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View Full Version : Looking for info on one of those wierd box replacement technologies.



#45
03-21-2009, 01:34 PM
I'm looking for info on a technology MMATS made that replaced the standard sub box. cause i'd like to find one.

Over a decade ago, MMATS advertised this thing that looks like a speaker grill. it fitted over the subs like a grill would but had some kind of Cells or membrane structure that mimic what a box would do.

so basically you reverse the polarity of the subs, put this grill thing on and it acted just like a box would. so it would save trunk space...blah blah. It was one of those technologies that i assume probably didnt sell so they stopped making it, but if it worked, sounded like an awesome technology.

I just wanted to know what the thing was called, if anyone knew much about it so i could try to hunt one down for sale. assuming it worked as good as a box does.

i'm also curious about pheonix gold's Cyclone. another one of those old technologies that vanished.

gotparts90
03-21-2009, 07:06 PM
I'm looking for info on a technology MMATS made that replaced the standard sub box. cause i'd like to find one.

Over a decade ago, MMATS advertised this thing that looks like a speaker grill. it fitted over the subs like a grill would but had some kind of Cells or membrane structure that mimic what a box would do.

so basically you reverse the polarity of the subs, put this grill thing on and it acted just like a box would. so it would save trunk space...blah blah. It was one of those technologies that i assume probably didnt sell so they stopped making it, but if it worked, sounded like an awesome technology.

I just wanted to know what the thing was called, if anyone knew much about it so i could try to hunt one down for sale. assuming it worked as good as a box does.

i'm also curious about pheonix gold's Cyclone. another one of those old technologies that vanished.

OOOO those are awesome my friend has two of them in his basement still. those with a basscube sounded so nice, just weird to watch it work

#45
03-21-2009, 09:44 PM
OOOO those are awesome my friend has two of them in his basement still. those with a basscube sounded so nice, just weird to watch it work

what were they called?
how well do they sound? do they really sound just like their in a box?

jdawg
03-21-2009, 10:30 PM
it started with an a

jdawg
03-21-2009, 10:32 PM
cyclone technology didnt disapear
http://www.rotarywoofer.com/

jdawg
03-21-2009, 10:35 PM
http://www.audiogroupforum.com/csforum//showthread.php?t=31539
What is an "aperiodic membrane?"

An "aperiodic membrane" is one part of a type of subwoofer enclosure. It is an air-permeable sheet which has frequency-dependent acoustical resistance properties. The original design goes back to Naim, for use in home systems, but has been applied by several individuals and companies in car audio.

The completed system will be aperiodic, which means it will prove to be over-damped with a Q well below 0.7. In contrast, the most commonly used sealed enclosures have Qtc's in the range of 0.8 to 1.1 which are considered, by definition, to be underdamped. When improperly used, a high-Q system may have poor transient response, nasty peaks in frequency response, and high rates of roll-off. Aperiodic systems are characterized by better transient response, flatter frequency response and somewhat extended low frequency response.

Another benefit of the system is that you can pretty much choose whichever driver you'd like to use, as long as they are big. The Thiele/Small parameters (which would normally determine what kind of box would be used) are taken into consideration by the membrane designers so that the response is extended and overdamped, regardless of the characteristics of the driver.

Physically, the aperiodic membrane isn't for every car. It requires sealing the trunk from the passenger compartment in an air-tight manner, as well as sealing the trunk from the outside for best results. The drivers are then mounted into the baffle between the passenger compartment and the trunk, as would be standard in an infinite-baffle/free-air set-up. The aperiodic membrane is then placed either in front of the driver or behind the driver, depending on the type. When mounting behind the driver, the membrane is used as the rear-wall of a very small box which the driver sits in (as in Richard Clark's infamous Buick Grand National). So, in short, it's not suitable for trucks, jeeps, R/V's, or hatchbacks.

You should probably only get an aperiodic membrane if you've got money to burn, lots of amplifier power, some big subs, a sedan, a desire for trunk space, and no wish to boom. If your tastes lean towards bass-heavy booming, as opposed to well-recorded acoustic instruments, you're not going to be pleased with the result.

jdawg
03-21-2009, 10:38 PM
http://www.audiogearreviews.com/tech/theory/enclosure_design/aperiodic_membrane.asp

#45
03-22-2009, 11:58 AM
thanks alot jdawg.

looks like its not quite ideal for me, i didnt realize you had to seal the trunk air tight or require specs in the sub or nothin. i knew there had to be a catch, otherwise everyone would be using them.