- Net volume
- 190L
- Tuning
- 33Hz
B&C gives the volume and tuning; the port is sized for the driver when you open it.
21-inch LF driver · 21SW series · 153 mm voice coil · 2,000 W
B&C 21SW152 8Ω
30–1000 Hz
£585.00
SteadyBlue Aran · 4 in stock · All 12 offers
- Fs
- 32Hz
- Xmax
- 15mm
- SPL
- 94dB
- Pe
- 2000W
- BL
- 39T·m
- Vd
- 2520cm³
- Qts
- 0.36
- Vas
- 200L
Manufacturer response and impedance data, with source and trace details below. The left and right arrow keys read every shown curve at a frequency, a twelfth of an octave at a time, or an octave with Shift. Escape clears the reading.
Curve provenanceInspect 2 traces
These plotted lines are Bits digitizations of manufacturer evidence, not new measurements. How provenance works
- Trace datasheet-response-trace-poc/v2
free-air SPL
Frequency response
240 plotted pointsSource file SHA-256 0daf26ae195a…Medium confidence4,329 selected pixels of 4,329 - Trace datasheet-response-trace-poc/v2
free-air impedance
Impedance response
240 plotted pointsSource file SHA-256 0daf26ae195a…Medium confidence2,781 selected pixels of 2,781
Published graphs
B&C 21SW152 is a 21-inch 8 ohm LF driver rated at 2000 W RMS. The validated T/S data includes Fs 32 Hz, Qts 0.36, Vas 200 L, Xmax 15 mm, sensitivity 94.4 dB, plus 2520 cm³ Vd and 84 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 £544.95.
The published T/S values agree with each other
Thiele/Small
- Fs
- 32Hz
- Qts
- 0.36
- Qes
- 0.38
- Qms
- 6.4
- Vas
- 200L
- Re
- 6Ω
- Le
- 2.20mH
Motor and cone
- BL
- 39T·m
- Sd
- 1680cm²
- Mms
- 450g
- Xmax
- 15mm
- Vd †
- 2520cm³
- Voice coil
- 153mm
- Flux density
- 1.20T
Power and response
- Sensitivity †
- 94.4dB
- Manufacturer sensitivity
- 96dB
- Power
- 2000W
- Nominal power
- 2000W
- Impedance
- 8Ω
- Min. impedance
- 7Ω
- Range
- 30–1000Hz
- EBP †
- 84 · Sealed or vented
Size and mounting
- Diameter
- 547mm
- Cutout
- 508mm
- Bolt circle
- 527mm
- Depth
- 261mm
- Weight
- 18.5kg
Sensitivity shows 94.4 dB, calculated from the T/S values. B&C publishes 96.0 dB, 1.6 dB apart.
† Calculated by bits from the published values
What this validation status means
Everything else B&C lists
LF
- BL
- 39T·m
- Fs
- 32Hz
- Le
- 2.20mH
- Re
- 6Ω
- Sd
- 1680cm²
- Mms
- 450g
- Qes
- 0.38
- Qms
- 6.4
- Qts
- 0.36
- SPL
- 94.4dB
- Vas
- 200L
- Xmax
- 15mm
- Power
- 2000W
- Impedance
- 8Ω
- Flux density
- 1.20T
- Sensitivity
- 96dB
- Low limit
- 30Hz
- Nominal power
- 2000W
- Calculated sensitivity †
- 94.4dB
- High limit
- 1000Hz
- Manufacturer sensitivity
- 96dB
- Min. impedance
- 7Ω
- Voice coil
- 153mm
- Weight
- 18.5kg
- Diameter
- 547mm
- Depth
- 261mm
- Cutout
- 508mm
- Bolt circle
- 527mm
- Bl
- 39 Tm
- Fs
- 32 Hz
- Le
- 2.2 mH
- Re
- 6 Ω
- Sd
- 1680 cm² (260.4 in²)
- Ebp
- 84 Hz
- Mms
- 450 g
- Qes
- 0.38
- Qms
- 6.4
- Qts
- 0.36
- Vas
- 200 dm³ (7.06 ft³)
- Η0
- 1.9 %
- Cone
- RCK21SW1528
- Xmax
- 15 mm
- Xvar
- 16 mm
- Depth
- 261 mm (10.28 in)
- Spider
- Double Silicone
- Cone shape
- Radial
- Net weight
- 18.5 kg (40.79 lb)
- Pole design
- T-Pole
- Sensitivity
- 96 dB
- Flux density
- 1.2 T
- Shipping box
- 570x570x320 mm (22.44x22.44x12.60 in)
- Winding depth
- 32 mm (1.26 in)
- Shipping units
- 1 pcs
- Surround shape
- Triple Roll
- Former material
- Glass Fibre
- Frequency range
- 30 Hz - 1000 Hz
- Magnet material
- Neodymium Inside Slug
- Shipping weight
- 20.8 kg (45.86 lb)
- Nominal diameter
- 530 mm (21 in)
- Overall diameter
- 547 mm (21.54 in)
- Winding material
- Copper
- Minimum impedance
- 7 Ω
- Nominal impedance
- 8 Ω
- Magnetic gap depth
- 12 mm (0.5 in)
- Recommended tuning
- 33 Hz
- Voice coil diameter
- 153 mm (6 in)
- Bolt circle diameter
- 527 mm (20.75 in)
- Recommended enclosure
- 190 dm³ (6.71 ft³)
- Woofer cone treatment
- TWP Waterproof Both Sides
- Baffle cutout diameter
- 508 mm (20 in)
- Nominal power handling
- 2000 W
- Continuous power handling
- 4000 W
- Flange and gasket thickness
- 16 mm (0.63 in)
- Air volume occupied by driver
- 16 dm³ (0.57 ft³)
02
Designs
Cabinets for the 21SW152: a suggested box from B&C and plans builders have published.
All 21SW152 designsHow we find designs03
Compare
Same-size drivers, compared with the 21SW152. Clear differences are green when better and red when worse.
This driver21SW152
Best price
£544.95
Fs
32 Hz
Qts
0.36
Vas
200 L
BL
39 T·m
Xmax
15 mm
Sensitivity
94.4 dB
Power
2000 W
Dayton AudioPSS555-8
£195.83 · 64% less, betterFs28 Hz −14%, better
Qts0.33 −8%
Vas444 L +122%, worse
BL29.7 T·m −24%, worse
Xmax11 mm −27%, worse
Sensitivity96.4 dB +2, better
SB AudienceNERO-21SW1100D
£343.60 · 37% less, betterFs32 Hz –
Qts0.34 −6%
Vas312.6 L +56%, worse
BL30 T·m −23%, worse
Xmax12.2 mm −19%, worse
Sensitivity96.7 dB +2.3, better
Beyma21QLEX1600FE
£425.00 · 22% less, betterFs30 Hz −6%
Qts0.28 −22%, better
Vas309 L +55%, worse
BL36.4 T·m −7%
Xmax13 mm −13%, worse
Sensitivity96.5 dB +2.1, better
Eighteen Sound21LW2600
£431.46 · 21% less, betterFs27 Hz −16%, better
Qts0.33 −8%
Vas333 L +67%, worse
BL32.5 T·m −17%, worse
Xmax14.6 mm –
Sensitivity94.9 dB +0.5
CelestionTSQ2145
£445.00 · 18% less, betterFs30 Hz −6%
Qts0.34 −4%
Vas253.8 L +27%, worse
BL33.8 T·m −13%, worse
Xmax15 mm –
Sensitivity94.8 dB –
Dayton AudioHTS545HE-4
£451.93 · 17% less, betterFs26 Hz −18%, better
Qts0.28 −22%, better
Vas179 L −11%, better
BL38.2 T·m –
Xmax21 mm +40%, better
Sensitivity92.5 dB −1.9
Eighteen Sound21NLW4100
£456.79 · 16% less, betterFs36 Hz +13%, worse
Qts0.46 +28%, worse
Vas210 L +5%
BL29.4 T·m −25%, worse
Xmax15.2 mm –
Sensitivity95 dB +0.6
B&C21SW115
£465.16 · 15% less, betterFs30 Hz −6%
Qts0.37 –
Vas318 L +59%, worse
BL30.1 T·m −23%, worse
Xmax14 mm −7%
Sensitivity95.5 dB +1.1
Beyma21LEX1600ND
£475.00 · 13% less, betterFs30 Hz −6%
Qts0.29 −19%, better
Vas305 L +53%, worse
BL36.6 T·m −6%
Xmax14 mm −7%
Sensitivity96.4 dB +2, better
B&C21DS115
£482.13 · 12% less, betterFs34 Hz +6%
Qts0.27 −25%, better
Vas204 L –
BL39.3 T·m –
Xmax16.5 mm +10%, better
Sensitivity96.6 dB +2.2, better
LavoceSAN214.50
£482.98 · 11% less, betterFs33 Hz +3%
Qts0.28 −22%, better
Vas218.3 L +9%
BL39.6 T·m –
Xmax15.4 mm –
Sensitivity96.4 dB +2, better
Eighteen Sound21NLW9001
£557.45 · 2% moreFs32 Hz –
Qts0.31 −14%, better
Vas244 L +22%, worse
BL37 T·m −5%
Xmax14 mm −7%
Sensitivity95.7 dB +1.3
Eighteen Sound21NTLW5000
£595.00 · 9% more, worseFs31 Hz −3%
Qts0.36 –
Vas270 L +35%, worse
BL32 T·m −18%, worse
Xmax17.5 mm +17%, better
Sensitivity95.3 dB +0.9
Eighteen Sound21NLW9601
£632.37 · 16% more, worseFs37 Hz +16%, worse
Qts0.29 −19%, better
Vas175 L −13%, better
BL43 T·m +10%, better
Xmax14 mm −7%
Sensitivity96.6 dB +2.2, better
EminenceNSW6021-6
£800.00 · 47% more, worseFs29 Hz −9%
Qts0.31 −14%, better
Vas224.6 L +12%, worse
BL33.8 T·m −13%, worse
Xmax21 mm +40%, better
Sensitivity94.5 dB –
No photo
Precision DevicesPD.2160-1N
£811.00 · 49% more, worseFs35 Hz +9%
Qts0.30 −17%, better
Vas177 L −12%, better
BL43 T·m +10%, better
Xmax16 mm +7%
Sensitivity95.9 dB +1.5
EminenceNSW6021-124
£922.71 · 69% more, worseFs31 Hz −4%
Qts0.32 −11%, better
Vas224.6 L +12%, worse
BL30.5 T·m −22%, worse
Xmax21 mm +40%, better
Sensitivity95 dB +0.6
No current price
Fs33 Hz +3%
Qts0.36 –
Vas241 L +21%, worse
BL30 T·m −23%, worse
Xmax14 mm −7%
Sensitivity95.7 dB +1.3
No photo
Precision DevicesPD.2155-1N
No current priceFs33 Hz +3%
Qts0.36 –
Vas241 L +21%, worse
BL30 T·m −23%, worse
Xmax14 mm −7%
Sensitivity95.7 dB +1.3
No current price
Fs35 Hz +9%
Qts0.34 −6%
Vas266 L +33%, worse
BL31.3 T·m −20%, worse
Xmax14 mm −7%
Sensitivity97.1 dB +2.7, better
No photo
Precision DevicesPD.2155-1F
No current priceFs35 Hz +9%
Qts0.34 −6%
Vas266 L +33%, worse
BL31.3 T·m −20%, worse
Xmax14 mm −7%
Sensitivity97.1 dB +2.7, better
BishopSoundBWN21/4
No current priceFs29 Hz −9%
Qts0.42 +16%, worse
Vas244.2 L +22%, worse
BL32.6 T·m −16%, worse
Xmax15 mm –
Sensitivity93.2 dB −1.2
BishopSoundBWN21/8
No current priceFs29 Hz −9%
Qts0.42 +16%, worse
Vas244.2 L +22%, worse
BL32.6 T·m −16%, worse
Xmax15 mm –
Sensitivity93.2 dB −1.2
RCFLF21X451
No current priceFs28 Hz −13%, better
Qts0.37 –
Vas385 L +93%, worse
BL30.5 T·m −22%, worse
Xmax14 mm −7%
Sensitivity95.4 dB +1
Eighteen Sound21NLW5300
No current priceFs31 Hz −3%
Qts0.32 −11%, better
Vas325 L +63%, worse
BL31 T·m −21%, worse
Xmax15.3 mm –
Sensitivity96.6 dB +2.2, better
Eighteen Sound21NLW9601C
No current priceFs38 Hz +19%, worse
Qts0.29 −19%, better
Vas140 L −30%, better
BL33.2 T·m −15%, worse
Xmax14 mm −7%
Sensitivity96 dB +1.6
CelestionNTR21-5010JD
No current priceFs32 Hz –
Qts0.32 −11%, better
Vas276.7 L +38%, worse
BL33.9 T·m −13%, worse
Xmax9 mm −40%, worse
Sensitivity96.4 dB +2, better
Sica21 S 4 PL
No current priceFs35 Hz +8%
Qts0.30 −17%, better
Vas255 L +28%, worse
BL36.1 T·m −7%
Xmax5.2 mm −65%, worse
Sensitivity97.4 dB +3, better
P.AudioSD21-125XB
No current priceFs35 Hz +9%
Qts0.38 +6%
Vas345.6 L +73%, worse
BL30.4 T·m −22%, worse
Xmax11.3 mm −25%, worse
Sensitivity97.7 dB +3.3, better
Dayton AudioPSS545HE-4
No current priceFs29 Hz −10%
Qts0.27 −25%, better
Vas212.2 L +6%
BL35.5 T·m −9%
Xmax21 mm +40%, better
Sensitivity94.6 dB –
Tune the match
Choose the published values that matter to your design. Size stays matched to this driver.
Qts
Qes
VasL
Xmaxmm
BLTm
- Thomann4.5 out of 54 ratings · Checked 7 Oct 2026Read reviews on Thomann
- Parts Express5.0 out of 51 rating · Checked 7 Oct 2026Read reviews on Parts Express
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 | £585.00, the lowest price | 4 in stock | Visit shop at Blue Aran | |
Thomann 3–4 weeks | £579.00 | In stock | Visit shop at Thomann | |
Blue Aran | £585.00 | Due 2 Dec 2026 | Visit shop at Blue Aran | |
JP Leisure Not currently listed · Last seen 7 Aug 2026 | £585.31 | 0.1% above the lowest price | In stock | Visit shop at JP Leisure |
JP Leisure | £585.31 | 0.1% above the lowest price | In stock | Visit shop at JP Leisure |
JP Leisure Not currently listed · Last seen 7 Aug 2026 | £586.19 | 0.2% above the lowest price | In stock | Visit shop at JP Leisure |
JP Leisure | £586.19 | 0.2% above the lowest price | In stock | Visit shop at JP Leisure |
Audio Video Parts Import VAT and duty may apply | £508.23 | Special order | Visit shop at Audio Video Parts | |
Parts Express Import VAT and duty may apply | £740.33 | 27% above the lowest price | 10 in stock | Visit shop at Parts Express |
Best price over time
Tracked since 1 Apr
Recent changes
- 2 SepThomann£588.00 → £589.00Up 0.2% from £588.00
- 25 AugThomann£585.00 → £588.00Up 0.5% from £585.00
- 17 AugThomann£589.00 → £585.00Down 0.7% from £589.00