Minimum power requirement


2001-12-02 3:53 am
Sonus Faber Concerto

In the past, I had 200W amps (Marantz mono-block) driving my Sonus Faber Concertos. I now drive them with a 60W Rega Mira with satisfying results. I'm ready for the next move down in wattage and up in quality. I'm considering building a tube amp and need to know the minimum wattage to drive these speakers. Thanks for the input.
This is one of those thorny questions that involves so many variables that it's well nigh impossible for anyone to answer for you. Consider the following general questions:
1) What kind of music do you listen to?
2) How loud do you listen to it?
3) How reflective/dead is your listening room?
4) How large is your listening room?
5) How efficient are your speakers?
Etc. etc. etc.
Don't treat this as a laundry list and answer the questions. They're just there to prompt your thinking. My advice would be to attach a load resistor to your stereo's output, put a signal in, and use masking tape to label your volume knob at various wattages--1W, 5W, 10W, whatever. Then see where you normally set your volume for the loudest listening you plan to do. Yes, this method is flawed in several ways, but it will give you a quick-and-dirty estimate of what you need. I'd play it safe and err on the upside--if you find that 10W usually does it for you, then go for 20 or 30W, just to have extra on hand for peaks.

Power requiremets

Have you considered bi-amping your speakers. You could keep the SS and go tube for your mids asnd highs. If your speakers have an SPL of 92 db or better you could get away with any type of tube amp including SE which will get you 5 watts or less. Don't let that scare you. My speakers are 92 db and I could get the volume up higher than what my sitting and listening level is with 3.5 watts per channel. If I had bi-amped I could have got the volume up high enough that I would be taxing my ears before the little amps started clipping.
Seville, small ported speakers tend not to be my favourites but the Sonus Faber Concertos are quite remarkable. I had the opportunity recently to audition them and am a little envious.
I am concerned by your belief that low power leads to higher fidelity. The Concertos are not very efficient speakers, (88dB/W/m, I think)you need to keep this in mind. I know that many low output amps have superior sonic qualities to many high power units but it isn’t a rule.
Even if you don’t play music loud you will be limiting your available headroom. If you listen to piano pieces be especially careful, the dynamism if the piano should not be underestimated. It has been my experience that piano recordings need plenty of power to reproduce at natural levels.
I am not aware of their bi-ampability, I have used multi-amped speakers now for more than 20 years and am of the belief that they are generally superior. If the Concertos have dual driver terminals I would recommend that you take advantage of them, if not I would be reluctant to modify them.

Please reply to Grey’s list and enjoy the music.
Regards WALKER