Box Building Tips

[Hardwarz]

When building a sub box, here's a couple tips.

Never have sides parallel.
Use glue to make each chamer airtight.
Use the thickest MDF you can afford. The thicker, the less flex it will have. (I have in the past laminated 3/4" MDF with 3/4" plywood. It was overkill, but the bass was very tight.)

Anyone have more help tips?

Hardwarz

 

[YukonMud]

This is what I try to do/use when building my enclosures...some are slightly different than Hardwarz's suggestions but have the same principal.

• Use 3/4" or 5/8" MDF, period.
• Avoid perfect squares; I guess cubes might be more appropriate, either way try to avoid them if you can.
• Do not use silicone sealant on the seams, yet do seal all seams. When drying the silicone fumes can harm some subwoofer surrounds. If you do use silicone wait 24+hrs before installing the subwoofer.
• Build an indestructible box, the closer you get to this the better the sound will be, and the longer the box will last.
  • When building a box that is of an irregular shape use bracing.
  • Glue & screw all seams, nails can work but screws are better. Oh, and don't be skimpy on the glue.
  • I generally try to make pilot holes for the screws as well as MDF can split pretty easy.
• When mounting the sub I found it much nicer to use screws or bolts with thread insert/cap things as it gives the sub a much more solid place to mount to. It also aids you if you have to remove the sub more than once. Since I don't know how to describe them here are a couple pictures.

• I would also recommend using speaker terminals as it allows for a quicker disconnect and less hassle.
• I don't know how many people have built boxes in the past, but with sub magnets getting larger and larger these boxes are getting more and more difficult to handle. In some of the larger boxes I have made I have also added handles.
• Add carpet or paint to add a final touch to the box.
• And, last but certainly not least I try to always add a subwoofer grill. There is nothing worse than seeing your $500 sub with a hole in it. This can be done several ways but I have found the easiest way is to just add another layer of MDF to the front of the box and add a simple grill. This way the sub is inset a little more so you can correct for excursion.

Sorry for the long post....

 

[YukonMud]

...I have in the past laminated 3/4" MDF with 3/4" plywood. It was overkill...Hardwarz

Hardwarz, how big was that box, that thing must have been huge. Got any pics? Howcome you did not use 2 sheets of 3/4" MDF?

 

[Hardwarz]

Hardwarz, how big was that box, that thing must have been huge. Got any pics? Howcome you did not use 2 sheets of 3/4" MDF?

Alas, I don't have picturs of a lot of the old competition systems I've built over the years.

The reason I did 3/4" MDF + 3/4" ply was because the MDF gave it the very solid feeling. The 3/4" Ply made it a lot more rigid. The more rigid the structure is, the less wall flex. Less wall flex = tighter bass.

Years ago, not too far from where I live, there was one competitor that replaced the rear springs in his Cougar with heavier duty ones and lined his trunk with cement (to act as the enclosure) There was ZERO wall flex when his system thumped!

You'll also find in the high end home stereo market, there are cement box home speakers. (Search for 'cement speaker enclosure" and you'll see a lot)

Of course, unless you're being judged on tight bass, broad spectrum from 20Hz-20kHz, imaging, etc, you'll be happy with a standard box you buy from a store.

Hope this helps.

Hardwarz

 

[JKmotorsports]

I use birch because it's denser than MDF and considerably lighter. It does cost a little more than MDF though, but had better sonic qualities than MDF.