Stock Audio Head Unit

[MazdaTree]

Just incase anyone is wondering
i took out the stock speakers today and on the back it said 25 watts so i guess each speakers limit is 25 watts even though you can push them way past that and since there are four speakers each 25 watts im going to make and estimate and say that the stock head unit is pushing out around 100 watts

[midnightfxgt]

No way the stock deck puts out 100W. Probably not even close. Most aftermarket decks are rated around 25Wx4. In actuallity they pump out like 12W per channel. I would guess the stock deck at 30-40W at VERY VERY most.

~JOHN

[MazdaTree]

most aftermarket decks are 50 X 4

[midnightfxgt]

Whatever a deck says it puts out you can usually cut that in half :D

Its MAX and not RMS power.

~JOHN

[majic]

Originally posted by midnightfxgt


Whatever a deck says it puts out you can usually cut that in half :D

Its MAX and not RMS power.

~JOHN

just a little explanation for those who dunno the difference

P=power
I=current
R=resistance(load)

(A) P=I^2 * R (constant current - DC)
(B) P=I(rms)^2 * R (alternating current, sinusoidal - AC)

MAX is the \'peak\' on a sinusoidal current (or DC constant equivalent) and RMS is calculated using

(C) I(rms)= I(peak)/sqrt(2)

so plugging (C) into (B) RMS power is really equal to P=I(peak)^2/2 * R

clear as mud? :D
EDIT: changed (1) to (A) .. (2) to (B) and (3) to (C)

[bluntman]

Fire bad. :(

[majic]

huh?

[bluntman]

Your formula went waay over my head...I was doing my best caveman impression. ;)

[majic]

umm.. i was just deriving what midnightfxgt already mentioned.

simplifying this

RMS power = half of \'peak\' power.. so if a manufacturer wants to make something seem bigger/better than it really is, they\'ll advertise it at 200W \'peak\' instead of 100W RMS even though the latter is the \'more\' correct one.

[majic]

as per the Mazda Workshop Manual:

Audio amplifier maximum output power 4x25(W)
Output impedance 4 (ohm)

and the speakers are rated 25W max (each) and are 5.5\" x 7.5\" and tweeters are 1\"

[MazdaTree]

Originally posted by midnightfxgt


No way the stock deck puts out 100W. Probably not even close. Most aftermarket decks are rated around 25Wx4. In actuallity they pump out like 12W per channel. I would guess the stock deck at 30-40W at VERY VERY most.

~JOHN

thank you majic I WAS RIGHT :p :p :p :p :p :p

[midnightfxgt]

So was I :p :p :p :p . It is MAX 100W. Like I said your lucky if it puts out around half that.

~JOHN

[MazdaTree]

fine truce we are both right:p :p :p :p :p :p

[midnightfxgt]

NO! NO TRUCE!!!!:p :p :p :p :p : Then who will use the excessive smilies??:p :p :p

~JOHN

[majic]

me me me :D :D :D :D :D :p :p :p

[MazdaTree]

fine then i win:p :p :p :D i win i win:p :D :D :D

[Flagrum_3]

Sorry, but your all wrong:p

peak rated wattage per channel = 25w

Rms=.707 of peak, so 25*.707=17.7w

17.7*4= a grand total of 70.8 Watts.


Just an observation, and its still shite. :D






_3


.

[MazdaTree]

well sorrrrrrry:p :p :p :p :p :p

[mazda3boss]

woahhhh, so whats the conclusion???? LOL:D

[McGuyver_3]

no way my 92 pathfinder had a 100 watt system there for i believe that the mazda 3 must have 100 or more watt system

[1flycdnM3]

I don\'t know whether to post what I know... or continue the \"battle of the smilies\" here :p :p :p

anyhow, I think everything has been answered (more or less in a \"civil\" manner) :p

Most Manufacturer systems won\'t be more than 50 Watts Peak, which means the Max RMS would be close to 100 Watts (70W in the M3). I\'d say it\'s a really nice system :)

[majic]

Originally posted by 1flycdnM3


I don\'t know whether to post what I know... or continue the \"battle of the smilies\" here :p :p :p

anyhow, I think everything has been answered (more or less in a \"civil\" manner) :p

Most Manufacturer systems won\'t be more than 50 Watts Peak, which means the Max RMS would be close to 100 Watts (70W in the M3). I\'d say it\'s a really nice system :)

umm.. P_RMS < P_Peak

to be exact, P_RMS = 1/2 * P_Peak (if you had read the posts instead of just looking at smilies you would know :p)