Instrument

This is a very good (and very *practical*) question, because with **small‑diameter steel tubes** the limitation is **not “can it vibrate?”**, but **whether the ear will clearly perceive the fundamental at all**.

Below I’ll give you a **clear, experience‑backed answer**, then explain *why* that limit exists so you can design confidently.

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## Short answer (design takeaway)

For **3/4" steel conduit (EMT)**, the **lowest practical note where the fundamental is clearly perceived** is:

> ✅ **C3 to D3**  
> (≈ **130–147 Hz**)

I have a full set of Rohr Schalmei pipes that I purchased locally.  They have a lovely sound, but I borked a bunch of them fitting them into my Topsy organ.  Here's some notes about these pipes and how to fix them.

A Rohr Schalmei rank is one of the hardest reed‑flue hybrids to regulate because it combines:

• a flue pipe body (like a Rohrflöte)
• a reed‑pipe reed (like a Schalmei)
• a chimney / rohr that radically affects tuning and speech
• a very narrow voicing window

Here's a series of tech articles on special organ pipes -- reed pipes, vox pipes, etc -- and how to make and/or tame them.

It is fascinating — and the deeper you go into these oddball pipes, the more you realize that organ builders were doing acoustic hacking long before we had the vocabulary for it. What you’ve stumbled into with those salvaged “saxophone” and “clarinet” pipes is basically the secret experimental branch of flue‑pipe voicing.

And the fact that you already have examples in your hands means you’re sitting on a toolkit of techniques that most builders never get to see up close.

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🎯 Why these pipes matter

They prove something that textbooks barely mention:

Ahh — you’ve got some of the really weird ones.
Those “saxophone” and “clarinet” wooden flue pipes with internal wooden obstructions are part of a small, fascinating family of formant‑shaping flue pipes that behave almost like reed pipes without actually using a reed.

They are exactly the missing link between:

• a normal flue pipe
• a violin pipe with a frein harmonique
• and a pseudo‑Vox‑Humana flue pipe

…and they tell us something very important:

Can we fabricate a pipe that sounds like a vox humana pipe using wood?

A Vox Humana is not just a “pipe shape”—it’s a reed stop, meaning the sound comes from a vibrating brass reed and shallot, with the wooden resonator acting as a short, carefully‑scaled acoustic amplifier. The sources we have describe the resonator geometry, materials, and historical variations, but they do not give a single universal recipe—because historically, builders experimented endlessly with shapes, tapers, and cavities.  Springer +1

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🪵 1. What makes a Vox Humana resonator special

Sources emphasize that Vox Humana pipes vary more than almost any other reed stop—over 10 distinct resonator types appear in historical organs.  Springer +1

Common traits:

• Very short resonators (often ⅛–¼ wavelength of the pitch)
• Cylindrical or conical (regular or inverted)
• Open, stopped, or half‑stopped
• Sometimes include a hole, hood, or vowel cavity
• Often narrower than Trumpet/Oboe resonators
• Designed to emphasize formant‑like peaks (the “human voice” illusion)

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I've been consulting Copilot ("Coppy") for input into various projects, and I wanted to share some of the creative visions my artificial friend created for an organ design.

These pages are the myriad tasks that coalesce into a functional street organ.