- Net volume
- 14L
- Tuning
- 80Hz
B&C gives the volume and tuning; the port is sized for the driver when you open it.
8-inch LF driver · 8FMB series · 51 mm voice coil · 250 W
B&C 8FMB51 8Ω
67–4500 Hz
£80.08
17%Blue Aran · 27 in stock · All 4 offers
- Fs
- 67Hz
- Xmax
- 5.5mm
- SPL
- 95dB
- Pe
- 250W
- BL
- 11.3T·m
- Vd
- 125cm³
- Qts
- 0.28
- Vas
- 21L
Published graphs
B&C 8FMB51 is an 8-inch 8 ohm LF driver rated at 250 W RMS. The validated T/S data includes Fs 67 Hz, Qts 0.28, Vas 20.7 L, Xmax 5.5 mm, sensitivity 95.1 dB, plus 125 cm³ Vd and 216 EBP. bits tracks UK, EU and US shop prices, price movement, datasheet links, simulator import data, and similar drivers, with a current best price of £80.08.
The published T/S values agree with each other
Thiele/Small
- Fs
- 67Hz
- Qts
- 0.28
- Qes
- 0.31
- Qms
- 3.1
- Vas
- 20.7L
- Re
- 4.7Ω
- Le
- 0.48mH
Motor and cone
- BL
- 11.3T·m
- Sd
- 227cm²
- Mms
- 20g
- Xmax
- 5.5mm
- Vd †
- 125cm³
- Voice coil
- 51mm
- Flux density
- 1.19T
Power and response
- Sensitivity †
- 95.1dB
- Manufacturer sensitivity
- 96.5dB
- Power
- 250W
- Nominal power
- 250W
- Impedance
- 8Ω
- Min. impedance
- 5.5Ω
- Range
- 67–4500Hz
- EBP †
- 216 · Leans vented
Size and mounting
- Diameter
- 225mm
- Cutout
- 187mm
- Bolt circle
- 210mm
- Depth
- 92mm
- Weight
- 3.4kg
Sensitivity shows 95.1 dB, calculated from the T/S values. B&C publishes 96.5 dB, 1.4 dB apart.
† Calculated by bits from the published values
What this validation status means
Everything else B&C lists
LF
- BL
- 11.3T·m
- Fs
- 67Hz
- Le
- 0.48mH
- Re
- 4.7Ω
- Sd
- 227cm²
- Mms
- 20g
- Qes
- 0.31
- Qms
- 3.1
- Qts
- 0.28
- SPL
- 95.1dB
- Vas
- 20.7L
- Xmax
- 5.5mm
- Power
- 250W
- Impedance
- 8Ω
- Flux density
- 1.19T
- Sensitivity
- 96.5dB
- Low limit
- 67Hz
- Nominal power
- 250W
- Calculated sensitivity †
- 95.1dB
- High limit
- 4500Hz
- Manufacturer sensitivity
- 96.5dB
- Min. impedance
- 5.5Ω
- Voice coil
- 51mm
- Weight
- 3.4kg
- Diameter
- 225mm
- Depth
- 92mm
- Cutout
- 187mm
- Bolt circle
- 210mm
- Bl
- 11.3 Tm
- Fs
- 67 Hz
- Le
- 0.48 mH
- Re
- 4.7 Ω
- Sd
- 227 cm² (35.19 in²)
- Ebp
- 216 Hz
- Mms
- 20.2 g
- Qes
- 0.31
- Qms
- 3.07
- Qts
- 0.28
- Vas
- 20.7 dm³ (0.73 ft³)
- Η0
- 1.91 %
- Cone
- RCK008FMB518
- Xmax
- 5.5 mm
- Xvar
- 5 mm
- Depth
- 92 mm (3.62 in)
- Spider
- Single
- Cone shape
- Curvilinear
- Net weight
- 3.4 kg (7.5 lb)
- Pole design
- T-Pole
- Sensitivity
- 96.5 dB
- Flux density
- 1.19 T
- Shipping box
- 255x255x150 mm (10.04x10.04x5.91 in)
- Winding depth
- 15 mm (0.59 in)
- Shipping units
- 1 pcs
- Surround shape
- Triple Roll
- Former material
- Glass Fibre
- Frequency range
- 67 Hz - 4500 Hz
- Magnet material
- Ferrite
- Shipping weight
- 3.85 kg (8.49 lb)
- Nominal diameter
- 200 mm (8 in)
- Overall diameter
- 225 mm (8.86 in)
- Winding material
- Aluminium
- Minimum impedance
- 5.5 Ω
- Nominal impedance
- 8 Ω
- Magnetic gap depth
- 8 mm (0.31 in)
- Recommended tuning
- 80 Hz
- Voice coil diameter
- 51 mm (2 in)
- Bolt circle diameter
- 210 mm (8.27 in)
- Recommended enclosure
- 14 dm³ (0.49 ft³)
- Woofer cone treatment
- Waterproof Impregnated Cone
- Baffle cutout diameter
- 187 mm (7.36 in)
- Nominal power handling
- 250 W
- Continuous power handling
- 500 W
- Flange and gasket thickness
- 9 mm (0.35 in)
- Air volume occupied by driver
- 1.2 dm³ (0.04 ft³)
B&C’s suggested box
From B&C’s 8FMB51 page
Open this box in 00 Simulator
Modelling the box in 00 Simulator…
03
Compare
Same-size drivers, compared with the 8FMB51. Clear differences are green when better and red when worse.
This driver8FMB51
Best price
£80.08
Fs
67 Hz
Qts
0.28
Vas
20.7 L
BL
11.3 T·m
Xmax
5.5 mm
Sensitivity
95.1 dB
Power
250 W
MonacorSP-8/150PRO
£60.46 · 24% less, betterFs56 Hz −16%, better
Qts0.32 +14%, worse
Vas22 L +6%
BL12.0 T·m +6%
Xmax6 mm +9%
Sensitivity91.8 dB −3.3, worse
Beyma8WRS300
£75.85 · 5% less, betterFs65 Hz –
Qts0.28 –
Vas15 L −28%, better
BL15.2 T·m +35%, better
Xmax6 mm +9%
Sensitivity93.4 dB −1.7
Beyma8P300FE
£79.99 · Same priceFs53 Hz −21%, better
Qts0.31 +11%, worse
Vas24.8 L +20%, worse
BL11.6 T·m –
Xmax6 mm +9%
Sensitivity92.7 dB −2.4, worse
Sica8 S 2.5 CP
£81.22 · 1% moreFs54 Hz −19%, better
Qts0.33 +18%, worse
Vas18.6 L −10%, better
BL11.9 T·m +5%
Xmax5 mm −9%
Sensitivity91 dB −4.1, worse
Sica8 FE 2.5 CP
£83.85 · 5% moreFs73 Hz +9%
Qts0.28 –
Vas15.6 L −25%, better
BL13.0 T·m +15%, better
Xmax4 mm −27%, worse
Sensitivity95.1 dB –
B&C8FG51
£95.71 · 20% more, worseFs49 Hz −27%, better
Qts0.32 +14%, worse
Vas20 L −3%
BL12.9 T·m +14%, better
Xmax6.5 mm +18%, better
Sensitivity90.4 dB −4.7, worse
EminenceBETA 8CX
£95.86 · 20% more, worseFs62 Hz −7%
Qts0.29 +4%
Vas21.4 L +4%
BL11.2 T·m –
Xmax3.2 mm −42%, worse
Sensitivity94.2 dB −0.9
B&C8MBX51
£113.58 · 42% more, worseFs60 Hz −10%, better
Qts0.29 +4%
Vas23 L +11%, worse
BL11.4 T·m –
Xmax6 mm +9%
Sensitivity94.1 dB −1
Eighteen Sound8NMB420
£120.21 · 50% more, worseFs61 Hz −9%
Qts0.28 –
Vas33 L +59%, worse
BL10 T·m −12%, worse
Xmax5.8 mm +5%
Sensitivity95.9 dB +0.8
MonacorSPH-225C
£130.43 · 63% more, worseFs39 Hz −42%, better
Qts0.30 +7%
Vas24 L +16%, worse
BL13.2 T·m +17%, better
Xmax6 mm +9%
Sensitivity88.6 dB −6.5, worse
WavecorWF182BD13
£159.76 · 100% more, worseFs38 Hz −43%, better
Qts0.26 −7%
Vas20.8 L –
BL6.9 T·m −39%, worse
Xmax5.5 mm –
Sensitivity88.3 dB −6.8, worse
WavecorWF211PA01
£187.78 · 134% more, worseFs68 Hz –
Qts0.29 +4%
Vas13.6 L −34%, better
BL10.7 T·m −5%
Xmax2 mm −64%, worse
Sensitivity93.6 dB −1.5
WavecorWF182BD03
£192.85 · 141% more, worseFs39 Hz −42%, better
Qts0.29 +4%
Vas24.4 L +18%, worse
BL6.8 T·m −40%, worse
Xmax5.5 mm –
Sensitivity88.9 dB −6.2, worse
WavecorWF182BD08
£192.85 · 141% more, worseFs33 Hz −50%, better
Qts0.29 +4%
Vas32.4 L +57%, worse
BL8.5 T·m −25%, worse
Xmax5.5 mm –
Sensitivity88.1 dB −7, worse
WavecorWF182BD16
£193.95 · 142% more, worseFs37 Hz −45%, better
Qts0.30 +7%
Vas23 L +11%, worse
BL8.5 T·m −25%, worse
Xmax5.5 mm –
Sensitivity87.8 dB −7.3, worse
B&C8CXN51
£225.53 · 182% more, worseFs68 Hz –
Qts0.27 −4%
Vas17 L −18%, better
BL12.6 T·m +12%, better
Xmax6 mm +9%
Sensitivity94.7 dB –
FaitalPRO8HX200
£252.39 · 215% more, worseFs76 Hz +13%, worse
Qts0.30 +7%
Vas13.1 L −37%, better
BL13.8 T·m +22%, better
Xmax4.9 mm −11%, worse
Sensitivity94.7 dB –
FaitalPRO8HX240
£282.04 · 252% more, worseFs70 Hz +4%
Qts0.30 +7%
Vas12.9 L −38%, better
BL13.8 T·m +22%, better
Xmax6.2 mm +12%, better
Sensitivity93.6 dB −1.5
Beyma8CX300ND
£321.98 · 302% more, worseFs61 Hz −9%
Qts0.29 +4%
Vas23 L +11%, worse
BL12 T·m +6%
Xmax6 mm +9%
Sensitivity94.4 dB −0.7
AccutonS220-6-222
£912.25 · 1039% more, worseFs25 Hz −63%, better
Qts0.26 −7%
Vas89.7 L +333%, worse
BL10.9 T·m −3%
Xmax5.3 mm −5%
Sensitivity89.2 dB −5.9, worse
Sica8 CX 2.5 PL P
No current priceFs74 Hz +10%, worse
Qts0.28 –
Vas16.2 L −22%, better
BL12.3 T·m +9%
Xmax5 mm −9%
Sensitivity95.1 dB –
WavecorWF182BD15
No current priceFs39 Hz −42%, better
Qts0.32 +14%, worse
Vas20.8 L –
BL8.5 T·m −25%, worse
Xmax5.5 mm –
Sensitivity87.8 dB −7.3, worse
SB AudienceROSSO-8CX250
No current priceFs70 Hz +4%
Qts0.32 +14%, worse
Vas15.8 L −24%, better
BL11.4 T·m –
Xmax5.4 mm –
Sensitivity93.7 dB −1.4
CelestionTN0820
No current priceFs62 Hz −8%
Qts0.28 –
Vas21.9 L +6%
BL11.8 T·m +4%
Xmax2 mm −64%, worse
Sensitivity93.8 dB −1.3
Tang BandW8-740P
No current priceFs30 Hz −55%, better
Qts0.28 –
Vas20.0 L −3%
BL13.7 T·m +21%, better
Xmax12.1 mm +120%, better
Sensitivity84.4 dB −10.7, worse
HiViSS8IIN
No current priceFs29 Hz −57%, better
Qts0.27 −4%
Vas80.1 L +287%, worse
BL10.6 T·m −6%
Xmax5 mm −9%
Sensitivity90.3 dB −4.8, worse
CIAREHSG200
No current priceFs38 Hz −43%, better
Qts0.31 +11%, worse
Vas19 L −8%
BL11.8 T·m +4%
Xmax7.5 mm +36%, better
Sensitivity87 dB −8.1, worse
CIAREHSG200-4
No current priceFs38 Hz −43%, better
Qts0.31 +11%, worse
Vas19 L −8%
BL11.8 T·m +4%
Xmax7.5 mm +36%, better
Sensitivity87 dB −8.1, worse
LavoceCAN082.00K
No current priceFs72 Hz +7%
Qts0.27 −4%
Vas15.1 L −27%, better
BL13.2 T·m +16%, better
Xmax6.7 mm +22%, better
Sensitivity94.8 dB –
PRV Audio8MB700FT
No current priceFs72 Hz +8%
Qts0.31 +11%, worse
Vas20 L −3%
BL12.3 T·m +8%
Xmax3.5 mm −36%, worse
Sensitivity95.6 dB +0.5
Tune the match
Choose the published values that matter to your design. Size stays matched to this driver.
Qts
Qes
VasL
Xmaxmm
BLTm
| Shop | Price | Against the lowest | Stock | Link |
|---|---|---|---|---|
Blue Aran 5-7 weeks | £80.08, the lowest price | 27 in stock | Visit shop at Blue Aran | |
JP Leisure Not currently listed · Last seen 7 Aug 2026 | £96.76 | 21% above the lowest price | In stock | Visit shop at JP Leisure |
JP Leisure | £96.76 | 21% above the lowest price | In stock | Visit shop at JP Leisure |
Best price over time
Tracked since 1 Apr
Recent changes
- 23 JunJP Leisure£91.90 → £96.76Up 5.3% from £91.90