Considerations in enclosure-building for full range drivers

[Taterworks]

Hi, everyone.

I finally got off my butt and picked up a couple of Tang Band W4-1052SD drivers from Parts Express, and have in mind to build a pair of standmount monitors with them. I'm aware that box-building for a full-range driver entails a different set of considerations than box-building for a midbass or bass driver, because a significant amount of mid- and high-frequency energy is also radiated from the rear of the cone into the enclosure, and it can be re-radiated through the driver's cone itself as well as any reflex ports if it bounces off of a flat untreated surface in the enclosure.

Here are my unanswered questions:

a) Is there any advantage to building a "golden ratio" box for a full-range driver? Or is it simply enough to make sure that none of the box dimensions are an integer multiple of any of the other dimensions?

b) Is it more advantageous to place the bass reflex port on the rear of the enclosure or the front? How important is it to prevent the radiation of any midrange or high frequency energy from the vent? Would lining the walls of the enclosure with egg-crate open-cell foam be sufficient to prevent stuff from bouncing around and then being re-radiated?

c) MDF is cheap and plentiful around here, and I have quite a bit of scrap that I'd like to use up. Is there any reason why it wouldn't be a highly suitable material for use in full-range speakers (again, where high-frequency energy is radiated into the enclosure)?

I'm interested in the potential for a single-driver system's sound to be greatly affected by design decisions like box shape, material, damping, driver/vent placement, and a host of other factors. I'd like to hear any personal enclosure design philosophies you've employed in your own speaker projects as I formulate my own.

Cheers!

(I've already bought these drivers -- so I intend to use them.)

[planet10]

Originally posted by Taterworks
a) Is there any advantage to building a "golden ratio" box for a full-range driver? Or is it simply enough to make sure that none of the box dimensions are an integer multiple of any of the other dimensions?

Basically. Irrational numbers are your friend.

b) Is it more advantageous to place the bass reflex port on the rear of the enclosure or the front? How important is it to prevent the radiation of any midrange or high frequency energy from the vent? Would lining the walls of the enclosure with egg-crate open-cell foam be sufficient to prevent stuff from bouncing around and then being re-radiated?

There are compromises and advantages with all potential port locations... with adequate internal damping i don't think HF energy should be much of an issue (mind you i avoid typical BR boxes so my experience is limited. Foam would be my last choice for lining the walls. Cotton or wool felt, fiberglass insulation, polyfluff batting (i do use foam for aperiodic vents)

c) MDF is cheap and plentiful around here, and I have quite a bit of scrap that I'd like to use up. Is there any reason why it wouldn't be a highly suitable material for use in full-range speakers (again, where high-frequency energy is radiated into the enclosure)?

There has been a lot of discussion on this subject -- some going on as we speak. MDF doesn't much fit into my box-building philosophy, but if you hsve it kicking sround, go ahead and use it....

I'd like to hear any personal enclosure design philosophies you've employed in your own speaker projects

Mine is discussed here (and more to come in the ongoing Geddes discussion)

Discussion on what materials to build speakers out of

Discussion arising from Geddes loudspeaker

dave

[hm]

Hello,

"I'm interested in the potential for a single-driver system's sound to be greatly affected by design decisions like box shape, material, damping, driver/vent placement, and a host of other factors. I'd like to hear any personal enclosure design philosophies you've employed in your own speaker projects as I formulate my own."

well i´ve done a new constructin for a (two) 4" driver,
for me one of my best, the KORNETT
take a look with measurements and plan.