GRS4SMP-8
£11.96 · 59% less, betterFs63 Hz −43%, better
Qts0.65 –
Vas4 L –
BL4.2 T·m −29%, worse
Xmax4 mm +18%, better
Sensitivity82.8 dB −7.9, worse
5-inch LF driver · CSF051 series · 30 mm voice coil · 50 W
Lavoce CSF051.21 8Ω
8 Ω · 110–22000 Hz
£29.17
SteadyParts Express · 6 in stock · Ships from United States · All 1 offer
- Fs
- 110Hz
- Xmax
- 3.4mm
- SPL
- 91dB
- Pe
- 50W
- BL
- 5.9T·m
- Vd
- 32cm³
- Qts
- 0.64
- Vas
- 4L
Lavoce CSF051.21 is a 5-inch 8 ohm LF driver rated at 50 W RMS. The validated T/S data includes Fs 110 Hz, Qts 0.64, Vas 4.1 L, Xmax 3.4 mm, sensitivity 90.7 dB, plus 32 cm³ Vd and 149 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 £29.17.
The published T/S values agree with each other
Thiele/Small
- Fs
- 110Hz
- Qts
- 0.64
- Qes
- 0.74
- Qms
- 4.8
- Vas
- 4.1L
- Re
- 5.7Ω
- Le
- 0.30mH
Motor and cone
- BL
- 5.9T·m
- Sd
- 95cm²
- Mms
- 7g
- Xmax
- 3.4mm
- Vd †
- 32cm³
- Voice coil
- 30mm
Power and response
- Sensitivity †
- 90.7dB
- Manufacturer sensitivity
- 92dB
- Power
- 50W
- Impedance
- 8Ω
- Min. impedance
- 6.1Ω
- Range
- 110–22000Hz
- EBP †
- 149 · Leans vented
Size and mounting
- Weight
- 0.8kg
Other published values
- Cms
- 0.32mm/N
- Xmech
- 4
- Power Program
- 100
Sensitivity shows 90.7 dB, calculated from the T/S values. Lavoce publishes 92.0 dB, 1.3 dB apart.
Excursion and motor values come from the LF section; the frequency range spans every section.
† Calculated by bits from the published values
What this validation status means
Components and manufacturer details
LF
- BL
- 5.9T·m
- Fs
- 110Hz
- Le
- 0.30mH
- Re
- 5.7Ω
- Sd
- 95cm²
- Cms
- 0.32mm/N
- Mms
- 7g
- Qes
- 0.74
- Qms
- 4.8
- Qts
- 0.64
- SPL
- 90.7dB
- Vas
- 4.1L
- Xmax
- 3.4mm
- Xmech
- 4
- Power
- 50W
- Impedance
- 8Ω
- Sensitivity
- 92dB
- Low limit
- 110Hz
- Power Program
- 100
- Calculated sensitivity †
- 90.7dB
- High limit
- 22000Hz
- Manufacturer sensitivity
- 92dB
- Min. impedance
- 6.1Ω
- Voice coil
- 30mm
- Weight
- 0.8kg
HF
- Throat
- 20mm
- Voice coil
- 14mm
02
Compare
Same-size drivers, compared with the CSF051.21. Clear differences are green when better and red when worse.
This driverCSF051.21
Best price
£29.17
Fs
110 Hz
Qts
0.64
Vas
4.1 L
BL
5.9 T·m
Xmax
3.4 mm
Sensitivity
90.7 dB
Power
50 W
PRV Audio4MR60-4
£14.89 · 49% less, betterFs90 Hz −18%, better
Qts0.68 +6%
Vas3.3 L −20%, better
BL3.4 T·m −42%, worse
Xmax2.9 mm −16%, worse
Sensitivity87 dB −3.7, worse
REDCATT5FR
£15.83 · 46% less, betterFs92 Hz −16%, better
Qts0.69 +8%
Vas3.8 L −7%
BL6.3 T·m +7%
Xmax2 mm −41%, worse
Sensitivity88.1 dB −2.6, worse
Sica5 D 1 CS
£19.68 · 33% less, betterFs79 Hz −28%, better
Qts0.52 −19%, better
Vas5.5 L +35%, worse
BL5.7 T·m −3%
Xmax3 mm −12%, worse
Sensitivity88.7 dB −2, worse
FaitalPRO4FE32
£21.94 · 25% less, betterFs100 Hz −9%
Qts0.61 −5%
Vas2.3 L −44%, better
BL4.8 T·m −19%, worse
Xmax2.7 mm −20%, worse
Sensitivity87.2 dB −3.5, worse
Dayton AudioDMA105-8
£22.10 · 24% less, betterFs72 Hz −35%, better
Qts0.63 –
Vas4.2 L +4%
BL4.5 T·m −24%, worse
Xmax2.5 mm −26%, worse
Sensitivity84.8 dB −5.9, worse
CIAREHW129
£23.44 · 20% less, betterFs75 Hz −32%, better
Qts0.55 −14%, better
Vas6.1 L +50%, worse
BL5.2 T·m −12%, worse
Xmax3.9 mm +15%, better
Sensitivity87.3 dB −3.4, worse
PeerlessSDS-P830656
£25.08 · 14% less, betterFs65 Hz −41%, better
Qts0.62 −3%
Vas6.6 L +61%, worse
BL5.5 T·m −6%
Xmax5.5 mm +61%, better
Sensitivity85.8 dB −4.9, worse
PRV Audio6MR250B-4
£26.11 · 10% less, betterFs143 Hz +30%, worse
Qts0.82 +28%, worse
Vas4 L –
BL5.8 T·m –
Xmax3.3 mm −4%
Sensitivity93.4 dB +2.7, better
PeerlessHDS-P830991
£28.05 · 4% lessFs76 Hz −31%, better
Qts0.55 −14%, better
Vas5.1 L +25%, worse
BL6.3 T·m +7%
Xmax6.5 mm +93%, better
Sensitivity87.1 dB −3.6, worse
Dayton AudioRS100-8
£29.91 · 3% moreFs92 Hz −16%, better
Qts0.58 −9%
Vas1.4 L −65%, better
BL4.2 T·m −29%, worse
Xmax3.5 mm –
Sensitivity83.7 dB −7, worse
Dayton AudioND105-8
£30.48 · 4% moreFs67 Hz −39%, better
Qts0.66 +3%
Vas3.0 L −27%, better
BL5.4 T·m −8%
Xmax4 mm +18%, better
Sensitivity82.8 dB −7.9, worse
Dayton AudioND140-8
£32.15 · 10% more, worseFs57 Hz −49%, better
Qts0.68 +6%
Vas7.7 L +90%, worse
BL6.0 T·m –
Xmax4 mm +18%, better
Sensitivity84.5 dB −6.2, worse
Sica6 D 1.5 CS
£37.26 · 28% more, worseFs109 Hz –
Qts0.63 –
Vas4.4 L +8%
BL7.4 T·m +25%, better
Xmax1.5 mm −56%, worse
Sensitivity90.6 dB –
Dayton AudioLW150-4
£41.13 · 41% more, worseFs63 Hz −43%, better
Qts0.64 –
Vas3.5 L −14%, better
BL6.5 T·m +10%, better
Xmax4 mm +18%, better
Sensitivity82.8 dB −7.9, worse
Sica5 N 1.5 PL
£65.31 · 124% more, worseFs111 Hz –
Qts0.56 −12%, better
Vas3 L −26%, better
BL6.2 T·m +5%
Xmax3 mm −12%, worse
Sensitivity89.5 dB −1.2
CelestionTFX0412
£69.00 · 137% more, worseFs95 Hz −14%, better
Qts0.59 −8%
Vas2.2 L −47%, better
BL5.4 T·m −9%
Xmax4 mm +18%, better
Sensitivity86.5 dB −4.2, worse
WavecorWF118WA06
£82.89 · 184% more, worseFs66 Hz −40%, better
Qts0.55 −14%, better
Vas3.5 L −14%, better
BL5.6 T·m −5%
Xmax3 mm −12%, worse
Sensitivity84.3 dB −6.4, worse
PRV Audio5MR450-NDY
£115.51 · 296% more, worseFs159 Hz +45%, worse
Qts0.64 –
Vas1.5 L −64%, better
BL9.4 T·m +59%, better
Xmax3.5 mm –
Sensitivity91.5 dB +0.8
AccutonC90-6-724
£527.46 · 1708% more, worseFs83 Hz −25%, better
Qts0.60 −6%
Vas5.1 L +25%, worse
BL6.0 T·m –
Xmax3 mm −12%, worse
Sensitivity88.4 dB −2.3, worse
LavoceWSF051.02
No current priceFs106 Hz −4%
Qts0.60 −6%
Vas3.3 L −20%, better
BL6.4 T·m +8%
Xmax3.1 mm −9%
Sensitivity89.7 dB −1
Dayton AudioCFC150-4
No current priceFs77 Hz −30%, better
Qts0.70 +9%
Vas4.2 L –
BL4.7 T·m −20%, worse
Xmax3.5 mm –
Sensitivity85.6 dB −5.1, worse
PRV Audio69FR250-4
No current priceFs82 Hz −25%, better
Qts0.70 +9%
Vas13.9 L +241%, worse
BL6.1 T·m +3%
Xmax3.5 mm –
Sensitivity92.2 dB +1.5
PeerlessFSL-0512R01-08
No current priceFs120 Hz +9%
Qts0.58 −9%
Vas3.5 L −15%, better
BL6.4 T·m +9%
Xmax4.3 mm +27%, better
Sensitivity91 dB –
HiViB4N
No current priceFs56 Hz −49%, better
Qts0.52 −19%, better
Vas4.5 L +10%, worse
BL5.1 T·m −14%, worse
Xmax3.2 mm −6%
Sensitivity83 dB −7.7, worse
MonacorSP-4/60PRO
No current priceFs92 Hz −16%, better
Qts0.60 −6%
Vas3 L −26%, better
BL5.8 T·m –
Xmax2.3 mm −32%, worse
Sensitivity87.5 dB −3.2, worse
Dayton AudioCFC120-8
No current priceFs60 Hz −45%, better
Qts0.56 −12%, better
Vas4.6 L +13%, worse
BL5.1 T·m −13%, worse
Xmax2.5 mm −26%, worse
Sensitivity83.6 dB −7.1, worse
Lii AudioST-5
No current priceFs56 Hz −49%, better
Qts0.66 +3%
Vas14.3 L +250%, worse
BL5.8 T·m –
Xmax4 mm +18%, better
Sensitivity86.7 dB −4, worse
Dayton AudioCFC150-8
No current priceFs80 Hz −27%, better
Qts0.87 +36%, worse
Vas4.1 L –
BL5.7 T·m –
Xmax3.5 mm –
Sensitivity84.8 dB −5.9, worse
Dayton AudioE150MR-8
No current priceFs74 Hz −33%, better
Qts0.58 −9%
Vas8 L +96%, worse
BL6.1 T·m +4%
Xmax2.7 mm −21%, worse
Sensitivity88.9 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
- Parts Express5.0 out of 53 ratings · Checked 25 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 |
|---|---|---|---|---|
Parts Express Import VAT and duty may apply | £29.17, the lowest price | 6 in stock | Visit shop at Parts Express |
Best price over time
Tracked since 27 Aug