comparing amps at different voltages?

Home / the12volt's Install Bay / Car Audio / comparing amps at different voltages? (

Topic Closed)

Welcome Guest :)

Members

< Prev Topic Next Topic >

luckydevil

Silver - Posts: 365

Joined: July 04, 2005

Location: United States

Posted: August 10, 2005 at 12:35 PM / IP Logged

How do you go about comparing the rms wattage output of two different amps whose specs list two different voltages that they were tested at? I searched and didn't find anything and I also looked over all the Ohm's Law info and just couldn't figure it out for the life of me.

For example which of these would have a higher rms output at 12.9v?

US Acoustics USX2050: 50w x 2 @4ohms+12.9v, 80w x 2 @2ohms+12.9v

Clarion APA2160: 80w x 2 @4ohms+14.4v, 125w x 2 @2ohms+14.4v

Thanks.

luckydevil

Silver - Posts: 365

Joined: July 04, 2005

Location: United States

Posted: August 10, 2005 at 12:36 PM / IP Logged

I know there will probably not even be an audible difference between the two, but I am just curious about how to do this problem.

tcss

Silver - Posts: 1,623

Joined: June 07, 2004

Location: United States

Posted: August 10, 2005 at 1:35 PM / IP Logged

This usually is comparing your car with the engine not running and the amps running on just the battery ( 12 volts ) versis the car running and the alternator spinning ( 14.4 volts )

boulderguy

Silver - Posts: 510

Joined: April 17, 2005

Location: United States

Posted: August 10, 2005 at 2:35 PM / IP Logged

The simple approach would be divide watts by voltage to get watts per volt, then multiply by new voltage to get new watts @ that voltage. This assumes everything is linear, which I think it would be. At that rate, your US acoustics amp would put out 56wpc @ 14.4v.

haemphyst

Platinum - Posts: 5,057

This member has been recognized as an authority in Electrical Theory. Click here for more info.

This member has been recognized as an authority in Mobile Audio and Video. Click here for more info.

Joined: January 19, 2003

Location: Michigan, Bouvet Island

Posted: August 11, 2005 at 12:01 AM / IP Logged

Also, the higher voltage of a running car will almost always provide a higher output voltage. Most amplifier power supplies are unregulated, so this makes perfect sense.

A regulated power supply will always put out the same power, whether the car is running or not.

The watts per volt theorem is a GRAND oversimplification, because as the voltage supply increases, the amp (current, not amplifier) demand will increase as well... A given amplifier will not always pull 10 amps, no matter the input voltage - it (the current) will increase as the voltage does... Most amplifiers will run more efficiently when allowed more input wattage as well, so the chances of getting only 56 watts is pretty low... it'll be higher than that.

It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

luckydevil

Silver - Posts: 365

Joined: July 04, 2005

Location: United States

Posted: August 11, 2005 at 5:54 AM / IP Logged

good info. thanks guys!

Sorry, you can NOT post a reply.
This topic is closed.

Printable version

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot delete your posts in this forum
You cannot edit your posts in this forum
You cannot create polls in this forum
You cannot vote in polls in this forum

Search the12volt.com

Follow the12volt.com

Disclaimer: *All information on this site ( the12volt.com ) is provided "as is" without any warranty of any kind, either expressed or implied, including but not limited to fitness for a particular use. Any user assumes the entire risk as to the accuracy and use of this information. Please verify all wire colors and diagrams before applying any information.

comparing amps at different voltages?

Sorry, you can NOT post a reply.This topic is closed.

Sorry, you can NOT post a reply.
This topic is closed.