Originally Posted by Holmz View Post
Well I admit I like passives.
That 12M that I had posted earlier has something like 4" of excursion... and therefore is rated as only needing a single unit for a 12" sub.

The "total box" is going to be fatter with a slotted... The port volume need to exist somewhere. (Whereas with a PR the air mass become steel mass, which is way denser than air, and hence the volume it ~nil.)
If realestate is precious, as it seems to be in the OP's case, then some serious consideration as to whether a PR makes sense seems warranted.

If he/she has the room for a slotted, then that is definitely cheaper. ....
While those are all valid points, there are a number of additional considerations WRT PRs and their application. Unfortunately, there does not seem to be a wealth of detailed information from first-hand experience; and to that extent, the uninitiated are sort of on their own.