X MAXX PASSIVE RADIATORS...Hmmm...vortex!!!!!

bogart · Post by **bogart** » Thu Mar 18, 2010 10:58 pm

So I've been reading about designing enclosures with passive radiators....anyone actually ever tried this and had to add mass to the pr. I an thinking of actually using one 10 driver and two ten pr's....

So the pr's have to have the same mass that the low frequency driver's port volume would displace....I get that, and I get seeing the fb of the pr's on a generator...but that would change grossly depending on the mass added to the pr would it not?

Or am I to weigh the mass of the cone without weight applied and see where it's notch is going to ?

If anyone has done this I would appreciate your feedback on this.

bogart · Post by **bogart** » Fri Mar 19, 2010 11:45 am

Not one....not one comment.....ok...I will post pic's this evening....that should do it

Post by **stipud** » Fri Mar 19, 2010 11:55 am

Hmmm I have always used PRs that were made for a specific sub/box combo. Never tuned them manually.

BassBox has a lot of graphing functions for PRs that would help you tune your mass a lot better than I can

bogart · Post by **bogart** » Fri Mar 19, 2010 11:58 am

I've been looking at that and have uploaded some stuff to assist....I am really looking for real world perspective.

It would be a freaking shame not to at least give it a shot...maybe two....and these enclosures are tuned low....like below what a cyclone can do low....

Post by **Rold Gold** » Fri Mar 19, 2010 12:23 pm

I say just go for it.....
See what happens and make adjustments from there.

bogart · Post by **bogart** » Fri Mar 19, 2010 12:33 pm

The right proper way of loading them if they arn't in a nifty little kit is a big ole sow of a bitch....doable but there is a reason for it. They roll off very poorly and the radiator creates a big notch where the roll off creates cancelation of the radiant waves and will not be good.

So the radiator in actuality functions and loads like an port that can be tuned far lower then a port could in a way smaller enclosure....but you have to build it just right in size and the dispacement of the radiator has to be tuned....by adding mass...to the exact weight or the "port" will roll off above the tuning frequency of the enclosure and will cancel itself out....the sub and the radiator will work against one another. However, in theory if you can get the roll off in a box to set below 8 hz you can in reality tune it to 17 or 18 on an 18 db slope...that is crazy....

bogart · Post by **bogart** » Fri Mar 19, 2010 1:14 pm

so these had the steel shaft on the back and were driven by a cyclone motor in one of the early vortex proto types....the 10's were the drive and the 15s were the passives in it and I guess that it was one noisy pig. We all know how bad the cyc noise can be...so I imagine that it was as bad as it could get.

then they tried to go with the plexi to stop the noise from resonating thru the enclosure itself....

So it looked at it for a couple weeks and did some research on how passives are tuned. You know, I could do something with the 15s and use 2 x maxxes in a push pull system in that box and see but from what I read about radiators and what I know about push pull enclosures I am 99 percent certain that it would be pretty bad....I am thinking about running one ten x maxx and using the two ten's as the passives....you have to have 1.5 to 2 percent more cone area in the each radiator for it to work so one for one it wouldn't enable me to get the roll off below 10 hz...the further the better if you consider the x over slope.....