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#1 | Link |
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Advanced Member
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Project Quick, Easy & Cheap – IXL18.4 LLT
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.
.:My Objectives/Requirements:. 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. .:Core Materials:. 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? .:Outstanding Questions:. 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. Last edited by mynym; 10-10-07 at 12:14 AM.. |
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#2 | Link |
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Advanced Member
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Some Build pics so far:
![]() The recommendation's from users here of TiteBond II glue makes a dramatic difference in the set times for the clamping. Just how long is everyone waiting for the glue to set anyways? ![]() PS. If you're in need of some aluminum bar clamps, Harbor Freight has them on sale this week. I bought the 36" ones shown for $4.99. Last edited by mynym; 10-09-07 at 10:37 PM.. |
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#4 | Link |
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Advanced Member
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I ended up waiting 24 hours for the TiteBond II glue to dry. I wasn't sure if you can continue clamping other pieces together before waiting a full day for the glue to dry?
In any case, more progress. The other side now glued and clamped. Unless I hear otherwise I'll wait another 24 hours. I still need to figure out which router and bits to buy. Any recommendations? I'd also welcome some answers on the bracing. ![]() |
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#5 | Link | |
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Joe
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There is no right answer for this stuff, just opinions...
The glue really depends on the glue type, temperature, humidity, working material and clamping. You have to use your judgement on a case by case basis. As far as bracing goes, I would use 3-5 braces parallel with the ends then fill in a couple between those. Even if you only went with 3 it would really be plenty. The more you use the more inert the cabinet, but the heavier it gets too. The law of diminishing returns takes effect very quickly here. I am sure there are a couple of pictures floating around. I will see if I can link one. If you want to use t-nuts, you will want to put a sheet of plywood inside or at the very least wood blocks where the bolts and nuts are coming through. MDF is not very stable where screws and nuts are concerned. Just about any type of Liquid Nails will work fine. The interior projects is will do nicely. If you put any screws in ANY panels, make sure you pre-drill the holes. You may or may not need an EQ, it will depend on your in room response. You won't know until you try it out. I would get a 1/4" round over bit just to take the sharp edges off. You really don't want to remove too much material. Last edited by jpmst3; 10-10-07 at 07:54 PM.. |
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#6 | Link |
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Joe
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Here is a quick example of bracing around ports and driver.
You don't have to make it overly complicated. Just make them so air flows easily. |
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#7 | Link | |
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Member
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Quote:
http://www.edmwi.com/home/edm/page_3...nch_shank.html Warmon - |
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#8 | Link | |
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Advanced Member
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Quote:
. Thanks for the review.I'm going to purchase that router online right now! |
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#9 | Link |
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Joe
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Check this thread out as well.
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#10 | Link | |
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Advanced Member
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Quote:
Thanks for your help! |
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#12 | Link | |
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Member
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Quote:
![]() The idea with bracing is to lock together all the surfaces in the box. This is why 'window' bracing is used. |
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#14 | Link |
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Member
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That finished design is a flexible flyer because.....
In either compression or expansion MDF has ZERO strength. It's claim to fame is being cheap, having high mass and machining nicely. Large expanese of MDF need a lot of bracing. When that's not done the wall vibrate (they become passive radiators) and the effect is the vibrations interfere with the output from the woofer. There are much better designs on the web to use as reference.... ![]() If one can't brace like this, they should build a tube sub... |
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#16 | Link | |
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N-tier Geek
AVS CLUB MEMBER
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Quote:
__________________
Signature Challenged. |
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#18 | Link | |
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Joe
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Quote:
It is not rocket science. Check out many of the commercial subs, (albeit smaller in size usually) some of them have little braces in the form of a couple of dowel rods, aor absolutely no bracing. So, throwing in 2 or 3 or 4 will do wonders. Don't feel the need to go out of control just put a couple in there and glue them in nice and secure. They work best if they are touching all sides. |
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#19 | Link | |
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16 Y/O DJ-Audiophile
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Quote:
__________________
"The choices we make define our lives, because choice, not chance, determines destiny" They call me the 17 year old DJ Audiophile-upgradeitis infected-guy! |
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#21 | Link |
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Advanced Member
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Yeah, really weird, their website doesn't reflect the in store sale price. I picked up these clamps on Monday. They had 48" clamps for $5.99 but had none in stock.
. They also had some 36" rachet clamps for $6.99. If Harbor Freight is close, I'd check it out if you need some clamps. PS. Odd Lots seems to have the cheapest bar/pipe clamps. $5.00. Harbor Freight sells identical ones for $7.99 |
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#22 | Link |
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Advanced Member
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Anyone know the actual depth of the IXL18 from behind mounting plate to base of magnet?
I'm trying to determine the best orientation for the sub and port. Ideally I'd prefer to have the sub down firing and the ports outlets are at the opposing end of the enclosure. Similar to SonoSub designs. With 34" length ports and a total interior length of 48", If the IXL is mounted flush how much room will there be between the end of the port and the magnet on the driver? Is this going to leave enough room? Ideas? |
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#24 | Link |
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heh.. he said member
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You could also position the ports closer to the corners of the box and perhaps avoid the magnet if there isn't enough clearance. Just go and buy another sheet or two of that same mdf and cut them into pieces that fit snugly inside your box on all sides. Then use a hole saw, jig saw, or that router you ordered to cut a generous number of holes on the braces. Make sure you have holes where the ports will pass through. I would put at least 3 braces spaced evenly, I'm not sure more would help but it doesn't hurt. Just be aware that mdf will kick your butt if you try to hole saw very many times, that stuff is dense.
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#25 | Link | |
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Advanced Member
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Quote:
Good thoughts. I was thinking about using a hole saw. Are you saying its difficult or that it wears down the hole saw rendering it useless? I appreciate your help. |
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#26 | Link | |
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Advanced Member
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Quote:
Also, I started thinking alot about the bracing today. I'm thinking the easiest way todo this would be to create 3 sets of 3 holes. a 5" hole will give me 1.75" worth of wood between the holes and the edge of the bracing. Is this too constrictive for airflow? Would I be better off using 6" holes which would yield 1" between the holes and the edge of the bracing? Is 1" strong enough? I got going with SketchUp tonight. Below is an illustration of what I am planning. In this case its a 1.75" wood gap using 5" holes. Or should I completely scrap the multiple holes idea and instead cut out a large circle? ![]() Last edited by mynym; 10-13-07 at 12:46 AM.. |
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#27 | Link |
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Hell is Cool.
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You get more air flow with one big circle or "window" type. http://www.avsforum.com/avs-vb/showt...6#post11207376
__________________
Evil is Good[SIGPIC][/SIGPIC] |
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#29 | Link |
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N-tier Geek
AVS CLUB MEMBER
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Yeah... what vitod said.
![]() I initially was going to use large-circle "rib" style of bracing, but now I switched to "window" style bracing. Steve Callus suggested window style bracing has a better strength to volume ratio, so I drew it up both ways and came to the conclusion that he was right. The small-hole "swiss cheese" approach, while strong, doesn't make efficient use of the space. Plus it's a lot of work to cut (and radius) all those holes. Here is what my bracing looks like now.
__________________
Signature Challenged. |
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#30 | Link | |
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Advanced Member
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