Parece-me q esta tabela será uma grande ajuda para quem está sempre a perguntar "o meu amplificar é o adequado para estas colunas?" e vice versa. Não resolve todo o problema da compatibilidade para o binómio amplificador/colunas mas já é uma grande ajuda IMHO.
Esta tabela e a maneira de a usar está descrita no site JAC Music no texto "What's in a Watt?" da autoria de Jac van de Walle
faço aqui a seleção do q me parece mais importante
quem quiser aceder à totalidade do texto aqui fica o Link >2.Amplifiers >link no 1º parágrafo
"First we need to define the loudness you want to have. Any terms like "loud" or "very loud" are not so clear to express what that means. So we describe the loudness by comparing it to sounds you know, and then we talk about the same. Suppose we can describe the loudness like this "Loud TV, playing action movie", that is relatively clear what that means. If you ever been inside a discotheque, you will recognize the meaning of "idiot sound level" as well. So check this table to see some more examples of sound levels, and how many dB that is (1 Watt is a 2x =0,5 Watt Stereo)."
"We take as an example 90dB loudness using one Amplifier 2x 50 Watt & Speakers 96 dB. That is the kind of loudness, where your neighbor in the apartment next door can hear when you're at home, listening to some music, but without being disturbed by it. What does it require for the equipment to produce this loudness (we mean 90dB)? For that you go into the table, where 90dB loudness crosses 96dB speaker efficiency. You will see in the box: 0.25Watt. This is all takes to produce this loudness."
"We close with a non working example. Suppose you have normal efficiency speakers like 87db types. You want real loudness for instance like in the above example: 111dB as we produced so easily with the Avantgarde's, with just a few Watt. So how many Watt does 111dB loudness that need? To find that out, you pick from the red numbers on the left, the number 87. From there you go horizontal and look at the numbers in the orange line. At 111dB you stop. Now you read from the box 256Watt. This means 2x128 Watt Stereo, and when you expect low distortion at 2x128 Watt you need to come up with a 2x200 Watt amplifier. So even the 2x50 Watt amp we did the calculations with, does not even come close to it."