We are talking about a single speaker (or pair of speakers), consequently there is no LFE, there is only that speaker and how it performs. We are talking about the design and construction of that speaker, not how to integrates it into a larger more complex system.
Now reasonably the system you put the speaker in will have some influence on the design. But as it stands, this is a stand alone speaker.
Both Low/Mid and Mid/High have to be in a reasonable working range for the drivers selected. Given that the Mids are 4", that leaves 3000hz or 4000hz on the high end. On the low end, the choices seem to be 350hz and 500hz. I explained the reason, and the advantages and disadvantages of both choices. While it is not locked in stone, the Midrange typically covers 3 octaves. But again, there is flexibility in that.
Three octave ups from 350hz is actually 2800hz. Three octaves up from 500hz is 4000hz. The 350hz crossover puts alot more strain on the Midrange drivers, because they cover the peak power band in the 250hz to 500hz range. Crossing at a higher 500hz, raise the Midrange right the the edge of its best functional range. All round it is a very fine balancing act.
As I said, the 3 octave Mid is not etched in stone, but it is very common. Though in a 3-way design, there is a limit to how low the tweeter can functionally go. It has to be over rated. By that I mean if it is functional down to 1500hz, then you really need to cross it in the range of 2500hz or higher to minimize excursion and to increase power handling.
Generally it is 3 octaves on the Bottom, 3 octaves in the Mid, and 4 octaves on the high end. But again, a lot of flexibility. Typically drivers do not work out on those boundaries, so you make do with the drivers in the range they do work in.
There isn't a lot of point in comparing the area anyway, just look up the bass outputs in the speaker specs? This comparison is probably only useful when DIYing where all other constants are equal such as volume and ports etc. Just look at how much more bass response (and less EQ needed) when comparing two sub's with identical drivers but one is ported, such as the SVS PB13 Ultra vs SB13 Ultra. The PB13 wins on output even though the SB13 actually has internal EQ in an attempt to boost the bottom few hz. Not that the SB is a slouch, I have two sat in front of me [emoji1]Hello blueWizard, thanks for the fascinating info.
Can you help a math-challanged fellow?
I'm trying to compare the bass area of two speakers - the B&W CM10s2 (3x6.5" drivers) vs the Martin Logan Electromotion (1x8" driver). Would 3 drivers be counted as 1 drivers 3?
There isn't a lot of point in comparing the area anyway, just look up the bass outputs in the speaker specs? This comparison is probably only useful when DIYing ...
In the same way as looking at the figures doesn't tell you how a speaker sounds, working out the bass area doesn't either. But at least looking at figures shows how low it actually goes.What is "bass outputs"? You have Frequency Response and general Sensitivity, neither tells you how a speaker sounds. Neither tells you how much air will be moved or how much bass output there will be.
When comparing speakers, how much bigger is a 6.5" (165mm) bass driver than a 5" (130mm) driver. While it doesn't seem intuitive, the 6.5" is TWICE as big as the 5". When buying speakers that is worth knowing.
2x8" are roughly equal to 3x6.5". When comparing speakers that is worth knowing.
If you are considering 2x6.5" and 2x8" speakers, how much bigger is the 2x8" than the 2x6.5", that might be worth knowing. Answer: the 2x8" are about 70% larger. That's might be an aid in helping you make your decision.
The same can be applied to Subwoofers. How much bigger is a 12" than a 10". Answer: about 53% larger.
The provided information tells you want it tells you, but no more than that.