Help! Factory Amp Question

[Explrr96XLT]

1998 Ford Explorer EB

My question is simple, I think. Does anyone know how many watts these amps are? I've looked all over the web and it's like this is the best kept secret in the world. I cannot find it anywhere.

Reason I ask is I bought a very cheap quick fix sub to replace a blown factory sub and it's getting absolutely no power. So I'm thinking the amp is too weak for even a cheap replacement sub.


Any info on these systems is greatly appreciated because I'm losing my mind!!!

 

[hworksinc]

I've never seen a power value listed, but one can deduce some things from the power supply. For a 1998 Ex, the subwoofer amp shares a power source with the radio, rear audio controls, and CD changer. The whole system is on a 25A fuse (25A@12V is 300W of power dissipation before you 're looking at blowing a fuse).

At maximum volume the fuse doesn't blow, so the power draw is likely much less than 25A at full volume. There's still a good amount of dynamic headroom built in for those particularly loud notes. For the sake of argument, lets look at the system at that split second at full volume when a loud note is playing.

To start, lets say that at this instant of maximum loudness we're pulling 22A (~260W) Let's be generous and assume the rear controls and CD changer together use a bit under 2A (~20W) - not too much. The head unit will be consuming a good amount of power - again we'll go for some lower numbers and say that it's kicking out 15W/channel, or 60W total audio output. With amp overhead/inefficiency (~30%) plus the power for the radio electronics/tape/CD (~3A), we're looking at around 10A (120W).

That leaves us about 10A (120W) to power the sub. If we assume 30% loss for for amp overhead/inefficiency, we're left with a max of 80W audio output at the sub. That would be the maximum reasonable dynamic power output. The RMS output would be lower - probably around 60W in this scenario. At normal listening volumes the power output would be much lower, probably in the 10-20W range for the sub (5-10W for the other speakers). These power levels are nowhere near enough to drive aftermarket subs at an acceptable level.

Now these numbers are all hypothetical, use many assumptions, lots of rounding, and are ignoring many of the details of calculating audio power consumption. I also probably underestimated the power of the head unit (which i believe is 15Wx4 RMS, 20Wx4 peak). However, I think it's easy to see that the sub amp really cannot be all that powerful.

 

[reighgan]

Mabey your new sub is a higher ohm speaker

 

[shadowless127]

Mabey your new sub is a higher ohm speaker

way to go all necrothread... this is a3yr old thread bro

 

[Joe Dirt]