4ohm Speaker / Amp Question

Home > Message Board > Home Audio > Amps > Archive through July 28, 2004 > 4ohm Speaker / Amp Question

Main Topics

Your Account

Help

Today's Posts | Last 3 Days

Author

Thread: 4ohm Speaker / Amp Question

Jakeandthefatman

Unregistered guest

Posted on Sunday, July 18, 2004 - 09:02 pm:

Hi,
I have some large Infinity Home speakers rated at 4 ohms. There are many power amps rated out there that are 100 wpc at 8 ohm and 200 wpc @ 4 ohm. If I hook one of these power amps to these speakers, will the amp automatically be putting out the 200 wpc @ 4 ohm because they are hooked up to a 4 ohm floor standing speaker?

Thanks
Jason

J. Vigne

Unregistered guest

Posted on Sunday, July 18, 2004 - 09:20 pm:

It depends on your amplifier. Ideally when the impedance load on the outputs of an amplifier is lowered the voltage (wattage) increases. In this ideal world when the impedance is halved the power doubles and when the impedance doubles the power halves.
The problem is this is not an ideal world and speakers are not simply 4 Ohm loads. Look at the section titled "definitions and descriptions" in the "Speaker" section of this forum for more information on impedance. The problem is no speakers is constantly one impedance. The impedance load is quite variable and will likely fall below 4 Ohms at some point. This could endanger an amplifier that cannot deliver the current required to handle low impedance loads. This will cause that amp to shut down or possibly blow up. Many amps can achieve their rated power into a test bench load but not into a real loudspeaker which represents a much more difficult load in the real world.

Home > Message Board > Home Audio > Amps > Archive through July 28, 2004 > 4ohm Speaker / Amp Question

[ « Previous ] [ Next » ]