Are there any reviews or comparisons of the PB13 Ultra (MSRP twice the MFW's) and a single MFW-15 floating around somewhere? The craigsub ratings are all I have found. I see that their output, etc. are similar with the advantage going to the PB13 Ultra but I have also read a few comments that the PB13 is in a whole other class. Of course, the comments seem to come with no direct comparison.

This is a perfect example of the law of diminishing returns.

The Ultra is twice as expensive as the 15.

Is the Ultra twice the sub, no.

Is the Ultra a better sub, yes.

How much better, that is for you to decide.:D

Agreed.... It would be nice to see someone do some thorough tests of the MFW
like those that were done like Ilkka's of the Ultra13. For a good comparison...