BMS 12N820 is a 12-inch 8 ohm LF driver rated at 800 W RMS. The validated T/S data includes Fs 38 Hz, Qts 0.16, Vas 98.7 L, Xmax 4.5 mm, sensitivity 97.3 dB, plus 239 cm³ Vd and 236 EBP. bits tracks vendor pricing, datasheet links, simulator import data, and similar drivers from the same loudspeaker database.
The published T/S values agree with each other
Thiele/Small
Fs 38Hz
Qts 0.16
Qes 0.16
Qms 5.3
Vas 98.7L
Re 5.7Ω
Le 0.62mH Motor and cone
BL 24.2T·m
Sd 531cm²
Mms 72g
Xmax 4.5mm
Vd † 239cm³
Voice coil 102mm Power and response
Sensitivity † 97.3dB
Manufacturer sensitivity 98dB
Power 800W
Impedance 8Ω
Range 45–1700Hz
EBP † 236 · Leans vented Size and mounting
Diameter 318mm
Cutout 284mm
Bolt circle 300mm
Depth 155mm
Weight 5.5kg Other published values
Cms 0.25mm/N † Calculated by bits from the published values
What this validation status means
Everything else BMS lists LF
BL 24.2T·m
Fs 38Hz
Le 0.62mH
Re 5.7Ω
Sd 531cm²
Cms 0.25mm/N
Mms 72g
Qes 0.16
Qms 5.3
Qts 0.16
SPL 97.3dB
Vas 98.7L
Xmax 4.5mm
Power 800W
Impedance 8Ω
Sensitivity 98dB
Low limit 45Hz
Calculated sensitivity † 97.3dB
High limit 1700Hz
Manufacturer sensitivity 98dB
Voice coil 102mm
10. basket Cast Aluminum
20. bl factor BL 24.2 Tesla m
1. application Low-Middle
18. moving mass Mms 0.072 kg
13. dc resistance Re 5.7 Ohm
9. magnet gap depth 10 mm
17. equivalent volume Vas 98.7 L
2. nominal impendance 8 Ohm
5. frequency response 45 – 1700 Hz
6. voice coil diameter 101.6 (4″) mm
7. voice coil material Cu
12. resonance frequency Fs 37.8 Hz
14. mechanical q factor Qms 5.3
15. electrical q factor Qes 0.16
16. total quality factor Qts 0.16
19. mechanical complience Cms 0.25 mm / N
21. effective piston area Sd 0.0531 m²
22. max. linear excursion Xmax +/- 4.5 mm
23. voice coil inductance Le1k 0.62 mH
4. sensitivity (1 w / 1 m) 98 dB
3. power handling aes noise 800 W
8. voice coil winding depth 19 mm
11. effect. diaphragm diameter d 260 mm