- Net volume
- 19L
- Tuning
- 49Hz
B&C gives the volume and tuning; the port is sized for the driver when you open it.
8-inch LF driver · 8BG series · 51 mm voice coil · 250 W
B&C 8BG51 8Ω
8 Ω · 50–4000 Hz
- Fs
- 52Hz
- Xmax
- 6.5mm
- SPL
- 90dB
- Pe
- 250W
- BL
- 11.8T·m
- Vd
- 143cm³
- Qts
- 0.40
- Vas
- 18L
Published graphs
B&C 8BG51 is an 8-inch 8 ohm LF driver rated at 250 W RMS. The validated T/S data includes Fs 52 Hz, Qts 0.40, Vas 18 L, Xmax 6.5 mm, sensitivity 89.8 dB, plus 143 cm³ Vd and 124 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 £106.72.
The published T/S values agree with each other
Thiele/Small
- Fs
- 52Hz
- Qts
- 0.40
- Qes
- 0.42
- Qms
- 12.3
- Vas
- 18L
- Re
- 5.1Ω
- Le
- 0.50mH
Motor and cone
- BL
- 11.8T·m
- Sd
- 220cm²
- Mms
- 35g
- Xmax
- 6.5mm
- Vd †
- 143cm³
- Voice coil
- 51mm
- Flux density
- 1.15T
Power and response
- Sensitivity †
- 89.8dB
- Manufacturer sensitivity
- 92dB
- Power
- 250W
- Nominal power
- 250W
- Impedance
- 8Ω
- Min. impedance
- 6Ω
- Range
- 50–4000Hz
- EBP †
- 124 · Leans vented
Size and mounting
- Diameter
- 225mm
- Cutout
- 187mm
- Bolt circle
- 210mm
- Depth
- 90mm
- Weight
- 1.9kg
Sensitivity shows 89.8 dB, calculated from the T/S values. B&C publishes 92.0 dB, 2.2 dB apart.
† Calculated by bits from the published values
What this validation status means
Everything else B&C lists
LF
- BL
- 11.8T·m
- Fs
- 52Hz
- Le
- 0.50mH
- Re
- 5.1Ω
- Sd
- 220cm²
- Mms
- 35g
- Qes
- 0.42
- Qms
- 12.3
- Qts
- 0.40
- SPL
- 89.8dB
- Vas
- 18L
- Xmax
- 6.5mm
- Power
- 250W
- Impedance
- 8Ω
- Flux density
- 1.15T
- Sensitivity
- 92dB
- Low limit
- 50Hz
- Nominal power
- 250W
- Calculated sensitivity †
- 89.8dB
- High limit
- 4000Hz
- Manufacturer sensitivity
- 92dB
- Min. impedance
- 6Ω
- Voice coil
- 51mm
- Weight
- 1.9kg
- Diameter
- 225mm
- Depth
- 90mm
- Cutout
- 187mm
- Bolt circle
- 210mm
- Bl
- 11.8 Tm
- Fs
- 52 Hz
- Le
- 0.5 mH
- Re
- 5.1 Ω
- Sd
- 220 cm² (34.1 in²)
- Ebp
- 124 Hz
- Mms
- 35 g
- Qes
- 0.42
- Qms
- 12.3
- Qts
- 0.4
- Vas
- 18 dm³ (0.63 ft³)
- Η0
- 0.6 %
- Cone
- RCK008BG518
- Xmax
- 6.5 mm
- Xvar
- 8 mm
- Depth
- 90 mm (3.5 in)
- Spider
- Single
- Cone shape
- Exponential
- Net weight
- 1.85 kg (4.08 lb)
- Pole design
- T-Pole
- Sensitivity
- 92 dB
- Flux density
- 1.15 T
- Shipping box
- 255x255x150 mm (10.04x10.04x5.91 in)
- Winding depth
- 17 mm (0.65 in)
- Shipping units
- 1 pcs
- Surround shape
- Roll
- Former material
- Glass Fibre
- Frequency range
- 50 Hz - 4000 Hz
- Magnet material
- Neodymium Inside Slug
- Shipping weight
- 2.3 kg (5.07 lb)
- Nominal diameter
- 200 mm (8 in)
- Overall diameter
- 225 mm (8.8 in)
- Winding material
- Copper
- Minimum impedance
- 6 Ω
- Nominal impedance
- 8 Ω
- Magnetic gap depth
- 8 mm (0.31 in)
- Recommended tuning
- 49 Hz
- Voice coil diameter
- 51 mm (2 in)
- Bolt circle diameter
- 210 mm (8.3 in)
- Recommended enclosure
- 19 dm³ (0.67 ft³)
- Woofer cone treatment
- WP Waterproof Front Side
- Baffle cutout diameter
- 187 mm (7.4 in)
- Nominal power handling
- 250 W
- Continuous power handling
- 500 W
- Flange and gasket thickness
- 11 mm (0.43 in)
- Air volume occupied by driver
- 1.1 dm³ (0.04 ft³)
B&C’s suggested box
From B&C’s 8BG51 page
Open this box in 00 Simulator
Modelling the box in 00 Simulator…
03
Compare
Same-size drivers, compared with the 8BG51. Clear differences are green when better and red when worse.
This driver8BG51
Best price
£106.72
Fs
52 Hz
Qts
0.40
Vas
18 L
BL
11.8 T·m
Xmax
6.5 mm
Sensitivity
89.8 dB
Power
250 W
FaitalPRO8FE300
£43.52 · 59% less, betterFs70 Hz +35%, worse
Qts0.44 +10%
Vas15.7 L −13%, better
BL11.3 T·m −4%
Xmax5.5 mm −15%, worse
Sensitivity92.7 dB +2.9, better
SB AudienceBIANCO-8MW250
£49.00 · 54% less, betterFs74 Hz +42%, worse
Qts0.40 –
Vas13.8 L −23%, better
BL11 T·m −7%
Xmax6.5 mm –
Sensitivity93 dB +3.2, better
FaneSOVEREIGN 8-225
£51.00 · 52% less, betterFs62 Hz +19%, worse
Qts0.38 −5%
Vas22 L +22%, worse
BL11 T·m −7%
Xmax5.5 mm −15%, worse
Sensitivity93 dB +3.2, better
CelestionTRUVOX 0820
£59.70 · 44% less, betterFs74 Hz +42%, worse
Qts0.39 –
Vas17.3 L −4%
BL11.5 T·m –
Xmax5 mm −23%, worse
Sensitivity94.3 dB +4.5, better
MonacorSP-8/150PRO
£60.46 · 43% less, betterFs56 Hz +8%
Qts0.32 −20%, better
Vas22 L +22%, worse
BL12.0 T·m –
Xmax6 mm −8%
Sensitivity91.8 dB +2, better
LavoceWAF082.00
£71.42 · 33% less, betterFs78 Hz +50%, worse
Qts0.37 −8%
Vas11.9 L −34%, better
BL12.5 T·m +6%
Xmax6.3 mm −3%
Sensitivity93.4 dB +3.6, better
FaitalPRO8PR320
£75.00 · 30% less, betterFs65 Hz +25%, worse
Qts0.41 –
Vas13.1 L −27%, better
BL12.9 T·m +9%
Xmax7.3 mm +13%, better
Sensitivity91.3 dB +1.5
CIAREPWA8.50
£77.92 · 27% less, betterFs74 Hz +42%, worse
Qts0.38 −5%
Vas12 L −33%, better
BL12.7 T·m +8%
Xmax6.8 mm +5%
Sensitivity92.8 dB +3, better
CelestionCF0820BMB
£85.00 · 20% less, betterFs51 Hz –
Qts0.37 −9%
Vas22.4 L +25%, worse
BL11.9 T·m –
Xmax7.3 mm +12%, better
Sensitivity90.7 dB +0.9
B&C8CL51
£85.54 · 20% less, betterFs69 Hz +33%, worse
Qts0.41 –
Vas12.5 L −31%, better
BL12 T·m –
Xmax6.5 mm –
Sensitivity91.7 dB +1.9
B&C8NDL51
£90.71 · 15% less, betterFs66 Hz +27%, worse
Qts0.37 −8%
Vas14 L −22%, better
BL12.4 T·m +5%
Xmax7 mm +8%
Sensitivity91.9 dB +2.1, better
PRV Audio8MR600X
£95.66 · 10% less, betterFs77 Hz +48%, worse
Qts0.40 –
Vas20.0 L +11%, worse
BL10.5 T·m −11%, worse
Xmax5.3 mm −19%, worse
Sensitivity95.3 dB +5.5, better
FaitalPRO8PR200
£99.14 · 7% less, betterFs58 Hz +12%, worse
Qts0.37 −8%
Vas16.9 L −6%
BL11.5 T·m –
Xmax8.2 mm +25%, better
Sensitivity91.4 dB +1.6
Beyma8G40
£101.22 · 5% less, betterFs70 Hz +35%, worse
Qts0.36 −10%, better
Vas17 L −6%
BL12.2 T·m +3%
Xmax6.5 mm –
Sensitivity93.9 dB +4.1, better
LavoceCSF082.00K
£143.11 · 34% more, worseFs81 Hz +56%, worse
Qts0.40 –
Vas14.8 L −18%, better
BL11.0 T·m −7%
Xmax5 mm −23%, worse
Sensitivity94.5 dB +4.7, better
B&C8CX21
£151.61 · 42% more, worseFs74 Hz +42%, worse
Qts0.36 −10%, better
Vas15 L −17%, better
BL11.5 T·m –
Xmax5.5 mm −15%, worse
Sensitivity94 dB +4.2, better
SB AudienceNERO-8MWN400D
£152.56 · 43% more, worseFs63 Hz +21%, worse
Qts0.38 −5%
Vas13.9 L −23%, better
BL11.9 T·m –
Xmax6.7 mm +3%
Sensitivity91.3 dB +1.5
FaitalPRO8HX150
£159.23 · 49% more, worseFs76 Hz +46%, worse
Qts0.41 –
Vas13 L −28%, better
BL11.6 T·m –
Xmax4.9 mm −24%, worse
Sensitivity93.3 dB +3.5, better
Dayton AudioRSS210HO-4
£177.82 · 67% more, worseFs30 Hz −43%, better
Qts0.40 –
Vas18.7 L +4%
BL12 T·m –
Xmax11 mm +69%, better
Sensitivity82.3 dB −7.5, worse
B&C8FCX51
£178.00 · 67% more, worseFs69 Hz +33%, worse
Qts0.34 −15%, better
Vas16 L −11%, better
BL11.5 T·m –
Xmax6 mm −8%
Sensitivity93.7 dB +3.9, better
Eighteen Sound8CX650
£344.69 · 223% more, worseFs65 Hz +25%, worse
Qts0.35 −13%, better
Vas16.6 L −8%
BL12 T·m –
Xmax6 mm −8%
Sensitivity92.9 dB +3.1, better
LavoceCAF082.00K
No current priceFs72 Hz +38%, worse
Qts0.34 −15%, better
Vas15.1 L −16%, better
BL11.7 T·m –
Xmax6.7 mm +3%
Sensitivity93.7 dB +3.9, better
No current price
Fs62 Hz +19%, worse
Qts0.38 −5%
Vas22 L +22%, worse
BL11 T·m −7%
Xmax5.5 mm −15%, worse
Sensitivity93 dB +3.2, better
CelestionCNX0820
No current priceFs95 Hz +82%, worse
Qts0.40 –
Vas9.9 L −45%, better
BL12.0 T·m –
Xmax6 mm −8%
Sensitivity94.7 dB +4.9, better
MonacorCF0820BMB/8
No current priceFs51 Hz –
Qts0.37 −9%
Vas22.4 L +24%, worse
BL11.9 T·m –
Xmax7.3 mm +12%, better
Sensitivity90.7 dB +0.9
LavoceNBASS08-20
No current priceFs55 Hz +6%
Qts0.48 +20%, worse
Vas18.4 L –
BL11.3 T·m −4%
Xmax6.5 mm –
Sensitivity89.9 dB –
Oberton8CX
No current priceFs76 Hz +46%, worse
Qts0.40 –
Vas16.8 L −6%
BL9.4 T·m −20%, worse
Xmax5.3 mm −19%, worse
Sensitivity94.3 dB +4.5, better
Oberton8NCX
No current priceFs77 Hz +49%, worse
Qts0.40 –
Vas14.9 L −17%, better
BL10.1 T·m −14%, worse
Xmax5.3 mm −19%, worse
Sensitivity94 dB +4.2, better
BMS8S219
No current priceFs82 Hz +58%, worse
Qts0.41 –
Vas9.7 L −46%, better
BL13.3 T·m +13%, better
Xmax6.3 mm −3%
Sensitivity92.8 dB +3, better
BMS8N519
No current priceFs75 Hz +44%, worse
Qts0.37 −8%
Vas10.9 L −39%, better
BL13.8 T·m +17%, better
Xmax6.3 mm −3%
Sensitivity92.5 dB +2.7, better
Tune the match
Choose the published values that matter to your design. Size stays matched to this driver.
Qts
Qes
VasL
Xmaxmm
BLTm
- Parts Express5.0 out of 55 ratings · Checked 9 Oct 2026Read reviews on Parts Express
- Thomann5.0 out of 51 rating · Checked 9 Oct 2026Read reviews on Thomann
Each shop collects its own ratings. Bits shows them as published and doesn't verify them.
| Shop | Price | Against the lowest | Stock | Link |
|---|---|---|---|---|
Blue Aran 5-7 weeks | £111.00, the lowest price | 54 in stock | Visit shop at Blue Aran | |
Thomann Not currently listed · Last seen 21 Apr 2026 | £110.00 | Stock not listed | Visit shop at Thomann | |
Thomann | £111.00 | In stock | Visit shop at Thomann | |
JP Leisure Not currently listed · Last seen 7 Aug 2026 | £114.86 | 3.5% above the lowest price | In stock | Visit shop at JP Leisure |
JP Leisure | £114.86 | 3.5% above the lowest price | In stock | Visit shop at JP Leisure |
Parts Express Import VAT and duty may apply | £133.66 | 20% above the lowest price | 4 in stock | Visit shop at Parts Express |
Best price over time
Tracked since 1 Apr
Recent changes
- 4 OctThomann£113.00 → £111.00Down 1.8% from £113.00
- 26 SepThomann£111.00 → £113.00Up 1.8% from £111.00
- 17 JulBlue Aran£118.78 → £111.00Down 6.5% from £118.78