/8 drywall screws directly into MDF?
5) Where can I source a cheap plunge router and round over bits? Some of the folks over at fatwallet recommended these cheap bits
I was looking at buying the Craftsman 9.5 amp 1-3/4 HP Plunge router
which is on sale for $59 until tomorrow. Will this fit the bill or are there better routers out there for the same price or a little more?
6) Bracing.. This is a touchy subject for me. Coming from the car audio world bracing was rarely used and if it was, it was minimal, even for large 20+ cu foot enclosures. Browsing many of the DIY HT forums it's apparent bracing in some cases IMHO looks way overkill for the application. Iggster
, if you're reading this, perhaps you can shed some light as I know you're into the DB Drag scene as I was. Anyone got some suggestions on bracing without going overkill?
6) Can the IXL18.4 be oriented in a down firing orientation?
According to Parts Express, here's the formula to calculate sag: Percentage of Sag = 24,849 / ( Xmax * Fs²)
Sag% = 24,849 / (22 * 17.7^2)
Sag% = 24,849 / (22 * 313.29)
Sag% = 24,849 / 6892.38
Sag% = 3.61
Is it true if sag is less than 5% this is suitable for a down firing application?
7) If I do down fire the sub, how much room (gap) should be left between the IXL18.4 sub and the baseplate or floor?
8) In many of my past car audio enclosures where space was a concern, port bends were common, especially in slot ported instances. Hypothetically speaking, How much impact would be brought to this project if I bent the ports in a 90 degree angle?
Last but not least, I welcome everyones ideas and suggestions.