Originally Posted by Jerusalem
So a couple newb questions:
1) Everyone says don't worry about bi-amp, if I have a 7.1 receiver can I set it up for 5 speakers instead of 7 and not worry about back channel surround?
2) If the receiver I buy has 100w/channel but I have front speakers that say 125w will that receiver still power those speakers or do I need to look at that when deciding on a receiver?
yes a 7.1 AVR can run in 5.1 just fine. I do that myself using a 9.2 channel AVR to run a 5.1 speaker system at present.
two things to remember about power ratings:
1. the power output rating of an amplifier is rated at full volume to a resistive load with a white noise tone generator. You listen to audio at a fraction of full volume, on a reactive load (speakers) with a dynamic audio source, meaning in short, that you typically won't be using more than about 20 watts of power on average, with only brief momentary peaks drawing more power (which is why the reserve power in an amplifier, determined by the quality of it's power supply and design, are far more important than the "RMS power output" specs manufacturers always quote to draw people in.)
2. power handling specs on a speaker are a thermal rating of how much heat the voice coils can handle without physical damage. These numbers have absolutely nothing to do with how much power a speaker needs to "get loud" or reach full excursion. Since you won't typically be feeding the speaker more than a few watts during normal use anyway, even at loud volumes in most situations, it's not really a hugely important factor. Typically due to the first point I mentioned above, you can go a good 20% above the speaker's power handling spec with the amp size without causing any damage to the speaker... ever.
Long story short; I wouldn't worry about power output or handling specs.