- Net volume
- 20L
- Tuning
- 67Hz
Eighteen Sound gives the volume and tuning; the port is sized for the driver when you open it.
8-inch LF driver · 280 W
Eighteen Sound 8NMB420 4Ω
60–5500 Hz
£121.21
SteadyLean Audio · 2 in stock · All 4 offers
- Fs
- 59Hz
- Xmax
- 5.8mm
- SPL
- 95dB
- Pe
- 280W
- BL
- 7T·m
- Vd
- 132cm³
- Qts
- 0.31
- Vas
- 31L
Published graphs
Eighteen Sound 8NMB420 is an 8-inch 4 ohm LF driver rated at 280 W RMS. The validated T/S data includes Fs 59 Hz, Qts 0.31, Vas 31 L, Xmax 5.8 mm, sensitivity 94.8 dB, plus 132 cm³ Vd and 174 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 £121.21.
The published T/S values agree with each other
Thiele/Small
- Fs
- 59Hz
- Qts
- 0.31
- Qes
- 0.34
- Qms
- 3.8
- Vas
- 31L
- Re
- 2.6Ω
- Le
- 0.27mH
Motor and cone
- BL
- 7T·m
- Sd
- 227cm²
- Mms
- 17g
- Xmax
- 5.8mm
- Vd †
- 132cm³
Power and response
- Sensitivity †
- 94.8dB
- Manufacturer sensitivity
- 95dB
- Power
- 280W
- Nominal power
- 280W
- Impedance
- 4Ω
- Range
- 60–5500Hz
- EBP †
- 174 · Leans vented
Size and mounting
- Diameter
- 210mm
- Cutout
- 186mm
- Bolt circle
- 195mm
- Depth
- 99mm
- Weight
- 1.7kg
Other published values
- Power Program
- 400
† Calculated by bits from the published values
What this validation status means
Everything else Eighteen Sound lists
LF · Primary · 8″
- BL
- 7T·m
- Fs
- 59Hz
- Le
- 0.27mH
- Re
- 2.6Ω
- Sd
- 227cm²
- Mms
- 17g
- Qes
- 0.34
- Qms
- 3.8
- Qts
- 0.31
- SPL
- 94.8dB
- Vas
- 31L
- Xmax
- 5.8mm
- Power
- 280W
- Impedance
- 4Ω
- Sensitivity
- 95dB
- Low limit
- 60Hz
- Nominal power
- 280W
- Power Program
- 400
- Calculated sensitivity †
- 94.8dB
- High limit
- 5500Hz
- Manufacturer sensitivity
- 95dB
- Weight
- 1.7kg
- Diameter
- 210mm
- Depth
- 99mm
- Cutout
- 186mm
- Bolt circle
- 195mm
02
Designs
What Eighteen Sound suggests for the 8NMB420. No published designs name it yet.
How we find designsEighteen Sound’s suggested box
From Eighteen Sound’s 8NMB420 page
Open this box in 00 Simulator
Modelling the box in 00 Simulator…
03
Compare
Same-size drivers, compared with the 8NMB420. Clear differences are green when better and red when worse.
This driver8NMB420
Best price
£121.21
Fs
59 Hz
Qts
0.31
Vas
31 L
BL
7 T·m
Xmax
5.8 mm
Sensitivity
94.8 dB
Power
280 W
SB AcousticsSB20PFCR30-4
£31.27 · 74% less, betterFs34 Hz −42%, better
Qts0.33 +6%
Vas66.2 L +114%, worse
BL6.6 T·m −6%
Xmax5.8 mm –
Sensitivity90.5 dB −4.3, worse
SB AcousticsSB20PFC30-4
£35.10 · 71% less, betterFs34 Hz −43%, better
Qts0.33 +6%
Vas66.2 L +114%, worse
BL6.6 T·m −6%
Xmax5.8 mm –
Sensitivity90.4 dB −4.4, worse
Dayton AudioRS180-8
£59.60 · 51% less, betterFs36 Hz −39%, better
Qts0.31 –
Vas24.4 L −21%, better
BL7.8 T·m +12%, better
Xmax6 mm +3%
Sensitivity86.3 dB −8.5, worse
REDCATT8FR
£65.98 · 46% less, betterFs53 Hz −10%, better
Qts0.38 +22%, worse
Vas36.8 L +19%, worse
BL7.9 T·m +12%, better
Xmax5.8 mm –
Sensitivity93.4 dB −1.4
Dayton AudioRS180P-8
£70.96 · 41% less, betterFs46 Hz −22%, better
Qts0.34 +10%
Vas22 L −29%, better
BL7.2 T·m –
Xmax6 mm +3%
Sensitivity88.8 dB −6, worse
Beyma8P300FE
£79.99 · 34% less, betterFs53 Hz −10%, better
Qts0.31 –
Vas24.8 L −20%, better
BL11.6 T·m +66%, better
Xmax6 mm +3%
Sensitivity92.7 dB −2.1, worse
SB AcousticsSB23NRXS45-4
£84.41 · 30% less, betterFs27 Hz −54%, better
Qts0.30 −3%
Vas87.5 L +182%, worse
BL6.9 T·m –
Xmax6.5 mm +12%, better
Sensitivity89.3 dB −5.5, worse
SB AcousticsSB23NACS45-4
£88.40 · 27% less, betterFs23 Hz −61%, better
Qts0.33 +6%
Vas95 L +206%, worse
BL6.7 T·m −4%
Xmax6.5 mm +12%, better
Sensitivity87.2 dB −7.6, worse
ETON7-612/C8/32 RP
£96.07 · 21% less, betterFs37 Hz −37%, better
Qts0.30 −3%
Vas28 L −10%
BL8.6 T·m +23%, better
Xmax4.5 mm −22%, worse
Sensitivity88.5 dB −6.3, worse
SB AcousticsSB23NBACS45-4
£98.70 · 19% less, betterFs23 Hz −61%, better
Qts0.33 +6%
Vas95 L +206%, worse
BL6.7 T·m −4%
Xmax6.5 mm +12%, better
Sensitivity87.2 dB −7.6, worse
SB AcousticsSB23CACS45-4
£111.07 · 8% less, betterFs23 Hz −61%, better
Qts0.33 +6%
Vas95 L +206%, worse
BL6.7 T·m −4%
Xmax6.5 mm +12%, better
Sensitivity87.2 dB −7.6, worse
WavecorWF182BD12
£117.74 · 3% lessFs30 Hz −50%, better
Qts0.37 +19%, worse
Vas32.4 L +5%
BL8.2 T·m +17%, better
Xmax5.5 mm −5%
Sensitivity85.4 dB −9.4, worse
WavecorWF182BD17
£121.47 · Same priceFs33 Hz −44%, better
Qts0.35 +13%, worse
Vas24.3 L −22%, better
BL6.5 T·m −7%
Xmax5.5 mm −5%
Sensitivity85.8 dB −9, worse
MonacorSPH-225C
£122.42 · 1% moreFs39 Hz −34%, better
Qts0.30 −3%
Vas24 L −23%, better
BL13.2 T·m +88%, better
Xmax6 mm +3%
Sensitivity88.6 dB −6.2, worse
Scanspeak18W/8542-10
£157.04 · 30% more, worseFs43 Hz −27%, better
Qts0.35 +13%, worse
Vas26 L −16%, better
BL6.9 T·m –
Xmax6.5 mm +12%, better
Sensitivity88.7 dB −6.1, worse
WavecorWF182BD13
£157.24 · 30% more, worseFs38 Hz −36%, better
Qts0.26 −16%, better
Vas20.8 L −33%, better
BL6.9 T·m –
Xmax5.5 mm −5%
Sensitivity88.3 dB −6.5, worse
WavecorWF182BD20
£188.05 · 55% more, worseFs30 Hz −50%, better
Qts0.37 +19%, worse
Vas32.4 L +5%
BL8.2 T·m +17%, better
Xmax5.5 mm −5%
Sensitivity85.4 dB −9.4, worse
WavecorWF182BD03
£190.31 · 57% more, worseFs39 Hz −34%, better
Qts0.29 −6%
Vas24.4 L −21%, better
BL6.8 T·m −4%
Xmax5.5 mm −5%
Sensitivity88.9 dB −5.9, worse
WavecorWF182BD08
£190.31 · 57% more, worseFs33 Hz −43%, better
Qts0.29 −6%
Vas32.4 L +5%
BL8.5 T·m +21%, better
Xmax5.5 mm −5%
Sensitivity88.1 dB −6.7, worse
WavecorWF182BD16
£191.39 · 58% more, worseFs37 Hz −37%, better
Qts0.30 −3%
Vas23 L −26%, better
BL8.5 T·m +21%, better
Xmax5.5 mm −5%
Sensitivity87.8 dB −7, worse
SB AcousticsMT19CP-8
£233.97 · 93% more, worseFs43 Hz −27%, better
Qts0.31 –
Vas37.1 L +20%, worse
BL8.1 T·m +15%, better
Xmax3.6 mm −38%, worse
Sensitivity91.5 dB −3.3, worse
WavecorWF182BD10
No current priceFs29 Hz −52%, better
Qts0.31 –
Vas32.4 L +5%
BL6.5 T·m −7%
Xmax5.5 mm −5%
Sensitivity85.7 dB −9.1, worse
WavecorWF182BD18
No current priceFs29 Hz −52%, better
Qts0.31 –
Vas32.4 L +5%
BL6.5 T·m −7%
Xmax5.5 mm −5%
Sensitivity85.7 dB −9.1, worse
Audio Technology18 H 52 17 06 SD
No current priceFs36 Hz −39%, better
Qts0.28 −10%
Vas34 L +10%
BL6.6 T·m −6%
Xmax6.3 mm +9%
Sensitivity88.8 dB −6, worse
WavecorWF182BD09
No current priceFs33 Hz −44%, better
Qts0.35 +13%, worse
Vas24.3 L −22%, better
BL6.5 T·m −7%
Xmax5.5 mm −5%
Sensitivity85.8 dB −9, worse
WavecorWF182BD15
No current priceFs39 Hz −34%, better
Qts0.32 +3%
Vas20.8 L −33%, better
BL8.5 T·m +21%, better
Xmax5.5 mm −5%
Sensitivity87.8 dB −7, worse
WavecorWF182BD07
No current priceFs40 Hz −32%, better
Qts0.34 +10%
Vas24.4 L −21%, better
BL8.5 T·m +21%, better
Xmax5.5 mm −5%
Sensitivity88.5 dB −6.3, worse
WavecorWF182BD04
No current priceFs34 Hz −43%, better
Qts0.25 −19%, better
Vas32.4 L +5%
BL6.8 T·m −4%
Xmax5.5 mm −5%
Sensitivity88.9 dB −5.9, worse
HiViSS8II
No current priceFs32 Hz −46%, better
Qts0.32 +3%
Vas61.6 L +99%, worse
BL8.5 T·m +21%, better
Xmax5.8 mm –
Sensitivity89.8 dB −5, worse
HiViSS8
No current priceFs30 Hz −49%, better
Qts0.33 +6%
Vas83.3 L +169%, worse
BL6.8 T·m –
Xmax6 mm +3%
Sensitivity89.6 dB −5.2, worse
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 55 ratings · Checked 4 Nov 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 |
|---|---|---|---|---|
Lean Audio | £121.21, the lowest price | 2 in stock | Visit shop at Lean Audio | |
Thomann usually 2-5 days | £169.00 | 39% above the lowest price | 4 in stock | Visit shop at Thomann |
Best price over time
Tracked since 1 Apr
Recent changes
- 27 OctThomann£170.00 → £169.00Down 0.6% from £170.00
- 19 OctThomann£171.00 → £170.00Down 0.6% from £171.00
- 15 OctThomann£173.00 → £171.00Down 1.2% from £173.00