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we all know good old ohms law.In the past you've been able to look at an amps fuse rating and tell if an amp was all hype or really had some omph. it seems like all this has changed with most of the newer amps.
examples
sundown 1500d benching @ 2kw+ w/ 160amps(assuming 14v) of fuses =>90% efficiency
arc audio ks1200.1 benching @15xx w w/120amps(assuming 14v) of fuse=>90% efficiency

if these were lesser brands we'd all raise the bs flag. but these amps are just a couple of the countless amps poppin up everyday that seem to put out more power than they draw.can anyone in laymans terms help me understand how numbers like these are possible?
 

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In short, fuses dont pop right at 160 amps, or whatever the fuse is rated at. I saw another thread specifically about this, and my dad could probably explain it perfectly, but thats the gist of it. They are designed to let brief spikes through, as long as the spike isnt too high or for too long.
 

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Research class D amplifier operation and you will find the answer you seek.



Sent from my DROID using Tapatalk
 

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i would say mostly the amperage thing for fuses. fuses are rated for X amps, but in reality a 20a fuse will allow more than 20a through for a given amount of time. the fuses are thin metal strips designed to overheat and burn when too much current is pushed through it over an amount of time so that the wire that the fuse "breaks" wont catch on fire and destroy whatever equipment it is hooked up to by setting it on fire.

so if we can imagine that music is dynamic, and not static - then we can see how a fuse will allow short bursts of amperage through it, but those short bursts over time will overheat the fuse and cause it to fail. this will throw a wrench into your efficiency calculation a bit :p

so a quick benchmark with specific conditions could put up a number on a piece of paper - but does that actually mean anything than some spec? not really.

when you race a car down a 1\4 mile track, does the top speed and the time it took really mean anything about the car other than in those specific conditions, it is that fast? no.

what it all comes down to is real world use. what kind of voltage range will the "music" range from? was the song recorded real loud, or very quiet? how strong is the electrical system? how many speakers? what kinds of enclosures? what is the goal of the system? how efficient are the speakers?

all these questions are way more important than "what is the benchmark wattage of my X brand amplifier"

so in real life, with regular music, the amplifier you are using is most likely doing a fraction of its "rated" power.

just my little rant.
 

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Not there to protect the amp, only to protect it from its clipped/shorted. All in all, I would change the fuses to lower and determine what EXACTLY works for my situation.
 

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Class D amps are getting very efficient and a fuse does pass more than rated for a little while. A lot of amps have huge fuses for no reason, especially cheap amps. Of course you should verify how much output the amp has to start with, via a real test.

Here are some ratings, looks like most have to pass 110% ratings for 100 hours.
OptiFuse ® Fuses - Regular (ATO/ATC) Automotive Blade
 

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i would say mostly the amperage thing for fuses. fuses are rated for X amps, but in reality a 20a fuse will allow more than 20a through for a given amount of time. the fuses are thin metal strips designed to overheat and burn when too much current is pushed through it over an amount of time so that the wire that the fuse "breaks" wont catch on fire and destroy whatever equipment it is hooked up to by setting it on fire.

so if we can imagine that music is dynamic, and not static - then we can see how a fuse will allow short bursts of amperage through it, but those short bursts over time will overheat the fuse and cause it to fail. this will throw a wrench into your efficiency calculation a bit :p

so a quick benchmark with specific conditions could put up a number on a piece of paper - but does that actually mean anything than some spec? not really.

when you race a car down a 1\4 mile track, does the top speed and the time it took really mean anything about the car other than in those specific conditions, it is that fast? no.

what it all comes down to is real world use. what kind of voltage range will the "music" range from? was the song recorded real loud, or very quiet? how strong is the electrical system? how many speakers? what kinds of enclosures? what is the goal of the system? how efficient are the speakers?

all these questions are way more important than "what is the benchmark wattage of my X brand amplifier"

so in real life, with regular music, the amplifier you are using is most likely doing a fraction of its "rated" power.

just my little rant.
I was with you up until the 1/4 mile part. ET and mph mean everything. It tells you what kind of power the car is making and how it puts the power down.
 

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There is one amp out there where a tech claims he can modify it to produce 1,500 watts, all day long, at 8 ohms, on a 60 amp slow blow fuse, at 12.5 volts of input. Aside from that claim, amplifiers do NOT defy the laws of physics.

Perhaps a better test when clamping would be to add another clamp to the power wire. That way the user can see current drawn versus output current.
 

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There is one amp out there where a tech claims he can modify it to produce 1,500 watts, all day long, at 8 ohms, on a 60 amp slow blow fuse, at 12.5 volts of input. Aside from that claim, amplifiers do NOT defy the laws of physics.

Perhaps a better test when clamping would be to add another clamp to the power wire. That way the user can see current drawn versus output current.
The engineer is considered a "Guru" by the followers :rolleyes:

Kelvin
 

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The engineer is considered a "Guru" by the followers :rolleyes:

Kelvin
Gotta love the power of marketing. He should have been a politician instead.:laugh:
 

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-Most fuses don't blow that quickly
-Capacitors inside of the amp hold some power...
-There are some pretty efficient amps out there.
 

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Class D amps are getting very efficient and a fuse does pass more than rated for a little while. A lot of amps have huge fuses for no reason, especially cheap amps. Of course you should verify how much output the amp has to start with, via a real test.

Here are some ratings, looks like most have to pass 110% ratings for 100 hours.
OptiFuse ® Fuses - Regular (ATO/ATC) Automotive Blade
I had an old Clarion amp "apa4152 somethin or other" that did 40x4 and 60x2 bridged. It was a weak amp and also the first amp I went active with. It was fused from the factory to 50a:eek:I bet I could have replaced the twin 25's with twin 10's and still been way overfused.:laugh:And the amp on my frontstage has quad 30's in it but have been told the amp will self destruct before it ever pops the fuses.
 

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In response to the fuse trip rating, here is an example fuse curve. X axis is current flow (k=thousand), y axis is time. Any point in the shaded area is a time when that device could trip. You can see that the devices will trip faster as there is more current. A current very close to the trip rating will not trip the device for quite a while

 

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I remember my old Cerwin Vega AT-12 home speakers specified to replace with a slow blow fuse. I of course replaced with a regular fuse of the right amperage and it blew much quicker.
 

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we all know good old ohms law.In the past you've been able to look at an amps fuse rating and tell if an amp was all hype or really had some omph. it seems like all this has changed with most of the newer amps.
examples
sundown 1500d benching @ 2kw+ w/ 160amps(assuming 14v) of fuses =>90% efficiency
arc audio ks1200.1 benching @15xx w w/120amps(assuming 14v) of fuse=>90% efficiency

if these were lesser brands we'd all raise the bs flag. but these amps are just a couple of the countless amps poppin up everyday that seem to put out more power than they draw.can anyone in laymans terms help me understand how numbers like these are possible?
To add to everything everyone is saying about fuses blowing slowly near limit and all...



@160A and 14v you get a calculated 2240w
@140A and 14v = 1960w

So yeah, they'll produce rated +

The old'ish RF Power 1000 5ch was stable to 1ohm on all channels and carried a 250A ANL fuse on board... what's that say?

If they can stretch the limits of the fuse, that extra bit of power is avalible..

What happens, should you remove the fuse and wire direct? how far can the system be pushed till destruction?
 

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Where does it say that the Sundown SAZ1500D does 2kw?

I own one. Every test I read showed capability above 1500 watts but you had to wire below 1 ohm for speakers. OR run high voltage.

Here are the two that I am aware of

SAZ-1500D POWER TESTING - SSA Car Audio Forum

Notice wired to .35 ohms.

Look at the strapped test. Wired to .35 ohms or a .175 at the amp. (Chad, is that to low?:laugh:) probably some slight almost inaudible degradation of sound quality:D


Uniform Amp Clamp Test - SSA Car Audio Forum

Yeah I know. I saw the power made. Again, the loads are crazy low to get it.
 
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