Do you know Harper whistle?
What do you think about?
I’ve got them in D, C, A, and low-G. They’re an Overton-style design with the very flat rectangular windway. They’re heavy-walled, but made from aluminum alloy, so they’re sturdy but still not that heavy. They’re very wide-bore.
The G/A set is prety understated. Very high backpressure, but not all that loud. The sound is kind of reedy and chiffy as one might expect from a whistle of this design. The Cnat is OXXXXO. The C and D have high backpressure, but I don’t find them hard to blow to an obnoxious degree. The D is pure and has a kind of sweet sound. The C is the same only less so – I think it’s the finest non-wooden C I’ve ever tried. They both have powerful sounds, but I don’t find them extremely shrill in the high notes.
I have a lot of trouble with the G/A set clogging, but curiously, but only moderate difficulty with the C and D. Maybe it’s the extra mass in the bigger ones, and I don’t warm them up for long enough.
They’re well-made, very solid whistles. I travel with the C and D. Whether they’re for you or not depends on what you like.
I just got a Harper (thru EBay) regular-D not tunable. I’m still adjusting to it but my first impression is that it takes more wind than my dixon or burke narrow bore and it is much louder. Mine is the loudest whistle I’ve ever played especially in the second octave, but also in the first. Louder than I remember the susato and louder than any of my dixons. Taking more wind, means I’m still squeaking and squelching in the second octave, but this is mostly because I tend to not blow hard enough. When I do blow with the correct pressure it is a very clear tone, and has just a little chiff. I can’t practice with this one inside and outside it can be heard for a long ways off. If I get it consistently under control, it may become my outside crowd noise killer, but I suspect it will be too loud to play in a session indoors. The look and design is similar to the Overton but not exact. I bought it because I was hoping to find a louder whistle, I could be comfortable with playing in sessions; but, this one is just toooooo LLLOOOUUUDD. So I’m still looking for a good whistle. … My Burke is lovely, but the narrow bore version is too quiet for most sessions. (Okay I admit it I have WhOA and its is no longer in remission).
Hope this mini-review, helps you…
I have a non-tunable high D. Very loud. Reedy tone. Very high back pressure, low air requirements. Gotta blow hard to hit the second octave or it honks. Definitely too loud for a session.
Tony
Anything short of a bazooka would be too soft for the session i regularly go to. I’ve been playing piccolo; it’s the only thing that cuts through 4 accordions and half a dozen fiddles plus banjo and pipes. 
4 accordions and half a dozen fiddles plus banjo and pipes.
Now, that’s a session that’s way too loud for me.
Tony 
… and i didn’t even mention the bodhrans! Sometimes 4 at a time. We have great nights when not too many people show up, but very often it’s just like i said. The piccolo cuts through nicely, though. The only whistle i have that would stand up to that kind of orchestra is the Sweetheart i bought from Cranberry. That thing is LOUD.
I got too much of a French education to call my black Sweetheart loud.
She just has a… er, powerful organ to express her personality. 
and oh-là-là, what a temper…
This gives me a name for her, btw… Queen of the Night suits her voice and looks perfectly.
Now I’ll have to learn and try to play that hysterical Mozart aria… Anyone tried yet?
I have two Harpers, both D’s (don’t ask me why!!!). I concur with Lee and Tony.
~Larry
Why not, 
Just to stay firmly off topic: i took my Sweetheart (old model) to session yesterday. I don’t play that whistle much at home because it’s so loud, but it fitted right perfectly in session. We had a medium large session last night, not as large as usual, but still 2 accordions, 2 banjos, 2 flutes (besides me), pipes, 2 fiddles, guitar and piano, and the killer: 4 bodhrans. When all bodhranistas were playing, i had trouble hearing the melody, even with all the other firepower in the room.
Anyway, the Sweet whistle worked beautifully and so did my Hammy Hamilton piccolo. The Sweet has to be played loud with a lot of air, or else the higher notes don’t speak at all.
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