REDCATT21NFR
£11.13 · 100% less, betterFs157 Hz −44%, better
Qts0.68 –
Vas0.25 L −7%
BL4.4 T·m −28%, worse
Xmax1.2 mm −50%, worse
Sensitivity82.7 dB −7.9, worse
3-inch LF driver · Ellipticor series
Scanspeak D8404/552000 4Ω
4 Ω
£2,647.56
2.3%Willys-Hifi · All 2 offers
- Fs
- 280Hz
- Xmax
- 2.4mm
- SPL
- 91dB
- Pe
- –
- BL
- 6.1T·m
- Vd
- 14cm³
- Qts
- 0.69
- Vas
- 0.27L
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/v2
on-axis frequency response
Frequency response
240 plotted pointsSource file SHA-256 6886c723db17…Medium confidence290 selected pixels of 290 - Trace datasheet-response-trace-poc/v2
free-air impedance
Impedance response
240 plotted pointsSource file SHA-256 6886c723db17…Medium confidence1,139 selected pixels of 1,139
Scanspeak D8404/552000 is a 3-inch 4 ohm LF driver. The validated T/S data includes Fs 280 Hz, Qts 0.69, Vas 0.27 L, Xmax 2.4 mm, sensitivity 90.6 dB, plus 14 cm³ Vd and 337 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 £2428.16.
The published T/S values agree with each other
Thiele/Small
- Fs
- 280Hz
- Qts
- 0.69
- Qes
- 0.83
- Qms
- 3.9
- Vas
- 0.27L
- Re
- 3Ω
- Le
- 0.04mH
Motor and cone
- BL
- 6.1T·m
- Sd
- 58cm²
- Mms
- 6g
- Xmax
- 2.4mm
- Vd †
- 14cm³
Power and response
- Sensitivity †
- 90.6dB
- Manufacturer sensitivity
- 92dB
- Impedance
- 4Ω
- Min. impedance
- 4.1Ω
- EBP †
- 337 · Leans vented
Size and mounting
- Diameter
- 84mm
Other published values
- Cms
- 0.06mm/N
- Rms
- 2.60kg/s
- Xmech
- 5
- Power Peak
- 220
Sensitivity shows 90.6 dB, calculated from the T/S values. Scanspeak publishes 92.0 dB, 1.4 dB apart.
† Calculated by bits from the published values
What this validation status means
Everything else Scanspeak lists
LF · Primary · 3″
- BL
- 6.1T·m
- Fs
- 280Hz
- Le
- 0.04mH
- Re
- 3Ω
- Sd
- 58cm²
- Cms
- 0.06mm/N
- Mms
- 6g
- Qes
- 0.83
- Qms
- 3.9
- Qts
- 0.69
- Rms
- 2.60kg/s
- SPL
- 90.6dB
- Vas
- 0.27L
- Xmax
- 2.4mm
- Xmech
- 5
- Impedance
- 4Ω
- Power Peak
- 220
- Sensitivity
- 92dB
- Calculated sensitivity †
- 90.6dB
- Manufacturer sensitivity
- 92dB
- Min. impedance
- 4.1Ω
- Diameter
- 84mm
02
Compare
Same-size drivers, compared with the D8404/552000. Clear differences are green when better and red when worse.
This driverD8404/552000
Best price
£2,428.16
Fs
280 Hz
Qts
0.69
Vas
0.27 L
BL
6.1 T·m
Xmax
2.4 mm
Sensitivity
90.6 dB
Power
–
Dayton AudioPC68-4
£11.26 · 100% less, betterFs117 Hz −58%, better
Qts0.65 −6%
Vas0.7 L +159%, worse
BL2.4 T·m −61%, worse
Xmax2 mm −17%, worse
Sensitivity83.1 dB −7.5, worse
VisatonFRS 5 X
£11.52 · 100% less, betterFs190 Hz −32%, better
Qts0.70 –
Vas0.23 L −15%, better
BL2.7 T·m −56%, worse
Xmax0.25 mm −90%, worse
Sensitivity84.6 dB −6, worse
FaitalPRO2FE24
£12.43 · 99% less, betterFs170 Hz −39%, better
Qts0.69 –
Vas0.2 L −26%, better
BL3.2 T·m −48%, worse
Xmax1.9 mm −21%, worse
Sensitivity82.7 dB −7.9, worse
PeerlessGBS-85N25PR07-04
£14.59 · 99% less, betterFs130 Hz −54%, better
Qts0.70 –
Vas0.47 L +72%, worse
BL4.5 T·m −27%, worse
Xmax3.0 mm +23%, better
Sensitivity83.1 dB −7.5, worse
PRV Audio4MR60-4
£14.89 · 99% less, betterFs90 Hz −68%, better
Qts0.68 –
Vas3.3 L +1107%, worse
BL3.4 T·m −44%, worse
Xmax2.9 mm +20%, better
Sensitivity87 dB −3.6, worse
VisatonFRS 5 XTS
£15.53 · 99% less, betterFs190 Hz −32%, better
Qts0.70 –
Vas0.23 L −15%, better
BL2.7 T·m −56%, worse
Xmax0.25 mm −90%, worse
Sensitivity84.6 dB −6, worse
Dayton AudioPC105-8
£16.70 · 99% less, betterFs85 Hz −70%, better
Qts0.64 −7%
Vas3.4 L +1159%, worse
BL4.1 T·m −33%, worse
Xmax2 mm −17%, worse
Sensitivity85.7 dB −4.9, worse
REDCATT25NFR
£19.63 · 99% less, betterFs123 Hz −56%, better
Qts0.71 –
Vas0.46 L +70%, worse
BL4 T·m −34%, worse
Xmax2.6 mm +10%, better
Sensitivity82.3 dB −8.3, worse
EminenceALPHA 3-32
£20.53 · 99% less, betterFs117 Hz −58%, better
Qts0.74 +7%
Vas1.0 L +263%, worse
BL6.5 T·m +6%
Xmax2.6 mm +8%
Sensitivity84.7 dB −5.9, worse
Dayton AudioDMA105-8
£22.10 · 99% less, betterFs72 Hz −74%, better
Qts0.63 −9%
Vas4.2 L +1473%, worse
BL4.5 T·m −26%, worse
Xmax2.5 mm +4%
Sensitivity84.8 dB −5.8, worse
Dayton AudioPS95-8
£22.10 · 99% less, betterFs120 Hz −57%, better
Qts0.72 +4%
Vas0.9 L +248%, worse
BL3.8 T·m −37%, worse
Xmax2.5 mm +4%
Sensitivity85.1 dB −5.5, worse
LavoceFSN030.71
£24.69 · 99% less, betterFs134 Hz −52%, better
Qts0.67 –
Vas1.0 L +285%, worse
BL3.8 T·m −37%, worse
Xmax2.1 mm −12%, worse
Sensitivity87.3 dB −3.3, worse
CelestionAF3010
£25.11 · 99% less, betterFs129 Hz −54%, better
Qts0.74 +7%
Vas0.7 L +148%, worse
BL6.0 T·m –
Xmax2.8 mm +15%, better
Sensitivity84.3 dB −6.3, worse
SB AcousticsSB65WBAC25-4
£25.12 · 99% less, betterFs115 Hz −59%, better
Qts0.68 –
Vas0.43 L +59%, worse
BL2.9 T·m −52%, worse
Xmax2.6 mm +10%, better
Sensitivity81.3 dB −9.3, worse
Sica4 L 1 SL
£25.87 · 99% less, betterFs108 Hz −61%, better
Qts0.63 −9%
Vas1.2 L +344%, worse
BL5.1 T·m −16%, worse
Xmax2.4 mm –
Sensitivity84.9 dB −5.7, worse
CIAREHM100
£27.63 · 99% less, betterFs160 Hz −43%, better
Qts0.70 –
Vas1.1 L +307%, worse
BL5.1 T·m −17%, worse
Xmax2.2 mm −8%
Sensitivity88.7 dB −1.9
CelestionAF4010
£30.13 · 99% less, betterFs105 Hz −63%, better
Qts0.81 +17%, worse
Vas2.1 L +689%, worse
BL6.0 T·m –
Xmax2.8 mm +15%, better
Sensitivity86.1 dB −4.5, worse
Dayton AudioND105-8
£30.48 · 99% less, betterFs67 Hz −76%, better
Qts0.66 −4%
Vas3.0 L +1000%, worse
BL5.4 T·m −11%, worse
Xmax4 mm +67%, better
Sensitivity82.8 dB −7.8, worse
CIAREPA100
£30.98 · 99% less, betterFs100 Hz −64%, better
Qts0.59 −14%, better
Vas2.5 L +826%, worse
BL4.4 T·m −28%, worse
Xmax2.5 mm +4%
Sensitivity87.6 dB −3, worse
CelestionAN3510
£41.86 · 98% less, betterFs113 Hz −60%, better
Qts0.65 −6%
Vas1.9 L +593%, worse
BL4.6 T·m −25%, worse
Xmax2.3 mm −6%
Sensitivity87.7 dB −2.9, worse
LavoceFSN021.02
No current priceFs151 Hz −46%, better
Qts0.68 –
Vas0.3 L +11%, worse
BL3.4 T·m −44%, worse
Xmax2.3 mm −4%
Sensitivity83.3 dB −7.3, worse
Dayton AudioCE58N-10
No current priceFs177 Hz −37%, better
Qts0.69 –
Vas0.16 L −41%, better
BL4.2 T·m −32%, worse
Xmax2.1 mm −12%, worse
Sensitivity82 dB −8.6, worse
EminenceALPHA 4-8
No current priceFs123 Hz −56%, better
Qts0.75 +9%
Vas1.9 L +619%, worse
BL4.9 T·m −19%, worse
Xmax2.6 mm +8%
Sensitivity88.4 dB −2.2, worse
MonacorSP-4/60PRO
No current priceFs92 Hz −67%, better
Qts0.60 −13%, better
Vas3 L +1011%, worse
BL5.8 T·m −4%
Xmax2.3 mm −4%
Sensitivity87.5 dB −3.1, worse
LavoceFSN020.71F
No current priceFs212 Hz −24%, better
Qts0.82 +19%, worse
Vas0.22 L −19%, better
BL3.2 T·m −47%, worse
Xmax2.4 mm –
Sensitivity85.5 dB −5.1, worse
REDCATT35FR-2
No current priceFs128 Hz −54%, better
Qts0.63 −9%
Vas1.1 L +322%, worse
BL4.8 T·m −21%, worse
Xmax2.4 mm –
Sensitivity87.5 dB −3.1, worse
Dayton AudioDMA90-8
No current priceFs94 Hz −66%, better
Qts0.57 −17%, better
Vas1.7 L +529%, worse
BL4.7 T·m −23%, worse
Xmax2.5 mm +4%
Sensitivity84.9 dB −5.7, worse
Dayton AudioCFC100-4
No current priceFs94 Hz −66%, better
Qts0.60 −13%, better
Vas0.8 L +209%, worse
BL3.1 T·m −48%, worse
Xmax2.5 mm +4%
Sensitivity81.7 dB −8.9, worse
EminenceALPHA 4-4
No current priceFs120 Hz −57%, better
Qts0.63 −9%
Vas1.8 L +552%, worse
BL4.1 T·m −32%, worse
Xmax2.6 mm +8%
Sensitivity88.4 dB −2.2, worse
Tune the match
Choose the published values that matter to your design. Size stays matched to this driver.
Qts
Qes
VasL
Xmaxmm
BLTm
- SoundImports5.0 out of 53 ratings · Checked 25 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 |
|---|---|---|---|---|
Willys-Hifi | £2,647.56, the lowest price | Stock not listed | Visit shop at Willys-Hifi | |
SoundImports Import VAT and duty may apply | £2,428.16 | 2 in stock | Visit shop at SoundImports |
Best price over time
Tracked since 1 Apr
Recent changes
- 1 OctWillys-Hifi£2,710.95 → £2,647.56Down 2.3% from £2,710.95
- 30 SepWillys-Hifi£2,701.95 → £2,710.95Up 0.3% from £2,701.95
- 29 SepWillys-Hifi£2,705.95 → £2,701.95Down 0.1% from £2,705.95