Transfer function magnitude graphs for two different drivers tuned to 16Hz.:

1. Is this essentially the modeling of the anechoic response curve?

2. Where does room gain start to kick in? I seem to remember 30Hz, but I'm not sure.

I found the following post by TheEar (thanks to Mike C.) this morning.

Is there a 'rule of thumb' I can apply to "pushing them" or is this strictly a trial and error thing? I am guessing this is where Klippel or Dumax tests would be useful (if one knew how to interpret them)??Correct,the drivers sound almost too close.Even the MJ-18`s sounds quite close to the LMS-Ultra/Acoupower units.

Only when pushing them,will the more linear and longer excursion of a LMS/Acoupower start to clearly show.

Not to say they sound exactly the same,they do not. But are close,very close.

Thanks all for your help so far.