SB AcousticsSB13PFC25-4
£22.98 · 53% less, betterFs44 Hz +28%, worse
Qts0.29 +4%
Vas13.4 L −35%, better
BL5.3 T·m +13%, better
Xmax4.5 mm −10%, worse
Sensitivity87.4 dB +0.9
5-inch LF driver · SB15 series · 31 mm voice coil · 50 W
SB Acoustics SB15NRX2C30-4 4Ω
4 Ω
- Fs
- 35Hz
- Xmax
- 5mm
- SPL
- 87dB
- Pe
- 50W
- BL
- 4.7T·m
- Vd
- 41cm³
- Qts
- 0.28
- Vas
- 21L
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/v1
30 degrees
Frequency response
240 plotted pointsMedium confidence1,327 selected pixels of 2,691 - Trace datasheet-response-trace-poc/v1
impedance
Impedance response
240 plotted pointsMedium confidence1,755 selected pixels of 4,371
Published graphs
SB Acoustics SB15NRX2C30-4 is a 5-inch 4 ohm LF driver rated at 50 W RMS. The validated T/S data includes Fs 35 Hz, Qts 0.28, Vas 20.5 L, Xmax 5 mm, sensitivity 86.5 dB, plus 41 cm³ Vd and 115 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 £49.12.
The published T/S values agree with each other
Thiele/Small
- Fs
- 35Hz
- Qts
- 0.28
- Qes
- 0.30
- Qms
- 3.6
- Vas
- 20.5L
- Re
- 3.1Ω
- Le
- 0.12mH
Motor and cone
- BL
- 4.7T·m
- Sd
- 82cm²
- Mms
- 10g
- Xmax
- 5mm
- Vd †
- 41cm³
- Voice coil
- 31mm
- Flux density
- 1T
Power and response
- Sensitivity †
- 86.5dB
- Manufacturer sensitivity
- 89.5dB
- Power
- 50W
- Impedance
- 4Ω
- EBP †
- 115 · Leans vented
Size and mounting
- Weight
- 1.5kg
Other published values
- Cms
- 2.15mm/N
Sensitivity shows 86.5 dB, calculated from the T/S values. SB Acoustics publishes 89.5 dB, 3.0 dB apart.
† Calculated by bits from the published values
What this validation status means
Everything else SB Acoustics lists
LF · Primary · 5″
- BL
- 4.7T·m
- Fs
- 35Hz
- Le
- 0.12mH
- Re
- 3.1Ω
- Sd
- 82cm²
- Cms
- 2.15mm/N
- Mms
- 10g
- Qes
- 0.30
- Qms
- 3.6
- Qts
- 0.28
- SPL
- 86.5dB
- Vas
- 20.5L
- Xmax
- 5mm
- Power
- 50W
- Impedance
- 4Ω
- Flux density
- 1T
- Sensitivity
- 89.5dB
- Calculated sensitivity †
- 86.5dB
- Manufacturer sensitivity
- 89.5dB
- Voice coil
- 31mm
- Weight
- 1.5kg
02
Compare
Same-size drivers, compared with the SB15NRX2C30-4. Clear differences are green when better and red when worse.
This driverSB15NRX2C30-4
Best price
£49.12
Fs
35 Hz
Qts
0.28
Vas
20.5 L
BL
4.7 T·m
Xmax
5 mm
Sensitivity
86.5 dB
Power
50 W
SB AcousticsSB13PFCR25-4
£22.98 · 53% less, betterFs44 Hz +28%, worse
Qts0.29 +4%
Vas13.4 L −35%, better
BL5.3 T·m +13%, better
Xmax4.5 mm −10%, worse
Sensitivity87.4 dB +0.9
SB AcousticsSB12PAC25-4
£23.67 · 52% less, betterFs53 Hz +52%, worse
Qts0.31 +11%, worse
Vas5.3 L −74%, better
BL4.3 T·m −7%
Xmax5 mm –
Sensitivity85.7 dB −0.8
SB AcousticsSB12PACR25-4
£23.67 · 52% less, betterFs53 Hz +52%, worse
Qts0.31 +11%, worse
Vas5.3 L −74%, better
BL4.3 T·m −7%
Xmax5 mm –
Sensitivity85.7 dB −0.8
SB AcousticsSB13PFCR25-4-COAX
£44.29 · 10% less, betterFs43 Hz +25%, worse
Qts0.27 −4%
Vas14.4 L −30%, better
BL5.1 T·m +9%
Xmax4.7 mm −7%
Sensitivity87.8 dB +1.3
SB AcousticsSB13PFC25-4-COAX
£46.01 · 6% less, betterFs43 Hz +25%, worse
Qts0.27 −4%
Vas14.4 L −30%, better
BL5.1 T·m +9%
Xmax4.7 mm −7%
Sensitivity87.8 dB +1.3
SB AcousticsSB15MFC30-4
£48.66 · Same priceFs36 Hz –
Qts0.28 –
Vas19.4 L −5%
BL4.8 T·m –
Xmax5 mm –
Sensitivity86.6 dB –
SB AcousticsSB15NRX2C30-8
£49.12 · Same priceFs37 Hz +6%
Qts0.34 +21%, worse
Vas20 L –
BL5.8 T·m +22%, better
Xmax5 mm –
Sensitivity86.2 dB –
SB AcousticsSB15NRXC30-4
£54.13 · 10% more, worseFs41 Hz +19%, worse
Qts0.29 +4%
Vas16.7 L −19%, better
BL4.7 T·m –
Xmax5 mm –
Sensitivity87.7 dB +1.2
SB AcousticsSB15NRXC30-8
£54.13 · 10% more, worseFs38 Hz +10%, worse
Qts0.33 +18%, worse
Vas20.7 L –
BL5.6 T·m +19%, better
Xmax5 mm –
Sensitivity87.1 dB +0.6
SB AcousticsSB17MFC35-4
£54.89 · 12% more, worseFs30 Hz −13%, better
Qts0.28 –
Vas45 L +120%, worse
BL4.9 T·m +4%
Xmax5.5 mm +10%, better
Sensitivity88.1 dB +1.6
SB AcousticsSB12CACS25-4
£58.31 · 19% more, worseFs51 Hz +48%, worse
Qts0.31 +11%, worse
Vas5.7 L −72%, better
BL4.3 T·m −9%
Xmax5 mm –
Sensitivity85.6 dB −0.9
SB AcousticsSB17NRX2L35-4
£59.85 · 22% more, worseFs41 Hz +19%, worse
Qts0.25 −11%, better
Vas21.9 L +7%
BL6.5 T·m +37%, better
Xmax4.8 mm −4%
Sensitivity89.7 dB +3.2, better
CIAREHWB130
£61.12 · 24% more, worseFs46 Hz +33%, worse
Qts0.28 –
Vas12.5 L −39%, better
BL5.6 T·m +19%, better
Xmax4.5 mm −10%, worse
Sensitivity88.3 dB +1.8
SB AcousticsSB17NBAC35-4
£65.93 · 34% more, worseFs30 Hz −13%, better
Qts0.29 +4%
Vas42.6 L +108%, worse
BL4.9 T·m +4%
Xmax5.5 mm +10%, better
Sensitivity87.7 dB +1.2
SB AcousticsSB15NBAC30-4
£69.45 · 41% more, worseFs33 Hz −4%
Qts0.29 +4%
Vas21 L –
BL4.7 T·m –
Xmax5 mm –
Sensitivity85.9 dB −0.6
SB AcousticsSB15NAC30-4
£69.45 · 41% more, worseFs35 Hz –
Qts0.30 +7%
Vas18.3 L −11%, better
BL4.8 T·m –
Xmax5 mm –
Sensitivity85.9 dB −0.6
SB AcousticsSB17NRX2L35-8
£71.13 · 45% more, worseFs38 Hz +10%
Qts0.28 –
Vas26.1 L +27%, worse
BL7.8 T·m +67%, better
Xmax4.8 mm −4%
Sensitivity88.7 dB +2.2, better
SB AcousticsSB15CAC30-4
£76.56 · 56% more, worseFs33 Hz −6%
Qts0.31 +11%, worse
Vas20.2 L –
BL4.6 T·m –
Xmax5 mm –
Sensitivity85.1 dB −1.4
SB AcousticsSB15CRC30-4
£81.08 · 65% more, worseFs37 Hz +7%
Qts0.32 +14%, worse
Vas17.3 L −16%, better
BL4.5 T·m −3%
Xmax5.5 mm +10%, better
Sensitivity85.9 dB −0.6
SB AcousticsSB17CAC35-4
£82.13 · 67% more, worseFs30 Hz −14%, better
Qts0.29 +4%
Vas37.8 L +84%, worse
BL5.3 T·m +13%, better
Xmax5.5 mm +10%, better
Sensitivity87 dB +0.5
SB AcousticsMW13P-4
£139.69 · 184% more, worseFs41 Hz +19%, worse
Qts0.27 −4%
Vas14.6 L −29%, better
BL4.9 T·m +4%
Xmax5 mm –
Sensitivity87.4 dB +0.9
SB AcousticsMW13PNW-4
£139.69 · 184% more, worseFs41 Hz +19%, worse
Qts0.27 −4%
Vas14.6 L −29%, better
BL4.9 T·m +4%
Xmax5 mm –
Sensitivity87.4 dB +0.9
SB AcousticsMW13P-8
£139.69 · 184% more, worseFs42 Hz +20%, worse
Qts0.30 +7%
Vas15 L −27%, better
BL5.7 T·m +21%, better
Xmax5 mm –
Sensitivity87.1 dB +0.6
SB AcousticsMW13PNW-8
£139.69 · 184% more, worseFs41 Hz +19%, worse
Qts0.31 +11%, worse
Vas15 L −27%, better
BL5.7 T·m +21%, better
Xmax5 mm –
Sensitivity87 dB +0.5
SB AcousticsMW16PNW-4
£148.32 · 202% more, worseFs28 Hz −19%, better
Qts0.27 −4%
Vas51.8 L +153%, worse
BL5 T·m +6%
Xmax6 mm +20%, better
Sensitivity88 dB +1.5
SB AcousticsMW13TX-4
£225.24 · 359% more, worseFs38 Hz +10%, worse
Qts0.26 −7%
Vas16 L −22%, better
BL5 T·m +6%
Xmax5 mm –
Sensitivity87.2 dB +0.7
SB AcousticsMW13TX-8
£225.24 · 359% more, worseFs40 Hz +16%, worse
Qts0.32 +14%, worse
Vas14.8 L −28%, better
BL5.7 T·m +21%, better
Xmax5 mm –
Sensitivity86.5 dB –
SB AcousticsMR13TX-4
£251.15 · 411% more, worseFs44 Hz +28%, worse
Qts0.27 −4%
Vas12.2 L −40%, better
BL4.9 T·m +4%
Xmax3 mm −40%, worse
Sensitivity87.7 dB +1.2
AccutonC158-6-851
£293.02 · 497% more, worseFs31 Hz −10%, better
Qts0.28 –
Vas25.7 L +25%, worse
BL8.7 T·m +85%, better
Xmax5 mm –
Sensitivity86.2 dB –
Tune the match
Choose the published values that matter to your design. Size stays matched to this driver.
Qts
Qes
VasL
Xmaxmm
BLTm
- SoundImports5.0 out of 51 rating · Checked 24 Oct 2026Read reviews on SoundImports
Each shop collects its own ratings. Bits shows them as published and doesn't verify them.
| Shop | Price | Against the lowest | Stock | Link |
|---|---|---|---|---|
Lean Audio | £49.12, the lowest price | 2 in stock | Visit shop at Lean Audio | |
Lean Business | £49.12 | Stock not listed | Visit shop at Lean Business | |
Willys-Hifi | £56.10 | 14% above the lowest price | Stock not listed | Visit shop at Willys-Hifi |
RumoH Import VAT and duty may apply | £56.27 | 15% above the lowest price | Stock not listed | Visit shop at RumoH |
SoundImports Import VAT and duty may apply | £57.31 | 17% above the lowest price | 8 in stock | Visit shop at SoundImports |
Best price over time
Tracked since 1 Apr
Recent changes
- 1 OctWillys-Hifi£57.95 → £56.10Down 3.2% from £57.95
- 4 AugWillys-Hifi£55.95 → £57.95Up 3.6% from £55.95
- 22 JulWillys-Hifi£56.95 → £55.95Down 1.8% from £56.95