Well you have to consider the crest factor of high quality recording.
Excellent orchestral recording have peak to average ratios that can exceed 20:1, which means that the average levels are 20 times lower power than the peaks. If you like to listen at an average of 85dB at your listening position, which might be 4 meters from the speakers, well the power requirements add up pretty quick.
Let's say you have speakers that run 85dB/W. You're 4m from them, so the level drops to 73dB (6dB for each time you double the distance, 1m - 2m - 4m). So, to reach your 85dB, you now need 4W instead of 1W. Now, the crest factor of 20:1 needs to be factored in, which puts the power required on peaks to be at least 80W. If you want your average level to be 88dB instead of 85, then you need 160W peaks. Any amp that puts out less than that will be clipping.
For clean reproduction from speakers that run low to mid 80s and normal listening distances, you should always pick an amp with higher power reserve. 250W would be my minimum choice with speakers like that.
Speakers that run near 90dB and above can get by with amps of quite a bit lesser rating.
Excellent orchestral recording have peak to average ratios that can exceed 20:1, which means that the average levels are 20 times lower power than the peaks. If you like to listen at an average of 85dB at your listening position, which might be 4 meters from the speakers, well the power requirements add up pretty quick.
Let's say you have speakers that run 85dB/W. You're 4m from them, so the level drops to 73dB (6dB for each time you double the distance, 1m - 2m - 4m). So, to reach your 85dB, you now need 4W instead of 1W. Now, the crest factor of 20:1 needs to be factored in, which puts the power required on peaks to be at least 80W. If you want your average level to be 88dB instead of 85, then you need 160W peaks. Any amp that puts out less than that will be clipping.
For clean reproduction from speakers that run low to mid 80s and normal listening distances, you should always pick an amp with higher power reserve. 250W would be my minimum choice with speakers like that.
Speakers that run near 90dB and above can get by with amps of quite a bit lesser rating.