Boxes boxes boxes....

[Big-Cat 10+ year member]

ok, i've just got some questions i was thinking about before building my box. Should i try to make the corners on the inside of the box round...like try to sand them or something, i thought maybe that would make the sound waves bounce a certain way and be smoother to make better SQ maybe?? And also, if i were to use Fiberglass instead of 3/4'' MDF would that have an effect on the amount of SPL or SQ i got??

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[bootleg 10+ year member]

As far as rounded edges go, there is not a large improvement but there is some. What you can do is pour some fiber resin, bondo or just some glue and stand it up on the corner, that'll give it a nice round corner. Fiber glassing is as good as it is thick and it's composition, the thicker it is, the stiffer (duh) but it also depends on how much hardener you put in the batch. I sudgest laying two or three layers down to the shape and then soking strips and applying them or you can just pour it on the inside so it dries very thick, I found that method very quick to do opposed to sitting there and trying to paint every frickin' layer on. Good Luck. bootleg

 

[audiolife 5,000+ posts]

why not combine your ideas? use the fiberglass resin to round the inside of the box?

 

[XtremeBass 10+ year member]

Originally posted by audiolife why not combine your ideas? use the fiberglass resin to round the inside of the box?

Yeah that sounds like a good idea.

 

[Big-Cat 10+ year member]

well, i was thinking that i could make a box out of like plywood or something, and then shape the fiberglass around the plywood....how's that sound?

 

[audiolife 5,000+ posts]

you want mdf and do it to the inside (especially if its your first go at building) will be much more forgiving and you will see how the materials go together and their tendancies

 

[dreamer 10+ year member]

Honestly, I don't know if anyone could tell a difference if the inside corners of the box were rounded or not. In such a small volume, theoretically, the air should act more like a piston than a wave. Basically the pressure would be equal or god dang near equal at any measured point within an enclosure at the same point of the wave. While, I'm not saying it's a waste of time, because I've never seen it in practice, I'm just not sure how much of a difference it would make.

About the MDF, yes, it's good stuff and it's cheap. The most improvement of the enclosure will be gained in its stiffness. I've heard talk of marine grade plywood and even baltic birch having a stiffness that is roughly 2 times greater than MDF. Mr. Dan Wiggins from the teampamp.com forum even had a post saying that marine grade ply is good stuff. I've never used this stuff either... but, jeez, if it really is 2x or 2.5x as good as MDF as many people say, it's totally worth it! You'd be getting a cabinet that is 1.5" or greater in thickness compared to MDF.

 

[Big-Cat 10+ year member]

ok, well if it's stiffness i'm after..then why don't i just use plywood to begin with?

 

[audiolife 5,000+ posts]

1" mdf with vblock works great

 

[dreamer 10+ year member]

Originally posted by Big-Cat ok, well if it's stiffness i'm after..then why don't i just use plywood to begin with?

because standard plywood isn't that stiff, but marine grade plywood is. =)