MickyMcD Posted March 4, 2008 Report Share Posted March 4, 2008 P = Power (wattage) P = work/time P = IxV (current x voltage) P = V2/R (voltage squared over resistance in ohms) V = IR (Voltage = Current x Resistance - Ohm's Law) Therefore, use a Voltmeter or preferrably a Multimeter and get the output voltage. Square that, then divide by the load impedance (resistance). You now have the power at the ouput terminal. If the amplifier is either a high output or high current design, please ensure that the multimeter is fused to prevent damage. Cheers, Mick Quote Work;DiGiCo D1 Live / MIDAS Heratige 1000 / MIDAS VeniceMeyer Sound CQ-1's, CQ-2's, PSW-2'sRAMSA Monitor AmplifiersP.Audio MonitorsBSS OMNIDRIVE and SoundwebDBX 231 and Klark Teknik DN360 EQ'sRCF TT22ARCF ART320 Link to comment Share on other sites More sharing options...
loganberry Posted March 4, 2008 Author Report Share Posted March 4, 2008 http://cgi.ebay.com/SOUNDSTORM-CR4000-1-40...1QQcmdZViewItem it says 2300 rms at 2 ohm... but no rms at 1 ohm..., any1 have any experience with that amp? or brand for that matter Quote My F-150 Build GET ON THE BANDWAGON what if they tried messing with the amps when the subs werent louder hahah jk Link to comment Share on other sites More sharing options...
Derrick824 Posted March 4, 2008 Report Share Posted March 4, 2008 The only way to know the actual power output is to bench the amplifier. You must clamp the + output to read AC amperage and use a dmm to read the output in AC voltage. Multiply those two #s together and you have your actual output in watts. Divide them for your actual impedance after rise. You can also clamp the input + for amperage & voltage then use those to figure actual efficiency. Simple volts x max rated amperage doesn't work or even come close. Voltage isn't constant and fuse ratings are just ratings. You must clamp it to know the actual current draw cause it doesn't always = the max rated draw. Also when using the input #s to estimate you must divide by efficiency which is different with every manufacturer. Class D amplifiers usually run 65-70% efficiency. As a general rule, I multiply the fuse rating by 10 to get the actual power output and its extremely close. An RF T1k has a 150a fuse rating and the ones I've tested have done around 1500watts. My Sundowns have a 160a fuse rating and they easily do 1600watts. Quote Link to comment Share on other sites More sharing options...
loganberry Posted March 4, 2008 Author Report Share Posted March 4, 2008 The only way to know the actual power output is to bench the amplifier. You must clamp the + output to read AC amperage and use a dmm to read the output in AC voltage. Multiply those two #s together and you have your actual output in watts. Divide them for your actual impedance after rise. You can also clamp the input + for amperage & voltage then use those to figure actual efficiency. Simple volts x max rated amperage doesn't work or even come close. Voltage isn't constant and fuse ratings are just ratings. You must clamp it to know the actual current draw cause it doesn't always = the max rated draw. Also when using the input #s to estimate you must divide by efficiency which is different with every manufacturer. Class D amplifiers usually run 65-70% efficiency.As a general rule, I multiply the fuse rating by 10 to get the actual power output and its extremely close. An RF T1k has a 150a fuse rating and the ones I've tested have done around 1500watts. My Sundowns have a 160a fuse rating and they easily do 1600watts. if thats tru then the power acoustik will only do 1200 watts, it has 5 30 amp fuses.... =\ Quote My F-150 Build GET ON THE BANDWAGON what if they tried messing with the amps when the subs werent louder hahah jk Link to comment Share on other sites More sharing options...
Derrick824 Posted March 4, 2008 Report Share Posted March 4, 2008 if thats tru then the power acoustik will only do 1200 watts, it has 5 30 amp fuses.... =\ 5 x 30 x 10 = 1500. Its just a general rule I go by. Which model is that and what is it rated? The PA amps are known for being a little over-rated just like the Hifonics Brutus. The bxi2006 has a rated current draw of 169amps yet claims 2000watts. I've used one of these and it only does around 1600watts. Quote Link to comment Share on other sites More sharing options...
loganberry Posted March 4, 2008 Author Report Share Posted March 4, 2008 5 x 30 x 10 = 1500. Its just a general rule I go by. Which model is that and what is it rated? The PA amps are known for being a little over-rated just like the Hifonics Brutus. The bxi2006 has a rated current draw of 169amps yet claims 2000watts. I've used one of these and it only does around 1600watts. its the 5500 mono, it does 3200 rms at 1 ohm, it claims Quote My F-150 Build GET ON THE BANDWAGON what if they tried messing with the amps when the subs werent louder hahah jk Link to comment Share on other sites More sharing options...
Derrick824 Posted March 4, 2008 Report Share Posted March 4, 2008 its the 5500 mono, it does 3200 rms at 1 ohm, it claims 3200watts w/ only 150a current draw?!? Must be on a 20v system. Seriosuly, that amp would have to be 200% efficient with absolutely no voltage drop. Quote Link to comment Share on other sites More sharing options...
loganberry Posted March 4, 2008 Author Report Share Posted March 4, 2008 3200watts w/ only 150a current draw?!? Must be on a 20v system. Seriosuly, that amp would have to be 200% efficient with absolutely no voltage drop. ok so the face says the amp blows.... for around that price what can i get that gives enuf power to 2 dc lvl 4 15"s... im gonna start competing, so its gotta give them power... dont wanna drop to much, id like to stay like under 350 bucks (i kno its not much, but its all i have now) Quote My F-150 Build GET ON THE BANDWAGON what if they tried messing with the amps when the subs werent louder hahah jk Link to comment Share on other sites More sharing options...
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