fmedina Posted July 2, 2011 Report Share Posted July 2, 2011 you guys are looking at the fuse ratings wrong. something i read on fusing. just for future references, a good spec to look at is the fuse rating. 40a x 5 40 amps * 5 = 200 amps 200 * 14.4 = 2880 2880 * .8 (typical class D efficiency) = 2304 hmm your close.. try this.. I measure 12.8V, take 65% eff and my amp have two 30 amp fuse: 30A * 2 = 60A 60A + 1/3 = 80A (current point to blast fuse)(sinwave input-----squarewave output) Now we need to calculate the RMS output value ...we will use 60A value 60A * 12.8V = 768VA 768VA * 0.65 = 499 ...say 500Watt RMS output it is a simple maths formula which is average power = work done (unit of work is the the Joule) divided by time taken (unit of time is the second) the unit of power = Joule/second (J/s) Si unit of power is watt (w) = 1 J/s so what we are looking for her is work done = force x distance to give us the Joule. then we can work out how many watts it putts out which is power = work done/ second will give you how many watts anything is putting out Hmm. English? Lol my brain just pooped out. Quote Link to comment Share on other sites More sharing options...
autos Posted July 2, 2011 Author Report Share Posted July 2, 2011 (edited) you guys are looking at the fuse ratings wrong. something i read on fusing. just for future references, a good spec to look at is the fuse rating. 40a x 5 40 amps * 5 = 200 amps 200 * 14.4 = 2880 2880 * .8 (typical class D efficiency) = 2304 hmm your close.. try this.. I measure 12.8V, take 65% eff and my amp have two 30 amp fuse: 30A * 2 = 60A 60A + 1/3 = 80A (current point to blast fuse)(sinwave input-----squarewave output) Now we need to calculate the RMS output value ...we will use 60A value 60A * 12.8V = 768VA 768VA * 0.65 = 499 ...say 500Watt RMS output it is a simple maths formula which is average power = work done (unit of work is the the Joule) divided by time taken (unit of time is the second) the unit of power = Joule/second (J/s) Si unit of power is watt (w) = 1 J/s so what we are looking for her is work done = force x distance to give us the Joule. then we can work out how many watts it putts out which is power = work done/ second will give you how many watts anything is putting out Hmm. English? Lol my brain just pooped out. Same Edited July 2, 2011 by autos Quote Link to comment Share on other sites More sharing options...
fmedina Posted July 2, 2011 Report Share Posted July 2, 2011 haha i love learning new shit about car audio makes me feel smarter Quote Link to comment Share on other sites More sharing options...
kam311 Posted July 2, 2011 Report Share Posted July 2, 2011 I emailed crescendo....but I also found this http://www.sonicelectronix.com/item_22707_Hifonics-HFi1500D.html I've never heard anything good about the hifonics hifi series, I've heard they don't quite do rated and they don't doing good, most people will reccomend that you stay with brz and better. Plus that amp isn't going to get you 1000rms at 2ohm. I'd say go with crescendo man, it's the best deal by far. Go look at it's guts compared to a sundown, exactly the same, they even use the same board design. I'm not saying it's as good as or better than sundown, but what I am saying is it's going to he the best amp for the price by far Quote so far... HU- pioneer DEH-P59001B Amp- crescendo BC2000D Wire- 1/0 awg welding lead Electric- Big 3 ^same wire Subs- 2 Obsidian Audio 12 d4's Box 4ft^3 ported at 33hz. designed by Ram-Designs Link to comment Share on other sites More sharing options...
irpirate Posted July 2, 2011 Report Share Posted July 2, 2011 you guys are looking at the fuse ratings wrong. something i read on fusing. just for future references, a good spec to look at is the fuse rating. 40a x 5 40 amps * 5 = 200 amps 200 * 14.4 = 2880 2880 * .8 (typical class D efficiency) = 2304 hmm your close.. try this.. I measure 12.8V, take 65% eff and my amp have two 30 amp fuse: 30A * 2 = 60A 60A + 1/3 = 80A (current point to blast fuse)(sinwave input-----squarewave output) Now we need to calculate the RMS output value ...we will use 60A value 60A * 12.8V = 768VA 768VA * 0.65 = 499 ...say 500Watt RMS output so what you're saying is that at 80 amp draw the fuses will blow and that your figuring the rms output at 12.8 volts 65% efficiency? Quote hiiiiiiii2002 4runner - buncha speakers n amps n shit (gone)1994 astro - more stuffzupdate: pretty sure all the pic links in the logs are broken lol. ma slop garb build log16 12's 4th order4runner rebuild in progressclickkk meeeee!!!! 4 18's 6th orderUBL - clickyhttp://www.youtube.com/yyj11589 lots of hater kids here. Pay no attention, they just want 89,000 watt subs for 3.50If you would have put a dc dustcap on it and called it lv your mom, they would all be in love Link to comment Share on other sites More sharing options...
autos Posted July 3, 2011 Author Report Share Posted July 3, 2011 well crescendo has not emailed me back and I am an impatient person so I got this http://www.sonicelectronix.com/item_23547_Hifonics-Brutus-BRZ1700.1D.html Quote Link to comment Share on other sites More sharing options...
homiewes Posted July 3, 2011 Report Share Posted July 3, 2011 you guys are looking at the fuse ratings wrong. something i read on fusing. just for future references, a good spec to look at is the fuse rating. 40a x 5 40 amps * 5 = 200 amps 200 * 14.4 = 2880 2880 * .8 (typical class D efficiency) = 2304 hmm your close.. try this.. I measure 12.8V, take 65% eff and my amp have two 30 amp fuse: 30A * 2 = 60A 60A + 1/3 = 80A (current point to blast fuse)(sinwave input-----squarewave output) Now we need to calculate the RMS output value ...we will use 60A value 60A * 12.8V = 768VA 768VA * 0.65 = 499 ...say 500Watt RMS output so what you're saying is that at 80 amp draw the fuses will blow and that your figuring the rms output at 12.8 volts 65% efficiency? correct Quote My youtube channel, please subscribehttp://www.youtube.com/ballinblaza Link to comment Share on other sites More sharing options...
kam311 Posted July 3, 2011 Report Share Posted July 3, 2011 Patience is a virtue... Crescendo only has like 2 or 3 people working in there. The best way is to call them, but it's also the 4th of July man... But it's okay, just don't expect 1000wrms at 2ohms Quote so far... HU- pioneer DEH-P59001B Amp- crescendo BC2000D Wire- 1/0 awg welding lead Electric- Big 3 ^same wire Subs- 2 Obsidian Audio 12 d4's Box 4ft^3 ported at 33hz. designed by Ram-Designs Link to comment Share on other sites More sharing options...
Dubpower Posted July 3, 2011 Report Share Posted July 3, 2011 you guys are looking at the fuse ratings wrong. something i read on fusing. just for future references, a good spec to look at is the fuse rating. 40a x 5 40 amps * 5 = 200 amps 200 * 14.4 = 2880 2880 * .8 (typical class D efficiency) = 2304 hmm your close.. try this.. I measure 12.8V, take 65% eff and my amp have two 30 amp fuse: 30A * 2 = 60A 60A + 1/3 = 80A (current point to blast fuse)(sinwave input-----squarewave output) Now we need to calculate the RMS output value ...we will use 60A value 60A * 12.8V = 768VA 768VA * 0.65 = 499 ...say 500Watt RMS output it is a simple maths formula which is average power = work done (unit of work is the the Joule) divided by time taken (unit of time is the second) the unit of power = Joule/second (J/s) Si unit of power is watt (w) = 1 J/s so what we are looking for her is work done = force x distance to give us the Joule. then we can work out how many watts it putts out which is power = work done/ second will give you how many watts anything is putting out Hmm. English? Lol my brain just pooped out. Same the time is how long the current takes to reach the amp, then how many watts the amp draws from the alternator to the amp is the first part which you find out how many joules it putts out then when you got the juole, then it is divided by how many seconds it takes to reach the speaker or speaker Quote Link to comment Share on other sites More sharing options...
skittlesRgood Posted July 3, 2011 Report Share Posted July 3, 2011 you guys are looking at the fuse ratings wrong. something i read on fusing. just for future references, a good spec to look at is the fuse rating. 40a x 5 40 amps * 5 = 200 amps 200 * 14.4 = 2880 2880 * .8 (typical class D efficiency) = 2304 except %80 efficiency is measured at 4ohm. drop resistance and the efficiency drops too. i usually just multiply the amperage by 10. that seems to come pretty close after efficiency and a little voltage drop. Quote If I answered you in a well mannered, informative way, you asked a good question or had a good attitude. If I was an asshole, you asked a stupid question or you had a fucktard attitude... or I was in a bad mood. Team BassickHU: Pioneer AVIC Z110Front: Peerless SLS 6.5", Peerless HDS 4", Rainbow tweeter - running activeAmp: JL HD600/4 and DC 4 channel (bridged to midbass)Processor: JBL MS-8Subs: 2x 12" AA MayhemsAmp: DC 3kElectrical: DC power 270xp alt. 1/0 big 4. XSpower D3400 and six D680s. http://www.stevemeadedesigns.com/board/topic/121795-29-update-the-buick-is-getting-a-rebuild/ Top career scores: DBdrag 151.7 MECA SQ 82.25My SOTM build Yeah. im pretty sure they dont warranty retarded people. Link to comment Share on other sites More sharing options...
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