B&C design · archived
S21AN
21" 3400W Subwoofer Enclosure - 21" Neo Subwoofer
- Drivers
- 21SW115, 8 Ω
- Power
- 3,400 W
21-inch LF driver · 21SW series · 116 mm voice coil · 1,700 W
B&C 21SW115 8Ω
30–1000 Hz
- Fs
- 30Hz
- Xmax
- 14mm
- SPL
- 96dB
- Pe
- 1700W
- BL
- 30.1T·m
- Vd
- 2352cm³
- Qts
- 0.37
- Vas
- 318L
Published graphs
B&C 21SW115 is a 21-inch 8 ohm LF driver rated at 1700 W RMS. The validated T/S data includes Fs 30 Hz, Qts 0.37, Vas 318 L, Xmax 14 mm, sensitivity 95.5 dB, plus 2352 cm³ Vd and 77 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 £464.13.
The published T/S values agree with each other
Thiele/Small
- Fs
- 30Hz
- Qts
- 0.37
- Qes
- 0.39
- Qms
- 10.9
- Vas
- 318L
- Re
- 5.4Ω
- Le
- 2.10mH
Motor and cone
- BL
- 30.1T·m
- Sd
- 1680cm²
- Mms
- 342g
- Xmax
- 14mm
- Vd †
- 2352cm³
- Voice coil
- 116mm
- Flux density
- 1.15T
Power and response
- Sensitivity †
- 95.5dB
- Manufacturer sensitivity
- 97dB
- Power
- 1700W
- Nominal power
- 1700W
- Impedance
- 8Ω
- Min. impedance
- 6.2Ω
- Range
- 30–1000Hz
- EBP †
- 77 · Sealed or vented
Size and mounting
- Diameter
- 547mm
- Cutout
- 503mm
- Bolt circle
- 527mm
- Depth
- 249mm
- Weight
- 14kg
Sensitivity shows 95.5 dB, calculated from the T/S values. B&C publishes 97.0 dB, 1.5 dB apart.
† Calculated by bits from the published values
What this validation status means
Everything else B&C lists
LF
- BL
- 30.1T·m
- Fs
- 30Hz
- Le
- 2.10mH
- Re
- 5.4Ω
- Sd
- 1680cm²
- Mms
- 342g
- Qes
- 0.39
- Qms
- 10.9
- Qts
- 0.37
- SPL
- 95.5dB
- Vas
- 318L
- Xmax
- 14mm
- Power
- 1700W
- Impedance
- 8Ω
- Flux density
- 1.15T
- Sensitivity
- 97dB
- Low limit
- 30Hz
- Nominal power
- 1700W
- Calculated sensitivity †
- 95.5dB
- High limit
- 1000Hz
- Manufacturer sensitivity
- 97dB
- Min. impedance
- 6.2Ω
- Voice coil
- 116mm
- Weight
- 14kg
- Diameter
- 547mm
- Depth
- 249mm
- Cutout
- 503mm
- Bolt circle
- 527mm
- Bl
- 30.1 Tm
- Fs
- 30 Hz
- Le
- 2.1 mH
- Re
- 5.4 Ω
- Sd
- 1680 cm² (260.4 in²)
- Ebp
- 77 Hz
- Mms
- 342 g
- Qes
- 0.39
- Qms
- 10.9
- Qts
- 0.37
- Vas
- 318 dm³ (11.23 ft³)
- Η0
- 2.2 %
- Cone
- RCK21SW1158
- Xmax
- 14 mm
- Xvar
- 16 mm
- Depth
- 249 mm (9.8 in)
- Spider
- Double Silicone
- Cone shape
- Radial
- Net weight
- 14 kg (30.8 lb)
- Pole design
- T-Pole
- Sensitivity
- 97 dB
- Flux density
- 1.15 T
- Shipping box
- 570x570x320 mm (22.44x22.44x12.60 in)
- Winding depth
- 34 mm (1.34 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
- 16.3 kg (35.94 lb)
- Nominal diameter
- 530 mm (21 in)
- Overall diameter
- 547 mm (21.5 in)
- Winding material
- Copper
- Minimum impedance
- 6.2 Ω
- Nominal impedance
- 8 Ω
- Magnetic gap depth
- 14 mm (0.55 in)
- Recommended tuning
- 32 Hz
- Voice coil diameter
- 116 mm (4.5 in)
- Bolt circle diameter
- 527 mm (20.7 in)
- Recommended enclosure
- 250 dm³ (8.83 ft³)
- Woofer cone treatment
- TWP Waterproof Both Sides
- Baffle cutout diameter
- 503 mm (19.8 in)
- Nominal power handling
- 1700 W
- Continuous power handling
- 3400 W
- Flange and gasket thickness
- 14 mm (0.53 in)
- Air volume occupied by driver
- 15 dm³ (0.53 ft³)
02
Designs
Cabinets for the 21SW115: a design and a suggested box from B&C.
All 21SW115 designsHow we find designsB&C’s design
From the maker, with plans to download
B&C’s suggested box
From B&C’s 21SW115 page
- Net volume
- 250L
- Tuning
- 32Hz
B&C gives the volume and tuning; the port is sized for the driver when you open it.
Modelling the box in 00 Simulator…
03
Compare
Same-size drivers, compared with the 21SW115. Clear differences are green when better and red when worse.
This driver21SW115
Best price
£464.13
Fs
30 Hz
Qts
0.37
Vas
318 L
BL
30.1 T·m
Xmax
14 mm
Sensitivity
95.5 dB
Power
1700 W
Dayton AudioPSS555-8
£196.85 · 58% less, betterFs28 Hz −8%
Qts0.33 −11%, better
Vas444 L +40%, worse
BL29.7 T·m –
Xmax11 mm −21%, worse
Sensitivity96.4 dB +0.9
SB AudienceNERO-21SW1100D
£343.60 · 26% less, betterFs32 Hz +7%
Qts0.34 −8%
Vas312.6 L –
BL30 T·m –
Xmax12.2 mm −13%, worse
Sensitivity96.7 dB +1.2
Beyma21QLEX1600FE
£425.00 · 8% less, betterFs30 Hz –
Qts0.28 −24%, better
Vas309 L –
BL36.4 T·m +21%, better
Xmax13 mm −7%
Sensitivity96.5 dB +1
Eighteen Sound21LW2600
£430.51 · 7% less, betterFs27 Hz −10%, better
Qts0.33 −11%, better
Vas333 L +5%
BL32.5 T·m +8%
Xmax14.6 mm +4%
Sensitivity94.9 dB −0.6
CelestionTSQ2145
£445.00 · 4% lessFs30 Hz –
Qts0.34 −7%
Vas253.8 L −20%, better
BL33.8 T·m +12%, better
Xmax15 mm +7%
Sensitivity94.8 dB −0.7
Eighteen Sound21NLW4100
£456.79 · 2% lessFs36 Hz +20%, worse
Qts0.46 +24%, worse
Vas210 L −34%, better
BL29.4 T·m –
Xmax15.2 mm +9%
Sensitivity95 dB −0.5
Beyma21LEX1600ND
£475.00 · 2% moreFs30 Hz –
Qts0.29 −22%, better
Vas305 L −4%
BL36.6 T·m +22%, better
Xmax14 mm –
Sensitivity96.4 dB +0.9
RCFLF21N451
£475.00 · 2% moreFs30 Hz –
Qts0.26 −30%, better
Vas375 L +18%, worse
BL34.5 T·m +15%, better
Xmax13 mm −7%
Sensitivity97.8 dB +2.3, better
LavoceSAN214.50
£481.92 · 4% moreFs33 Hz +10%, worse
Qts0.28 −24%, better
Vas218.3 L −31%, better
BL39.6 T·m +32%, better
Xmax15.4 mm +10%, better
Sensitivity96.4 dB +0.9
B&C21SW152
£543.75 · 17% more, worseFs32 Hz +7%
Qts0.36 –
Vas200 L −37%, better
BL39 T·m +30%, better
Xmax15 mm +7%
Sensitivity94.4 dB −1.1
Eighteen Sound21LW1400
£550.00 · 19% more, worseFs28 Hz −7%
Qts0.24 −35%, better
Vas385 L +21%, worse
BL33.5 T·m +11%, better
Xmax9.5 mm −32%, worse
Sensitivity97.5 dB +2, better
Eighteen Sound21NLW9001
£556.22 · 20% more, worseFs32 Hz +7%
Qts0.31 −16%, better
Vas244 L −23%, better
BL37 T·m +23%, better
Xmax14 mm –
Sensitivity95.7 dB –
Eighteen Sound21NTLW5000
£595.00 · 28% more, worseFs31 Hz +3%
Qts0.36 –
Vas270 L −15%, better
BL32 T·m +6%
Xmax17.5 mm +25%, better
Sensitivity95.3 dB –
Eighteen Sound21NLW9601
£630.98 · 36% more, worseFs37 Hz +23%, worse
Qts0.29 −22%, better
Vas175 L −45%, better
BL43 T·m +43%, better
Xmax14 mm –
Sensitivity96.6 dB +1.1
EminenceNSW6021-6
£800.00 · 72% more, worseFs29 Hz −3%
Qts0.31 −16%, better
Vas224.6 L −29%, better
BL33.8 T·m +12%, better
Xmax21 mm +50%, better
Sensitivity94.5 dB −1
No photo
Precision DevicesPD.2160-1N
£811.00 · 75% more, worseFs35 Hz +17%, worse
Qts0.30 −19%, better
Vas177 L −44%, better
BL43 T·m +43%, better
Xmax16 mm +14%, better
Sensitivity95.9 dB –
EminenceNSW6021-124
£927.53 · 100% more, worseFs31 Hz –
Qts0.32 −14%, better
Vas224.6 L −29%, better
BL30.5 T·m –
Xmax21 mm +50%, better
Sensitivity95 dB −0.5
RCFLF21X451
No current priceFs28 Hz −7%
Qts0.37 –
Vas385 L +21%, worse
BL30.5 T·m –
Xmax14 mm –
Sensitivity95.4 dB –
No current price
Fs33 Hz +10%, worse
Qts0.36 –
Vas241 L −24%, better
BL30 T·m –
Xmax14 mm –
Sensitivity95.7 dB –
No photo
Precision DevicesPD.2155-1N
No current priceFs33 Hz +10%, worse
Qts0.36 –
Vas241 L −24%, better
BL30 T·m –
Xmax14 mm –
Sensitivity95.7 dB –
No current price
Fs35 Hz +17%, worse
Qts0.34 −8%
Vas266 L −16%, better
BL31.3 T·m +4%
Xmax14 mm –
Sensitivity97.1 dB +1.6
No photo
Precision DevicesPD.2155-1F
No current priceFs35 Hz +17%, worse
Qts0.34 −8%
Vas266 L −16%, better
BL31.3 T·m +4%
Xmax14 mm –
Sensitivity97.1 dB +1.6
P.AudioSD21-125XB
No current priceFs35 Hz +17%, worse
Qts0.38 –
Vas345.6 L +9%
BL30.4 T·m –
Xmax11.3 mm −20%, worse
Sensitivity97.7 dB +2.2, better
Eighteen Sound21NLW5300
No current priceFs31 Hz +3%
Qts0.32 −14%, better
Vas325 L –
BL31 T·m –
Xmax15.3 mm +9%
Sensitivity96.6 dB +1.1
BishopSoundBWN21/4
No current priceFs29 Hz −3%
Qts0.42 +13%, worse
Vas244.2 L −23%, better
BL32.6 T·m +8%
Xmax15 mm +7%
Sensitivity93.2 dB −2.3, worse
BishopSoundBWN21/8
No current priceFs29 Hz −3%
Qts0.42 +13%, worse
Vas244.2 L −23%, better
BL32.6 T·m +8%
Xmax15 mm +7%
Sensitivity93.2 dB −2.3, worse
CelestionNTR21-5010JD
No current priceFs32 Hz +7%
Qts0.32 −14%, better
Vas276.7 L −13%, better
BL33.9 T·m +12%, better
Xmax9 mm −36%, worse
Sensitivity96.4 dB +0.9
Eighteen Sound21NLW9601C
No current priceFs38 Hz +27%, worse
Qts0.29 −22%, better
Vas140 L −56%, better
BL33.2 T·m +10%, better
Xmax14 mm –
Sensitivity96 dB +0.5
Sica21 S 4 PL
No current priceFs35 Hz +15%, worse
Qts0.30 −19%, better
Vas255 L −20%, better
BL36.1 T·m +20%, better
Xmax5.2 mm −63%, worse
Sensitivity97.4 dB +1.9
Eighteen Sound21ID
No current priceFs38 Hz +27%, worse
Qts0.23 −38%, better
Vas143 L −55%, better
BL25.2 T·m −16%, worse
Xmax14 mm –
Sensitivity97.2 dB +1.7
Tune the match
Choose the published values that matter to your design. Size stays matched to this driver.
Qts
Qes
VasL
Xmaxmm
BLTm
- Thomann5.0 out of 52 ratings · 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 |
|---|---|---|---|---|
Thomann | £479.00, the lowest price | In stock | Visit shop at Thomann | |
Blue Aran | £481.99 | 0.6% above the lowest price | 2 in stock | Visit shop at Blue Aran |
JP Leisure Not currently listed · Last seen 7 Aug 2026 | £491.16 | 2.5% above the lowest price | In stock | Visit shop at JP Leisure |
JP Leisure | £491.16 | 2.5% above the lowest price | In stock | Visit shop at JP Leisure |
Audio Video Parts Import VAT and duty may apply | £418.98 | Special order | Visit shop at Audio Video Parts |
Best price over time
Tracked since 1 Apr
Recent changes
- 4 OctThomann£485.00 → £479.00Down 1.2% from £485.00
- 26 SepThomann£484.00 → £485.00Up 0.2% from £484.00
- 18 SepThomann£485.00 → £484.00Down 0.2% from £485.00