badjuju342
03-09-2006, 05:32 AM
Building an enclosure for subs isn't that hard if you have a little patience , forethought and some decent tools . Here's some tips to get you started.
Selecting wood for the enclosure is a key step . 3/4" or 1" MDF is an economical and solid foundation for any enclosure . Marine grade birch is more expensive but slightly better in choice. Regular plywood or particle board is not that great. Plywood has a nasty resonance to it and is very disapointing in terms of sound quality. Particle is not dense enough and not as durable as MDF.The more solid of a wood you use , the stiffer the enclosure will be . Stiffness is a very good thing for enclosures but the box can swell and vibrate causing cancellation of sound frequencies. This results in los of loudness. Spend the extra bucks and buy the proper wood for your enclosure.
Next up, measure and design your box. A lot of folks will measure the exact demensions on the space in the vehicle and begin building. BAD idea. The box might not fit if you do this because you didn't take into account of a raised area of the vehicle or a bracket in the vehicle . You need to study the area carefully even if it looks like it will fit right in. And , measuring for a box in the trunk of a car , you need to make sure you can get it into the trunk after you build it. If you build it too big , it is useless to you. Another thing is to take into account of the travel of the wofers themselves, if you a woofer slamming itself against a body panel , it won't live long . It's a very good idea to deduct at least 1" from all of your measurements of the different sides. You can always make filler panels later if needed.Measure everything twice.
Now that you measured for the outer demensions of the box , it's time to consider the needs of the woofer itself. Most manufacturers include a sheet on the minimum and maximum area of the interior of the box for ideal performance of the woofer. Let's say you have a two chamber box design you wish to build out of 1" MDF for some subs. You've decided your box can be 20" tall , 48" wide and 20" deep . Your interior measurements compensating for the thickness of the wood will be 18" tall (1" each for top and bottom panels) 45" wide (1" each for left side , center divider, and right side) and 18" deep (1" each for front and back) . This gives your interior dimensions. To get the cubic square feet measurement for each woofer you multiply 18" X 22.5" (half of the 45" ) x 18" . Then you divide by 1728 . This gives you your square feet of each chamber. You now know if the box is within spec for your subs.
Once you've got that out of way , it's time to construct the box . You want this thing to be as solid as possible so here's what you do. First off , use woodscrews and wood glue. It's very tempting to use a power nailer or stapler but this causes a joint that can loosen itself over time. A wood screw is a vastly better idea . Glue you panels together along with the screw for a rock solid joint. If your panels in your box are large , some well placed braces are a good idea. Just incorporate them into your densions when figuring the interior of the box. Spend a few extra dollars and buy yourself a countersink drill bit and predrill your holes for the screws. Along with a better appearance , the wood is less likely to split. 1/8" bit is ideal and drill the holes as deep as you can.
Finally , seal everything. Clear silicone caulk does a great job but a nice thick coat of fiberglass resin is even better. Mix small batches of it with the hardener so it does cure before you done coating an area. The resin will also stiffen the box even further along with it superior sealing qualities. Coat the entire panel areas for best results. Thick coats are great .
One last thing , if you decide to go advanced and port your in accordance with the instructions, use a router to radius the edges of your slot port or round port for reduced port noise or "whistle" .
Building a box can be very satisfying and great source of pride if you follow these basic steps and let patience prevail. Enjoy your new box!
Selecting wood for the enclosure is a key step . 3/4" or 1" MDF is an economical and solid foundation for any enclosure . Marine grade birch is more expensive but slightly better in choice. Regular plywood or particle board is not that great. Plywood has a nasty resonance to it and is very disapointing in terms of sound quality. Particle is not dense enough and not as durable as MDF.The more solid of a wood you use , the stiffer the enclosure will be . Stiffness is a very good thing for enclosures but the box can swell and vibrate causing cancellation of sound frequencies. This results in los of loudness. Spend the extra bucks and buy the proper wood for your enclosure.
Next up, measure and design your box. A lot of folks will measure the exact demensions on the space in the vehicle and begin building. BAD idea. The box might not fit if you do this because you didn't take into account of a raised area of the vehicle or a bracket in the vehicle . You need to study the area carefully even if it looks like it will fit right in. And , measuring for a box in the trunk of a car , you need to make sure you can get it into the trunk after you build it. If you build it too big , it is useless to you. Another thing is to take into account of the travel of the wofers themselves, if you a woofer slamming itself against a body panel , it won't live long . It's a very good idea to deduct at least 1" from all of your measurements of the different sides. You can always make filler panels later if needed.Measure everything twice.
Now that you measured for the outer demensions of the box , it's time to consider the needs of the woofer itself. Most manufacturers include a sheet on the minimum and maximum area of the interior of the box for ideal performance of the woofer. Let's say you have a two chamber box design you wish to build out of 1" MDF for some subs. You've decided your box can be 20" tall , 48" wide and 20" deep . Your interior measurements compensating for the thickness of the wood will be 18" tall (1" each for top and bottom panels) 45" wide (1" each for left side , center divider, and right side) and 18" deep (1" each for front and back) . This gives your interior dimensions. To get the cubic square feet measurement for each woofer you multiply 18" X 22.5" (half of the 45" ) x 18" . Then you divide by 1728 . This gives you your square feet of each chamber. You now know if the box is within spec for your subs.
Once you've got that out of way , it's time to construct the box . You want this thing to be as solid as possible so here's what you do. First off , use woodscrews and wood glue. It's very tempting to use a power nailer or stapler but this causes a joint that can loosen itself over time. A wood screw is a vastly better idea . Glue you panels together along with the screw for a rock solid joint. If your panels in your box are large , some well placed braces are a good idea. Just incorporate them into your densions when figuring the interior of the box. Spend a few extra dollars and buy yourself a countersink drill bit and predrill your holes for the screws. Along with a better appearance , the wood is less likely to split. 1/8" bit is ideal and drill the holes as deep as you can.
Finally , seal everything. Clear silicone caulk does a great job but a nice thick coat of fiberglass resin is even better. Mix small batches of it with the hardener so it does cure before you done coating an area. The resin will also stiffen the box even further along with it superior sealing qualities. Coat the entire panel areas for best results. Thick coats are great .
One last thing , if you decide to go advanced and port your in accordance with the instructions, use a router to radius the edges of your slot port or round port for reduced port noise or "whistle" .
Building a box can be very satisfying and great source of pride if you follow these basic steps and let patience prevail. Enjoy your new box!