lefreQue Plates???

[DutchEupho]

http://www.dwerden.com/forum/showthr...s#.WWh1LoSLSUk

[highpitch]

Hope we cross paths someday, John...sounds like we'd have a lot to discuss! I was hoping there would be another ham radio operator here on the forum, since a lot of what goes on inside a euphonium (nodes, antinodes, feedpoints, impedance, standing waves, etc) is very close to how antennas work.
Have I already asked if you have amateur radio among your myriad skills? I'm also getting forgetful...
Jim

I'm a retired broadcast engineer of a half-century experience and currently an amateur extra W7TFO.

Yep, a brass horn does share some physical commonalities with electrical wave resonance.

Microwave radio waves travel through a hollow pipe called waveguide, from amplifier to antenna. Many of those waveguides are fine tuned by dimpling with a hammer...

73DG

[RickF]

Not to hijack this thread but...

Microwave radio waves travel through a hollow pipe called waveguide, from amplifier to antenna. Many of those waveguides are fine tuned by dimpling with a hammer...

So true. I worked in radar for 30+ years. Air Force (10 cm radar, MPN-13) then FAA. When I was stationed in Sondrestrom Air Base, Greenland in 1968 to '69, we had a technical inspection of our radar. The inspector wrote up a short piece of waveguide because it had a small dent in it. This was between the magnetron going toward the antenna. The replacement piece of waveguide came in a few days later with a dent in almost the same place. Found out that there was a trained tech in the supply depot who's job it was to 'fine tune' these pieces of waveguides for lowest VSWR by using a ball peen hammer.

[Snorlax]

HIGHPITCH: Once I figure out how to get rid of the S9+10 noise on all bands, let's QSO! I'm also an Extra--N9EJR. I'm going to try to retrofit my Kenwood TS-690s for the new digital modes.

Couple of other points:
*I was kinda tickled by the statement about putting a piece of tape underneath the plates to avoid scratching...if the plates are so incredibly sensitive, won't a piece of tape compromise the installation? And for that matter, the "attachment device" (elastic band) that comes with the plates lends itself to inconsistent application--decidedly low-tech. Remember: people used to use golf tape pre-LeFreque.

*The shape of a player's own resonant cavity may also play a role in any possible (lack of) response to the plates.

*The plates MAY possibly produce some combination of amplification of some overtones and attenuation of others (so will a block of lead). That held true for the heavy-wall mouthpiece experiment I described above. In the case of the LeFreque, that combination of amplification/attenuation may be good, bad, or ugly, and may change if the attachment bands lose elasticity over time or if the player does not put the plates back on in the EXACT same location with the EXACT same tension in the low-tech installation bands.

*Since I view this as a SOCIAL science experiment rather than a PHYSICAL science one, I never ignore the halo effect: Because Ignatz happens to possess ONE positive trait (Ignatz is a virtuoso bassoon player), we may tend to create a "halo" around Ignatz and assume Ignatz is equally virtuosic at the physics of bassoon playing as reflected in eponymous bocal design AND equally virtuosic at analyzing effectiveness of metal plates at possible nodal points and points of structural weakness in bassoons.

*Rick: I frequently wish to apply the "impact engineering" you describe to my horns to correct their (not my) VSWN (Very Stinky Wrong Notes)

[jkircoff]

Given it costs $300 for 2 pieces of metal and an elastic band to produce a change in sound that is completely subjective and unscientific, I tend to agree with Snorlax -- lefreQue Plates are a social experiment....a very expensive one at that.

[davewerden]

I think I've already said this or something similar, but...

It is not hard to believe that the plates would change something. I know Miel Adams does not prefer including a trigger and nearly refuses to include a 4th valve lock because he does not want to inhibit the resonance/vibration of the tubes. (Of the two options, he feels the most strongly about the lock, which makes me think that place on the tubes' path is particularly susceptible.)

A major reservation I have is about the unanticipated consequences. If I am having trouble with a note, like a high Bb or B or C#, maybe putting the plates in the right position would fix the problem. But what might it do elsewhere? Could it make some other notes, maybe in the mid or low range, a bit stuffier? Maybe. But the tradeoff might be worth it, depending on your needs.

When I was working with Sterling on their design, we tried several different design changes to adjust intonation and tone. Overall, I found that most changes had a plus and a minus side, depending on what I was testing. A fairly major (i.e. expensive) change was made to one of the major tubes for intonation purposes on the 6th partial. It did indeed help the 6th partial on the plus side, but had a minus effect on a couple notes in the middle range. In total, it was a good change and remained part of the design.

I have not had a lot of before-the-fact exposure to the fundamental design of the Adams euphonium. It was well-cooked when I first played one. Improvement since then were mostly without my input, so I don't know what magic was being done. But let's look at the outcome. The Adams has the best response overall of any horn I have tried, and has the best balance of intonation. Of the two pieces, intonation seems like it is clearly a win-win. I don't find any particularly odd notes as a price of having such improvement on the traditionally out-of-tune notes. In the response area, though, it has a plus side and a minus side, with a major balance toward plus. Some other players might not agree, but I find the high Bb not quite as free as my Bessons or Sterlings were. That's not to say it's stuffy, but I don't get the wide-open "Whoopee!" feeling when I hit it. The sound is fine; it's just not as much fun to hit it. Maybe Miel will tweak something that brings the whoopee to that note, and that would be swell. But in the meantime, all the other free-blowing notes have solved some problems I had in certain pieces and made playing more fun and more relaxing.

Now, take that above paragraph as my personal impressions, based on my 4AL mouthpiece and my personal chops. Then put a set of plates on my horn that make the high Bb whoopee-worthy. Might that happen without negatively affecting anything else? Maybe. But if it adversely affected a note or two among the "certain pieces" list mentioned above, it could take me a long time to notice it. Once I found the negatives, I could still make a decision that the plates are worth it, especially if I can deal with the negatives more easily that I can bring whoopee to the high Bb. But it is complicated.

And it's more complicated because my chops are not in a Semper Paratus mode. My wobbly practice schedule makes it challenging. I'm not sure I could judge these little plates in any reasonable time frame.

But if you are in a good place, practice-wise, and have very consistent chops/playing from day to day, you would be in a much better place to evaluate such things. You might be able to tell whether this is just Dumbo's Magic Feather or whether it's a good invention for your uses. (Sorry for the old reference to Dumbo, but... I'm old!)

[jkircoff]

Solid points and analysis David. I don’t dispute the plates might benefit some players — my social experiment comment had more to do with the price point. When people buy expensive things, they often do so with a preconceived notion it is high quality or improve something. When an individual spends $300 for 2 pieces of metal and an elastic band, more often than not they will be biased to believe it will improve some aspect of their playing, whether it actually does or not.