In my 18X20 family room and 11' listening distance and 88db speakers, my normal listening level is 75 db. The highest peak I have recorded dissipates 18 watts without the subwoofer. I don't remember the name of the movie but it is a scene in which Vin Diesel skis down a slope chased by by a roaring avalanche. 95 db. If my normal level were 10 db greater I would require around 140 watts for the same peak. Add the subwoofer and I would need significantly less. That is calculated, not measured. Your room could have less boundary gain than mine and require even more power dissipation. I can only give you numbers from my own room. But the point is that, if you have a subwoofer, you should be able to blow yourself out of the room with virtually any modern AV receiver.
I can't imagine being comfortable at 85 db listening level but others might. People seem to rely on the internet calculators and they don't figure the boundary gain. They can't, of course, because they have no way to know what it is without a measurement.
First of all, thank you for sharing your data.
I took measurements during the Spiderman 3 scene where the crane was tearing the building apart and got the following results:
Volume: -20, Audyssey XT32 on DEQ off
Crossovers for L/R : 80 Hz
Sub: SVS PC12U, PB13U
All measurements were taken from the left channel only
Recorded highest voltage 6.063V, I had it set to record peak in order to get the fastest capture rate of 250 micro second.
Recorded highest current 1.6A, I had it set to record maximum and display peaks
The recorded "Max" RMS values were much lower, about 1/3 to 1/4 but measuring RMS V and I precludes the selection of Fast and Peak and that results in slower response therefore potentially missing the highest peaks that Seth was on about in some of his post.
So my recorded highest peak power in VA = V X I = 6.063X1.6 = 9.7VA, that's not watt, watt would obviously be slightly less but as far as the amp is concern, it still has to deliver the current whether that translates into real power or not. Just for ease of illustration, let's just call it 10W.
So now you know full well if I turn the volume to 0, and if everything remain linear, my amp will have to cope with a whopping 1000VA or 1000W just for simplicity. I did not check SPL with my RS meter but I did similar measurements using Jurrasic world a few days before and was in fact getting about 20 dB peaks during the loudest scene. I am not assuming they would be the same or almost the same but I am too busy to go back and measure it now.
The fact is, I typically set my volume to -20, that measns I only need 10W, or 100W if I go up to -10. I have never watched any movie at -10 but I have occasionally crank it up to -18 to -15 top. So like you, I have much more power reserve than I would ever need in my room even if I set my speakers to large. However, the fact remains that even with the help of all my subs (total of 5) and power amps, if I were to set the volume to 0, I can't say clipping can be avoided, albeit for very few and short moments.
Again, I do agree with you that most people have power they want and don't need. I am only trying to make the point that there are people who claim they enjoy listening at reference level and not all of them have Klipsch speakers and multiple subwoofers. Having said that, you and I both know in the real world those people likely have speakers that cannot handle 1000W peak without producing audible distortions or becoming compressed anyway, so in the end it could all be moot.
