alpine pdx 8 ohm rating

does anyone know the 8 ohm rating on the PDX-F6?

Do you know the 2 ohm and the 4 ohm rating?

ok so it is the same as the 2 and 4 ohm rating. i was afraid of that, but ok thanks.

That's not what he asked... Into 8-ohms, those amps will possibly make a bit less than their 4/2-ohm rating. I'm guessing between 50 and 75% of it. That's a guess. This being said, why would you afraid of the amp making the same power into 8-ohms as it would into 4-ohms? It's normal for EVERY amplifier to make less power into a higher impedance, and more power into a lower impedance. The PDX amplifiers are (though not COMPLETELY) unique, in that they make the same rated power into 4-ohms and 2-ohms. This is due to the smart power supply that limits the current into 2-ohms. Because it doesn't have to limit the current into a higher impedance, it will probably make about the same current into an 8-ohm load as it does into a 4-ohm load, with roughly the same output voltage. If it doesn't change the output voltage or current into an 8-ohm load, relative to a 4-ohm load, the power would be half. Having never done any testing or experiments on these amps into higher impedances, I can't say... It's all guesses.

They are all guesses, but probably pretty accurate guesses. 

well i wanted to bi-amp my components. the woofers are 4 ohm and the tweeters are 8 ohm. the rms rating on the woofers is 200W and the rms on the tweeters is 75W. so i was going to use two channels for my woofers and send them 150W and use the other set of outputs for the tweeters and give them potentially about 90 to 100W. but that is only if the amp will lower its output on a higher ohm load. im not worried about blowing the woofers but i dont want to overpower the tweeters by that much. all in all i need a 4ch amp that will give me close to or above 200W into 4 ohms and about 100W into 8 ohms. i really wanted the PDX mainly because its probably one of the cleanest amps out there(spec wise anyway) and its small enough to fit where i need it to, and its not ridiculously expensive.

Do you know the 4 ohm and the 2 ohm rating of the amp?  If it does 200 per channel into a 4 ohm load, theoretically it will produce 100 watts into an 8 ohm load. 

the 2 ohm and 4 ohm rating are the same at 150W/channel. i know that normally an amp roughly doubles or halves its output depending on the ohm load it sees. the PDX outputs the same power into either load but it wont give me an 8 ohm spec. my woofers call for 200W but im willing to make the sacrifice so that i can use just one amp to bi-amp my highs and go completely active. any other amp i look at that gives me 200W/ch into 4 ohms, that is not regulated like the PDX, costs way too much. these amps are all rated by their 2 ohm load specs which means that in the end i would need a 1600W RMS 4 channel amp. i know that doesnt seem like a challenge to some people but im looking for a very clean SQ amp, not boss or hifonics. a good clean 1600W 4 channel amp is generally pretty expensive and also physically larger than i have space for.

i am an idiot wrote: If it does the same power into 2 or 4, as Haem stated they are regulating something when it runs into a 2 ohm load.  The power supply in the amp will only produce + and - X voltage.  The voltage will not go any higher if you run it into a lighter load.  So if it does 150 into 4, it will do 75 into 8.

yay, normally if it were any other idiot saying that, then i wouldn't trust them but i know you know your stuff. ill probably order the amp sometime this weekend. thanks for all your help guys.