Any questions, please feel free to ask. These substantial MADE FOR VALVES floor standing speakers are designed are designed to get the best of of low to medium powered amplifiers (9 to 90W), but suitable for amplifiers of up to 150W. Designed to be "an easy load" for valve and transistor amps, the simple crossover makes for greater efficiency. Taking up no more room than a stand mount the larger cabinet allows deeper bass to be reproduced with ease. Using high excellent quality drive units and a simple crossover gives an excellent pure sound with minimal processing making them an efficient and and easy load ideal for valve amplifiers.