Eighteen Sound design
Manifolded 2x21” band-pass subwoofer
- Drivers
- 21NLW9000or 21LW1400or 21NLW9600
The plans name the earlier 21NLW9000.
21-inch LF driver · 1,800 W
Eighteen Sound 21NLW9001 8Ω
25–1500 Hz
£576.21
SteadyLean Business · All 3 offers
- Fs
- 32Hz
- Xmax
- 14mm
- SPL
- 96dB
- Pe
- 1800W
- BL
- 37T·m
- Vd
- 2327cm³
- Qts
- 0.31
- Vas
- 244L
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 confidence2,718 selected pixels of 2,816
Published graphs
Eighteen Sound 21NLW9001 is a 21-inch 8 ohm LF driver rated at 1800 W RMS. The validated T/S data includes Fs 32 Hz, Qts 0.31, Vas 244 L, Xmax 14 mm, sensitivity 95.7 dB, plus 2327 cm³ Vd and 94 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 £549.89.
The published T/S values agree with each other
Thiele/Small
- Fs
- 32Hz
- Qts
- 0.31
- Qes
- 0.34
- Qms
- 4.5
- Vas
- 244L
- Re
- 5.9Ω
- Le
- 3.10mH
Motor and cone
- BL
- 37T·m
- Sd
- 1662cm²
- Mms
- 390g
- Xmax
- 14mm
- Vd †
- 2327cm³
Power and response
- Sensitivity †
- 95.7dB
- Manufacturer sensitivity
- 98dB
- Power
- 1800W
- Nominal power
- 1800W
- Impedance
- 8Ω
- Range
- 25–1500Hz
- EBP †
- 94 · Sealed or vented
Size and mounting
- Diameter
- 545mm
- Cutout
- 492mm
- Bolt circle
- 520mm
- Depth
- 250mm
- Weight
- 13.4kg
Other published values
- Power Program
- 3600
Sensitivity shows 95.7 dB, calculated from the T/S values. Eighteen Sound publishes 98.0 dB, 2.3 dB apart.
† Calculated by bits from the published values
What this validation status means
Everything else Eighteen Sound lists
LF · Primary · 21″
- BL
- 37T·m
- Fs
- 32Hz
- Le
- 3.10mH
- Re
- 5.9Ω
- Sd
- 1662cm²
- Mms
- 390g
- Qes
- 0.34
- Qms
- 4.5
- Qts
- 0.31
- SPL
- 95.7dB
- Vas
- 244L
- Xmax
- 14mm
- Power
- 1800W
- Impedance
- 8Ω
- Sensitivity
- 98dB
- Low limit
- 25Hz
- Nominal power
- 1800W
- Power Program
- 3600
- Calculated sensitivity †
- 95.7dB
- High limit
- 1500Hz
- Manufacturer sensitivity
- 98dB
- Weight
- 13.4kg
- Diameter
- 545mm
- Depth
- 250mm
- Cutout
- 492mm
- Bolt circle
- 520mm
02
Designs
Cabinets for the 21NLW9001: a design and a suggested box from Eighteen Sound, and flatpack kits of the Manifolded 2x21” band-pass subwoofer.
All 21NLW9001 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 21NLW9001 page
- Net volume
- 300L
- Tuning
- 33Hz
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 21NLW9001. Clear differences are green when better and red when worse.
This driver21NLW9001
Best price
£549.89
Fs
32 Hz
Qts
0.31
Vas
244 L
BL
37 T·m
Xmax
14 mm
Sensitivity
95.7 dB
Power
1800 W
Dayton AudioPSS555-8
£194.48 · 65% less, betterFs28 Hz −14%, better
Qts0.33 +6%
Vas444 L +82%, worse
BL29.7 T·m −20%, worse
Xmax11 mm −21%, worse
Sensitivity96.4 dB +0.7
SB AudienceNERO-21SW1100D
£343.60 · 38% less, betterFs32 Hz –
Qts0.34 +10%
Vas312.6 L +28%, worse
BL30 T·m −19%, worse
Xmax12.2 mm −13%, worse
Sensitivity96.7 dB +1
Eighteen Sound21LW2600
£425.60 · 23% less, betterFs27 Hz −16%, better
Qts0.33 +6%
Vas333 L +36%, worse
BL32.5 T·m −12%, worse
Xmax14.6 mm +4%
Sensitivity94.9 dB −0.8
CelestionTSQ2145
£445.00 · 19% less, betterFs30 Hz −6%
Qts0.34 +11%, worse
Vas253.8 L +4%
BL33.8 T·m −9%
Xmax15 mm +7%
Sensitivity94.8 dB −0.9
RCFLF21X451
£448.61 · 18% less, betterFs28 Hz −13%, better
Qts0.37 +19%, worse
Vas385 L +58%, worse
BL30.5 T·m −18%, worse
Xmax14 mm –
Sensitivity95.4 dB –
Dayton AudioHTS545HE-4
£448.82 · 18% less, betterFs26 Hz −18%, better
Qts0.28 −10%
Vas179 L −27%, better
BL38.2 T·m +3%
Xmax21 mm +50%, better
Sensitivity92.5 dB −3.2, worse
Eighteen Sound21NLW4100
£456.79 · 17% less, betterFs36 Hz +13%, worse
Qts0.46 +48%, worse
Vas210 L −14%, better
BL29.4 T·m −21%, worse
Xmax15.2 mm +9%
Sensitivity95 dB −0.7
B&C21SW115
£458.85 · 17% less, betterFs30 Hz −6%
Qts0.37 +19%, worse
Vas318 L +30%, worse
BL30.1 T·m −19%, worse
Xmax14 mm –
Sensitivity95.5 dB –
Beyma21LEX1600ND
£475.00 · 14% less, betterFs30 Hz −6%
Qts0.29 −6%
Vas305 L +25%, worse
BL36.6 T·m –
Xmax14 mm –
Sensitivity96.4 dB +0.7
RCFLF21N451
£475.00 · 14% less, betterFs30 Hz −6%
Qts0.26 −16%, better
Vas375 L +54%, worse
BL34.5 T·m −7%
Xmax13 mm −7%
Sensitivity97.8 dB +2.1, better
B&C21DS115
£475.59 · 14% less, betterFs34 Hz +6%
Qts0.27 −13%, better
Vas204 L −16%, better
BL39.3 T·m +6%
Xmax16.5 mm +18%, better
Sensitivity96.6 dB +0.9
Beyma21QLEX1600FE
£493.97 · 10% less, betterFs30 Hz −6%
Qts0.28 −10%
Vas309 L +27%, worse
BL36.4 T·m –
Xmax13 mm −7%
Sensitivity96.5 dB +0.8
B&C21SW152
£537.55 · 2% lessFs32 Hz –
Qts0.36 +16%, worse
Vas200 L −18%, better
BL39 T·m +5%
Xmax15 mm +7%
Sensitivity94.4 dB −1.3
No photo
Precision DevicesPD.2155-1N
£555.00 · Same priceFs33 Hz +3%
Qts0.36 +16%, worse
Vas241 L –
BL30 T·m −19%, worse
Xmax14 mm –
Sensitivity95.7 dB –
Eighteen Sound21NTLW5000
£595.00 · 8% more, worseFs31 Hz −3%
Qts0.36 +16%, worse
Vas270 L +11%, worse
BL32 T·m −14%, worse
Xmax17.5 mm +25%, better
Sensitivity95.3 dB –
Eighteen Sound21NLW4000
£608.33 · 11% more, worseFs29 Hz −9%
Qts0.37 +19%, worse
Vas305 L +25%, worse
BL30 T·m −19%, worse
Xmax15 mm +7%
Sensitivity94.9 dB −0.8
Eighteen Sound21NLW9601
£623.80 · 13% more, worseFs37 Hz +16%, worse
Qts0.29 −6%
Vas175 L −28%, better
BL43 T·m +16%, better
Xmax14 mm –
Sensitivity96.6 dB +0.9
No photo
Precision DevicesPD.2160-1N
£799.00 · 45% more, worseFs35 Hz +9%
Qts0.30 −3%
Vas177 L −27%, better
BL43 T·m +16%, better
Xmax16 mm +14%, better
Sensitivity95.9 dB –
FaitalPRO21XL3000
£899.00 · 63% more, worseFs30 Hz −6%
Qts0.25 −19%, better
Vas284.6 L +17%, worse
BL43 T·m +16%, better
Xmax17.7 mm +26%, better
Sensitivity96.9 dB +1.2
EminenceNSW6021-124
£916.36 · 67% more, worseFs31 Hz −4%
Qts0.32 +3%
Vas224.6 L −8%
BL30.5 T·m −18%, worse
Xmax21 mm +50%, better
Sensitivity95 dB −0.7
No current price
Fs35 Hz +9%
Qts0.34 +9%
Vas266 L +9%
BL31.3 T·m −15%, worse
Xmax14 mm –
Sensitivity97.1 dB +1.4
No photo
Precision DevicesPD.2155-1F
No current priceFs35 Hz +9%
Qts0.34 +9%
Vas266 L +9%
BL31.3 T·m −15%, worse
Xmax14 mm –
Sensitivity97.1 dB +1.4
Eighteen Sound21NLW5300
No current priceFs31 Hz −3%
Qts0.32 +3%
Vas325 L +33%, worse
BL31 T·m −16%, worse
Xmax15.3 mm +9%
Sensitivity96.6 dB +0.9
No current price
Fs33 Hz +3%
Qts0.36 +16%, worse
Vas241 L –
BL30 T·m −19%, worse
Xmax14 mm –
Sensitivity95.7 dB –
Eighteen Sound21NLW9601C
No current priceFs38 Hz +19%, worse
Qts0.29 −6%
Vas140 L −43%, better
BL33.2 T·m −10%, worse
Xmax14 mm –
Sensitivity96 dB –
Sica21 S 4 PL
No current priceFs35 Hz +8%
Qts0.30 −3%
Vas255 L +5%
BL36.1 T·m –
Xmax5.2 mm −63%, worse
Sensitivity97.4 dB +1.7
CelestionNTR21-5010JD
No current priceFs32 Hz –
Qts0.32 +3%
Vas276.7 L +13%, worse
BL33.9 T·m −9%
Xmax9 mm −36%, worse
Sensitivity96.4 dB +0.7
B&C21SW150
No current priceFs29 Hz −9%
Qts0.26 −16%, better
Vas254 L +4%
BL32.6 T·m −12%, worse
Xmax15 mm +7%
Sensitivity95.6 dB –
Eighteen Sound21LW2500
No current priceFs29 Hz −9%
Qts0.37 +19%, worse
Vas305 L +25%, worse
BL30 T·m −19%, worse
Xmax14 mm –
Sensitivity94.9 dB −0.8
Dayton AudioPSS545HE-4
No current priceFs29 Hz −10%
Qts0.27 −13%, better
Vas212.2 L −13%, better
BL35.5 T·m −4%
Xmax21 mm +50%, better
Sensitivity94.6 dB −1.1
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 | £576.21, the lowest price | Stock not listed | Visit shop at Lean Business | |
Lean Audio | £576.21 | 1 in stock | Visit shop at Lean Audio |
Best price over time
Tracked since 1 Apr