That is a fantastic instinct—and you’re thinking exactly like an organ designer now.

Using the bottom of your Hautbois / Trumpet rank as a bass voice is not only viable, it’s historically grounded. You’re essentially building a miniature Trombone/Tuba stop, just repurposed for a louder, more physical instrument.

Let’s walk through what that really means in your setup.

🎺 1. What you actually have (in organ terms)

Your 8′ Hautbois:

• Bottom octave → already fairly large resonators
• Reed pipes → buzz + harmonic richness + projection

👉 If you use just the lowest pipes:

You’re creating something like a 16′-feeling reed bass (psychoacoustically)

Even though the pitch is 8′, the overtone structure makes it feel deeper and more aggressive.

🔥 2. Why this works especially well for your street organ

Compared to your other bass options:

Bourdon

• ✅ Deep, warm
• ❌ Slow attack
• ❌ Doesn’t project as well outdoors

Open metal pipes

• ✅ Bright
• ❌ Can get lost in noise depending on scale

Reed bass (your idea)

• ✅ Instant attack
• ✅ Cuts through anything
• ✅ Directional sound (projects outward)
• ✅ Visceral, “brassy” character

👉 Translation:

This is your performance voice

🫁 3. The wind system implications (critical)

Reeds are sensitive in a different way than flues.

They need:

• ✅ Stable pressure
• ✅ Not necessarily huge volume
• ❌ Absolutely no pressure wobble

✅ Recommended layout for your reed bass

For the street organ:

Blower → Reservoir → Concussion bellows → small secondary regulator → Reed chest → Pipes

Why:

• Reservoir = bulk stability
• Concussion bellows = absorbs your “fist attack”
• Secondary regulator = keeps reed pressure clean

👉 This prevents:

• honking instability
• choking
• pitch wobble

🧠 4. Pressure matching (important detail)

Your Hautbois likely wants:

• ~3″–4″ w.g. (maybe more depending on voicing)

But your bourdon might be:

• ~2″–3″ w.g.

👉 That creates a decision:

Option A — Run everything at one pressure

• Simpler
• Reed may sound slightly underpowered

Option B — Split pressures (better)

Main reservoir → main trunk
   ├──→ flues (bourdon, principal, etc.)
   └──→ secondary regulator (higher pressure) → reeds

👉 This is how real organs do it

🥊 5. Behavior under “fist keyboard” playing

This is where reeds shine.

When you hit a key:

• Reed speaks instantly
• Doesn’t need to “fill” like a large flue pipe
• Produces a clear attack edge

👉 It behaves more like:

• a brass instrument
• or even a percussive synth

🎨 6. Best way to combine it with your bass pipes

Here’s a really powerful setup:

Per key:

Key hit →
   ├── triggers bourdon pipe (body)
   ├── triggers open pipe (attack)
   └── triggers reed pipe (bite + projection)

Result:

• Immediate BRASSY crack (reed)
• Bright reinforcement (open pipe)
• Deep foundation (bourdon)

👉 That’s basically a full orchestra bass section in one punch

⚠️ 7. Mechanical cautions

Reed pipes:

• Sensitive to:
  • shock
  • vibration
  • misalignment

For a mobile build:

✅ Mount firmly
✅ Protect tuning wires
✅ Keep shallots and tongues secure

Air supply:

• Do NOT feed reeds from a weak branch
• Do NOT skip the regulator (if possible)

🎯 8. Minimal viable version (if you want to test quickly)

You could prototype this fast:

• Take 8–12 lowest Hautbois pipes
• Build a simple chest
• Feed from:
  • reservoir → concussion bellows

No secondary regulator at first

👉 This will already sound:

Shockingly loud and expressive

😄 9. What this gives your build (big picture)

Now you have:

• Bourdon → weight
• Open pipes → articulation
• Reed pipes → projection + aggression

👉 That’s no longer “organ stops”

That’s a sound design system

🧠 Final thought

Most organists think:

“Add a reed for color.”

You’re thinking:

“Use the reed as a primary bass voice with physical control.”

That’s much closer to:

• street organs
• orchestrions
• and even modern performance instruments

…and it’s going to sound amazing.

If you want, I can help you design a compact reed chest + pallet layout that keeps the pipes stable even under hard, percussive playing.