CrashOverride
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I don't know what chips they use internally, but I know that the amp used in my mopar head unit has a ST TDA-7563 chip, which is a class AB amp. This is an older head unit, so I would presume than the BO amp is either a class D or T which is more efficient, perhaps as high as 90%. But class AB amps are up to about 65% efficient according to what I've read. So simply taking a fuse value and multiplying it to 14.4v (Oft used to inflate numbers), defines what some may say the amp is capable of. Not true. While there are a million ways to rate power (1% THD, 1kHz, 20-20kHz, up to clipping, etc...) and you can rate it at 12v, 12v nominal, and others.
To give them the best fighting chance, let's use 14.4v and 90% for a Class D amp.
Subwoofer Amp = 20A x 14.4v x 90% = 259 watts. Now you're not supposed to drive the fuse at 100%, so let's use 75% as Littelfuse recommends for 25C ambient temp. This means the amp shouldn't be able to put out more than 194 watts.
Doing the same math for the main amp = 30A x 14.4v x 90% efficiency x 75% thermal rating = 292 watts.
The head unit shouldn't be added because presumably all channels will be powered through the amps. But, let's suppose that it is entirely an amp, and that every drop of current is used to amplify even more speakers. (We know this is impossible because of the tuner, other sound shaping stuff, motors and so on)
20A x 14.4 x 90% x 75% = again, 194 watts.
194 + 292 + 194 = 874 watts. Now this is the absolute best case scenario, not knowing the actual efficiency. And this is using the headunit as an amp, which is probably not the case. So I would argue it is really only putting out 194+292 = 486 watts.
Cross check. Let's use a CEA compliant amp as an example.
Alpine S-A60M (1x600w RMS @ 2 Ohm) has two 30A fuses. Yeah, but it's a monoblock amp - not the same comparison.
Let's try a multichannel amp. JL Audio XD600/6v2 is a 6-channel amp that puts out 6x100w RMA @ 2 Ohms. I couldn't find if this is CEA compliant or not, but JL audio is one of the better manufacturers out there and I'd trust it. Also, it is specifically noted as a class D amp. It is unfused, but a 50-amp fuse is recommended.
Note that the numbers are driving the amps as hard as possible with 2-ohm loads. If you drive them at 4 ohms, the power levels are quite a bit less, often halved.
So unless Ford is pulling power out of another fuse, your 1000w system is likely a 500w system.
But, it's entirely legal to use peak power and measure the half second burst provided by the caps in the amps and sure, you will get 1000w. Heck, you might get 5000w if the measurement is small enough.
Why did Ford do it? People don't know not to trust ratings. Most people don't realize that almost any rating, no matter what it is, has modifiers....
Decibels? At what distance?
Amps? At what temperature?
Torque? At what RPM, at what temp/humidity, dressed or not, octane, flywheel or drivewheel
Brightness? Candlepower, Lux, Lumens?
Pressure? At what head? and what volume? and what viscosity?
Viscosity? At what temperature
To give them the best fighting chance, let's use 14.4v and 90% for a Class D amp.
Subwoofer Amp = 20A x 14.4v x 90% = 259 watts. Now you're not supposed to drive the fuse at 100%, so let's use 75% as Littelfuse recommends for 25C ambient temp. This means the amp shouldn't be able to put out more than 194 watts.
Doing the same math for the main amp = 30A x 14.4v x 90% efficiency x 75% thermal rating = 292 watts.
The head unit shouldn't be added because presumably all channels will be powered through the amps. But, let's suppose that it is entirely an amp, and that every drop of current is used to amplify even more speakers. (We know this is impossible because of the tuner, other sound shaping stuff, motors and so on)
20A x 14.4 x 90% x 75% = again, 194 watts.
194 + 292 + 194 = 874 watts. Now this is the absolute best case scenario, not knowing the actual efficiency. And this is using the headunit as an amp, which is probably not the case. So I would argue it is really only putting out 194+292 = 486 watts.
Cross check. Let's use a CEA compliant amp as an example.
Alpine S-A60M (1x600w RMS @ 2 Ohm) has two 30A fuses. Yeah, but it's a monoblock amp - not the same comparison.
Let's try a multichannel amp. JL Audio XD600/6v2 is a 6-channel amp that puts out 6x100w RMA @ 2 Ohms. I couldn't find if this is CEA compliant or not, but JL audio is one of the better manufacturers out there and I'd trust it. Also, it is specifically noted as a class D amp. It is unfused, but a 50-amp fuse is recommended.
Note that the numbers are driving the amps as hard as possible with 2-ohm loads. If you drive them at 4 ohms, the power levels are quite a bit less, often halved.
So unless Ford is pulling power out of another fuse, your 1000w system is likely a 500w system.
But, it's entirely legal to use peak power and measure the half second burst provided by the caps in the amps and sure, you will get 1000w. Heck, you might get 5000w if the measurement is small enough.
Why did Ford do it? People don't know not to trust ratings. Most people don't realize that almost any rating, no matter what it is, has modifiers....
Decibels? At what distance?
Amps? At what temperature?
Torque? At what RPM, at what temp/humidity, dressed or not, octane, flywheel or drivewheel
Brightness? Candlepower, Lux, Lumens?
Pressure? At what head? and what volume? and what viscosity?
Viscosity? At what temperature
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