Well, you may easily know more about these matters than I, well I am no expert but probably like you have been at it a long time. Built a pair of JBL L300 clones about 40 years ago, really considering building another pair.

As for the most amps don't like low impedance, they need to be able to supply the power as the impedance goes low, the ones I run keep doubling from 300w into 8 ohms to 1200w into 2 ohms, large enough reserve power, pretty much able to weld with it, just a bigger battery.

I went in the opposite direction. My amp makes 8 WPC. And I have all the loudness I could ever want. The Cornwalls are 102db sensitivity. That would basically be about four times as loud as my 89db speakers, at 1 Watt of power. At full power (8WPC), loudness would be about the same as being in the front row at a rock concert.

problem with an under powered amp is that you don't have the head room for audio bursts and you'll drive your amp into clipping. Efficient speakers are key. You'll distort speakers with a smaller amp than larger during normal use. All depends on what your output transistor max rail voltage is. the rest is clipping noise and distortion.

Indeed, the part of an amp (certainly a tube amp) which is most important, by far, is the transformer. Commonly, amps have gobs of power to (in theory) handle transients. But power alone doesn't get you there. My little SET amp handles transients well, according to my sources. My ear can offer no evidence in refute.

I think we lost Shaun with all the technical mumbo jumbo, possibly decided to go with headphones.

Ha! Yes, but I appreciate all the information and help greatly. Considering everything, it makes the most sense to get a B&K 307. It's insanely loud while being extremely clean and clear. And they go for $60 to $300.

Not sure what I'll do with the Hafler, just squirrel it away I suppose. The Rotel I was never happy with to be honest, it's a little too new and not the same as a friend's, though her entire system is several steps up from mine, so can't really say.

If you go with a B&K 307 you could use the Hafler to drive the low freq section of you large speakers, and should be able to control crossover frequency and level with the B&K. Instant powered sub.

Surprised you didn't like the Rotel, they possibly roll off the upper frequency more than you like, I find Denon tend to have a softer high freq also, but I sort of prefer that.

The B&K 307s were made in the eary 2000s which is both good and bad. There is a computer inside where you can dial in high, low and midrange tones and volume for each speaker. It's pretty intense what you can do. the problem is it was made in 2000. That means the ability for it to do it and you being able to figure out how to do it are two totally different things. Even with a proper manual, I think it would be easier to decipher and arm nuclear launch codes for ICBMs. I have a manual...

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When I get

I take full responsibility. I also laud Shaun's skills in ignoring the BS and keeping his eye on the ball. Something with which those of us suffering from OCD struggle.

Yeah, I'd say just use two power amps, one for the highs and one for the lows. And you will likely need a way to balance the loudness levels of both, which is where something like the Schiit Sys could come in. $49. It would go between your preamp and one of the power amps. It is perfectly acceptable to feed two power amps with one preamp.

Or perhaps one amp feeds one pair of speakers while the other amp feeds the other pair. Or maybe just the woofers on one pair. With some inexpensive devices, you could fool around with different configurations. Power amps can be had for a song, really.