Same amp,same speakers 4x12 vs 1x12 which is louder...

[rockon1]

My ears have painfully seemed to tell me that a 4x12 cab is louder than a 1x12 cab given the same speakers and amount of power(amp) put into them.For hypothetical reasons lets say the speakers being used can handle the output of say a 50 watt head without breaking up so thats not an issue. So is a 4x12 louder or are my ears deceiving me?:confused:

[Old Tele man]

...yes!

[rockon1]

OTM,care to elaborate? (in language I can understand:D ) Bob

[Old Tele man]

elaborate?
...more total speaker SURFACE AREA "moving" air with 4x12", that's why two speakers SOUNDS louder than one speaker even though it's the SAME power being delivered!

[rockon1]

So its a percieved not actual volume increase?

[Old Tele man]

So its a percieved not actual volume increase?
VOLUME and LOUDNESS are synonymous (to the human ear), but they're not the same as POWER.

[vibroverbus]

check out a quick ref on comparative speaker area of typical bass cabs (table 1/2 way down the page). interesting if you never calc'd or thought about it before.
http://www.guitarnoise.com/print_article.php?id=166

[gw_bluesman]

assuming impedance is matched, the more speakers usually the louder.

For example, if you have a 4ohm head and use it with an 8ohm bottom, you will effectively loose 33% of your power so your 50W head would sound more like a 33w head. (50W x .66 = 33W)

However, assuming all things equal .... what happens when you add speakers you get "speaker coupling" where the 2nd speaker adds to the 1st. As a general rule you can assume an increase of approx. 3db each time you add a speaker. If you are wondering what 3 db is like, it is about the smallest increment the human ear can detect.

So if you put numbers to this .... if one speaker got you to let's say 90db, the 4 speakers (same power, again assuming an impedance match) would get you to approx. 100db.

This same "coupling" effect happens as you add a surface. An amp against a wall is "X" db now move it to a corner and you add "Y" db's. You also add standing waves which can cause cancellation or make your sound muddy. This is especially a problem in a SQUARE room where there is nothing to absorb the reflective sound like in an empty gym.

Another thing to consider is that you have to double your power to get about a 3db increase on volume. So you have to realize that a 50W amp is only about 3-5 db louder than a 25W amp. The extra power can provide better bass reproduction and more clean headroom.

I am simplifying this and I realize I answered a few questions that you did not ask but you get the idea that acoustics can get complicated. The good news is that producing Guitar tones is fairly easy as it is all mainly in the mid-range spectrum.

Good Luck