Tube amps and speaker ohms


In your opinion , do push pull amps work better with 8 ohms or 4 ohms. .I am under the impression the lower the ohms, the more power is demanded from the amp....Another question, are there low powered SET amps ,and high power SET amps?
I'm looking at a 40 watt 845 tube amp for my 8 ohm, 89 db speaker.. just cked the Thor has a 86 db W18 midwoofers(2 per cabinet) and a 88 db tweeter. Will an 845 amp rated 40 watts be able to drive the 86/88 db speaker? With authority, bass, mids, highs, in dynamic sound stage? Synergy? Or poor match?
bartokfan
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???
+++ the only way to achieve constant voltage drive with a changing load impedance is by having very low amplifier impedance+++

This statement is not totally accurate.

Constant voltage can be achieved when the amplifier has a relatively low output impedance compared to the speaker impedance AND when the speaker has a benign impedance curve across the frequency range.

In the same manner that some carts require very careful matching with a specific tonearm to perform their best, vacuum tube amplifiers require the same careful attention in matching them to the appropriate speakers.

But then I am not telling you something you do not know already Raul? ;-)

Regards
Paul
Castle Acoustics made their own drivers in-house.

Gamut, which is owned by Lars Goller, uses Scanspeak drivers in their loudspeakers. For twenty years until he bought Gamut, Lars Goller was the inventor and developer of every important driver at Scanspeak.

There are many others, I'm sure.

What I don't understand is the importance of a speaker company designing their own drivers when it's the implementation of drivers in a good design that results in a good speaker.

Tyler Acoustics doesn't design its own drivers, but rather uses widely available SEAS drivers in their speaker designs. As you are a huge fan of Tyler loudspeakers, certainly you understand this.

Your argument ascribing the importance of in-house driver design and manufacturing to quality speaker building seems to undermine your support of Tyler Acoustics.
>>They seem to be disgusted with my cheering the Seas labs creation<<

Not really. It's your inability to grasp the technology and related issues that's disgusting. Your cheering is simply an extension of that.
Tvad, I should have posted about driver in house design vs mass market poly cones, on the topic Harbeth vs Tyler. i goofed up, and mixed comments. Back to topic of tube amps transformers and the resistance from the motor and crossovers in speaker designs. A low volt tube amp, or lets say one that has trouble maintaining proper volt current when demand gets high, will not bring out the FULL potential of certain demanding speakers. Go to Jadis' web page, look inside the DA88. Designed to meet any demand from any speaker. Quality doesn't come cheap. Although certain chinese labs are comming along quite nicely. We can talk theoy here all we want. We are more interested in which labs are actually producing a tube amp to meet demanding power hungry speakers. I'll leave the tech stuff to their engineers. I am only interested in the end result. Does the setup produce a high fidelity musical image? Thats all, nothing more.