Baffle step question in wide-range 2way

[Josephjcole]

So here is my plan. I've got a pair of the fostex 108e sigmas. Which I'm going to put in sealed ceramic enclosures. This should take me down to the 150-200 hz range. Then something to fill in the bottom end. The baffle on the fostex ceramic enclosure will be something like 6-8" (don't have them made quite yet).
Here is the first question: should I make the sealed enclosure small enough to get a small rise out of the fostex? I think, if my memory is correct, that with something like a .7 litter enclosure I could get a slight rise up to 200hz which would be up like 3db, falling from there. Would this help comensate for the small baffle?
Second question: The fostex is around 90db effecient, to correct for baffle step should I look for a woofer of around 93-94db effeciency?
Any input would be appriciated....
Also any suggestions on cheap (under $80 ) good woofers that would fit the bill would be appriciated
Joe

[Josephjcole]

Or could I just go "psuedo baffleless"... ie the baffle not more than a 1/2" wider than the actual driver itself, with a round over that started almost immediatly following the drivers edge. Then go for a bottom end that matches the 90Db fostex? This would certainly allow for a bigger selection of drivers, and allow for a lower QTC, letting the fostex cover slightly more of the lower end, and keeping the woofer out of more of the midrange.
Any thoughts?
Joe

[navin]

baffle step is relared to baffle width and the smaller the width the higher the freq at which baffle step starts. over what range do you want to use the 108? the larger the range the less the max SPLs u will get.

let your SPL needs dictate the XO freq. and the XO freq. dictate baffle width. in any case a more sens woofer 92-93 db would be most certainly preferred. I'd look at the SEAS H333 or H372 or maybe even 2 x H397.

[Josephjcole]

Originally posted by navin
baffle step is relared to baffle width and the smaller the width the higher the freq at which baffle step starts. over what range do you want to use the 108? the larger the range the less the max SPLs u will get.

let your SPL needs dictate the XO freq. and the XO freq. dictate baffle width. in any case a more sens woofer 92-93 db would be most certainly preferred. I'd look at the SEAS H333 or H372 or maybe even 2 x H397.

I'm not so worried about maximum SPL's. I listen to the 108 in a backloaded horn right now and am happy with the volume I'm able to achieve. What I'm looking for is more extension on the bottom end and slightly cleaner mid-bass. I'll look into the SEAS drivers....
Joe