Onyx_8151_vertical3 Walt_Playing_Onyx "ONYX" is made of black polymer and pitched in the key of low D (tenor voice, non-transposing). As with my other instruments, the conical bore and profiled, undercut toneholes give rich harmonics with ease of playing. The player can lean on a note to build the tone: low D is robust and freely speaking. Ornamentation is crisp with ample "chiff" for that familiar pennywhistle presence. Has excellent harmonic alignment (octave registration) and an accurate scale on A=440. Built on the essentials of an Irish Flute, "ONYX" adds the latest dimension of expression in Irish Traditional Music.

The player can easily tune this 3-piece instrument by moving the slender tenon that slides in the head's internal o-rings (while other o-rings serve as tuning spacers). The tip of the mouthpiece is turned slim for comfort. The curved windway tends to shed moisture and reduce the chance of clogging. Backpressure is moderate, and the response is balanced throughout the compass (with resonant lows and gentle highs). Transitions are easy, smooth and stable. I have voiced hundreds and hundreds of whistles, doing my best work in polymers (with the approval of the FDA, of course). Onyx_2pc_IMG_8430The head and block are machined in polycarbonate so they can be welded together; the body is acetal (like Delrin) for performance, satisfaction, a beautiful finish, low maintenance, durability and affordability. Laser engraving complements the fine workmanship.

Comfortable hole spacing on the left hand (2.86", 73mm) and right (2.70", 69mm). The F# hole has a diameter of (0.35", 8.9mm). The A-hole (left hand, #3) is offset for easy reach. An adjustable thumb rest is included. No extra charge for zero offset or "piper's grip;" just contact me to place a special order. Lengths are 9.1" (head), 8.2" (upper body), 8.2" (lower body) or 23.1" assembled (231, 208, 208 and 587mm respectively). A joint between the hands means that the player can adjust the angular position for comfort. Not found on other low whistles, this feature greatly reduces hand fatigue.

Price of the "ONYX" Model Pennywhistle: $350.00

SHIPPING INFORMATION: All U.S Domestic orders will be shipped at a flat rate of $8 per order.  International orders will be charged an initial $8 for shipping and upon completion of order processing through PayPal, the customer will be contacted and billed by WD Sweet Flutes for additional shipping charges based on the international location and value of the order.  European customers should contact me prior to ordering for the best shipping options.

The Sideblowing Adapter is available separately. This accessory slips over the end of “ONYX” and seals around the mouthpiece. A short blowpipe comes out at a right angle, putting the pennywhistle in the same orientation as a flute for ease of playing. When holding the instrument this way, the lowest holes are easier to reach and playing is much more comfortable over time. The Sideblowing Adapter installs and removes quickly and easily for freedom of choice.   An additional benefit: this Adapter tends to trap moisture, further reducing the chance of clogging. "ONYX" gives the best tone without the Sideblowing Adapter.

Price of the Sideblowing Adapter: $40.00

.mp3 Sound Samples 

mp3     "ONYX" Pennywhistle
played by Walt Sweet
mp3     "ONYX" Pennywhistle 
The Reconciliation
played by Walt Sweet

Padded Nylon Case with Velcro


Fits ONYX and SLIGO $39

ONYX Testimonials


"Just wanted to say many thanks for a fabulous whistle. I've had it about a month now, it's my third low whistle, the first was a [famous make]. Your [ONYX low D pennywhistle] stands out in many ways: the tuning, the strong low D, ergonomic fingering, just the right amount of resistance and a nice "chiff." Just love it!"
Graeme, South Australia               February, 2019


Got the whistle Friday, and after a day of playing and getting used to the new ergonomics, all I can say is wow! What a great whistle: nice chiff, solid bell note, not shrill on the high end, low air requirements and beautifully finished. My playing just went up a notch.

Scott, Minnesota                 January, 2015

This is my second "ONYX." The first I had foolishly traded away, and couldn't wait to get back to the real deal. I can tell you over the years I've played nearly every low whistle there is, and in recent months I've owned both a [famous make #1] and a [famous make #2]. Quality whistles, both of them. However, in my experience, neither of them matched the "ONYX" which is much easier on the hands, has a richer bell note and is very expressive. What a super whistle you have produced.

Randy Thomas                    July, 2012 

I received the whistles today!  Beautiful craftsmanship and beautiful playing.  Both the "BLACK PEARL" High-D and the "ONYX" Low-D are excellent instruments, beyond any of my expectations.  They will be played and enjoyed for quite some time.

Bernard Keilty                    Milford CT                   June 2012

I've been saying for years that somebody needed to make a conical low D in Delrin. Well, Walt Sweet has gone and done it and what a Low D it is! The "ONYX" is machined from solid rod-stock polymer and has the look, feel and tone of polished blackwood. Because of the conical bore, the hole spacing is much more forgiving than most low Ds, allowing quick ornamentation and much less hand fatigue. The tone is wonderful, the bottom D is rock-solid and you can really lay into it. Octave breaks are clean and the craftsmanship is top-notch. Walt has hit a real home run with this one. I almost always play flute when I'm looking for this octave, but the "ONYX" has been sneaking into my gig bag a lot lately. Well done, Walt!
Patrick P. Jones DVM, Buhl Idaho, Jan 2011

The "ONYX" whistle is just a fantastic instrument! It re-quires only a little pressure to produce a beautiful, clear sound. The body, made in two parts, allows you to ad-just the joint between your hands. This feature allows a playing position that's more comfortable than on any other whistle we've ever seen before. Great Job! 

Jo-hannes Schultz, FolkFriends. Hamburg, Germany, February 2011


The "ONYX" whistle arrived today and I can play it!! I'm amazed and so very happy. I really thought my skinny fin-gers prevented me from playing low D's. My thanks to Mr. W. D. Sweet for designing this lovely instrument. I'm one happy girl right now.

Kathy Willett, January 2011

The “ONYX” whistles and “STEALTH” fifes arrived last night - they are great. Thanks for making such quality instruments - they play like silk! I'm sure we'll be ordering again soon. Thanks again,
Michael White, North Art Heritage Music, Salmon Arm, British Columbia, February 2011

The passage below is an excerpt from

My needs for a whistle are simple: make it easy for me to make pleasant music. The "ONYX" has surely done that in the category of low D whis-tles. I've always been a fan of offset holes, and found that the reach was natural and not at all uncomfortable for me with my small woman's hands. (N.B.: the only low D whistle I've ever cared to play was the original Sweetheart low D. I've owned three other low Ds that I'm dissatisfied with). The mouthpiece is comfortable, there is an adjustable thumbrest, and the balance of the instrument is such that I don't need a tight grip to keep it in place. The air requirements are the best I've played yet. My test for that is simply running the scale as many times as I can. Now as for those scales...

I was sold. I love that thrum on the low D. I went up to the next D and felt the thrum THERE too, then with no real effort, I went up to the third D, and it was mellow and delightful! I've played it for a few hours and have-n't lost my breath, gotten achey hands, or found a note that makes me unhappy.

I'm truly delighted with this low D. Walt has designed another winner.
Amy L. Bissell, New Britain CT, August 2010

Your "ONYX" in low D is a great pennywhistle. I found it very easy to play. It felt and handled good with easy-to-reach holes (I'm 5'8" with average-sized hands). It sounded great with a good bottom end; the tone is much like that on my Delrin® flute made by [insert famous maker's name here]. This kind of instru-ment should be in the hands of a pro to gig with, and I'm thrilled to have one of the first ones made!

Ed Gilkison, Lakebay, Washington, July 2010