# 2-10’s or 1-15

Discussion in 'Amps and Cabs [BG]' started by Billy the kid, Dec 17, 2018.

1. ### fermata

Nov 10, 2015
Mountain West
This is at least the second time this assertion has been made in this thread. How can this be true, when a 115 has more surface area than 2 10s?

A 10" speaker has an area of 78.5", so 2 x 10 = 157" of surface area. A 15" speaker has 176.7" of surface area, which is 19.7" more than 2 10s. Since 'moving air' is correlated to surface area, a 15 will move more air than 2 10s. Granted, it's not a huge difference, but the fact remains a 15 has more surface area than 2 10s.

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2. ### Fumble Fingers

Jul 5, 2018
St. Nowhere
You are correlating speaker surface area to "moving air". While logically it makes sense to do this, in reality factors such as coil throw and other physics come into play.

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3. ### fermata

Nov 10, 2015
Mountain West
But can that be generalized? Isn't that down to the specific speakers and cab design? Of course, there's also the fact that two identical speakers interact in positive ways a single speaker can't, which is a point for the 210. (I guess this all adds up to why it's impossible to make general statements about a specific speaker size--each cab is its own thing.)

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4. ### AstroSonic

Dec 10, 2009
rural New Mexico

It's correct if we add, that for a given excursion the 15 moves more air than two 10's. However, the difference is marginal. And, yes, many other things come into play.

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5. ### ctmullinsfueled by beer and coconutGold Supporting Member

Apr 18, 2008
MS Gulf Coast
I'm highly opinionated and extremely self-assured
Displacement = Sd (cone surface area) x Xmax (cone throw).

Acoustic output (“air moved”) in the lowest octaves is determined by the cabinet/driver(s) interaction, not the driver(s) alone.

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