FaitalPRO3FE25
£8.68 · 55% less, betterFs110 Hz –
Qts0.66 +14%, worse
Vas1.3 L –
BL3.6 T·m –
Xmax1.8 mm +66%, better
Sensitivity85.4 dB −0.6
3-inch LF driver · SPX series · 20 mm voice coil · 20 W
Monacor SPX-31M 8Ω
8 Ω · 3–20000 Hz
- Fs
- 110Hz
- Xmax
- 1.1mm
- SPL
- 86dB
- Pe
- 20W
- BL
- 3.6T·m
- Vd
- 4cm³
- Qts
- 0.58
- Vas
- 1L
Monacor SPX-31M is a 3-inch 8 ohm LF driver rated at 20 W RMS. The validated T/S data includes Fs 110 Hz, Qts 0.58, Vas 1.3 L, Xmax 1.1 mm, sensitivity 86 dB, plus 4 cm³ Vd and 159 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 £19.26.
The published T/S values agree with each other
Thiele/Small
- Fs
- 110Hz
- Qts
- 0.58
- Qes
- 0.69
- Qms
- 3.7
- Vas
- 1.3L
- Re
- 6.4Ω
- Le
- 0.18mH
Motor and cone
- BL
- 3.6T·m
- Sd
- 32cm²
- Mms
- 2g
- Xmax
- 1.1mm
- Vd †
- 4cm³
- Voice coil
- 20mm
Power and response
- Sensitivity †
- 86dB
- Manufacturer sensitivity
- 86dB
- Power
- 20W
- Impedance
- 8Ω
- Range
- 3–20000Hz
- EBP †
- 159 · Leans vented
Size and mounting
- Diameter
- 93mm
- Cutout
- 71mm
- Depth
- 55mm
- Weight
- 0.5kg
Other published values
- Cms
- 0.92mm/N
- Power Peak
- 40
Other dimensions
- Mounting Depth
- 53
† Calculated by bits from the published values
What this validation status means
Everything else Monacor lists
LF · Primary · 3″
- BL
- 3.6T·m
- Fs
- 110Hz
- Le
- 0.18mH
- Re
- 6.4Ω
- Sd
- 32cm²
- Cms
- 0.92mm/N
- Mms
- 2g
- Qes
- 0.69
- Qms
- 3.7
- Qts
- 0.58
- SPL
- 86dB
- Vas
- 1.3L
- Xmax
- 1.1mm
- Power
- 20W
- Impedance
- 8Ω
- Power Peak
- 40
- Sensitivity
- 86dB
- Low limit
- 3Hz
- Calculated sensitivity †
- 86dB
- High limit
- 20000Hz
- Manufacturer sensitivity
- 86dB
- Voice coil
- 20mm
- Weight
- 0.5kg
- Diameter
- 93mm
- Depth
- 55mm
- Mounting Depth
- 53
- Cutout
- 71mm
02
Compare
Same-size drivers, compared with the SPX-31M. Clear differences are green when better and red when worse.
This driverSPX-31M
Best price
£19.26
Fs
110 Hz
Qts
0.58
Vas
1.3 L
BL
3.6 T·m
Xmax
1.1 mm
Sensitivity
86 dB
Power
20 W
Dayton AudioPC68-8
£11.26 · 42% less, betterFs109 Hz –
Qts0.64 +10%, worse
Vas1.3 L –
BL3.3 T·m −9%
Xmax2 mm +82%, better
Sensitivity84.8 dB −1.2
REDCATT41FR
£12.52 · 35% less, betterFs134 Hz +22%, worse
Qts0.75 +29%, worse
Vas1.3 L –
BL4.8 T·m +31%, better
Xmax1.1 mm –
Sensitivity87.9 dB +1.9
Dayton AudioPC83-8
£13.10 · 32% less, betterFs82 Hz −25%, better
Qts0.63 +9%
Vas1.7 L +31%, worse
BL3.5 T·m −4%
Xmax2 mm +82%, better
Sensitivity83 dB −3, worse
Sica3.5 F 1 CS
£16.66 · 13% less, betterFs107 Hz –
Qts0.57 –
Vas1.4 L +8%
BL4.2 T·m +15%, better
Xmax1.5 mm +36%, better
Sensitivity86.4 dB –
MonacorSPX-32M
£18.42 · 4% lessFs110 Hz –
Qts0.56 −3%
Vas1.6 L +23%, worse
BL3.7 T·m –
Xmax1.1 mm –
Sensitivity87.5 dB +1.5
Sica3.5 L 1 SL
£23.36 · 21% more, worseFs108 Hz –
Qts0.57 –
Vas1.4 L +8%
BL4.3 T·m +17%, better
Xmax1.5 mm +36%, better
Sensitivity86.6 dB +0.6
VisatonKT 100 V
£24.24 · 26% more, worseFs42 Hz −62%, better
Qts0.56 −3%
Vas7.5 L +477%, worse
BL3.3 T·m −9%
Xmax2 mm +82%, better
Sensitivity81.1 dB −4.9, worse
LavoceFSN030.71
£24.69 · 28% more, worseFs134 Hz +22%, worse
Qts0.67 +16%, worse
Vas1.0 L −20%, better
BL3.8 T·m +5%
Xmax2.1 mm +91%, better
Sensitivity87.3 dB +1.3
Dayton AudioND90-4
£25.04 · 30% more, worseFs90 Hz −18%, better
Qts0.63 +9%
Vas1.1 L −18%, better
BL3.5 T·m −5%
Xmax4 mm +264%, better
Sensitivity82.4 dB −3.6, worse
Tang BandW3-871B
£27.63 · 43% more, worseFs110 Hz –
Qts0.52 −10%, better
Vas1.2 L −9%
BL3.7 T·m –
Xmax0.5 mm −55%, worse
Sensitivity86.1 dB –
Dayton AudioRS100-8
£29.91 · 55% more, worseFs92 Hz −16%, better
Qts0.58 –
Vas1.4 L +10%
BL4.2 T·m +15%, better
Xmax3.5 mm +218%, better
Sensitivity83.7 dB −2.3, worse
Dayton AudioRS100-4
£29.91 · 55% more, worseFs85 Hz −23%, better
Qts0.53 −9%
Vas1.4 L +12%, worse
BL3.2 T·m −13%, worse
Xmax4 mm +264%, better
Sensitivity83.3 dB −2.7, worse
Dayton AudioRS100P-8
£29.91 · 55% more, worseFs96 Hz −13%, better
Qts0.54 −7%
Vas1.8 L +40%, worse
BL4.0 T·m +9%
Xmax3.7 mm +236%, better
Sensitivity85.5 dB −0.5
Tang BandW3-871SC
£30.90 · 60% more, worseFs110 Hz –
Qts0.59 –
Vas1.6 L +27%, worse
BL3.5 T·m −4%
Xmax0.5 mm −55%, worse
Sensitivity86.9 dB +0.9
Tang BandW3-315E
£32.19 · 67% more, worseFs100 Hz −9%
Qts0.52 −10%, better
Vas1.7 L +29%, worse
BL3.9 T·m +7%
Xmax1.3 mm +14%, better
Sensitivity86.7 dB +0.7
FountekFR58EX
£37.60 · 95% more, worseFs134 Hz +22%, worse
Qts0.55 −5%
Vas0.01 L −99%, better
BL3.4 T·m −7%
Xmax2.9 mm +164%, better
Sensitivity67.5 dB −18.5, worse
WavecorWF095WA02
£41.14 · 114% more, worseFs86 Hz −22%, better
Qts0.62 +7%
Vas1.6 L +23%, worse
BL3.6 T·m –
Xmax2.7 mm +145%, better
Sensitivity83.7 dB −2.3, worse
WavecorWF095WA01
£41.14 · 114% more, worseFs89 Hz −19%, better
Qts0.64 +10%, worse
Vas1.5 L +15%, worse
BL3 T·m −18%, worse
Xmax2.7 mm +145%, better
Sensitivity83.8 dB −2.2, worse
Tang BandW3-1364SA
£50.24 · 161% more, worseFs105 Hz −5%
Qts0.59 –
Vas1.9 L +45%, worse
BL3.1 T·m −13%, worse
Xmax0.5 mm −55%, worse
Sensitivity86.5 dB +0.5
MarkaudioALPAIR 7 MS
£58.61 · 204% more, worseFs75 Hz −32%, better
Qts0.56 –
Vas5.0 L +282%, worse
BL3.9 T·m +6%
Xmax4.5 mm +309%, better
Sensitivity86.5 dB +0.5
Scanspeak10F/8414G10
£66.31 · 244% more, worseFs100 Hz −9%
Qts0.51 −12%, better
Vas1.6 L +21%, worse
BL4.3 T·m +18%, better
Xmax2.3 mm +109%, better
Sensitivity85.9 dB –
VisatonB 80
£72.39 · 276% more, worseFs110 Hz –
Qts0.63 +9%
Vas1.8 L +38%, worse
BL4.2 T·m +14%, better
Xmax2.2 mm +100%, better
Sensitivity87.4 dB +1.4
MonacorSP-45/8
No current priceFs120 Hz +9%
Qts0.55 −5%
Vas1.5 L +15%, worse
BL3.4 T·m −7%
Xmax0.75 mm −32%, worse
Sensitivity87.8 dB +1.8
Tang BandW3-532SQ
No current priceFs100 Hz −9%
Qts0.61 +5%
Vas1.7 L +29%, worse
BL3.5 T·m −3%
Xmax0.2 mm −82%, worse
Sensitivity85.9 dB –
Tang BandW3-582A
No current priceFs100 Hz −9%
Qts0.60 +3%
Vas1.8 L +36%, worse
BL3.6 T·m –
Xmax0.25 mm −77%, worse
Sensitivity86.2 dB –
Tang BandW3-1319SA
No current priceFs110 Hz –
Qts0.55 −5%
Vas1.8 L +36%, worse
BL3.5 T·m −3%
Xmax0.5 mm −55%, worse
Sensitivity87.4 dB +1.4
Dayton AudioCFC100-4
No current priceFs94 Hz −15%, better
Qts0.60 +3%
Vas0.8 L −36%, better
BL3.1 T·m −13%, worse
Xmax2.5 mm +127%, better
Sensitivity81.7 dB −4.3, worse
EminenceALPHA 4-4
No current priceFs120 Hz +9%
Qts0.63 +9%
Vas1.8 L +35%, worse
BL4.1 T·m +13%, better
Xmax2.6 mm +136%, better
Sensitivity88.4 dB +2.4, better
MonacorSP-45/4
No current priceFs120 Hz +9%
Qts0.55 −5%
Vas1.5 L +15%, worse
BL2.4 T·m −34%, worse
Xmax0.75 mm −32%, worse
Sensitivity87.8 dB +1.8
Tune the match
Choose the published values that matter to your design. Size stays matched to this driver.
Qts
Qes
VasL
Xmaxmm
BLTm
- SoundImports4.7 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 |
|---|---|---|---|---|
LTT Import VAT and duty may apply | £19.26, the lowest price | Stock not listed | Visit shop at LTT | |
SoundImports Import VAT and duty may apply | £22.15 | 15% above the lowest price | 2 in stock | Visit shop at SoundImports |
Audiophonics Import VAT and duty may apply | £23.03 | 20% above the lowest price | In stock | Visit shop at Audiophonics |
Best price over time
Tracked since 1 Apr