Speakers Loudness

[vaustin89]

i have some question here, would be glad if all of them will be answered.

1.for example I have 2 amplifiers one is a 50w in a 2x12 stack the other is a 30w connected to a 4x12, which will be louder? and why?

2.How critical is the sound on the size of a cabinet? for example a 4x12 marshall, what would happen if i increase or decrease the size proportionally of the cabinet, would it affect the tone?

3.if a guitar head say it allows 8ohms and i plug a cabinet that is more than the specified, would it affect the loudness?

4.has there been a amp head where you can hook up multiple cabinets?

misc question-->is it possible to run 2 or more pre-amps through one power amp? if yes, then what are some of the thing that should be considered?

[J M Fahey]

1) if everything else is the same (same head although differing wattage, same speakers) in practice they will sound about the same.
It isn't that 4 speakers are more efficient than 2 (although many think so) but 4 focus the sound more than 2.
That said, niow you will understand why 2x12"is a popular Club configuration, since sound "opens up" a bit more, good on a small cramped stage and where patrons sit on tables relatively close but all around the place.
4x12" is a popular festival, stadium, similar large stages with people further away (say over 10/15 meters instead of 2/4 meters as in a Pub)
2) in a 4x12"Marshall , making it bigger probably would not add much; making it much smaller (as in thinner, front area can't be smaller than 4x12" speakers side by side) would reduce bass somewhat, making it sound boxier (with a nasal low mid hump)
3) mismatching impedance lowers useful power, lowering sound level
4) Many do, why? As far as you match impedances, you can hook 16 cabinets to one single head, if you wish.

[vaustin89]

thanks for the quick response.. 

[joecool85]

1) if everything else is the same (same head although differing wattage, same speakers) in practice they will sound about the same.
It isn't that 4 speakers are more efficient than 2 (although many think so) but 4 focus the sound more than 2.

Sort of.  Technically they do get a little more efficient.  If you have 2 x 90db/w speakers, they will produce 93db/w.  If you have 4 x 90db/w speakers, they will produce 96db/w.  Or at least on paper it seems this is true, please correct me if I'm wrong.

[phatt]

Hey Vaustin,

Plenty to read here;
http://www.ssguitar.com/index.php?topic=1968.15

Re the last Q, (misc question-->is it possible to run 2 or more pre-amps through one power amp? if yes, then what are some of the thing that should be considered?)

Answer, A mixer.
Phil.