Materials

[johninCR]

Originally posted by BassAwdyO
You could make your enclosures from MDF concrete and lead and end up with something heavier and probably deader

But it won't sound ANY different than a well braced sub made out of MDF or good plywood, so why waste the time ? Mains MAY be worth some extra effort in this area because they are playing a very wide range of frequencies.

I believe the amount of effort put into the area of cabinet walls by many DIYers is complete nonsense. Why go to all that trouble to:

1. Make a box with parallel sides.

2. Invest so much time and expense to create a "dead" box
that has this huge driver hole in it. The only thing separating
the inside of the box from the outside world is the driver cone.
This is made of a just a thin layer of paper or other lightweight
material that if you just scratch or tap lightly on, makes a very
audible sound.

Do people really believe all these forces that they are so concerned about with regard to every other surface on the interior of the box magically don't affect the cone, a thin lightweight surface mounted on a magnetic spring?

If you want a sufficiently dead box, build a well braced box. If you want an extra dead box that can't support a standing wave, make it a truncated pyramid with no parallel surfaces. The alternative is to follow the overkill experts and jump right off the bridge with them.

[Madmike2]

I dont like 'boxes' so i always build slanted or 5 sided. Also in sub frequencies i dont think ill be building anything long enough to nessecitate worring about standing waves regardless as those wave lengths are much to large. My top 2 ways are 5 sided enclosures.

I get the point though. I dont 'need' exotic material, i just need to build better braced enclosures. I have a bad habit of spending what i got when i got it. I thought it would be cool to build my own 'X' material enclosure i guess i will stick with the 'B' material for now.

As a side note John, they do it so no acoustical energy is emitted from anything BUT the little paper or thin materialed transducers in them , where it is supposed to come out of. Well as near to 100% as possible. Listen to an NHT floor stander next to an Energy c5 in the same room and tell me there isnt a difference in the way they image. The NHT is a dense cabinet and has great sound, much better then the Energy in my HUMBLE opinion and i would attribute that to the box that energy builds thumping away to the music along with the drivers inside them. Put a drink on top of the NHT and it wont even ripple.

[johninCR]

Mike,

Sound is supposed to come from the front and generated by cone movement, not from inside the box through the cone. I understand and appreciate the benefits of a good, heavy, non-resonant enclosure.

[BassAwdyO]

the weight of the enclosure(especially sub) has a large effect. When a subwoofer with a moving mass of say 350 grams is pumping away 3 inches peak to peak excursion(which is basically what a tumult can do) at a frequency higher than 20hz there is a pretty good deal of mechanical inertial force on the enclosure. A light enclosure no matter how stiff it is will vibrate due to this. The only way to prevent it is either a heavy enclosure, or push push opposing driver mounting.

[Madmike2]

ya i see Dave mention that alot. They have to be opposite of each other i assume, no fancy schmancy stuff side/top or side/side ?