The 802D has an impedeance of around 4 ohms over most of the spectrum (not counting the bass peaks), but the impedance rises to well over 20 ohms at about 3 kHz. Here, take a look:
http://www.stereophile.com/floorloudspeakers/1205bw/index4.html
A normal voltage-source-approximating solid state amp will deliver about 1/5 as much power (wattage) into that peak as into the 4-ohm portion of the spectrum. Presumably the speaker is "voiced" in anticipation of this sort of amplification.
Note that tube amps and McIntosh solid state amps have different characteristics, and will deliver closer to the same amount of power into that impedance peak as into the 4-ohm portion of the spectrum, resulting in a frequency response peak there. I suspect this is behind the "tinny" sound that Guiness heard with the 4-ohm taps on his Mac amps; there would be less tonal discrepancy with the 8-ohm taps. I also suspect that the tonal balance of this speaker would be smoother still when driven by a non-transformer-coupled solid state amp.
In my opinion, speakers with impedance curves like the 802D has are not good candidates for tube amps or for transformer-coupled solid state amps unless they were specifically "voiced" for such amps.
Duke
http://www.stereophile.com/floorloudspeakers/1205bw/index4.html
A normal voltage-source-approximating solid state amp will deliver about 1/5 as much power (wattage) into that peak as into the 4-ohm portion of the spectrum. Presumably the speaker is "voiced" in anticipation of this sort of amplification.
Note that tube amps and McIntosh solid state amps have different characteristics, and will deliver closer to the same amount of power into that impedance peak as into the 4-ohm portion of the spectrum, resulting in a frequency response peak there. I suspect this is behind the "tinny" sound that Guiness heard with the 4-ohm taps on his Mac amps; there would be less tonal discrepancy with the 8-ohm taps. I also suspect that the tonal balance of this speaker would be smoother still when driven by a non-transformer-coupled solid state amp.
In my opinion, speakers with impedance curves like the 802D has are not good candidates for tube amps or for transformer-coupled solid state amps unless they were specifically "voiced" for such amps.
Duke