I've owned the Joseph Audio Perspective speakers for several years (now have the Graphene 2 version). I've also auditioned the Pulsars and have heard the flagship Pearls at an audio show
In case it helps...because we audiophiles often like to hear from owners of a speaker we are interested in I'll give some detailed impressions as an owner (and fan of the brand).
I don't think Joseph speakers are state of the art in terms of measurements. As pointed out, at least the Perspectives have a bit of rising top end (less so in the new Graphene version). Though they have a generally flat bass to midrange and do a nice job of even dispersion which means they sound great both on and off axis.
Do they compete with speakers that measure even more "ASR friendly?" Sonically, to my ears the certainly do. I auditioned Revel, Kii Audio 3, Paradigm Persona, Vivid Audio and plenty of others and preferred the Joseph speakers to all of them. The Joseph speakers just sounded more "real" and beautiful to my ears.
I think a question to ask is what are you looking for in your speaker? Is it as strict neutrality as possible, to satisfy yourself that you know you signal is being reproduced as accurately as possible? Or...are you seeking a "certain sound" that you tend to like?
The reason the Joseph Speakers appeal to me is that Jeff Joseph seemed to be designing for the type of sound I was seeking. As he writes on the website:
"Live, unamplified music has unmistakable presence and clarity. Yet, at the same time it also sounds relaxed and warm."
That is as succinct a description of how I personally hear live sound sources as any I've read. I think he's going for mostly neutral, with just a bit of tweaking to where it sounds more like the above to him (and many other listeners). If that's not how YOU (or someone else) hears live sound...or if you aren't using it as part of your criteria, then a designer seeking that sound may not be up your alley.
But I find the Joseph speakers nail just that combination. So I'd describe the Joseph sound: a rich, full, warm bottom up to the lower midrange. It gives voices, especially male, richness, body and warmth, and provides a really wonderful 'heft' for instruments in that power range. Low brass, Oboes playing in the lower register are among my favorite instruments on the Joseph speakers. The midrange is just utterly boxless and lucid and as it moves up to the highs the sound is smooth and "grain-free" - in the sense of hearing no hash or distortion, like looking through a clear stream. Yes the highs have a bit of a rise, which adds some detail and vividness, but they are also laid back and so smooth they don't (for me and most others) come off as "bright" or artificial. It's just ultra clarity and timbral complexity. Again, the reproduction of an Oboe is a good example of how this all comes together. You get that clear upper detail of that vibrating reed...with a smooth, unmechanical clarity, attached to a deep vibrating body - the sense of a dense vibrating column of air in front of you that you can feel.
The Joseph bass straddles this wonderful line: it's not leaned out or under some iron fist - "audiophile bass" as I sometimes think of it. It's full, round, and punchy. Bass instruments don't just sit back in the soundfield, they have "reach out in to the room feel" - you feel the projected thump of a bass drum - so the Josephs are also "fun" speakers for just about any genre, I find.
Any detriments? Sure. I think you can find even more dynamic sounding speakers. Especially in the midrange upwards, the Joseph sound can be very clear, but more polite than some other more exciting speakers. Some other speakers may also sound more full and rich from top to bottom, especially in maintaining richness from the upper mids. With the Josephs on, for instance female vocals, you may get more "throat" than "chest" sound, if you know what I mean, which will give those vocals more density on, say, some Revel speakers (or Harbeth and others). (The Paradigm Persona also sounded even through most of the range...but with tipped up highs that, unlike the Josephs, I found harder and more fatiguing over time).
Joseph speakers are known for being ranked best of, or near best of show year after year. There's no speaker for everyone, but I've rarely seen a brand garner as consistant high marks from those who have heard them, whether "subjectivist" or "objectivist." Doesn't mean the sound will be for you, though, of course. Someone else here heard the Pearls at a dealer and didn't like the sound (first time I've ever heard of that), then later heard them properly set up by Jeff Joseph at a show and was more impressed. But still wanted a different sound.
In any case, I just posted a photo of my Joseph Perspectives in my room, linked here:
In my room I'm getting a total disappearing act from the speakers, a massive wide and deep soundstage with precise imaging, tons of timbral nuance, dynamic bass and a "happening now, live" sense of tonal presence. I was playing the Star Wars soundtrack and there was a wonderful sense of hearing through the distance of a hall to the brass instruments placed back in the stage, with wonderful rumbling power in the lows and that specific, brilliant metallic "blat" of horns played hard that light up the acoustics of the hall. Very happy. They are keepers!
Best of luck, enjoy the ride!