what type of subwoofer is good for ribbons


I am looking to buy a new set of speakers I am very interested in some magnepan ribbon speakers but they dont have enough bass i also heard that you need a special subwoofer for these in order for them to sound right what would make a good subwoofer for ribbon speakers
justinroxxx
http://www.harman.com/EN-US/OurCompany/Technologyleadership/Documents/White%20Papers/multsubs.pdf

I don't know how I found it.......and can't read it. My eyes are watering so bad from this cold I can hardly see.

Somebody read it and summarize, please.
Also, please note in your answer how well your listening space conforms to the test space....mine? It couldn't.....I have an 8 sided asymmetric room with a vaulted ceiling.....a largish LR / DR in the California fashion.
> all the placement recommendations mentioned in the multisub paper on the Harman web site were very symmetrical not asymmetrical. Whether 2 subs or 4 subs, they are always in the same position on opposing walls.

The idea behind asymmetrical placement is to minimize standing waves by decreasing constructive interference i.e. each sub has a different interaction with its respective room boundary or boundaries, which smooths the overall response.

I have placed my four SWARM subs in many, many different locations, including a symmetrical setup. Trust me, you do not want to do this.
If I may infer, the speed, articulation, and seemingly endless senergy that REL subs offer with it's ability to intergrate easily, is a Company that I had to suggest. Just my MHO, others may have suggestion that are noteworthy also.
the problem with panels and cone subs is the dispersion patterns of each driver type is unique.

i think i can hear the discontinuity of a panel and cone sub in all cases in a blindfold test.

i have heard many panels with subs and i have heard two different speakers in each case.

there is another issue. subs have a cabinet. there is a considerable amount of wood which may have a resonant frequency, whereas a panel sub has less wood and its dispersion characteristics are closer to the main speaker.