Originally Posted by pokekevin
Curious to see what peaks movies have. That crown amp calc any useful?
Dolby/THX spec having 20 dB available for peaks (we are not getting into a discussion of "instantaneous peaks"); with an assumed baseline average of 85 dB at the listening position, the ability to drive peaks of 105 dB. You spec power for 105 dB. Assuming you want this (I do not, and I've read many other members mention they do not as well - 75 dB seems more popular) as reference level on your system, you have to know speaker sensitivity and distance to figure power needs for 105 dB. Generally it's around 100W in a small-ish room with sensitive-ish speakers (how convenient is that) - we don't really worry about if the receiver can do that ACD, because it never has to. If it can do it into one or two, it's fine. If you need more power, add more power; "audiophile high end" amplifiers are not where I'd start. The first step would be Emotiva or AudioSource; that'll get you to about 500W (which is more than probably any conventional domestic speaker can realistically handle as a continuous program), if that fails, next step: RMX Express! If your needs exceed ~5000W/ch you should probably re-think things...
The bottom line there, and the bottom line here, and the bottom line everywhere is quite simple: two amplifiers operating within their output ranges, not clipping, and properly level-matched (you've heard it before) will be indistinguishable - if you can't pick A apart from B, you cannot preference A over B. Any of the quasi-religious challenges about "open-mindedness" or "trust your ears" are a sad result of the over-aggressive marketing campaigns under-taken in the last ten or so years by "hi-fi" companies; customers shilling customers. If you want to make the argument about recession economics dictating "self lying" or whatever else, that's a slippery slope - prove that it's mediated (I'll tell you right here and now this is NOT going to be an easy study). I think a more fair assessment would be that in the last decade or so, the "high end" types have gotten substantially more aggressive as the market has contracted, and quite a lot has been written critically about them and their wares - think about Monster Cable as a single example.
Regarding the build quality argument:
Irrelevant because we can put all amplifiers inside of a "black box" - if the output is hitting the bar, it doesn't matter what exists inside the "black box." You cannot have it both ways - you cannot summarize all "cheap" component as bad due to their weight, cost, size, etc and then use more minute details to justify more expensive units. You either "black box" all of it, or pick all of it apart (and if you take the second road, you'll find that even some "high end" components perform like hell, and there are a lot of inexpensive devices that do really really well; of course this challenges the "cost = quality" belief system that we all have factually known to define the entire world and everything in it since about the second grade).
If you really want to pick at nits though - the total capacitance even in fancy-pants amplifiers allows for *maybe* a few watts of headroom assuming an (impossible) ACD situation - that's less than a fraction of a dB (which is not audibly different). If you look at true high-power devices, they don't try to sell an ocean of caps as a substitute for more robust output stages and bigger power supplies. I'll let whoever wants to argue with this go off and figure out the math (start by reading this: http://electronics.howstuffworks.com/capacitor2.htm
and then probably hop over to Wikipedia (or Wolfram if you're really lazy - like me) to figure the exact values out). Basically, the amplifiers talking about how many million uF they have are blowing lots of smoke - it doesn't increase their output power magically, but it looks great on paper. Toroidal transformers are not universally "better" than conventional models either, but again, they look great in a brochure.
Once we jump beyond that, we can get into the argument about THD and SNR in preamps and receivers, and whine about how having the FM tuner "attracts" noise and other assorted lunacy. We can also hear the arguments about video degradation and all of that due to the "separation" of things (despite many of these components having no RF/EM shielding and not using any sort of shielded connection). And then we can get into benchmarks that demonstrate both solutions to be equally competent.
Dumping equalization and competent video scaling to have a "name brand" on separates will do nothing beneficial for the owner, but it will sure make the salesman a nice margin at the end of the day! If your calculations demand more power due to room size, I'd start with more efficient speakers, and then move into larger amplifiers as needed; generally speaking domestic settings should not require more than a few watts nominally though (and this is for reference level - if you listen quieter then you need less power).
Plus there's lots of nifty measurements available from Home Theater for a wide array of (but not all) AV receivers and separate systems. In some cases AV receivers match or even better separate systems costing more. I'm not going to exhaustively link them all though.