Wattages and Ohms and Cabs. Help a confused dude understand!

[solarplexus]

Hi,

I might be opening a useless thread so please feel free to remove it (Moderators), or please redirect me to where I could find the information, I just can't find it.

Ok so I want to REALLY understand what are the differences in perceptible volumes with different variables. Here:

Theoretically using the same Bass, Head/Combo, Speaker efficiency, Cab design and excluding all Wattage differences from one company to another, what would be the perceptible differences:

A 150W @ 4ohms amp into 1x15" vs a 350W @ 4ohms amp into a 1x15"?


A 200W @ 2ohms amp into 2x15" vs a 350W @ 2ohms amp into 2x15"?


A little more complicated:

A 200W @ 2ohms into 2x15" vs a 350W @ 4ohms amp into 2x15"?



I am trying to understand the math behind all the wattage and ohms and cabs so I can make some concise choices in rigs and not feel like missing something.

Any help will be greatly appreciated.

[billfitzmaurice]

Ohms FAQ

[Jaco who?]

I'm trying to understand what you don't understand, but the "ohms" is really impedance, and it's a set amount depending on what the impedance of the cab is, so don't get too mired down in that.

Generally, more speakers will always be louder than more wattage - your 200W into a 2x15 will be louder than the 350W into a 1x15, for example.

The impedance of the cab pretty much dictates how much wattage the head will produce, so your examples mean little without knowing whether the cabs are 4Ωs or 8Ωs, and even then, more speakers will be the loudest.

[solarplexus]

Ok so the ohms in a cab will affect the perceivable volume because of the wattage that goes into it -> 2ohms load = less loss wattage = more efficient cab meaning louder than 4 ohms cab with same wattage rating?

[Rick Auricchio]

No, the loudness of the cab is much more dependent on the cab design and driver choice. Wattage is the least important item; all that tells you is the power needed to burn out the voice coil. Typically, a speaker hits its maximum mechanical limits well below that point.

[solarplexus]

Ok and how to know that the driver choice is superior from one to another?