Please help... power question!

[IdealWay]

So I just received my EA VL210B cab, and I'm really liking the sound so far. I'm running it through my EA iAmp head and am curious about how I can calculate the amount of power it's producing.

The iAmp says 500w with a 4 ohm min. load.
The cab is rated at 500w and is 8 ohm.

Is there any reason I should get distortion, even if I cranked the head?

 

[dog1]

About 350 watts @ 8 ohms

 

[thirtypoint87]

If you're getting distortion, it may be the power amp clipping if it can't push hard enough against the "higher powered" speaker. A power amp that's rated a bit more powerful than the cab will give a cleaner sound.

Think of it this way: a 200 watt amp running at half power will sound cleaner than than a 100 watt amp running on full. Extra power = headroom = GOOD!

 

[B-string]

ANY amp cranked will distort unless the gain stages or your bass is VERY weak. Most bass amps will reach their "clean" peak with the master volume between 11:00 and 2:00 with gain at the input properly set.

 

[dog1]

Yup. I have always figured that if you need to turn your amp past half way, then you need a more powerful amp.

 

[JimmyM]

Yup. I have always figured that if you need to turn your amp past half way, then you need a more powerful amp.

Which you don't unless you play arenas or in a doom band :scowl:

 

[Bassmec]

If you're getting distortion, it may be the power amp clipping if it can't push hard enough against the "higher powered" speaker. A power amp that's rated a bit more powerful than the cab will give a cleaner sound.

Think of it this way: a 200 watt amp running at half power will sound cleaner than than a 100 watt amp running on full. Extra power = headroom = GOOD!

An interesting set of theories! the only problem is no bass player under the age of 35 has ever used less than every last watt available plus that little bit of acceptable crunch that comes with good old fashioned power stage clipping. loudspeaker thermal ratings may be generous enough to forgive highly exaggerated power output figures.
The best advise is get a recording oscilloscope and a shunt. Or learn to recognize and analyze using ears the onset of distortion throughout the
various gain stages in the amplifier, the best thing to do this with
is a cabinet that will take the whole output of the amp at eight ohms
with ease, that might be by borrowing an eight by ten cab.
Then having found the maximum clean available test your own cab at the settings found with the larger cab. If the distortion is increased by a lower speaker count at the same impedance then you must look to the idea that a cab may be farting out on you at less that the maximum RMS thermal rating, this is always a shocking revelation.