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 How to check amp RMS?

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TSnightzstar
post Dec 5 2006, 04:38 PM, updated 19y ago

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Eh, i go scout for amp at few accesories shop and i noticed that the amp itself don't state how much RMS it provide. So how to check for the RMS? sad.gif
(N)3
post Dec 5 2006, 07:42 PM

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depends on what sort of amps your ar looking at
branded amps like alpine, steg, tru, genesis usually isplay their RMS ratings
those cap ayam ones will display peak

RMS ratings are usually 200w and below
empire23
post Dec 5 2006, 07:48 PM

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Use an RMS multimeter. (expensive)

Or you could learn basic electronic theory and find other ways to find out.
loon1031
post Dec 5 2006, 08:21 PM

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looking at the box loh....
BuFung
post Dec 5 2006, 09:18 PM

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use a much higher programme power speaker, know the fact of this speaker .. the important one.. the sensitivity of it( say 100dB SPL @ 1w/1m) ... full blast the amp.. input a tone.. say 1000Hz( 1kHz is a standard tone for testing).. make sure ur input is 0dBv ( u should use an pre-amp to do this)..

put a SPL meter 1m away on axis of the speaker... see wat kind of level it is... let say u get 115dB...

115db - 100db = 15dB extra u get compare to 1W/1m...

the RMS power of ur amp can do is added 15dB to the speaker compare to a 1W amplifier..

every time power double.. double of 1W = 2W.. double of 2W=4W.. double of power will give u extra 3dB to speaker..

15db=3+3+3+3+3...

u need 5 times double of 1W then only u get 115db..

which is 1 X2 X2 X2 X2 X2 = 32W RMS...

*** all calculation above assuming amp n spk also @ 4ohms rating..



driftmeister
post Dec 6 2006, 12:36 AM

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easiest way is to "guess" it
by the num of the fuse

80% accuracy
TSnightzstar
post Dec 6 2006, 10:32 AM

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Thks Bufung for its detailed calculation. Really useful la..Eh sifu driftmeister, i saw the fuse put number 12? The possible rms is?
driftmeister
post Dec 6 2006, 12:48 PM

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12A fuse ?
TSnightzstar
post Dec 6 2006, 04:41 PM

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QUOTE(driftmeister @ Dec 6 2006, 12:48 PM)
12A fuse ?
*
Yup, red color ones 12A fuse
craziechild
post Dec 7 2006, 12:50 AM

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(12*12V)/2=72W rms total power...

how accurate? god knows...

This post has been edited by craziechild: Dec 7 2006, 12:51 AM
BuFung
post Dec 7 2006, 10:05 AM

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look @ the fuse and guess the power.. sound senseless for me..
craziechild
post Dec 7 2006, 10:42 AM

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BuFung... theorically its correct...
driftmeister
post Dec 7 2006, 11:32 AM

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howiechoo
post Dec 7 2006, 03:36 PM

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use the price and brand reputation maybe? haha..
just save ur trouble....normally a cheap amp will use overrated fuse....
like a branded amp use 40A to provide 4x90 rms @ 12v, a chapalang amp can use 40A to provide only 4x40rms @ 12v.....

use fuse to calculate are determined by the amp circuit design....and other factor which i not sure wat is it...but there is some....
TSnightzstar
post Dec 8 2006, 08:05 PM

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Icic, how can recommend any low entry amp? FYI. damaged amp can repair?

This post has been edited by nightzstar: Dec 8 2006, 08:06 PM
howiechoo
post Dec 9 2006, 06:56 PM

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better state ur budget..to somebody, rm1k amp are low end amp.....
damaged amp can repair like other electronic...but depend on the damaga...
btw, a ddamaged amp can never repair to perform like ori....better or lousier...depend on luck
TSnightzstar
post Dec 11 2006, 10:45 AM

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My budget ah 300 plus only
craziechild
post Dec 11 2006, 07:51 PM

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hehe.... RM 300 amp you use what to calculate also no use... cuz it will always be over overrated.... so jus buy the one tht can nicely power up your driver is enough lo...

cheers...
TSnightzstar
post Dec 11 2006, 11:06 PM

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Erm any economic amp in that range of budget?
craziechild
post Dec 12 2006, 08:55 AM

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mayb can try kenwood or debezt...

how many channel do you need?
howiechoo
post Dec 13 2006, 12:14 AM

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debezt is not cheap also ler bro.....ya, how many channel u want?
TSnightzstar
post Dec 13 2006, 02:52 PM

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2 channel enough for me

 

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