Speaker Efficiency Ratio

[Jammin'John]

You know how it takes twice as much power to gain around 3 or 4 db of sound and 10 times the power to be twice as loud ?
Well,I was wondering how that works for speakers.
I know that if the magnet size is increased the loudness of the speaker is also increased.
I was wondering about the ratio.
If you had a speaker like the 15F150 w/40 oz. magnet how much larger would the magnet have to be to gain 3 or 4 db ?
Would a 60 oz. magnet give you 3 or 4 db. ?
How much larger would double the sound ?
Is it physically possible to double the sound ?
JJ

[Old Tele man]

...that's a question probably better asked of someone like Ted Weber.

[greeny]

i don't think just increasing the magnet size will increase efficiency. But unless you are manufacturing your own speakers why is this of any concern anyway?

Simply look at the speaker specs.

Changing from a Greenback with 97db/W sensitivity to say a Vintage30 with 100db/W would be equivalant to changing from a 50W to a 100W amplifier.

To Double the volume this is generally deemed to be a 10db increase in sound presure.

So you would have to change your speaker from say a 90db to 100db efficiency (Most guitart speaker are much more efficient than 90db), Or you amp from 50W to around 500W.

[bob-i]

I'm of the mindset that there is no such thing as "twice as loud" any more than light can be twice as bright or a color can be twice as green. Remember that as volume goes up, our hearing sensitivity goes down, called threshold shift.

I've been in many situations where my amp was outpowered by the other musicians, yet my tone cut through. The reason is simple, I look for sonic space and make sure to find the tone and proper things to play to fill this space. Good examples of this concept would be the Southern rock bands like the Allman Brothers and Skynard. Each guitar has a distinct tone that stood out on it's own.

That said, there's much more to engineering a speaker for efficency than magnet weight. Materials, voice coil design, cone design, spider design etc are all factors.

As musicians we're best simply listening and using our ears to determine what's best for a given situation.

JMO

[Jammin'John]

Good points all.

With the Weber speakers you can order different size magnets if you want to.
If you like a certain speaker you can get it with a larger magnet.

I like the 15F150.

I would like the LOUDEST {most efficient} 15" speaker available.

I want to mate it to a low powered amp for max headroom.

And YES,increasing magnet size DOES increase efficiency.

JJ