Wattage meter questions

BigFishCombo · January 7, 2023 at 6:18 PM

My power rack is connected to an 8 ohm 75 watt 1x12 cab. In the Kemper power meter section the upper scale goes to 0 to 800, the lower sale goes 0 to something beyond 400 (end value of scale is not indicated), and there is a small triangle marker sitting on the lower scale that lines up with 200 on the upper scale.

What is the significance of the triangle?

What is a good safe setting for the power meter for my speaker?

BayouTexan · January 8, 2023 at 6:35 PM

From the manual...

Wattage Meter

The internal power amp is mono, and delivers 600 watts at 8 ohms — however, the wattage will be lowered to 300 watts when used at 16 ohms. At 4 ohms, the wattage is electronically limited to 600 watts. If these 600 watts are exceeded, the power amp is deactivated for a moment, which will result in a short dropout. It would require insane volumes for such dropouts to occur — however, if you are connecting a 4-ohms cabinet, you should test it carefully to ensure that your loudest signals stay below that critical level.

The power amplifier provides sufficient headroom to avoid clipping, even with dynamic clean sounds. Very loud signals and transients will then be compressed by a soft-clipping circuit with a nice, organic sound.

If you are afraid of damaging your speakers with the built-in 600 watts power amp, then use the Wattage Meter to monitor exactly how much power is being delivered.

A speaker doesn’t get damaged by too much peak level, but by accumulating too much heat over time. Think of a traditional light bulb: When you switch it on, it takes a moment to reach full brightness. When you switch it off, it will dim slowly even though the current is cut immediately. Due to this time lag, it takes one or two seconds of overpowering a light bulb before it breaks. The same applies to the coils of your speakers.

The Wattage Meter takes account of this time lag and simulates the accumulated heat in your voice coil measured in watts. It is a unique tool that allows you to get a feel for the kind of volume you should expect for a given number of watts. You might be surprised just how loud a few watts can be!

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

If your speaker is rated to 75 watts peak then best not to go over 75 watts consistently. If your speaker is rated 75 watts RMS then you can use it at 75 consitently but maybe not much more than 10- 15% over that, is my guess.

Palm mutes are really going to push the wattage over any other pick/strum technique. So watch for that.

Note that even 5 watts at a 1 meter distance can be ear-piercing on the highs which can cause damage to your hearing.