Hi,

I'd say interactions between amp, speaker and room.

Make sure to use the 4-Ohm amplifier tap if available.

Well, as I have some involvement with MF-Audio and the PMP I'd better not say to much, but it was conceived as concept by me and realised mainly by JB from S&B (credit also to John Chapman of Bent Audio and Brian Cherry of DIYHiFisupply) in order to break that "iron law"...

Keep trying, but try systematically.

I wrote about WASP ages back in TNT and it is possibly the most usefull and most secret page on TNT....

Here goes, TNT-Audio's best kept secret:

WASP: speaker placement made easy

Ciao T