A learning point for me from this thread is that it appears there are no
standardized measurements for current and damping factor.
@dsper This statement is tricky. But you are on to something - they can be misleading. 'Current' is the one that is bandied about the most and it can quite often be meaningless. Take a look at this link (which is an easy read) for why:
http://www.atma-sphere.com/Resources/Common_Amplifier_Myths.phpNow damping factor is the output impedance vs 8 ohms and is expressed as a ratio (IOW its standardized). What is less understood is that speakers require a certain amount of damping and that varies by design, even if the same drivers are used in a different box. Some speakers (certain open baffles for example) seem to work better if the damping factor is extremely low- 1/10th :1; and some speakers need as high as 20:1. No speaker needs more damping than that; higher damping factors are often deleterious to neutrality.
Amplifier designers thus have a challenge- from their perspective a lower output impedance is good to insure that the amplifier has the proper 'voltage source' response which is to say that it can maintain a constant voltage output regardless of load. And speaker designers are **usually** expecting this too- but they are working with drivers that quite simply don't work right if they are overdamped!
So its no surprise that confusion exists- because you can easily hear when the speaker is overdamped ('tight bass' being a symptom; while many audiophiles like this, it is in fact a coloration). It makes the right amp/speaker combination a lot harder than you would think and a lot harder than it supposed to be!