Actually, no..., the difference between 1 watt and 100 watts would be less than 20 dB because the speakers will undergo power/thermal compression at higher power levels (especially sustained) and this reduces their dB output. The reduction could be substantial.
How much power needed to drive 91db speakers?
Sonus Farber lists the sensitivity of my speakers at 91 db SPL@ 1 meter @4 ohms. They also say I should use 50-450 watts of power. My PS Audio amps pump out 500 watts @4ohms, so the max isn’t a problem, but if I switched to something 15-50 class A watts, would that be more than enough power?
Thanks in advance.
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What you are saying is true but as a rough estimate my approach gets you in the ballpark of what you are looking for. Speakers that are rated for much higher power than 100 watts won’t suffer significant power compression or at least they shouldn’t. How much there is is going to be depends on the dynamics of the music...if its heavy metal head banging stuff then this is a real possibility due to the lack of dynamic range in the music. Classical guitar would be a whole different ball of wax. I would expect a speaker rated for 400 watts to be able to handle 100 watts with little to no compression. After all that is 6 db less than rated power. |
No experience with Coda. An under the radar company that produces high current amplifiers you might find interesting. https://coda.cc/amplifiers This is not a suggestion, just my experience. According to Audio Science Review (I have no knowledge or reason not to trust his methods) my Carver 180 watt KT120 tube monos measured the most distortion he’s ever measured yet they sound absolutely stunning driving my very revealing Avalon Acoustics Eidolon speakers. Better presentation than my legendary sanctified Marantz 8B. |
Two things for me when thinking about this. 1. Headroom, going from the PS Audio amp that has tons of headroom to something much much smaller that may not have that extra in the gas tank. But I think overall you should be fine. Your ears will tell you if the SF speakers will get enough to sing. |
"I would expect a speaker rated for 400 watts to be able to handle 100 watts with little to no compression. After all that is 6 db less than rated power." You would be surprised! I use JBL 2241H 18" woofers rated at 600 watts continuous. These were redeveloped from the 2240 specifically to overcome the effects of power compression. At 600 watts, they loose 4.3 dB. At 300 watts, (i.e., -3 dB), they loose 2.6 dB. At 60 watts (i.e., -10 dB), they loose 0.8 dB. As I noted, these are 18" woofers with 4" vented voice coils specifically designed to mitigate power compression and I can imagine that a "lesser" woofer would undergo more compression that this. |
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