Generic: How BIG for mid duty driver

[weltersys]

Say THX levels (85db continuous, 105db peak) at 1m with subs (one or two) below 80Hz and sealed enclosure for the speaker.

If that can provide required xmax, will size be not imp as long as that driver has that xmax ?

As driver size is reduced, the surround needed for long excursions becomes relatively larger compared to Sd, around half the surround does not contribute to Sd, so size is somewhat important, you can't get the level you want out off too small of a speaker. That said, Earl's response to your question was quite conservative. A single Eminence Alpha 8" in a tiny sealed box can do 105 dB SPL at one meter without exceeding it's 3.2mm Xmax at 80 Hz.

B&C has 8" drivers with more than double that Xmax, so could do more than 6 dB more clean SPL, given more power.

Art

 

[freddi]

seems to me more spl is needed - so a good 10" driver for impact

 

[gedlee]

That said, Earl's response to your question was quite conservative.
Art

I am always conservative when it comes to excursion. I just see no reason to push the issue.

 

[Hifisound]

A single Eminence Alpha 8" in a tiny sealed box can do 105 dB SPL at one meter without exceeding it's 3.2mm Xmax at 80 Hz.

B&C has 8" drivers with more than double that Xmax, so could do more than 6 dB more clean SPL, given more power.

I see that some 7" drivers like Dayton RS180 have 6mm Xmax. Would that be sufficient then ?

 

[Hifisound]

Btw, the reason for asking about a 7" is because (apart from the small size) it can take a 2nd order acoustic crossover at even 2kHz.
Unless the crossover order differences are not audible too....