TonyD'Amore Posted October 14, 2011 Report Share Posted October 14, 2011 If you don't have faceboook or don't "like" D'Amore Engineering's page, here is the text: D'Amore Engineering Daily Rant October 14, 2011 Today's message is going to be more about educating instead of ranting. I feel like you can't rant about something that very few people know about. So here goes: I have noticed in the past few years how many people are testing their amplifiers by "clamping". If I understand it correctly people are taking their clamp-on style AC current meter and placing in on a speaker wire while simultaneously measuring the AC voltage with a voltmeter. Then they perform the following math AC current X AC voltage = Watts. This is where the problem lies.... and this is going to be really hard to explain without a chalkboard in front of me (us). I will try my best using just text and no pictures. If you want to dig into this topic more, and enough people are interested I can draw some pics and try to explain better. It boils down to this though: YOU CANNOT use this method and claim "my amp did xxxx Watts". The reason is that the Voltage and the Current ARE most likely NOT IN PHASE. This is because a speaker is an inductive load, meaning; when you apply a voltage to the speaker there is come lag time before the current starts flowing. An analogy might be: Your name is Voltage and can bench 300 lbs, your friend's name is Current and they can bench 300 lbs. Using the method above we are saying "together we can bench 600 lbs". Well try it and see what happens. Unless you are perfectly in phase (in sync), you wouldn't be able to bench 600. With a speaker, you are basically never in sync. If you did the clamping method and calculated your watts, you can pretty much guarantee that your number is 10 - 25% high. The only way to the clamping method properly is to use special non-inductive loads. I wasn't intending on turning this into an advertisement, but this is what the SMD/D'Amore Engineering AD-1 Amp Dyno does, it uses real non-inductive loads and actually measures Watts. It has been called "The Truth Teller" for a reason: it's not nice, it has no feelings and doesn't care about yours. It tells the facts. Link to comment Share on other sites More sharing options...
dkindle613 Posted October 14, 2011 Report Share Posted October 14, 2011 Bravo sir. Great explanation. And I'm liking the page now.. Thanks Mr. D'Amore WARNING: I speak 4 languages, profanity, English, sarcasm & real shit 2003 ford explorer 2 RF T1 D4 15s in a 6.8 cubic ft box 1 T1500.1bdcp 250amp ALT by Mike Singer 2 runs of 0 gauge 3 yellow tops Link to comment Share on other sites More sharing options...
AMI CUSTOMS Posted October 14, 2011 Report Share Posted October 14, 2011 Well then how do you explain imp rise? If you know the power factor it doesnt matter if u are in phase or not that is the power in watts right? TEAM SOUNDQUBED -- TEAM SOUTH TEAM S.O.B. - Founder & Captain 3x Streetbeat World Record Holder 2017 MWSPL 1st place Mayhem & 4th Xtreme 4 2016 MWSPL 1st place Mayhem/2nd Adv 4/2nd Xtreme 4 2015 MWSPL 2nd place Mayhem & 4th Xtreme 4 2014 USACI 2nd place Streetbeat 5 - 162.6 db 2014 MWSPL 2nd place Xtreme 4 - 144.9 db 2013 USACI 1st place Streetbeat 4 - 161.9 db 2013 USACI 1st place Street Q+ - 162.8 db 2013 MWSPL 3rd Kaos2 & 4th Xtreme 4 2011 USACI 2nd place MOD 1001-2k - 160.0 db 2011 MWSPL 4th place: Adv3 - 157.8 db, Kaos2 - 150s db, Xtreme4 - 140s db 2010 ARSPL 1st place 501-750 - 160.3 db Arkansas loudest Best score to date 164.4 db - Termlab Outlaw Streetbeat 4 - 161.9 db Streetbeat 5 - 162.6 db MWSPL on Dash Legal door open (Music) - 162.5 db Sealed on dash Legal (Music) - 161.1 db - Termlab THE BLACK NASTY CURRENT BUILD & FAB The Black Nasty (6) 15 Rebuild Log 2012 (4) 15 Walled Sierra Build Log Evo X build log Facebook page The Black Nasty Link to comment Share on other sites More sharing options...
TonyD'Amore Posted October 14, 2011 Author Report Share Posted October 14, 2011 Well then how do you explain imp rise? If you know the power factor it doesnt matter if u are in phase or not that is the power in watts right? If you are not in phase, it is called VA. Look on the back of your TV or home stereo receiver, you might see something like "400VA" Link to comment Share on other sites More sharing options...
AMI CUSTOMS Posted October 14, 2011 Report Share Posted October 14, 2011 So are you saying you are out of phase from the + to - or vise versa on the amp output? TEAM SOUNDQUBED -- TEAM SOUTH TEAM S.O.B. - Founder & Captain 3x Streetbeat World Record Holder 2017 MWSPL 1st place Mayhem & 4th Xtreme 4 2016 MWSPL 1st place Mayhem/2nd Adv 4/2nd Xtreme 4 2015 MWSPL 2nd place Mayhem & 4th Xtreme 4 2014 USACI 2nd place Streetbeat 5 - 162.6 db 2014 MWSPL 2nd place Xtreme 4 - 144.9 db 2013 USACI 1st place Streetbeat 4 - 161.9 db 2013 USACI 1st place Street Q+ - 162.8 db 2013 MWSPL 3rd Kaos2 & 4th Xtreme 4 2011 USACI 2nd place MOD 1001-2k - 160.0 db 2011 MWSPL 4th place: Adv3 - 157.8 db, Kaos2 - 150s db, Xtreme4 - 140s db 2010 ARSPL 1st place 501-750 - 160.3 db Arkansas loudest Best score to date 164.4 db - Termlab Outlaw Streetbeat 4 - 161.9 db Streetbeat 5 - 162.6 db MWSPL on Dash Legal door open (Music) - 162.5 db Sealed on dash Legal (Music) - 161.1 db - Termlab THE BLACK NASTY CURRENT BUILD & FAB The Black Nasty (6) 15 Rebuild Log 2012 (4) 15 Walled Sierra Build Log Evo X build log Facebook page The Black Nasty Link to comment Share on other sites More sharing options...
Bmike Posted October 14, 2011 Report Share Posted October 14, 2011 Does this apply to both musical and burp set ups? 2007 trailblazer lthead unit- pioneer p4300dvd crescendo ft-1 supertweeters pioneer m650 pros audiocontrol 2xs crossover Rockford fosgate p200-2 highsrockford fosgate p400-2 mids1- fi btl 18amps- saz 3500battery- evermax in front, 2 9a31 dekas in rearwires all knuconceptz 1/0 and rcas Link to comment Share on other sites More sharing options...
speedball1978 Posted October 14, 2011 Report Share Posted October 14, 2011 Most likely it does Link to comment Share on other sites More sharing options...
AMI CUSTOMS Posted October 14, 2011 Report Share Posted October 14, 2011 I have to think on this cuz I see your point but not sure yet lol. TEAM SOUNDQUBED -- TEAM SOUTH TEAM S.O.B. - Founder & Captain 3x Streetbeat World Record Holder 2017 MWSPL 1st place Mayhem & 4th Xtreme 4 2016 MWSPL 1st place Mayhem/2nd Adv 4/2nd Xtreme 4 2015 MWSPL 2nd place Mayhem & 4th Xtreme 4 2014 USACI 2nd place Streetbeat 5 - 162.6 db 2014 MWSPL 2nd place Xtreme 4 - 144.9 db 2013 USACI 1st place Streetbeat 4 - 161.9 db 2013 USACI 1st place Street Q+ - 162.8 db 2013 MWSPL 3rd Kaos2 & 4th Xtreme 4 2011 USACI 2nd place MOD 1001-2k - 160.0 db 2011 MWSPL 4th place: Adv3 - 157.8 db, Kaos2 - 150s db, Xtreme4 - 140s db 2010 ARSPL 1st place 501-750 - 160.3 db Arkansas loudest Best score to date 164.4 db - Termlab Outlaw Streetbeat 4 - 161.9 db Streetbeat 5 - 162.6 db MWSPL on Dash Legal door open (Music) - 162.5 db Sealed on dash Legal (Music) - 161.1 db - Termlab THE BLACK NASTY CURRENT BUILD & FAB The Black Nasty (6) 15 Rebuild Log 2012 (4) 15 Walled Sierra Build Log Evo X build log Facebook page The Black Nasty Link to comment Share on other sites More sharing options...
Bmike Posted October 14, 2011 Report Share Posted October 14, 2011 just curious, trying to learn something. 2007 trailblazer lthead unit- pioneer p4300dvd crescendo ft-1 supertweeters pioneer m650 pros audiocontrol 2xs crossover Rockford fosgate p200-2 highsrockford fosgate p400-2 mids1- fi btl 18amps- saz 3500battery- evermax in front, 2 9a31 dekas in rearwires all knuconceptz 1/0 and rcas Link to comment Share on other sites More sharing options...
AMI CUSTOMS Posted October 14, 2011 Report Share Posted October 14, 2011 They don't measure your power used at your house in VA so I don't get that statement. And that is out of phase. TEAM SOUNDQUBED -- TEAM SOUTH TEAM S.O.B. - Founder & Captain 3x Streetbeat World Record Holder 2017 MWSPL 1st place Mayhem & 4th Xtreme 4 2016 MWSPL 1st place Mayhem/2nd Adv 4/2nd Xtreme 4 2015 MWSPL 2nd place Mayhem & 4th Xtreme 4 2014 USACI 2nd place Streetbeat 5 - 162.6 db 2014 MWSPL 2nd place Xtreme 4 - 144.9 db 2013 USACI 1st place Streetbeat 4 - 161.9 db 2013 USACI 1st place Street Q+ - 162.8 db 2013 MWSPL 3rd Kaos2 & 4th Xtreme 4 2011 USACI 2nd place MOD 1001-2k - 160.0 db 2011 MWSPL 4th place: Adv3 - 157.8 db, Kaos2 - 150s db, Xtreme4 - 140s db 2010 ARSPL 1st place 501-750 - 160.3 db Arkansas loudest Best score to date 164.4 db - Termlab Outlaw Streetbeat 4 - 161.9 db Streetbeat 5 - 162.6 db MWSPL on Dash Legal door open (Music) - 162.5 db Sealed on dash Legal (Music) - 161.1 db - Termlab THE BLACK NASTY CURRENT BUILD & FAB The Black Nasty (6) 15 Rebuild Log 2012 (4) 15 Walled Sierra Build Log Evo X build log Facebook page The Black Nasty Link to comment Share on other sites More sharing options...
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