Class A 30 Watt Amps: Are they enough to drive my book shelfs?

Hi Kijanki,

Al, yes but doesn't it apply to open space or anechoic chamber only? 

Yes, as I indicated the 6 db of falloff per doubling of distance applies if the effects of room reflections are put aside, i.e., if they are not included.

I hear pretty much constant loudness walking in my room. What do you think?

I've seen a number of references over the years indicating that "room gain" typically adds something like 3 db or so to the SPL that is heard at typical distances in typical rooms, for non-planar non-line source speakers.  Obviously that number will vary somewhat depending on the room, its acoustic characteristics, the dispersion characteristics of the speaker at various frequencies, and other variables.

Best regards,
-- Al
 

I drive a pair of Vandersteen 5As with a Class A 30wpc amp.  They are 87db but have powered subs.  Should not be an issue as Class A is high current.  Happy Listening.

P.S. to my previous post, regarding the Benchmark statement that was quoted by Kijanki:

Looking at it quantitatively, and choosing a listening distance of 10 feet as an example, and putting aside room effects for the moment, an SPL reduction of 6 db per doubling of distance can be calculated to result in a reduction of 9.68 db at a listening distance of 10 feet, compared to a distance of 1 meter.

A difference of 9.68 db corresponds to a difference of 9.28 times in terms of power. So at that 10 foot listening distance only 1/9.28th as much acoustic power would reach the listener’s ears via the direct path from the speaker compared to what would reach the listener’s ears at 1 meter, in the absence of room reflections.

So for room reflections to compensate for the distance-related loss of 9.68 db it would mean that 8.28 times as much acoustic power would have to be reaching the listener’s ears as a result of room reflections than would be reaching the listener’s ears via the direct path from the speakers. And that would seem to be much too large an effect to be expectable under usual conditions. Especially under conditions that are conducive to good sonics.

Best regards,
-- Al

I just bought that same amp here. I have Sonus faber Chameleon B's, 4 ohm 87 db, and was worried about driving them. But I can tell you it drives them well beyond my listening needs and never once has left Class A. Fantastic amp.

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