dollarlongnecks wrote:
Can you give me a little info on the fiberglass resin you use for the box? Is this something you spread on the inside of the box? |
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Get it at HomeDepot along with ur MDF... the smaller size will be more than adequeate... i think its like a quart for $12. Get an extra tube of hardner. Get a box of disposable latex gloves. VERY IMPORTANT. If you get resin on your skin it will not only stick worse than super glue, it will sting and itch like 10 jellyfish... the resin will eat the latex too so change ur gloves if you get any on them. Get a couple of disposable brushes.
Anyway, its a binary liquid.. a little tube of hardner a the big tub of resin. You mix like 1oz of resin with 1 drop of hardner, and stir. It only comes with enough hardner for like 1/2 the tub of resin so grab an extra one while ur there.
Then paint the resin on the inside of the box. Wait about 20 minutes or so, apply a second coat. Repeat 3 or 4 times. This effectively paints very durable plastic onto and into the wood... MDF is a phenomenally good substrate for resin.. very porous... Let it cure overnight and .. viola! ... ur box is smaller and 25% lighter than a comparable 3/4" MDF enclosure.
The resin will ruin everything you get it on and everything it touches. Completely unremoveable with anything less than sandpaper. Handle carefully with lotsa newspaper over your work area.
Oh yea.. it smells and the fumes make gas smell like perfume. I heard a story about a guy that stuck his head inside his box to make sure he'd gotten the resin in all the corners... and woke up in the emergency room with his head shaved hooked up to an iron lung.
dollarlongnecks wrote:
And in the relation to the ports, when I look at the air velocity graph in WinISD, it looks like it is way above other recommendations I have read, which was to keep it below 110 fps. Should I try to bring this down |
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Hmm... I think you're talking about port noise. I actually use an older version of WinISD that calls port noise 'vent mach' and it didn't have any problems with that configuration... I really need to start using WinISD alpha that graph you have up there is neato.
I had a 12 for sometime that was in an enclosure almost identical to the one we are talking about .. 1.25 cft.. I don't remember exactly what I was trying to tune it to... something around 30hz. Anyway I used 3 1" ports that were 4" long and I thought it sounded quite good... no 'chuffing' or any other anomolies.
Playing with the calculator I have on my computer right now, it tells me this configuration is perfectly acceptable.. actually calculated right about to your number of 110fps. Generally I try to keep this number below about 150.. Can you point to something that says something different? I'd take a look. That graph you have up there isn't something I've seen before, but it does make sense.
I'm not sure dude. I tried several other configurations and get the same results.. two 2 inch ports gives me the same air velocity.... so does a single 3" port... but I don't have the nifty graph and it looks like you aren't going to have problems until about 50hz or so..
Point to whatever you've read, I'd like to read it too. Try graphing a pair of 2 inch ports against that graph above and see what comes out. Or a single 3" port.. that looks like it would work out to about 11inches.. not unworkable really.
"I'm finished!" - Daniel Plainview