Question about amp and cab setups

[jamisonsalamand]

I had a somewhat specific question about people's setups because I'm trying to get an understanding of amp heads and cabs before I buy anything. I apologize if this has been asked before, I don't browse this site a lot.

I'll look at people's setups, and see they have things such as 300 watt heads running through 8x10 cabs which can go up to 800 or 1200 watts. I was wondering what the significance would be of having an 800 watt cabinet if the head can only go up to 300. Does it create a clearer, less distorted tone than if you were using a 4x10 cabinet?

[somedumbguy]

It's more likely that they are doing that so that one day they can upgrade their head and still be ok.

[mcapote]

more than likely its more of the fact its 8 x 10" . overall cone area of speakers has a greater impact on SPL than actual wattage. 1000 watts to 1 10" wont get as loud as 300 watts to 8 10" or 4 15" woofers on most cabinet designs.

[IvanMike]

i would go to the FAQ sticky and read up a bunch. FWIW, you don't need an 8x10....just sayin'....

but short answer is matching power output of an amplifier to maxim RMS power handling of a cabinet isn't an exact formula by any means. lots and lots of considerations and variables.

[jtc_hunter]

Originally Posted by mcapote

more than likely its more of the fact its 8 x 10" . overall cone area of speakers has a greater impact on SPL than actual wattage. 1000 watts to 1 10" wont get as loud as 300 watts to 8 10" or 4 15" woofers on most cabinet designs.

+1

[PSPookie]

Yup, the most common 300W head and 1000W cab combination you will see is an Ampeg SVT CL into an Ampeg 8x10. The 300W rating can be misleading as that is the rated output at 5% THD, IIRC, but the head can put out more power albeit at a higher level of distortion. Likewise the 1000W rating on the cab is easy to misinterpret since that is just the power rating at which the voice coils will melt. In reality, you will hit the limits of that cab far before 1kW in a real-world application.

Your best plan is to:

1. Read the stickies
2. Try as many heads & cabs together as you can and get the combination you like
3. Use your ears to tell you if you're pushing something too hard. If the amp starts making ugly noises, turn down.