fi q 12 passive radiator

[arntsmag 0]

Wondering if anyone has matched a passive radiator with the Q 12 before? If so what radiator, if not is there any recommendations? Looking at making a home theater sub

[NDMstang65 403]

Just gotta have twice the cone area..so you will have to build a box with 3 mounting holes in it, 2 for the PR's and 1 for the sub.

[95Honda 486]

One of these-

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-142

Or 2 of these-

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-140

One of these if you have a big budget-

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=293-680

[arntsmag 0]

I was actually looking at that tc 15 as an option. Was wanting to do a 15 instead of 2 12s so I could achieve a lower fs. Wonder if that dayton 15 would be over powered considering that radiator was designed for the matching low profile sub with a 4 or 500 rms ?

[95Honda 486]

#1 The un-weighted Fs will have nothing to do with the overall outcome of your alignment. This is the Fs without adding any weight, and you will/can change this.

#2 The power rating of a sub has nothing whatsover to do with the passive radiator requirments.

You need to shoot for a passive radiator that will have roughly 2X the displacment of the active driver at full output. The Dayton 15 will just about do this, the TC 15 will definetly do this and the TC 12 will just about do this also.

The signle Dayton 12 will not come close, a pair would be about the minimum.

All this assumes you are going to use enough power to get full stroke out of the driver. If you are just going to use a few hundred watts or so, than any of the combos will work and you won't have to worry about a thing..

[Fi Car Audio 64]

We have been getting more and more requests for PRs. I have always been a big fan of them and have used them on many of my own applications for past 20 years. We do OEM PRs for home applications and will be offering them for BPD shortly. But, it seems we might need to make a tutorial for them and offer them for Fi too.

As mentioned, it is twice volumetric displacement. Just having twice cone area isnt enough if they dont move as far. So... for a single Q 12 you would need either a 15" that moves as far as the Q12" or a pair of 12" PRs that move as far as the Q12. Some of the cheaper PRs out there simply are not up to the task... volumetric displacement and not just surface area.

Thanks,

Scott

[Duran 387]

Perhaps you can answer a question for me Scott, why is twice the theoretical volume displacement recommended? It seems a waste of money and space to have that much displacement; wouldn't a PR that can displace an equal volume of air as the active radiator be minimum, and any extra displacement, such as extra PR, be beneficial, not required?