amplifier's "slam-factor"


I wonder if anyone can explain me why there are differences in the so called "slam-factor" between different amplifiers (with comparable power ratings). It is well known that for example Krell amplifiers have a high slam-factor, while Mark Levinson amplifiers are quite tame in comparison, even the most powerful ones (> 300 watts per channel). Spectral amplifiers are very fast regarding signal amplification and transmission, but I find them not very "powerful" sounding (high slam-factor), assuming speed is one of the factors which determine whether an amplifier has a high slam-factor or not.
dazzdax
Onhwy61 I think you need to get out more as live music is fast without "sounding" fast.....This is a real trick to reproduce in solid state gear, some can, but most can't.....The odd order higher harmonics normally make the slam come across as hard sounding if the musical peak takes the SS amp out of it's Class A region....The solution is to allow more Class A, enough for the musical peaks.....BEAR runs the Symphony No. 1 to about 40w Class A and we run the JC-1s to almost 30w Class A....Using 89 dB efficient speakers neither amp gets out of Class A on peaks and is one reason that the line between tube and solid state has become blurred in the past decade.....
As a general rule, I have found that MOSFET amps tend to provide "one note" bass that sounds like a wet pillow being struck by a canoe paddle. The sort of bass heard on early Telarc recordings. Bi-polar designs seem to be much better in this respect. Over the years, I have found that the biggest challenge in hi-end audio is getting good, tight, deep, natural sounding bass. Attaining air, depth, detail, extended highs and natural timbre are all easier by comparison.
The trouble with buzzwords like "slam factor" is that they invariably tend to mean somewhat different things to different people. Oh the joy of subjective audio where you have large watts and small watts and where the more murky the explanation the better. One man's slam is another man's unnatural exaggerated bass. Go figure! They all sound the same. They all sound different. Take your pick. It's a free country. Has anyone ever heard the sound of an amp without speakers? Maybe everyone should consider the two as inseparable. Maybe then one would say: "amp a when driving my speakers at exactly matched level, in the same room, playing the same source material sounds, to my ear at least, as producing more natural or more accurate bass than amp b". Good day.
I witnessed a similar effect when trying out a Classe CA100. The dealer said its damping factor is about 30 and my McIntosh MC7100 is 100. This is not the only difference but the Mc definately has more controlled slam than the Ca100 (the rest of the system was the same for both: Mc C712, Paradigm Ref 100.2, MIT). I have been trying to find a technical definition of damping factor but to no avail. Does anyone know how it is calculated? Arthur