Beyma 12BR70
Beyma 12BR70: inexpensive 12″ driver with ferrite motor and 2″ voice coil – with Fs 31 Hz and Qts 0.50 one of the few entry-level drivers suitable for bass reflex with complete parameters.
Current · Last checked: 2026-09-28
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General data
Link to section “General data”- Type
- Woofer
- Nominal size
- 12″
- Nominal impedance
- 8 Ω Manufacturer
- Minimum impedance
- 6.6 Ω Manufacturer
- Sensitivity
- 93 dB 1 W / 1 m · 2π (half space) Manufacturer
- Frequency range
- 35 Hz – 4,000 Hz Manufacturer
- Voice coil Ø
- 50.8 mm Manufacturer
- Winding height
- not available
- Gap depth
- not available
- Flux density
- not available
- Magnet
- ferrite
- Weight
- 3.6 kg Manufacturer
- Baffle cut-out Ø
- 278 mm Manufacturer
- Overall diameter
- 312 mm Manufacturer
- Mounting depth
- 134 mm Manufacturer
- Displacement
- not available
- Recommended enclosure volume
- 50 – 120 L Manufacturer
According to the datasheet, sensitivity applies to 1 W at 1 m in half space (2π) – this makes the value higher than a measurement in full space. Power handling is given here as “RMS”, not according to AES; Beyma gives the two volume values (50/120 L) without stating which enclosure type they refer to.
Beyma also states a swept volume Vd of 340 cm³. This does not match the stated Xmax of 8 mm (with Sd = 540 cm² it would be 432 cm³), so we do not list Vd as a specified value here.
What can this driver do?
Link to section “What can this driver do?”Simulation from the datasheet values above. The suggestions are calculated, not stated by the manufacturer.
The EBP is between 50 and 100 – by the rule of thumb, both a bass reflex and a sealed enclosure are possible. This is based on an EBP of 55.4.
- Net volume
- 368 L
- Tuning frequency
- 23.5 Hz
- F3 (−3 dB)
- 20.8 Hz
- F6 (−6 dB)
- 19.2 Hz
- F10 (−10 dB)
- 17.6 Hz
- Sensitivity (2.83 V / 1 m)
- 92.4 dB
- Max. SPL at 20.8 Hz
- 104.1 dB
- Max. SPL at 41.6 Hz
- 109.3 dB
- Xmax limits below
- 56.6 Hz
- Ports
- 1 × 200 mm
- Port area for 17 m/s
- 262 cm²
- Max. port velocity
- 14.2 m/s
- Port length
- 31.5 cm
- at 125 W
- Maximum SPL (limited by Xmax)
- Power into 8 Ω (nominal impedance of the wiring).
- Flattest alignment: lowest F3 without the response rising more than 0.25 dB above the passband level or dropping more than 0.5 dB at 2 × F3.
- The 17 m/s limit (about 5 % of the speed of sound) is a common rule of thumb against port noise, not a standard. Rounded port ends allow higher values.
- Lumped-element Thiele/Small model, Half space, 1 m, chamber losses QL 7, Le as a plain inductance, no room influence. At high levels (heating, non-linear Bl and Cms) real results are lower.
Thiele-Small parameters
Link to section “Thiele-Small parameters”Small-signal parameters as stated by the manufacturer. They change with temperature and level.
Plausibility check
Link to section “Plausibility check”We recalculate dependent values from the datasheet. We flag deviations above 3 %.
| Check | Formula | Datasheet | Calculated | Result |
|---|---|---|---|---|
| Qts from Qes and Qms | Qts = Qes · Qms / (Qes + Qms) | 0.5 | 0.497 | consistent |
Power handling
Link to section “Power handling”- Continuous power (standard not stated)125 W
- Programme power250 W
Sources
Link to section “Sources”-
Tier A · primary source
Beyma 12BR70 (8 Ω) – Product page with Thiele-Small parameters
Acústica Beyma S.L.U. · accessed on 28 September 2026
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Tier A · primary source
Beyma 12BR70 – Datasheet (PDF)
Acústica Beyma S.L.U. · October 2020 · accessed on 13 November 2026
Revision code “10/20” in the footer of the dimension drawing. Unlike the product page, contains the complete mounting dimensions.