Eighteen Sound design
Manifolded 2x21” band-pass subwoofer
- Drivers
- 21NLW9000or 21LW1400or 21NLW9600
The plans name the earlier 21NLW9600.
21-inch LF driver · 1,800 W
Eighteen Sound 21NLW9601 8Ω
25–2000 Hz
£699.33
SteadyLean Business · All 4 offers
- Fs
- 37Hz
- Xmax
- 14mm
- SPL
- 97dB
- Pe
- 1800W
- BL
- 43T·m
- Vd
- 2327cm³
- Qts
- 0.29
- Vas
- 175L
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 1 trace
These plotted lines are Bits digitizations of manufacturer evidence, not new measurements. How provenance works
- Trace datasheet-response-trace-poc/v1
frequency response
Frequency response
240 plotted pointsMedium confidence2,090 selected pixels of 2,593
Published graphs
Eighteen Sound 21NLW9601 is a 21-inch 8 ohm LF driver rated at 1800 W RMS. The validated T/S data includes Fs 37 Hz, Qts 0.29, Vas 175 L, Xmax 14 mm, sensitivity 96.6 dB, plus 2327 cm³ Vd and 119 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 £626.00.
The published T/S values agree with each other
Thiele/Small
- Fs
- 37Hz
- Qts
- 0.29
- Qes
- 0.31
- Qms
- 5.5
- Vas
- 175L
- Re
- 5.9Ω
- Le
- 3.10mH
Motor and cone
- BL
- 43T·m
- Sd
- 1662cm²
- Mms
- 408g
- Xmax
- 14mm
- Vd †
- 2327cm³
Power and response
- Sensitivity †
- 96.6dB
- Manufacturer sensitivity
- 98dB
- Power
- 1800W
- Nominal power
- 1800W
- Impedance
- 8Ω
- Range
- 25–2000Hz
- EBP †
- 119 · Leans vented
Size and mounting
- Diameter
- 545mm
- Cutout
- 492mm
- Bolt circle
- 520mm
- Depth
- 250mm
- Weight
- 13.5kg
Other published values
- Power Program
- 3600
Sensitivity shows 96.6 dB, calculated from the T/S values. Eighteen Sound publishes 98.0 dB, 1.4 dB apart.
† Calculated by bits from the published values
What this validation status means
Everything else Eighteen Sound lists
LF · Primary · 21″
- BL
- 43T·m
- Fs
- 37Hz
- Le
- 3.10mH
- Re
- 5.9Ω
- Sd
- 1662cm²
- Mms
- 408g
- Qes
- 0.31
- Qms
- 5.5
- Qts
- 0.29
- SPL
- 96.6dB
- Vas
- 175L
- Xmax
- 14mm
- Power
- 1800W
- Impedance
- 8Ω
- Sensitivity
- 98dB
- Low limit
- 25Hz
- Nominal power
- 1800W
- Power Program
- 3600
- Calculated sensitivity †
- 96.6dB
- High limit
- 2000Hz
- Manufacturer sensitivity
- 98dB
- Weight
- 13.5kg
- Diameter
- 545mm
- Depth
- 250mm
- Cutout
- 492mm
- Bolt circle
- 520mm
02
Designs
Cabinets for the 21NLW9601: a design and a suggested box from Eighteen Sound, plans builders have published, and flatpack kits of the Manifolded 2x21” band-pass subwoofer.
All 21NLW9601 designsHow we find designsEighteen Sound’s design
From the maker, with plans to download
Cut in the UKEighteen Sound’s suggested box
From Eighteen Sound’s 21NLW9601 page
- Net volume
- 200L
- Tuning
- 38Hz
Eighteen Sound 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 21NLW9601. Clear differences are green when better and red when worse.
This driver21NLW9601
Best price
£626.00
Fs
37 Hz
Qts
0.29
Vas
175 L
BL
43 T·m
Xmax
14 mm
Sensitivity
96.6 dB
Power
1800 W
Dayton AudioPSS555-8
£194.79 · 69% less, betterFs28 Hz −25%, better
Qts0.33 +14%, worse
Vas444 L +154%, worse
BL29.7 T·m −31%, worse
Xmax11 mm −21%, worse
Sensitivity96.4 dB –
SB AudienceNERO-21SW1100D
£343.60 · 45% less, betterFs32 Hz −14%, better
Qts0.34 +17%, worse
Vas312.6 L +79%, worse
BL30 T·m −30%, worse
Xmax12.2 mm −13%, worse
Sensitivity96.7 dB –
Beyma21QLEX1600FE
£425.00 · 32% less, betterFs30 Hz −19%, better
Qts0.28 −3%
Vas309 L +77%, worse
BL36.4 T·m −15%, worse
Xmax13 mm −7%
Sensitivity96.5 dB –
Eighteen Sound21LW2600
£427.11 · 32% less, betterFs27 Hz −27%, better
Qts0.33 +14%, worse
Vas333 L +90%, worse
BL32.5 T·m −24%, worse
Xmax14.6 mm +4%
Sensitivity94.9 dB −1.7
CelestionTSQ2145
£445.00 · 29% less, betterFs30 Hz −19%, better
Qts0.34 +19%, worse
Vas253.8 L +45%, worse
BL33.8 T·m −21%, worse
Xmax15 mm +7%
Sensitivity94.8 dB −1.8
RCFLF21X451
£448.61 · 28% less, betterFs28 Hz −24%, better
Qts0.37 +28%, worse
Vas385 L +120%, worse
BL30.5 T·m −29%, worse
Xmax14 mm –
Sensitivity95.4 dB −1.2
Dayton AudioHTS545HE-4
£449.52 · 28% less, betterFs26 Hz −29%, better
Qts0.28 −3%
Vas179 L –
BL38.2 T·m −11%, worse
Xmax21 mm +50%, better
Sensitivity92.5 dB −4.1, worse
Eighteen Sound21NLW4100
£456.79 · 27% less, betterFs36 Hz –
Qts0.46 +59%, worse
Vas210 L +20%, worse
BL29.4 T·m −32%, worse
Xmax15.2 mm +9%
Sensitivity95 dB −1.6
B&C21SW115
£460.47 · 26% less, betterFs30 Hz −19%, better
Qts0.37 +28%, worse
Vas318 L +82%, worse
BL30.1 T·m −30%, worse
Xmax14 mm –
Sensitivity95.5 dB −1.1
Beyma21LEX1600ND
£475.00 · 24% less, betterFs30 Hz −19%, better
Qts0.29 –
Vas305 L +74%, worse
BL36.6 T·m −15%, worse
Xmax14 mm –
Sensitivity96.4 dB –
RCFLF21N451
£475.00 · 24% less, betterFs30 Hz −19%, better
Qts0.26 −10%, better
Vas375 L +114%, worse
BL34.5 T·m −20%, worse
Xmax13 mm −7%
Sensitivity97.8 dB +1.2
B&C21DS115
£477.27 · 24% less, betterFs34 Hz −8%
Qts0.27 −7%
Vas204 L +17%, worse
BL39.3 T·m −9%
Xmax16.5 mm +18%, better
Sensitivity96.6 dB –
B&C21SW152
£539.45 · 14% less, betterFs32 Hz −14%, better
Qts0.36 +24%, worse
Vas200 L +14%, worse
BL39 T·m −9%
Xmax15 mm +7%
Sensitivity94.4 dB −2.2, worse
Eighteen Sound21NLW9001
£551.83 · 12% less, betterFs32 Hz −14%, better
Qts0.31 +7%
Vas244 L +39%, worse
BL37 T·m −14%, worse
Xmax14 mm –
Sensitivity95.7 dB −0.9
No photo
Precision DevicesPD.2155-1N
£555.00 · 11% less, betterFs33 Hz −11%, better
Qts0.36 +24%, worse
Vas241 L +38%, worse
BL30 T·m −30%, worse
Xmax14 mm –
Sensitivity95.7 dB −0.9
No photo
Precision DevicesPD.2160-1N
£799.00 · 28% more, worseFs35 Hz −5%
Qts0.30 +3%
Vas177 L –
BL43 T·m –
Xmax16 mm +14%, better
Sensitivity95.9 dB −0.7
FaitalPRO21XL3000
£799.00 · 28% more, worseFs30 Hz −19%, better
Qts0.25 −14%, better
Vas284.6 L +63%, worse
BL43 T·m –
Xmax17.7 mm +26%, better
Sensitivity96.9 dB –
EminenceNSW6021-6
£800.00 · 28% more, worseFs29 Hz −22%, better
Qts0.31 +7%
Vas224.6 L +28%, worse
BL33.8 T·m −21%, worse
Xmax21 mm +50%, better
Sensitivity94.5 dB −2.1, worse
EminenceNSW6021-124
£917.80 · 47% more, worseFs31 Hz −17%, better
Qts0.32 +10%, worse
Vas224.6 L +28%, worse
BL30.5 T·m −29%, worse
Xmax21 mm +50%, better
Sensitivity95 dB −1.6
Eighteen Sound21NLW9601C
No current priceFs38 Hz –
Qts0.29 –
Vas140 L −20%, better
BL33.2 T·m −23%, worse
Xmax14 mm –
Sensitivity96 dB −0.6
Sica21 S 4 PL
No current priceFs35 Hz −6%
Qts0.30 +3%
Vas255 L +46%, worse
BL36.1 T·m −16%, worse
Xmax5.2 mm −63%, worse
Sensitivity97.4 dB +0.8
Dayton AudioPSS545HE-4
No current priceFs29 Hz −22%, better
Qts0.27 −7%
Vas212.2 L +21%, worse
BL35.5 T·m −17%, worse
Xmax21 mm +50%, better
Sensitivity94.6 dB −2, worse
B&C21SW150
No current priceFs29 Hz −22%, better
Qts0.26 −10%, better
Vas254 L +45%, worse
BL32.6 T·m −24%, worse
Xmax15 mm +7%
Sensitivity95.6 dB −1
No current price
Fs35 Hz −5%
Qts0.34 +17%, worse
Vas266 L +52%, worse
BL31.3 T·m −27%, worse
Xmax14 mm –
Sensitivity97.1 dB +0.5
No photo
Precision DevicesPD.2155-1F
No current priceFs35 Hz −5%
Qts0.34 +17%, worse
Vas266 L +52%, worse
BL31.3 T·m −27%, worse
Xmax14 mm –
Sensitivity97.1 dB +0.5
Eighteen Sound21ID
No current priceFs38 Hz –
Qts0.23 −21%, better
Vas143 L −18%, better
BL25.2 T·m −41%, worse
Xmax14 mm –
Sensitivity97.2 dB +0.6
Eighteen Sound21NLW5300
No current priceFs31 Hz −16%, better
Qts0.32 +10%, worse
Vas325 L +86%, worse
BL31 T·m −28%, worse
Xmax15.3 mm +9%
Sensitivity96.6 dB –
No current price
Fs33 Hz −11%, better
Qts0.36 +24%, worse
Vas241 L +38%, worse
BL30 T·m −30%, worse
Xmax14 mm –
Sensitivity95.7 dB −0.9
CelestionNTR21-5010JD
No current priceFs32 Hz −13%, better
Qts0.32 +10%, worse
Vas276.7 L +58%, worse
BL33.9 T·m −21%, worse
Xmax9 mm −36%, worse
Sensitivity96.4 dB –
Eighteen Sound21LW2500
No current priceFs29 Hz −22%, better
Qts0.37 +28%, worse
Vas305 L +74%, worse
BL30 T·m −30%, worse
Xmax14 mm –
Sensitivity94.9 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
| Shop | Price | Against the lowest | Stock | Link |
|---|---|---|---|---|
Lean Business | £699.33, the lowest price | Stock not listed | Visit shop at Lean Business | |
Lean Audio | £654.82 | Back order | Visit shop at Lean Audio |
Best price over time
Tracked since 1 Apr