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JLashhhh
08-14-2009, 08:23 PM
so i built my own ported box for one alpine type R 12" the box has 2cubic feet of air and its tuned at 35hz. I constructed this out of 3/4" MFD board. its held together by some wood glue 1 1/2inch dry wall screws ( may be 2" im not sure) and all the seams are sealed with wood putty. so basically the problem im having is when my sub hits hard it makes like a creaking noise ( not cracking ) basically the kinda noise a old hardwood floor usually makes when you step on it. Any ideas whats causing this and how to fix it?

phemps
08-14-2009, 08:29 PM
didnt seal it quite good enough? or maybe if the box is not completely structurally sound the box flexes enough shifting the joints causing the noise you hear

JLashhhh
08-14-2009, 08:38 PM
this is prolly it... when i first built it it didnt do it but after about a week of use it started this... any suggestions on how to make it more structurally sound

phemps
08-14-2009, 08:42 PM
it sounds like it started to loosen itself apart after you started running the sub in it. well it depends how you buit it but bracing is always good but you cant add bracing without changing the tuning and airspace. and for a single? twelve box you shouldnt really even need extra bracing or double baffeling

fshanda
08-14-2009, 08:43 PM
Wood putty is not a good sealer for joints in a sub enclosure. Its brittle and not very adhesive. All the joined edges should be glued with a good carpenters wood glue. If you have big gaps fill them with silicone adhesive. Dont use liquid nails. I have used reinforced fiberglass body filler to fill gaps before with good results. You might also need some bracing in the box if you havent installed any. Keeps the box flexing to a minimum.

JLashhhh
08-14-2009, 08:47 PM
it really doesnt do it constantly on every song just when it hits really hard but most of the songs i listen to with my sub have alot of the bass that causes the sub to hit hard especially 24/27 (Kobe/Lebron) by young jeezy that just makes it creak like no other

JLashhhh
08-14-2009, 08:49 PM
well i guess ill try some bracing on the inside of the box ill try to just add it in key areas and keep it to a min so i dont mess up my air space and port tune to much

fshanda
08-14-2009, 08:52 PM
Also dont know if you predrilled the holes for your screws or not. If you didnt you could have split the MDF in a few places. That could cause the creaking too. One side of the split moving when the sub hits hard.

JLashhhh
08-14-2009, 08:56 PM
yes i predrilled my holes but i did notice when i removed my sub that were the top and bottom screw go the wood is split some

dappa5
08-15-2009, 08:35 AM
dont bother with bracing (slugs) just go buy a box of 1 5/8 deck screws (grey coated ) not drywall screws / they do not hold mdf / get deck screws and screw that bish every where if still have gaps use silicone/caulk to seal it