Matching speaker to amplifier?

How do you match your speaker to a particular amplifier? What determines the type of amplifier you should match with your speaker ie; OTL,SET, Tube or SS?
Look for an amp whose output matches the needs of the speaker. For example SETs work well with very efficient speakers such as horns. Very difficult loads call for large SS or standard tube amps. The impedance curve and efficiency of the speaker is the place to begin.

Stan's input is correct as usual. I’d offer too you contact the speaker makers and ask them for some input as well.

You’ve a few factors in making a good amp to speaker match. The room size. The spl you prefer to listen to. And the type of sound you enjoy…. SET, tubes, SS, Tubes plus SS, etc.

If the speakers are already on hand, one factor is in place. Now optimizing for the room and subjective sound type and volume level is all that’s left to address as best one can.. there are tons of info here at the ‘gon in the archives, and online too at various outlets like TAS speaker buying guide.

Design topology isn’t predicated to one sort of speaker vs another. Normally. Some low powered, < 100 wpc tubes or SS can push most speakers OK. Even some in the < 50wpc arena can make good sounds. Once you get into the < 20-25wpc arena speaker matching gets way more critical…. If all else is maintained to some degree of reasonableness. In the less than 10wpc…. Or even <5wpc… the speaker selection is incredibly important. As much so with the spweakers numbers as is the type of speaker design. 100+ db speakers don’t grow on trees. Each of them has it’s own voice too… just like the amp does.

IN SET amps like 300b, 845, 211, etc. where amps are only making 3-11wpc, horns are indeed a way to go. Dynamic transducers too can be an option, but their eff has to be way up there. Folks like Coincident, Zu, some Von Schewgert units… and even some hybrid speakers whose bottom ends are self powered now might do ok with flea power.

My last note… figure out which sound you truly truly enjoy…. Then go that way. I’ve heard some SET systems I loved and tried to emulate them with other than sET amps… sorry. That didn’t work out as planned. But I do like it. Now.

What I want is a SET like sound with the guts & slam of a live reproduction.

Wavelength audio used to have a chart of higher eff speakers online. With some amp suggestions. These primarily revolve around lower powered amps & speaker combos.

There are as well, charts online which will predict the amount of power per speaker eff rating to achieve a certain DB at a certain distance from the speakers. .. this will tell you what you may need by way of the power an amp needs to make in your arrangement and room.
Impedance and sensitivity, in my opinion are less important than phase angle of the load across frequency.
Tube amps do not like certain reactive loads. Some SS won't produce the goods, either.

If a speaker were 100db sensitive, and had a huge phase angle at some frequencies, you'd need large amount of power....just to deliever the right amount of power to the load. If this were a nice horn than the 8watt SET which you may think would work.....won't like the load.

Some speakers, like the LS 3/5 series are considered tube friendly and are pretty low in sensitivity.
look at the speakers it flat and stable at 8 ohms or does it look like a ski jump dropping down to 2 and up above eight? crazy curves will like high current ss amps that "double down" as their impedance drops while you can run a low power tube rig on something that's 8 ohm stable. efficiency comes into play but not as much as the impedance imho
My default position on this kind of question is as follows:

I highly recommend the white papers on the website of Atma-sphere, the amplifier manufacturer called Debunking Common Power Amplifier Myths and Voltage and Power Paradigms. The pair of white papers, taken together, are very interesting and highly instructional.
Years ago I asked ProAC which amps they used to test there speakers. Would not tell me, as they felt it was a matter for MI15, or a break in to the factory.