Sorry, 3dB is not twice as loud as before. 10dB is twice as loud as it was before. 10dB requires 10x the amount of power. Doesn't seem intuitive, but it is the way it is.

Also, a ported box is only louder than a sealed box around the resonant frequency of the port. Below that resonant frequency it is less loud, above it, it is roughly equally as loud.

 

3dB is unarguably twice the power but 10dB is a purely subjective number for twice as loud. There is nothing magical about the 10dB number - some professor somewhere did a test one day where he asked people when the music became twice as loud; 10dB was probably just a nice round number.

6dB is twice the pressure and I think is a more accurate number for "twice as loud" especially at the higher volumes. So in my opinion 4X the wattage into the same speaker (provided it can handle it) will increase volume 6dB and become psycologically "twice as loud".

-Mr. Wigggles

Ps. for low frequencies you can get a 6dB SPL increase by adding another woofer with the same wattage as the first. In this case you would be getting 6dB increase in sound with only twice as much power.

 

10 dB is 10x the sound intensity level.

http://www.glenbrook.k12.il.us/gbssc...nd/u11l2b.html

 

Ta... Darrrrrrr

 

I said pressure. There's a difference and it is an important one.

http://www.sengpielaudio.com/TableOf...sureLevels.htm

If you notice in the chart it takes a 20dB increase in SPL to increase pressure 10X.

At low frequencies (where waves can't cancel out), 10 subs all playing at the same level will create 10X the pressure or 20dB more SPL than just 1 sub.

You can use this calculator:

http://www.sengpielaudio.com/calculator-soundlevel.htm

To see that increaseing pressure by a factor of 2 (ie. 2 subs versus 1) does infact create a 6dB increase not 3dB.

Trust me on this one.

-Mr. Wigggles

 

Thanks C.

If anyone cares, I found shots of the actual box, and junk (with the baffles removed).

amp:



sub box (downward-firing)

 

We are both correct.

Horsepower(Intensity) vs. Torque(Pressure) argument rekindled... more or less.