Dayton AudioPSS555-8
£194.48 · 56% less, betterFs28 Hz −8%
Qts0.33 −4%
Vas444 L +75%, worse
BL29.7 T·m −12%, worse
Xmax11 mm −27%, worse
Sensitivity96.4 dB +1.6
21-inch LF driver · TSQ2145 series · 115 mm voice coil · 1,800 W
Celestion TSQ2145 8Ω
8 Ω · 30–1000 Hz
£445.00
SteadyLean Business · All 4 offers
- Fs
- 30Hz
- Xmax
- 15mm
- SPL
- 95dB
- Pe
- 1800W
- BL
- 33.8T·m
- Vd
- 2493cm³
- Qts
- 0.34
- Vas
- 254L
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
LF frequency response
Frequency response
101 plotted pointsMedium confidence121 selected pixels of 211
Published graphs
Celestion TSQ2145 is a 21-inch 8 ohm LF driver rated at 1800 W RMS. The validated T/S data includes Fs 30 Hz, Qts 0.34, Vas 253.8 L, Xmax 15 mm, sensitivity 94.8 dB, plus 2493 cm³ Vd and 84 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 £445.00.
The published T/S values agree with each other
Thiele/Small
- Fs
- 30Hz
- Qts
- 0.34
- Qes
- 0.36
- Qms
- 8.4
- Vas
- 253.8L
- Re
- 5Ω
- Le
- 3.91mH
Motor and cone
- BL
- 33.8T·m
- Sd
- 1662cm²
- Mms
- 435g
- Xmax
- 15mm
- Vd †
- 2493cm³
- Voice coil
- 115mm
Power and response
- Sensitivity †
- 94.8dB
- Manufacturer sensitivity
- 97dB
- Power
- 1800W
- Impedance
- 8Ω
- Range
- 30–1000Hz
- EBP †
- 84 · Sealed or vented
Size and mounting
- Diameter
- 547mm
- Cutout
- 505mm
- Bolt circle
- 528mm
- Depth
- 255mm
- Weight
- 13.8kg
Other published values
- Cms
- 0.065mm/N
- Rms
- 9.77kg/s
- Power Program
- 3600
Sensitivity shows 94.8 dB, calculated from the T/S values. Celestion publishes 97.0 dB, 2.2 dB apart.
† Calculated by bits from the published values
What this validation status means
Everything else Celestion lists
LF · Primary · 21″
- BL
- 33.8T·m
- Fs
- 30Hz
- Le
- 3.91mH
- Re
- 5Ω
- Sd
- 1662cm²
- Cms
- 0.065mm/N
- Mms
- 435g
- Qes
- 0.36
- Qms
- 8.4
- Qts
- 0.34
- Rms
- 9.77kg/s
- SPL
- 94.8dB
- Vas
- 253.8L
- Xmax
- 15mm
- Power
- 1800W
- Impedance
- 8Ω
- Sensitivity
- 97dB
- Low limit
- 30Hz
- Power Program
- 3600
- Calculated sensitivity †
- 94.8dB
- High limit
- 1000Hz
- Manufacturer sensitivity
- 97dB
- Voice coil
- 115mm
- Weight
- 13.8kg
- Diameter
- 547mm
- Depth
- 255mm
- Cutout
- 505mm
- Bolt circle
- 528mm
02
Compare
Same-size drivers, compared with the TSQ2145. Clear differences are green when better and red when worse.
This driverTSQ2145
Best price
£445.00
Fs
30 Hz
Qts
0.34
Vas
253.8 L
BL
33.8 T·m
Xmax
15 mm
Sensitivity
94.8 dB
Power
1800 W
SB AudienceNERO-21SW1100D
£343.60 · 23% less, betterFs32 Hz +7%
Qts0.34 –
Vas312.6 L +23%, worse
BL30 T·m −11%, worse
Xmax12.2 mm −19%, worse
Sensitivity96.7 dB +1.9
Eighteen Sound21LW2600
£425.60 · 4% lessFs27 Hz −10%, better
Qts0.33 −4%
Vas333 L +31%, worse
BL32.5 T·m −4%
Xmax14.6 mm –
Sensitivity94.9 dB –
RCFLF21X451
£448.61 · Same priceFs28 Hz −7%
Qts0.37 +8%
Vas385 L +52%, worse
BL30.5 T·m −10%
Xmax14 mm −7%
Sensitivity95.4 dB +0.6
Dayton AudioHTS545HE-4
£448.82 · Same priceFs26 Hz −12%, better
Qts0.28 −19%, better
Vas179 L −29%, better
BL38.2 T·m +13%, better
Xmax21 mm +40%, better
Sensitivity92.5 dB −2.3, worse
Eighteen Sound21NLW4100
£456.79 · 3% moreFs36 Hz +20%, worse
Qts0.46 +34%, worse
Vas210 L −17%, better
BL29.4 T·m −13%, worse
Xmax15.2 mm –
Sensitivity95 dB –
B&C21SW115
£458.85 · 3% moreFs30 Hz –
Qts0.37 +8%
Vas318 L +25%, worse
BL30.1 T·m −11%, worse
Xmax14 mm −7%
Sensitivity95.5 dB +0.7
Beyma21LEX1600ND
£475.00 · 7% more, worseFs30 Hz –
Qts0.29 −16%, better
Vas305 L +20%, worse
BL36.6 T·m +8%
Xmax14 mm −7%
Sensitivity96.4 dB +1.6
RCFLF21N451
£475.00 · 7% more, worseFs30 Hz –
Qts0.26 −24%, better
Vas375 L +48%, worse
BL34.5 T·m –
Xmax13 mm −13%, worse
Sensitivity97.8 dB +3, better
B&C21DS115
£475.59 · 7% more, worseFs34 Hz +13%, worse
Qts0.27 −22%, better
Vas204 L −20%, better
BL39.3 T·m +16%, better
Xmax16.5 mm +10%, better
Sensitivity96.6 dB +1.8
Beyma21QLEX1600FE
£493.97 · 11% more, worseFs30 Hz –
Qts0.28 −19%, better
Vas309 L +22%, worse
BL36.4 T·m +8%
Xmax13 mm −13%, worse
Sensitivity96.5 dB +1.7
B&C21SW152
£537.55 · 21% more, worseFs32 Hz +7%
Qts0.36 +5%
Vas200 L −21%, better
BL39 T·m +15%, better
Xmax15 mm –
Sensitivity94.4 dB –
Eighteen Sound21NLW9001
£549.89 · 24% more, worseFs32 Hz +7%
Qts0.31 −10%
Vas244 L −4%
BL37 T·m +9%
Xmax14 mm −7%
Sensitivity95.7 dB +0.9
No photo
Precision DevicesPD.2155-1N
£555.00 · 25% more, worseFs33 Hz +10%, worse
Qts0.36 +5%
Vas241 L −5%
BL30 T·m −11%, worse
Xmax14 mm −7%
Sensitivity95.7 dB +0.9
Eighteen Sound21NTLW5000
£595.00 · 34% more, worseFs31 Hz +3%
Qts0.36 +5%
Vas270 L +6%
BL32 T·m −5%
Xmax17.5 mm +17%, better
Sensitivity95.3 dB +0.5
Eighteen Sound21NLW4000
£608.33 · 37% more, worseFs29 Hz −3%
Qts0.37 +8%
Vas305 L +20%, worse
BL30 T·m −11%, worse
Xmax15 mm –
Sensitivity94.9 dB –
Eighteen Sound21NLW9601
£623.80 · 40% more, worseFs37 Hz +23%, worse
Qts0.29 −16%, better
Vas175 L −31%, better
BL43 T·m +27%, better
Xmax14 mm −7%
Sensitivity96.6 dB +1.8
No photo
Precision DevicesPD.2160-1N
£799.00 · 80% more, worseFs35 Hz +17%, worse
Qts0.30 −13%, better
Vas177 L −30%, better
BL43 T·m +27%, better
Xmax16 mm +7%
Sensitivity95.9 dB +1.1
EminenceNSW6021-124
£916.36 · 106% more, worseFs31 Hz –
Qts0.32 −7%
Vas224.6 L −12%, better
BL30.5 T·m −10%
Xmax21 mm +40%, better
Sensitivity95 dB –
No current price
Fs35 Hz +17%, worse
Qts0.34 –
Vas266 L +5%
BL31.3 T·m −7%
Xmax14 mm −7%
Sensitivity97.1 dB +2.3, better
No photo
Precision DevicesPD.2155-1F
No current priceFs35 Hz +17%, worse
Qts0.34 –
Vas266 L +5%
BL31.3 T·m −7%
Xmax14 mm −7%
Sensitivity97.1 dB +2.3, better
No current price
Fs33 Hz +10%, worse
Qts0.36 +5%
Vas241 L −5%
BL30 T·m −11%, worse
Xmax14 mm −7%
Sensitivity95.7 dB +0.9
Eighteen Sound21NLW5300
No current priceFs31 Hz +3%
Qts0.32 −7%
Vas325 L +28%, worse
BL31 T·m −8%
Xmax15.3 mm –
Sensitivity96.6 dB +1.8
Eighteen Sound21LW2500
No current priceFs29 Hz −3%
Qts0.37 +8%
Vas305 L +20%, worse
BL30 T·m −11%, worse
Xmax14 mm −7%
Sensitivity94.9 dB –
CelestionNTR21-5010JD
No current priceFs32 Hz +7%
Qts0.32 −7%
Vas276.7 L +9%
BL33.9 T·m –
Xmax9 mm −40%, worse
Sensitivity96.4 dB +1.6
B&C21SW150
No current priceFs29 Hz −3%
Qts0.26 −24%, better
Vas254 L –
BL32.6 T·m −4%
Xmax15 mm –
Sensitivity95.6 dB +0.8
Eighteen Sound21NLW9601C
No current priceFs38 Hz +27%, worse
Qts0.29 −16%, better
Vas140 L −45%, better
BL33.2 T·m –
Xmax14 mm −7%
Sensitivity96 dB +1.2
Sica21 S 4 PL
No current priceFs35 Hz +15%, worse
Qts0.30 −13%, better
Vas255 L –
BL36.1 T·m +7%
Xmax5.2 mm −65%, worse
Sensitivity97.4 dB +2.6, better
P.AudioSD21-125XB
No current priceFs35 Hz +17%, worse
Qts0.38 +10%, worse
Vas345.6 L +36%, worse
BL30.4 T·m −10%, worse
Xmax11.3 mm −25%, worse
Sensitivity97.7 dB +2.9, better
Dayton AudioPSS545HE-4
No current priceFs29 Hz −4%
Qts0.27 −22%, better
Vas212.2 L −16%, better
BL35.5 T·m +5%
Xmax21 mm +40%, better
Sensitivity94.6 dB –
Tune the match
Choose the published values that matter to your design. Size stays matched to this driver.
Qts
Qes
VasL
Xmaxmm
BLTm
- Parts Express2.0 out of 51 rating · Checked 26 Oct 2026Read reviews on Parts Express
Each shop collects its own ratings. Bits shows them as published and doesn't verify them.
| Shop | Price | Against the lowest | Stock | Link |
|---|---|---|---|---|
Lean Business | £445.00, the lowest price | Stock not listed | Visit shop at Lean Business | |
Lean Audio | £456.00 | 2.5% above the lowest price | Back order | Visit shop at Lean Audio |
Parts Express Import VAT and duty may apply | £522.89 | 18% above the lowest price | 1 in stock | Visit shop at Parts Express |
Best price over time
Tracked since 1 Apr