It always amuses me when people who don’t understand Klipsch speakers review Klipsch speakers! I didn’t spend much time with the first review as to be honest I’ve no interest in the non-Paul Klipsch stuff, it’s just a totally different company, but I watched the Heresy review. For a start I didn’t realise they’d added a port to the MkIV! No idea what PWK would think about that. I owned some odd mid-point between MkIs and MkII and enjoyed them a lot.
My guess is the reviewer used some totally inappropriate modern tight dry solid state muscle amp ‘because measurements’, which is exactly not the way to drive these speakers. They are an ancient design and expect a nice clean little valve amp with some output impedance which has the effect of making them sound far bigger and weightier plus bringing the quality such sensitive horn drivers require not to sound harsh. They don’t need high power, a even 2 Watt Decware Zen works fine. I also notice he played no acoustic music at all. PWK was a classical listener and to my ears Klipsch speakers get something ‘right’ about piano so, so many conventional speakers get wrong. I grew up in a house with a grand piano in it so I have an instinctive and embedded understanding of how the things sound and these little high efficiency speakers just get the note shape right in a way so many bigger and fancier speakers fail.
Regardless I was astonished to see that they measured within 3db for much of the frequency range! I bet my pair didn’t, but I’m of the mindset that a speaker is good or bad long before it produces a straight line on a graph. People focus on frequency response purely because it is so easy to measure, so easy to look clever doing so. Time domain, phase and dynamic ability is way way harder to assess and I’m pretty sure far more important to whether I personally like a speaker.
FWIW I’m not defending Klipsch here, I’d almost certainly hate the first pair in the thread due to the spacing of the drivers which the guy had focused on. The only time I like multi-driver speakers is three-ways where the mid carries all the important stuff. From a Klipsch perspective that’s KHorns and La Scalas which run a very wide mid horn (400Hz - 6kHz crossover). The Heresy gets away with it as the mid and tweeter are close to one another, though all Klipsch speakers have issues in the time domain as the generators are so far apart front to back in the cabinet.
To sum up I would agree classic Klipsch are flawed, but they do give a taste of the super high-end at a bargain price. If you can't afford Avant Garde, Cessaro, JBL Everests etc but want to see what proper front-loaded high-efficiency horns are about (I count back-loaded horns such as GRFs, Lowthers etc as something very different) then Klipsch are a way in and they do give you a lot of it. I really enjoyed owning La Scalas, I found them phenomenal in some regards, awful in others, and a great learning curve.