Published loudspeaker frequency response is virtually always measured with a solid state amp which puts out increased wattage into an impedance dip, and decreased wattage into an impedance peak. Most speakers are "voiced" for this type of amplifier.
Relative to a solid state amp, a tube amp puts out more wattage into the impedance peaks, and less wattage into the impedance dips. So the speaker’s frequency response will be modified accordingly. In general the lower the speaker’s impedance, the more pronounced this effect.
Ime a relatively high and smooth impedance curve tends to work well with tube amps. The bass impedance peaks can sometimes be manipulated a bit by lowering the port tuning frequency, and/or adding damping material inside the cabinet, if necessary.
Occasionally you find a loudspeaker whose impedance curve zigs where its frequency response curve zags, and that can work well with tube amps. I recall seeing such "complementary" measurements for one or two Silverline Audio models.
I’d suggest asking the loudspeaker manufacturer whether they recommend tube amps for their speakers. Audio show reports can also be a source of information about amp/speaker pairings.
See this paper by amp designer Ralph Karsten:
http://www.atma-sphere.com/en/resources-paradigms-in-amplifier-design.html
Duke
tube amp dealer, tube-friendly speaker designer
Relative to a solid state amp, a tube amp puts out more wattage into the impedance peaks, and less wattage into the impedance dips. So the speaker’s frequency response will be modified accordingly. In general the lower the speaker’s impedance, the more pronounced this effect.
Ime a relatively high and smooth impedance curve tends to work well with tube amps. The bass impedance peaks can sometimes be manipulated a bit by lowering the port tuning frequency, and/or adding damping material inside the cabinet, if necessary.
Occasionally you find a loudspeaker whose impedance curve zigs where its frequency response curve zags, and that can work well with tube amps. I recall seeing such "complementary" measurements for one or two Silverline Audio models.
I’d suggest asking the loudspeaker manufacturer whether they recommend tube amps for their speakers. Audio show reports can also be a source of information about amp/speaker pairings.
See this paper by amp designer Ralph Karsten:
http://www.atma-sphere.com/en/resources-paradigms-in-amplifier-design.html
Duke
tube amp dealer, tube-friendly speaker designer