How loud is loud, What DB is actually loud?

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.

Weseixas & Viggen900, one 100db/100W speaker will put out a certain small number of acoustic watts, in response to the 100 electrical watts that are being fed into it.

A second 100db/100W speaker, also being driven with 100 electrical watts, will put out that same small number of acoustic watts.

If the two speakers are at identical distances from the listening position, the number of acoustic watts arriving at the listening position will be double what it would have been with one speaker. Twice the number of watts (acoustic or electrical) corresponds to a 3db increase.

You may be thinking of the fact that a larger driver will tend to be more efficient than a smaller driver, everything else being equal, producing more acoustic watts for a given number of electrical watts. However, that has no relevance to the question being considered.

See "Multiple Sources" near the bottom of this page:

https://ccrma.stanford.edu/CCRMA/Courses/152/SPL.html

Kijanki's post and my previous post are correct.

Regards,
-- Al

there are vehicles now that score well over 170db in these competitions

I had absolutely no idea this was a realm of human aspiration. I must not get out enough.

"Takes all kinds to make a world," my old man used to say. :)

John