Tube amps and speaker ohms

Dear Bartokfan: The speaker efficiency ( 86db,89db,etc )is not the only subject when you want to choose an amplifier, either the nominal speaker impedance ( 8 Ohms, 4 Ohms, etc, etc ) because what you need to know is not only the nominqal impedance but the electrical curve speaker impedance where you can " see " how low goes that impedance.

The other critical subject that you have to take in count is the output amplifier impedance that IMHO must be a low one: say below 0.1 Ohm.

Regards and enjoy the music.
Raul.

raul. i googled amplifier output impedance and got several hits. The info if over my understanding, but will try to work with the ideas. I grasp that quality of transformers is vital in tube design, especially when driving a devil of a speaker such as are the Seas Excel. The motor on these speakers causes havoc on most tube amps. I assume.
Lets see if this link loads:
http://www.transcendentsound.com/amplifier_output_impedance.htm

Raul and Bartok.

I can't imagine a better pairing.

Dear bartokfan: +++++ " This is the way loudspeakers behave. Loudspeakers are not constant power devices. Loudspeakers must have a constant drive voltage to provide a constant acoustic output with changing frequency. As demonstrated by the simple mathematical relationships shown above, the only way to achieve constant voltage drive with a changing load impedance is by having very low amplifier impedance. " +++++

This is what you can read on the link you posted, as you can " see " this subject is critical.

Now, the tube amplifier technology has many trouble to handle in the right way all those speaker needs, so ( if you want to go with this technology ) you have to make big trade-offs with it.
Of course that you could choose for SS technology that could mate in a better way your speakers needs and your music sound reproduction priorities.

Regards and enjoy the music.
raul.

Raul you hit on a essential issue in tube amp output. The impedance factor of the speakers, how difficult is it to keep the motor of the speakers moving in a musical line as the fq's change or amount of fq's are thrown at the amp. Which big orch does. Here the quality of transformers and other internal parts is critical. Thats why i leave it up to the amp manufactore to provide me with the best possible dynamics to run the demanding speaker as are the Seas Excel. I think I have the correct amp. I am waiting on components to arrive. many folks here boo hoo the Seas Excel with no foundation of their criticisms. They seem to be disgusted with my cheering the Seas labs creation, The Excel. Funny that these complainers have nothing to say good about their favorite driver. (not speaker, DRIVERs). Most don;'t have a clue what driver is in their speakers. Most drivers are bought on the open market. Seas actually makes their drivers IN THEIR OWN LAB> Which speaker manufacturer does that???