Wow, thanks Mike! I really don't understand WinISD all that well. Would you mind explaining how you arrived at your conclusions? I found looking at the cone excursion confusing because there are two red lines. On which graph does it show how much power the sub can handle before Xmax is exceeded?
Also, from memory, WinISD recommends the PRs to be weighted at about 456gms to achieve a box tuning of around 20hz. Is this in total (228gms per
PR or 456gms per
PR?)? Also, does that account for the inital weight of the PRs of 425gms each? I.e., is WinISD recommending a further weight or should I subtract the intial weight from the recommended (456gms-425gms=31gms). Further, how close is the WinISD recommended weighting to the 790gms (425+365gms) recommeded by the box designer you mentioned earlier?
Would changing the tuning of the box, and so weights on the PRs, elleviate the driver excursion? While the amp can be modified, I'm not sure how confident I'd feel soldering/changing resistors (although I'd like to do it if I can) and I'll have to check if I have the correct modification instructions for my amp. So it would be much easier to change the
PR weights.
Finally, do you think changing the amp will make a very big difference (is it worth it)? It sounds like being able to deliver twice as much power (210 vs. 100watt) would make a big difference but you say it's only 2db more at 20hz. I still plan on building the 18" sonotube - so maybe I should just leave this sub as is and just accept that it's the best I've been able to achieve with this design (my first build)?
Thanks again for all the help.
