[fdandrews]

I have a pair of 15" Selenium 1509 woofers, with a Qts of .35. I know that if I put them on an open baffle, I would need some significant equalization to get low bass. This equalization would require significantly more amplifier power. Are there any other disadvantages to using otherwise good quality, but low Qts, woofers for open baffle?

[FullRangeMan]

My 2 cents: more cone excursion seems.

[Rudolf]

My 2 cents: more cone excursion seems.

Of course not.
If you want to achieve a certain sound pressure level, you need to move a certain amount of air. This is cone area multiplied by excursion. It doesn't change with Qts in any way.
If you have the means and the power to equalise a low Qts driver, you will get the same maximum SPL  - compared to a high Qts driver of same size and excursion.

[Toaster]

I'd be more concerned about the relatively low excursion limit. There does seem to be a bit of folklore suggesting that high(er) Q woofers have greater output capability than low Q ones, but as stated above, that isn't the case. The relevant parameters, assuming the Fs is low enough to allow the desired bass extension, is excursion capability x cone area, (ie swept area) x power handling. As has often been said before, the best resources are http://musicanddesign.com/tech.html and http://www.linkwitzlab.com/frontiers.htm.

[scorpion]

Toaster is right, there are serious problems around the relatively small X-max of the SELENIUM driver,
nothing to do with the Q value by itself, but practical it will be a problem.

/Erling

[fdandrews]

Thanks, everybody.