Passive Radiator / Folded Port

Unknown BC25TG15-04

Best box: 0.003 L sealed · Fc 1555.6 Hz · F3 1328.8 Hz

Predicted SPL response of the Unknown BC25TG15-04 in the recommended 0.003 L sealed box versus the alternative — open it in the simulator Open and tweak this box live ↗

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⚠️ Engineering Notice for Builders

  • Straight vent would be -7.1 cm long: not physically buildable as a simple tube. Use a passive radiator, a folded slot port or model a 3D folded duct in Load Forge Studio.
  • Limited linear excursion (Xmax: 1.17 mm); set a high-pass subsonic filter at 25–30 Hz when driven with high power.

Textbook Bass Reflex — not recommended

PORT NOT BUILDABLE
Net Box Volume (Vb) 1.5 Liters
Tuning Frequency (Fb) 935.0 Hz
F3 (-3 dB Cutoff) 890.7 Hz
F6 / F10 Extension 860.5 Hz / 820.0 Hz
Port Inner Diameter Ø 20.0 cm
Port Physical Length No real tube length at this tuning — use a passive radiator
First Pipe Resonance 0.0 Hz
Estimated MOL @ F3 73.7 dB SPL
⚠️ Port feasibility: a straight tube would need -7.1 cm and cannot fit in a practical cabinet, and no nearby retune stays buildable without a bass hump. Prefer the sealed alignment, a passive radiator, or a 3D folded duct in Load Forge Studio.
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Sealed (Acoustic Suspension) — compromise

SUITS INFINITE / OPEN BAFFLE

With Qts 0.98 a Butterworth (Qtc 0.707) box would be many times Vas. A box equal to Vas reaches Qtc 1.386; for a flat response this driver is better used on an infinite (IB) or open baffle.

Net Box Volume (Vb) 0.003 Liters
System Q (Qtc) 1.386 (above Butterworth: Qtc cannot fall below Qts (0.98))
System Resonance (Fc) 1555.6 Hz
F3 (-3 dB Cutoff) 1328.8 Hz
F6 / F10 Extension 1142.2 Hz / 946.5 Hz
Air Spring Linearity High (Zero port compression)
Simulate This Sealed Box in App →

Thiele/Small Parameters

Resonance (Fs) 1100.0 Hz
Total Q (Qts) 0.98
Electrical Q (Qes) 1.523
Mechanical Q (Qms) 2.75
Equivalent Volume (Vas) 0.0 Liters
Diaphragm Area (Sd) 6.2 cm²
DC Resistance (Re) 3.2 Ω
Efficiency Bandwidth Product (EBP) 722.4
Linear Excursion (Xmax) 1.2 mm
Thermal Power (Pe) 7.0 W
Nominal Diameter 1.0"
Catalog Source Load Forge catalog (manufacturer datasheets and retailer listings)

Frequently Asked Questions

What is the recommended ported (bass reflex) box volume for Unknown BC25TG15-04?

A simple ported box is not recommended for Unknown BC25TG15-04: the textbook alignment (1.5 liters tuned to 935.0 Hz) needs a -7.1 cm port, and no nearby retune stays buildable without a bass hump. A sealed box, a passive radiator or a folded duct is the practical choice.

Can Unknown BC25TG15-04 be used in a sealed box?

Yes. In a sealed (acoustic suspension) enclosure of 0.003 liters with a Qtc of 1.386 (above Butterworth: Qtc cannot fall below Qts (0.98)), the system exhibits an F3 of 1328.8 Hz.

What port dimensions should be used for Unknown BC25TG15-04 to avoid port chuffing?

A straight 20.0 cm port would need -7.1 cm of length, which does not fit a practical cabinet. Use a passive radiator or a folded/3D duct instead of a straight tube.

Shareable Acoustic Card for Forums & Social Media

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Unknown BC25TG15-04 Enclosure Card
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