Any way to relate db to wattage?

[longblock454]

I'm attempting to further illustrate the importance of driver sentivity.

For example, Sub A with 84db 1w/1m to say sub B with 90db 1w/1m. How much harder would you have to drive sub A to match sub B?

From my limited experience is seems like it would be in the hundreds of watts. Can this be estimated or calculated?

Thanks
Andy

[richie00boy]

Well as the difference is 6dB, and each +3dB requires a doubling of power, the theoretical answer is 4x power.

However, in practice sub efficiency ratings are largely nonsense IMO and you are far better off comparing plotted SPL vs frequency graph at various input powers to see the real truth.

[sreten]

Hi,

the important thing with subs is to match driver sensitivity,
amplifier power, subwoofer size and maximum excursion.

e.g. two sealed subs, one 1cuft, the other 2cuft.

They can be fitted with drivers that in the boxes have the same
response and the same excursion capability at any frequency.

This would mean one driver is 3db less efficient than the other
and would therefore need an amplifier twice as powerful. So you
are trading the cost of double the power with double the size.

The above applies in the region output is limited by excursion
capabilities, i.e. low bass, at some point higher in frequency
output is determined by driver sensitivity and driving power.

Low efficiency drivers are very useful if you like small subs,
and as they are low efficiency for a given excursion they
need lots of power - which is a fine compromise for some.

/sreten.