measuring watts??

[mat3833 10+ year member]

i was wondering if there is anything that can measure the actual watts a speaker is seeing while its playing. i figure its not nessecary but its a bit of information id like to kno. i googled and all i came up with was industrial crap, nothing for consumer use.

Matt

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[JimJ 5,000+ posts]

A DMM for voltage and a true RMS clamp meter for current...

 

[nauc 10+ year member]

A DMM for voltage and a true RMS clamp meter for current...

what is this

 

[AllDayMJ 10+ year member]

this : http://www.multimeterwarehouse.com/clampmeter.htm

measures current, current x voltage x efficiency= watts..ppl tune their systems this way.

 

[Mass Car Audio 10+ year member]

To find out the amount of wattage going to your speakers you need a DMM.

Take your DMM and set it to AC voltage, then take the DMM leads and put them on the output terminals of your amp with the speakers still hooked up, then play a test tone with your volume turned up to your desired level. You will see the voltage on the DMM screen, then figure out the impedance load the amp is seeing and put the voltage number and impedance number in this formula.

volts/impedance = amperage

Volts x amperage = watts

 

[PaulD 10+ year member]

The impedance varies a good bit with frequency with subs. That type of reading will only be a guesstimate

 

[Mass Car Audio 10+ year member]

Yes that would be a estimation using this calculation without the true amperage, i was giving him the easiest and cheapest way to find out wattage without buying two different types of meters.

 

[azbass 5,000+ posts]

measure a measurement?

 

[smgreen20 10+ year member]

You're to disconnect the sub. It's a bit safer and there's no resistive load.

There's also no way to tell when you're clipping the signal into distortion at which point that's what the amp will produce cleanly. You can crank the gain to max, but 9/10 times the signals clipped. For that you'll need an O-Scope.

 

[Mass Car Audio 10+ year member]

You're to disconnect the sub. It's a bit safer and there's no resistive load.
There's also no way to tell when you're clipping the signal into distortion at which point that's what the amp will produce cleanly. You can crank the gain to max, but 9/10 times the signals clipped. For that you'll need an O-Scope.

If the output is regulated then how will the amp produce power if there is no impedance load ? You need a impedance load on the amp or it wont produce any output power.

 

[smgreen20 10+ year member]

The same way that the HU still sends a signal through the RCA's. It's AC voltage. Just because there's no load doesn't mean the amp still isn't producing power. I see where you're coming from, just not sure how to explain it.

 

[Mass Car Audio 10+ year member]

The same way that the HU still sends a signal through the RCA's. It's AC voltage. Just because there's no load doesn't mean the amp still isn't producing power. I see where you're coming from, just not sure how to explain it.

Wouldn't the amp produce more power with a impedance load ?

 

[cotjones 10+ year member]

Wouldn't the amp produce more power with a impedance load ?

No. bigger the impedance load, bigger the resistance of flow of power to the subs = less power.

no resistance means the most power.

8 ohms of resistance restricts the amp more than 4 ohms does and thus you double the power by cutting the resistance in half

 

[mat3833 10+ year member]

woah, thats alot of info. so if i had a volt meter and an ohm meter(or a multimeter that has both) i could figure it out?? all i need to kno is Volts, Ohms, and Amps?

Matt

 

[roarzorz 10+ year member]

You must have a true rms clamp meter to read ac amperage output and a true rms multi meter to read ac voltage output.

Volts x amps = watts

Volts / amps = impedance (after rise)

Do not use peak hold functions. You must measure them in real time for accurate readings. Both meters must be true rms for accurate readings.