SB Acoustics SB12NRXF25-8 is a 4-inch 8 ohm LF driver rated at 30 W RMS. The validated T/S data includes Fs 63 Hz, Qts 0.42, Vas 4.2 L, Xmax 5 mm, sensitivity 85.6 dB, plus 25 cm³ Vd and 137 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 £45.28.

The published T/S values agree with each other

Thiele/Small

Fs: 63Hz
Qts: 0.42
Qes: 0.46
Qms: 5.4
Vas: 4.2L
Re: 6.4Ω
Le: 0.34mH

Motor and cone

BL: 5.5T·m
Sd: 50cm²
Mms: 6g
Xmax: 5mm
Vd †: 25cm³
Voice coil: 25mm
Flux density: 1.07T

Power and response

Sensitivity †: 85.6dB
Manufacturer sensitivity: 85dB
Power: 30W
Impedance: 8Ω
EBP †: 137 · Leans vented

Size and mounting

Weight: 0.9kg

Other published values

Cms: 1.18mm/N

† Calculated by bits from the published values

What this validation status means

Everything else SB Acoustics lists

LF · Primary · 4″

BL: 5.5T·m
Fs: 63Hz
Le: 0.34mH
Re: 6.4Ω
Sd: 50cm²
Cms: 1.18mm/N
Mms: 6g
Qes: 0.46
Qms: 5.4
Qts: 0.42
SPL: 85.6dB
Vas: 4.2L
Xmax: 5mm
Power: 30W
Impedance: 8Ω
Flux density: 1.07T
Sensitivity: 85dB
Calculated sensitivity †: 85.6dB
Manufacturer sensitivity: 85dB
Voice coil: 25mm
Weight: 0.9kg

Compare

Same-size drivers, compared with the SB12NRXF25-8. Clear differences are green when better and red when worse.

This driverSB12NRXF25-8

Best price

£45.28

63 Hz

Qts

0.42

Vas

4.2 L

5.5 T·m

Xmax

5 mm

Sensitivity

85.6 dB

Power

30 W

PeerlessSDS-P830855

£14.18 · 69% less

Fs66 Hz +5%

Qts0.48 +14%

Vas3.3 L −22%

BL5.2 T·m −5%

Xmax5.0 mm –

Sensitivity84.4 dB −1.2

Dayton AudioDA115-8

£18.90 · 58% less

Fs60 Hz −5%

Qts0.41 –

Vas4.4 L +5%

BL5.7 T·m +4%

Xmax2.5 mm −50%

Sensitivity84.9 dB −0.7

Dayton AudioDS115-8

£20.41 · 55% less

Fs55 Hz −12%

Qts0.38 −10%

Vas4.3 L +3%

BL5.9 T·m +7%

Xmax4.1 mm −18%

Sensitivity84 dB −1.6

Dayton AudioND91-4

£21.16 · 53% less

Fs74 Hz +17%

Qts0.41 –

Vas1.4 L −67%

BL4.6 T·m −17%

Xmax4.6 mm −8%

Sensitivity83 dB −2.6

FaitalPRO5FE100

£21.52 · 52% less

Fs65 Hz +3%

Qts0.45 +7%

Vas5.7 L +36%

BL6.9 T·m +25%

Xmax5.3 mm +5%

Sensitivity87.2 dB +1.6

FaitalPRO5FE105

£21.90 · 52% less

Fs65 Hz +3%

Qts0.45 +7%

Vas5.7 L +36%

BL6.9 T·m +25%

Xmax5.3 mm +5%

Sensitivity87.2 dB +1.6

SB AcousticsSB12PFC25-4

£22.25 · 51% less

Fs58 Hz −8%

Qts0.43 –

Vas5.2 L +24%

BL3.5 T·m −36%

Xmax5 mm –

Sensitivity85.2 dB –

Dayton AudioSIG120-4

£24.95 · 45% less

Fs75 Hz +18%

Qts0.43 –

Vas3.1 L −26%

BL5 T·m −9%

Xmax4 mm −20%

Sensitivity86.4 dB +0.8

Dayton AudioDS135-8

£30.24 · 33% less

Fs53 Hz −17%

Qts0.39 −7%

Vas7.3 L +73%

BL6.2 T·m +13%

Xmax4.8 mm −3%

Sensitivity85.4 dB –

Dayton AudioDSA135-8

£30.24 · 33% less

Fs52 Hz −18%

Qts0.38 −10%

Vas7.9 L +89%

BL6.2 T·m +13%

Xmax4.9 mm –

Sensitivity85.7 dB –

Dayton AudioDSA115-8

£30.44 · 33% less

Fs63 Hz –

Qts0.42 –

Vas4.0 L −6%

BL5.4 T·m –

Xmax4.1 mm −18%

Sensitivity84.8 dB −0.8

MonacorSP-100/8

£31.53 · 30% less

Fs61 Hz −3%

Qts0.37 −12%

Vas4.7 L +12%

BL5.5 T·m –

Xmax2.5 mm −50%

Sensitivity85.9 dB –

PeerlessSLS-P830945

£31.61 · 30% less

Fs56 Hz −11%

Qts0.40 −5%

Vas4.7 L +11%

BL6.2 T·m +13%

Xmax7 mm +40%

Sensitivity84.7 dB −0.9

Dayton AudioRS125P-8

£37.81 · 17% less

Fs70 Hz +11%

Qts0.44 +5%

Vas4.0 L −5%

BL5.1 T·m −8%

Xmax4 mm −20%

Sensitivity86.1 dB +0.5

WavecorWF118WA08

£47.66 · 5% more

Fs58 Hz −8%

Qts0.42 –

Vas4.9 L +17%

BL5.8 T·m +5%

Xmax4 mm −20%

Sensitivity85.3 dB –

WavecorWF118WA02

£52.95 · 17% more

Fs65 Hz +3%

Qts0.44 +5%

Vas4.3 L –

BL5.8 T·m +5%

Xmax3 mm −40%

Sensitivity86.1 dB +0.5

Tang BandW4-2417

£65.18 · 44% more

Fs65 Hz +3%

Qts0.44 +5%

Vas4.6 L +9%

BL5.4 T·m –

Xmax2.5 mm −50%

Sensitivity85.8 dB –

Tang BandW4-2414

£67.72 · 50% more

Fs65 Hz +3%

Qts0.40 −5%

Vas3.9 L −8%

BL5.5 T·m –

Xmax2.5 mm −50%

Sensitivity85.6 dB –

Tang BandW4-1720

£83.20 · 84% more

Fs60 Hz −5%

Qts0.42 –

Vas5.9 L +41%

BL3.8 T·m −31%

Xmax5 mm –

Sensitivity86 dB –

WavecorWF120BD08

£122.14 · 170% more

Fs63 Hz –

Qts0.45 +7%

Vas4.3 L –

BL5.5 T·m –

Xmax4 mm −20%

Sensitivity85.4 dB –

WavecorWF120BD03

£122.14 · 170% more

Fs70 Hz +11%

Qts0.42 –

Vas3.3 L −23%

BL4.5 T·m −18%

Xmax4 mm −20%

Sensitivity85.9 dB –

FaitalPRO5HX140

£134.77 · 198% more

Fs100 Hz +59%

Qts0.41 –

Vas3.4 L −19%

BL8 T·m +45%

Xmax5.1 mm –

Sensitivity90.8 dB +5.2

WavecorWF120BD14

£134.77 · 198% more

Fs58 Hz −9%

Qts0.46 +10%

Vas3.9 L −7%

BL5.3 T·m −4%

Xmax3 mm −40%

Sensitivity83.8 dB −1.8

VisatonTI 100

£156.83 · 246% more

Fs62 Hz –

Qts0.41 –

Vas5.7 L +35%

BL5.0 T·m −9%

Xmax4 mm −20%

Sensitivity86.9 dB +1.3

SEASE0044-08S W12CY003

£203.38 · 349% more

Fs60 Hz −5%

Qts0.36 −14%

Vas4 L −5%

BL5.5 T·m –

Xmax3 mm −40%

Sensitivity85 dB −0.6

CIARECW131

No current price

Fs65 Hz +3%

Qts0.39 −7%

Vas5.3 L +26%

BL5.7 T·m +3%

Xmax4 mm −20%

Sensitivity87.1 dB +1.5

BMS5S117

No current price

Fs95 Hz +51%

Qts0.42 –

Vas3.3 L −23%

BL11.3 T·m +105%

Xmax5 mm –

Sensitivity89.6 dB +4

VisatonTI 100 - 8 OHM

No current price

Fs62 Hz –

Qts0.41 –

Vas5.7 L +35%

BL5.0 T·m −9%

Xmax4 mm −20%

Sensitivity86.9 dB +1.3

CIAREHWL130

No current price

Fs53 Hz −16%

Qts0.43 –

Vas11.2 L +167%

BL5.8 T·m +5%

Xmax4 mm −20%

Sensitivity87.6 dB +2

BMS5C150

No current price

Fs99 Hz +58%

Qts0.43 –

Vas2.4 L −43%

BL11.4 T·m +107%

Xmax5 mm –

Sensitivity88.9 dB +3.3

Search similar

Tune the match

Choose the published values that matter to your design. Size stays matched to this driver.

Qts

Qes

Vas

Xmax

Reviews

How reviews work

5.0 out of 5

from 1 rating at 1 shop

SoundImports5.0 out of 51 rating · Checked 12 Oct 2026
Read reviews on SoundImports

Each shop collects its own ratings. Bits shows them as published and doesn't verify them.

Where to buy

Prices for delivery to the UK, including VAT. How prices work

Watch price

Shop	Price	Against the lowest	Stock	Link
Lean Audio Checked 12 Oct 2026 · 8 Ω · Source: inc VAT · 20%	£45.28, the lowest price		2 in stock	Visit shop at Lean Audio
Lean Business Checked 11 Oct 2026 · 8 Ω · Source: inc VAT · 20%	£45.28		Stock not listed	Visit shop at Lean Business
Willys-Hifi Checked 12 Oct 2026 · 8 Ω · Source: ex VAT · 20%	£59.22	31% above the lowest price	Stock not listed	Visit shop at Willys-Hifi
RumoH Checked 12 Oct 2026 · Ships from Netherlands · 8 Ω · Source: inc VAT Import VAT and duty may apply	£52.50	16% above the lowest price	Stock not listed	Visit shop at RumoH
SoundImports Checked 12 Oct 2026 · Ships from Netherlands · 8 Ω · Source: inc VAT Import VAT and duty may apply	£52.93	17% above the lowest price	5 in stock	Visit shop at SoundImports

Best price over time

Tracked since 1 Apr

Recent changes

1 OctWillys-Hifi£60.95 → £59.22Down 2.8% from £60.95
11 AugWillys-Hifi£52.95 → £60.95Up 15% from £52.95
4 AugWillys-Hifi£51.95 → £52.95Up 1.9% from £51.95

bits00 AUDIO

4-inch LF driver · SB12 series · 25 mm voice coil · 30 W

SB Acoustics SB12NRXF25-8 8Ω

8 Ω

1 rating at 1 shop

£45.28

Steady

9.3% below the average of 3 shops

Lean Audio · 2 in stock · All 6 offers

Open in 00 Simulator

Fs: 63Hz
Xmax: 5mm
SPL: 86dB
Pe: 30W
BL: 5.5T·m
Vd: 25cm³
Qts: 0.42
Vas: 4L

See all 21 specs

Published graphs

Specifications

Published by SB Acoustics

Manufacturer page

Datasheet PDF

The published T/S values agree with each other

Thiele/Small

Fs: 63Hz
Qts: 0.42
Qes: 0.46
Qms: 5.4
Vas: 4.2L
Re: 6.4Ω
Le: 0.34mH

Motor and cone

BL: 5.5T·m
Sd: 50cm²
Mms: 6g
Xmax: 5mm
Vd †: 25cm³
Voice coil: 25mm
Flux density: 1.07T

Power and response

Sensitivity †: 85.6dB
Manufacturer sensitivity: 85dB
Power: 30W
Impedance: 8Ω
EBP †: 137 · Leans vented

Size and mounting

Weight: 0.9kg

Other published values

Cms: 1.18mm/N

† Calculated by bits from the published values

What this validation status means

Everything else SB Acoustics lists

LF · Primary · 4″

BL: 5.5T·m
Fs: 63Hz
Le: 0.34mH
Re: 6.4Ω
Sd: 50cm²
Cms: 1.18mm/N
Mms: 6g
Qes: 0.46
Qms: 5.4
Qts: 0.42
SPL: 85.6dB
Vas: 4.2L
Xmax: 5mm
Power: 30W
Impedance: 8Ω
Flux density: 1.07T
Sensitivity: 85dB
Calculated sensitivity †: 85.6dB
Manufacturer sensitivity: 85dB
Voice coil: 25mm
Weight: 0.9kg

Compare

Same-size drivers, compared with the SB12NRXF25-8. Clear differences are green when better and red when worse.

This driverSB12NRXF25-8

Best price

£45.28

63 Hz

Qts

0.42

Vas

4.2 L

5.5 T·m

Xmax

5 mm

Sensitivity

85.6 dB

Power

30 W

PeerlessSDS-P830855

£14.18 · 69% less

Fs66 Hz +5%

Qts0.48 +14%

Vas3.3 L −22%

BL5.2 T·m −5%

Xmax5.0 mm –

Sensitivity84.4 dB −1.2

Dayton AudioDA115-8

£18.90 · 58% less

Fs60 Hz −5%

Qts0.41 –

Vas4.4 L +5%

BL5.7 T·m +4%

Xmax2.5 mm −50%

Sensitivity84.9 dB −0.7

Dayton AudioDS115-8

£20.41 · 55% less

Fs55 Hz −12%

Qts0.38 −10%

Vas4.3 L +3%

BL5.9 T·m +7%

Xmax4.1 mm −18%

Sensitivity84 dB −1.6

Dayton AudioND91-4

£21.16 · 53% less

Fs74 Hz +17%

Qts0.41 –

Vas1.4 L −67%

BL4.6 T·m −17%

Xmax4.6 mm −8%

Sensitivity83 dB −2.6

FaitalPRO5FE100

£21.52 · 52% less

Fs65 Hz +3%

Qts0.45 +7%

Vas5.7 L +36%

BL6.9 T·m +25%

Xmax5.3 mm +5%

Sensitivity87.2 dB +1.6

FaitalPRO5FE105

£21.90 · 52% less

Fs65 Hz +3%

Qts0.45 +7%

Vas5.7 L +36%

BL6.9 T·m +25%

Xmax5.3 mm +5%

Sensitivity87.2 dB +1.6

SB AcousticsSB12PFC25-4

£22.25 · 51% less

Fs58 Hz −8%

Qts0.43 –

Vas5.2 L +24%

BL3.5 T·m −36%

Xmax5 mm –

Sensitivity85.2 dB –

Dayton AudioSIG120-4

£24.95 · 45% less

Fs75 Hz +18%

Qts0.43 –

Vas3.1 L −26%

BL5 T·m −9%

Xmax4 mm −20%

Sensitivity86.4 dB +0.8

Dayton AudioDS135-8

£30.24 · 33% less

Fs53 Hz −17%

Qts0.39 −7%

Vas7.3 L +73%

BL6.2 T·m +13%

Xmax4.8 mm −3%

Sensitivity85.4 dB –

Dayton AudioDSA135-8

£30.24 · 33% less

Fs52 Hz −18%

Qts0.38 −10%

Vas7.9 L +89%

BL6.2 T·m +13%

Xmax4.9 mm –

Sensitivity85.7 dB –

Dayton AudioDSA115-8

£30.44 · 33% less

Fs63 Hz –

Qts0.42 –

Vas4.0 L −6%

BL5.4 T·m –

Xmax4.1 mm −18%

Sensitivity84.8 dB −0.8

MonacorSP-100/8

£31.53 · 30% less

Fs61 Hz −3%

Qts0.37 −12%

Vas4.7 L +12%

BL5.5 T·m –

Xmax2.5 mm −50%

Sensitivity85.9 dB –

PeerlessSLS-P830945

£31.61 · 30% less

Fs56 Hz −11%

Qts0.40 −5%

Vas4.7 L +11%

BL6.2 T·m +13%

Xmax7 mm +40%

Sensitivity84.7 dB −0.9

Dayton AudioRS125P-8

£37.81 · 17% less

Fs70 Hz +11%

Qts0.44 +5%

Vas4.0 L −5%

BL5.1 T·m −8%

Xmax4 mm −20%

Sensitivity86.1 dB +0.5

WavecorWF118WA08

£47.66 · 5% more

Fs58 Hz −8%

Qts0.42 –

Vas4.9 L +17%

BL5.8 T·m +5%

Xmax4 mm −20%

Sensitivity85.3 dB –

WavecorWF118WA02

£52.95 · 17% more

Fs65 Hz +3%

Qts0.44 +5%

Vas4.3 L –

BL5.8 T·m +5%

Xmax3 mm −40%

Sensitivity86.1 dB +0.5

Tang BandW4-2417

£65.18 · 44% more

Fs65 Hz +3%

Qts0.44 +5%

Vas4.6 L +9%

BL5.4 T·m –

Xmax2.5 mm −50%

Sensitivity85.8 dB –

Tang BandW4-2414

£67.72 · 50% more

Fs65 Hz +3%

Qts0.40 −5%

Vas3.9 L −8%

BL5.5 T·m –

Xmax2.5 mm −50%

Sensitivity85.6 dB –

Tang BandW4-1720

£83.20 · 84% more

Fs60 Hz −5%

Qts0.42 –

Vas5.9 L +41%

BL3.8 T·m −31%

Xmax5 mm –

Sensitivity86 dB –

WavecorWF120BD08

£122.14 · 170% more

Fs63 Hz –

Qts0.45 +7%

Vas4.3 L –

BL5.5 T·m –

Xmax4 mm −20%

Sensitivity85.4 dB –

WavecorWF120BD03

£122.14 · 170% more

Fs70 Hz +11%

Qts0.42 –

Vas3.3 L −23%

BL4.5 T·m −18%

Xmax4 mm −20%

Sensitivity85.9 dB –

FaitalPRO5HX140

£134.77 · 198% more

Fs100 Hz +59%

Qts0.41 –

Vas3.4 L −19%

BL8 T·m +45%

Xmax5.1 mm –

Sensitivity90.8 dB +5.2

WavecorWF120BD14

£134.77 · 198% more

Fs58 Hz −9%

Qts0.46 +10%

Vas3.9 L −7%

BL5.3 T·m −4%

Xmax3 mm −40%

Sensitivity83.8 dB −1.8

VisatonTI 100

£156.83 · 246% more

Fs62 Hz –

Qts0.41 –

Vas5.7 L +35%

BL5.0 T·m −9%

Xmax4 mm −20%

Sensitivity86.9 dB +1.3

SEASE0044-08S W12CY003

£203.38 · 349% more

Fs60 Hz −5%

Qts0.36 −14%

Vas4 L −5%

BL5.5 T·m –

Xmax3 mm −40%

Sensitivity85 dB −0.6

CIARECW131

No current price

Fs65 Hz +3%

Qts0.39 −7%

Vas5.3 L +26%

BL5.7 T·m +3%

Xmax4 mm −20%

Sensitivity87.1 dB +1.5

BMS5S117

No current price

Fs95 Hz +51%

Qts0.42 –

Vas3.3 L −23%

BL11.3 T·m +105%

Xmax5 mm –

Sensitivity89.6 dB +4

VisatonTI 100 - 8 OHM

No current price

Fs62 Hz –

Qts0.41 –

Vas5.7 L +35%

BL5.0 T·m −9%

Xmax4 mm −20%

Sensitivity86.9 dB +1.3

CIAREHWL130

No current price

Fs53 Hz −16%

Qts0.43 –

Vas11.2 L +167%

BL5.8 T·m +5%

Xmax4 mm −20%

Sensitivity87.6 dB +2

BMS5C150

No current price

Fs99 Hz +58%

Qts0.43 –

Vas2.4 L −43%

BL11.4 T·m +107%

Xmax5 mm –

Sensitivity88.9 dB +3.3

Search similar

Tune the match

Choose the published values that matter to your design. Size stays matched to this driver.

Qts

Qes

Vas

Xmax

Reviews

How reviews work

5.0 out of 5

from 1 rating at 1 shop

SoundImports5.0 out of 51 rating · Checked 12 Oct 2026
Read reviews on SoundImports

Each shop collects its own ratings. Bits shows them as published and doesn't verify them.

Where to buy

Prices for delivery to the UK, including VAT. How prices work

Watch price

Shop	Price	Against the lowest	Stock	Link
Lean Audio Checked 12 Oct 2026 · 8 Ω · Source: inc VAT · 20%	£45.28, the lowest price		2 in stock	Visit shop at Lean Audio
Lean Business Checked 11 Oct 2026 · 8 Ω · Source: inc VAT · 20%	£45.28		Stock not listed	Visit shop at Lean Business
Willys-Hifi Checked 12 Oct 2026 · 8 Ω · Source: ex VAT · 20%	£59.22	31% above the lowest price	Stock not listed	Visit shop at Willys-Hifi
RumoH Checked 12 Oct 2026 · Ships from Netherlands · 8 Ω · Source: inc VAT Import VAT and duty may apply	£52.50	16% above the lowest price	Stock not listed	Visit shop at RumoH
SoundImports Checked 12 Oct 2026 · Ships from Netherlands · 8 Ω · Source: inc VAT Import VAT and duty may apply	£52.93	17% above the lowest price	5 in stock	Visit shop at SoundImports

Best price over time

Tracked since 1 Apr

Recent changes

1 OctWillys-Hifi£60.95 → £59.22Down 2.8% from £60.95
11 AugWillys-Hifi£52.95 → £60.95Up 15% from £52.95
4 AugWillys-Hifi£51.95 → £52.95Up 1.9% from £51.95