S15_Silvia Posted January 14, 2015 Report Posted January 14, 2015 Power factor and efficiency are not the same thing, no. At the driver's Fs you would have a purely resistive load, which means that current and voltage would be in phase. This is where the power factor would be 1, or unity. At all other frequencies you have a load that is inductive, resistive, and even capacitive. This means it would be pretty 'fun' to calculate the real power under those conditions. 2016 Subaru BRZ | Sony XAV-AX100 | Rockford Fosgate DSM 4080 & DSM 40ix | On 6/6/2012 at 6:32 PM, 'LZTYBRN' said: 3. Don't put speakers outside the car unless you are the ice cream man. My feedback thread
Guest Posted January 14, 2015 Report Posted January 14, 2015 Man, I get it haha, buy the product. But, all things considered though and price aside, I would like to at least know how internal calculations are done (even if it is just abstractly) rather than just ignorantly having the computer do it for me.
S15_Silvia Posted January 14, 2015 Report Posted January 14, 2015 So play the woofer at its Fs (probably would need a signal/function generator since it may be a decimal number) and divide the squared measured amp output (open circuit voltage) by the driver's impedance. And by impedance I mean nominal impedance. 2016 Subaru BRZ | Sony XAV-AX100 | Rockford Fosgate DSM 4080 & DSM 40ix | On 6/6/2012 at 6:32 PM, 'LZTYBRN' said: 3. Don't put speakers outside the car unless you are the ice cream man. My feedback thread
Guest Posted January 14, 2015 Report Posted January 14, 2015 Power factor and efficiency are not the same thing, no. At the driver's Fs you would have a purely resistive load, which means that current and voltage would be in phase. This is where the power factor would be 1, or unity. At all other frequencies you have a load that is inductive, resistive, and even capacitive. This means it would be pretty 'fun' to calculate the real power under those conditions. Thanks for an honest answer! Yeah, it would never be purely resistive in AC current. It seems like regardless of how "fun" the computations are that the measurements required to do need to be pretty precise and rapid.
Broke_Audio_Addict Posted January 14, 2015 Report Posted January 14, 2015 Wouldn't you want f3 and not the fs? Power at f3 should technically be your lowest power output do to being the highest impedance. That being said a lot of people's definition of "music" is a clipped 30 hz sine wave with some 80 IQ knuckle head grunting about committing crimes and his genitals.
Keith77 Posted January 14, 2015 Report Posted January 14, 2015 Thats cool. Im way too old to be upset by shit like that. Your name is winston. Your own parents hated you even before you were born. My penis is bigger than your penis I'm far from loud and my roof/headliner flaps around like Adam's ass on a windy day. I think it depends more on the structure of the vehicle.
S15_Silvia Posted January 14, 2015 Report Posted January 14, 2015 Wouldn't you want f3 and not the fs? Power at f3 should technically be your lowest power output do to being the highest impedance. Fs would just make the math easier since the resistance is the only impedance at play (ideally) 2016 Subaru BRZ | Sony XAV-AX100 | Rockford Fosgate DSM 4080 & DSM 40ix | On 6/6/2012 at 6:32 PM, 'LZTYBRN' said: 3. Don't put speakers outside the car unless you are the ice cream man. My feedback thread
Broke_Audio_Addict Posted January 14, 2015 Report Posted January 14, 2015 Right but doesn't that change once loaded in the enclosure and placed in the car? Or even in different positions inside the car? That being said a lot of people's definition of "music" is a clipped 30 hz sine wave with some 80 IQ knuckle head grunting about committing crimes and his genitals.
Wicks Posted January 14, 2015 Report Posted January 14, 2015 PF = COS(phase angle) Real power = VA * PF Some meters measure power factor but they're obviously expensive. Helps to have access to an Oscope.... No easy way to do it. As was said the AMM1 is really a great tool for the job and many others. Also as was said the impedance will change with frequency so there's no simple answer for all music. This post sent with 100% recycled electrons. 2004 BMW M3Mechman 280A 2 - XS Power XP30001 - XS Power D375 500F of Maxwell SuperCaps (soon to be 1000F) iPadMini2Dash mounted O-scopeAudison bitOne (Remote DRC MP) Highs Amp - PPI Art A404 Hertz HSK130 (HSK165 waiting...) DC Audio DC9.0K 2- DC Audio XL12m2LEGAL - 147.3dB @ 41Hz OUTLAW - 150.2dB @ 45Hz OUTLAW - 145.7dB @ 30Hz JUNE 2014 SOTM WINNER 2014 COLORADO PEOPLE'S CHOICE WINNER SOTM BUILD:http://www.stevemeadedesigns.com/board/topic/141656-wicks-e46-m3-build-bass-turbo-button-and-a-big-new-addition/page-68#entry2802026
S15_Silvia Posted January 14, 2015 Report Posted January 14, 2015 Right but doesn't that change once loaded in the enclosure and placed in the car? Or even in different positions inside the car? Yeah. I was going with woofer out on a table haha. (so using the published T/S parameters of Fs, or finding it with a tester) The combination of enclosure and vehicle changes the game entirely. I guess the answer is again AMM-1... 2016 Subaru BRZ | Sony XAV-AX100 | Rockford Fosgate DSM 4080 & DSM 40ix | On 6/6/2012 at 6:32 PM, 'LZTYBRN' said: 3. Don't put speakers outside the car unless you are the ice cream man. My feedback thread
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