"Power hungry" speakers


Hi folks, can you please explain to me why certain speakers so demanding with regard to amplifier power? I'm not talking about some notoriously-difficult-to-drive Apogees or some old Thiel models, but about speakers like the Sonus Faber Extrema's. These speakers do not belong to the realm of the less-than-1-Ohm-impedance-drop speakers, but need high powered amplifiers if you want to make them sing. Even 300 Watts wouldn't be enough! What is this for some ridiculous statement (or is this a fact?). What is the explanation for this phenomenon? I do not know much about physics, but I wonder what is happening with those Watts inside the speakers: will they be converted into warmth or something?
dazzdax
Capacitors have varying levels of dielectric absorption and thermal losses as frequency is varied. Their transfer characteristics ( linearity ) can be measured and compared over a given frequency range. None of this is new technology and studying these factors along with many others is what have led to the breakthroughs in higher resolution / lower loss circuitry. This is part of why newer gear has the potential to sound better than older gear i.e. improvements in passive parts. Some capacitors that were believed to be "excellent" in the past are actually quite horrid in performance. Most electrolytics are amongst that group along with several others.

In order to get around this problem, some have experimented with using two different types of capacitors wired in parallel i.e. "bypasses". The non-linearities of one cap offset those of the other, summing together to improve the transfer characterstics of the circuit on the whole. This can be a VERY tricky business though as you can end up with two ( or more ) non-complimentary distortions, resulting in even poorer performance. This is why some folks say that "bypasses work well" and "bypasses create other problems". Sean
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I am running b+w 801s which are said to be power hungry.I can tell you that I tried a 170 watt bryston amplifier and it drove the speakers to earth shattering levels.You must remember that 99% of the time your speakers are only using a few watts(usually less then 20 to be sure).I think this "POWER" thing has been very much over stated.99.9% of the time a 25 watt amp would do the job.However it is when the large dynamic swings take place that one could use more power...the differnce between a 300 watt amp and a 600 watt amp is only 3 db (for every 3 db increase then double the power is required)...so the difference between a 150 watt amp and a 300 watt amp is miniscule...
Start looking at bass transients into low sensitivity and / or low impedance and / or highly reactive loads and you need hundreds upon hundreds of watts. Combining all of the above will mean that you need a MONSTER sized amp to do the job right. This is part of the reason why high powered "digital" or high effiency amplifier designs have been finding their way into more and more systems. They can work quite effectively as sub amplifiers. There are some simple tricks that can be done to these amps that make them even better for this purpose. Sean
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Sean...Even as I typed it I knew that you would take issue with my comment about capacitors dissipating no power! OK. An ideal capacitor dissipates no power. Real capacitors are not ideal. But, with regard to power dissipation, they are darned close.

Have you ever experimented with a capacitorless crossover? What do you think? With your multiKilowatt amplification system a little power loss could be tolerated.

Sean125...As you say, "Earth shattering" or "ear splitting" volume does not require many watts. Doing it so that your ears are not split is the purpose of high powered amps. By the way, we tend to judge loudness by the presence of distortion. If it is distorted it sounds loud, even if an accurate SPL meter proves otherwise.