Fuse raing vs watts?

[ahole-ic]

Noob question - are RMS wattage figures for amps quoted as watts RMS drawn or watts RMS produced? I mean, if I see an amp that apparently has 4 x 50W RMS channels, is it drawing 200W RMS and only producing 100W due to efficiency losses? Or, is it producing 200W and drawing, say, 400W?

That's actual output.

 

[Avery22]

Hello,

rms is basically continual wattage supplied. max is at a peak or, for instance, when you bridge out 2 circuits into one

replacement side mirrors

 

[VWBobby 10+ year member]

Don't forget the days of cheater fuses too. You can use fuses made of different material or hidden material added for higher amp rating than stamped. Slow blow fuses, etc. I remember reading about some classes where they supplied the fuse to be used in the comp to help prevent cheaters.

 

[outsideshot23 10+ year member]

cant always go by fuse ratings, fuses can take bursts over what its rated at, for instance the cadence a7hc which i run 4 of them to keep me in the 200 watt and under class puts out 1400rms at 1 ohm with only a 80 amp fuse, tested and proven many times. one of the best cheater old school amps ever made by zed audio.

this.. there is no way to tel. ask meca guys.. ive seen them run 3k+ on 80A fuses. different brands of fuses handle more power.. not really a way to pinpoint how much any given fuse can take

 

[teamquakecelica 10+ year member]

Withought knowing the efficiency of them amp and the thermal/current properties of the internal fusing its self.. you can only make an estimate.. 80amps of internal fusing typically represents around 900-1000wRMS.. but there can be annomilies...

 

[SicAudio 5,000+ posts]

You just have to understand how it works. A fuse has an amp rating meaning it is designed to only allow up to this amount of current to pass through before it blows. We use slow blowing fuses so they will allow over twice the amount of current to pass for a considerable amount of time before they blow so you cannot use this as a definitive guide as others will tell you BUT, Voltage x current(amps) / efficiency = power(watts)
HOLY RUN ON SENTENCE BATMAN!!!

basically you have a 12 volt car so here is simple math using a 30 amp fuse:
12 volts * 30 amps = 360 watts. most amps are around 80% efficient so multiply the 360 like this..

360* .80 = 288 watts rms...

it is only a general guideline tho

but if you see an amp that says 2000 watts but it only has 100 amps of fuse you know it is a bs story...

anyone miss the bold parts?

 

[ahole-ic]

anyone miss the bold parts?

Hey we agree! //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[d2k 10+ year member]

Withought knowing the efficiency of them amp and the thermal/current properties of the internal fusing its self.. you can only make an estimate.. 80amps of internal fusing typically represents around 900-1000wRMS.. but there can be annomilies...

how does the above tie in with below...??

basically you have a 12 volt car so here is simple math using a 30 amp fuse:
12 volts * 30 amps = 360 watts. most amps are around 80% efficient so multiply the 360 like this..

360* .80 = 288 watts rms...

they seem to conflict..... the first quote shows higher watts than amperage seems to allow, the 2nd one shows watts actually being lower than rated amperage could allow..????????

this is a real head fk trying to work out..... watts / amps / impedance rise / efficiency

if your both right thats a pretty large margin of error were all working from.....//content.invisioncic.com/y282845/emoticons/crazy.gif.c13912c32de98515d3142759a824dae7.gif

 

[SicAudio 5,000+ posts]

Hey we agree! //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

OHMS law doesn't lie... that's why it is LAW lolz //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[SicAudio 5,000+ posts]

how does the above tie in with below...??



they seem to conflict..... the first quote shows higher watts than amperage seems to allow, the 2nd one shows watts actually being lower than rated amperage could allow..????????

this is a real head fk trying to work out..... watts / amps / impedance rise / efficiency

if your both right thats a pretty large margin of error were all working from.....//content.invisioncic.com/y282845/emoticons/crazy.gif.c13912c32de98515d3142759a824dae7.gif

read the post where i quoted it all and bolded it...

that is simple OHMS law at it's very basic form... me and Ecrack are both dead on 100% infallibly correct...

the amplifiers efficiency is the biggest variable...

 

[CRXBMPN 5,000+ posts]

interestingly enough, my buddy has an Alpine or something that is supposed to do the same power @ 2 and 1 ohm - ~900w... well on a d4 15 @ 2 he dropped to low 13's and high 12's, we swapped out for a dual 2 15 @ 1 ohm (diff box, may matter in this case, less imp rise), and the voltage is honestly dropping to mid 10's and going into protect... Albeit the reading was coming from a digital readout on a cap but anywho... efficiency is very important.

on another note, I have two MTX6500d's, they are supposed to do 500w @ 2 but have 3x25a fuses sooo I am hesitant to believe they do anything less than 650-700, perhaps more.

 

[SicAudio 5,000+ posts]

MTX6500 is under-rated a common practice for alot of companies

Power 14.4 VDC

2 Ohm Load 775 w x 1

4 Ohm Load 450 w x 1

at 14 volts it will need that 75a fusing //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[CRXBMPN 5,000+ posts]

The one in my car I was using @ 1 ohm //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif the one I just got was babied, in mint condition, and never ran below 2... but @ 1 ohm my 6500 in the car never skipped a beat on an Orion H2 15d2

 

[d2k 10+ year member]

Withought knowing the efficiency of them amp and the thermal/current properties of the internal fusing its self.. you can only make an estimate.. 80amps of internal fusing typically represents around 900-1000wRMS.. but there can be annomilies...

MTX6500 is under-rated a common practice for alot of companies
Power 14.4 VDC

2 Ohm Load 775 w x 1

4 Ohm Load 450 w x 1

at 14 volts it will need that 75a fusing //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

& my amp..??

Mutant MT1500 XXX

1500wrms @ 1ohm ...with a 150A external fuse rating..??

am i to assume this amp has the ability to produce 1500wrms but im not gonna see that due to efficiency..??

 

[SicAudio 5,000+ posts]

wow nice

I always had a soft spot for Thunder amps especially the O/S models