How loud is loud, What DB is actually loud?

Doesn't adding a 2nd driver add 3db if the power stays the same? Been so long I forget. But if 100w does 100db with a single 12 then that same 100w going into a pair of 12's would equal 103db?

Driving two 100db/100W subs with two separate amplifiers, each providing 100W, would result in an spl of 103db, assuming that the subs are positioned such that their outputs are in-phase at the listening position.

Connecting two 100db/100W subs in parallel to a single amplifier, that would provide 100W into one sub, would also result in 103db, IF the amplifier is capable of providing the 200W that would be drawn by the halved impedance that the paralleled speakers would present to it. And assuming also that the amplifier has negligibly small output impedance (which is the case for most solid state amps, but not for most tube amps).

Connecting the two subs in series, btw, would not make sense as it would result in a reduction to 97db spl, with only 50W being drawn from the amplifier.

Rayray8 -- truly awesome. I'd imagine that one reason for keeping the tone bursts short is to prevent the voicecoils from melting!

Regards,
-- Al

double speaker sq area and then doubling of power would result in a 6 db gain ...

yea, I would think if you double the cone area & also double the power you would get a 6db gain vs a just increasing the power.

If each speaker is getting 50w I would think it would move more air then a single driver with 100w.

No clue with the focal stuff..... I have had really good luck with Image dynamics subs. They are excellent for SQ & do not require lots of power or a big heavy box. Great stuff........

If you replace one 8ohm speaker with two 16ohm speakers in parallel then area will double but power to each speaker will half and SPL will stay the same.

Two 8ohm speakers in parallel will receive total of 2x power resulting in 3dB increase in SPL. It is the same as two exactly same subs, that Al mentioned, driven by separate identical amplifiers also resulting in 3dB increase.

It seems logical to me since adding more transducers (area) of the same efficiency without increase in power cannot improve overall efficiency. SPL is increased by 6dB only if power is doubled to each of two speakers (quadrupled power from the amp)

">>01-07-11: Systembuilder
I was looking at the quad esl's and people say they wont play loud but how loud is loud? Is more of a question of House party loud or just rocking out?"<<

Drop $35 or whatever on a Radio Shack meter and you'll have your answer.