MonacorSPM-100/8
£13.40 · 12% more, worseFs75 Hz +19%, worse
Qts0.67 +3%
Vas4 L –
BL4.1 T·m –
Xmax1 mm −75%, worse
Sensitivity84.3 dB +1.5
4-inch LF driver · 26 mm voice coil · 30 W
GRS 4SMP-8 8Ω
8 Ω · 50–6000 Hz
£11.96
SteadyParts Express · 115 in stock · Ships from United States · All 2 offers
- Fs
- 63Hz
- Xmax
- 4mm
- SPL
- 83dB
- Pe
- 30W
- BL
- 4.2T·m
- Vd
- 22cm³
- Qts
- 0.65
- Vas
- 4L
GRS 4SMP-8 is a 4-inch 8 ohm LF driver rated at 30 W RMS. The validated T/S data includes Fs 63 Hz, Qts 0.65, Vas 4 L, Xmax 4 mm, sensitivity 82.8 dB, plus 22 cm³ Vd and 76 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 £11.96.
The published T/S values agree with each other
Thiele/Small
- Fs
- 63Hz
- Qts
- 0.65
- Qes
- 0.83
- Qms
- 3
- Vas
- 4L
- Re
- 5.5Ω
- Le
- 0.58mH
Motor and cone
- BL
- 4.2T·m
- Sd
- 54cm²
- Mms
- 7g
- Xmax
- 4mm
- Vd †
- 22cm³
- Voice coil
- 26mm
Power and response
- Sensitivity †
- 82.8dB
- Manufacturer sensitivity
- 84.4dB
- Power
- 30W
- Impedance
- 8Ω
- Range
- 50–6000Hz
- EBP †
- 76 · Sealed or vented
Size and mounting
- Diameter
- 101.6mm
Other published values
- Cms
- 0.97mm/N
Sensitivity shows 82.8 dB, calculated from the T/S values. GRS publishes 84.4 dB, 1.6 dB apart.
† Calculated by bits from the published values
What this validation status means
Everything else GRS lists
LF · Primary · 4″
- BL
- 4.2T·m
- Fs
- 63Hz
- Le
- 0.58mH
- Re
- 5.5Ω
- Sd
- 54cm²
- Cms
- 0.97mm/N
- Mms
- 7g
- Qes
- 0.83
- Qms
- 3
- Qts
- 0.65
- SPL
- 82.8dB
- Vas
- 4L
- Xmax
- 4mm
- Power
- 30W
- Impedance
- 8Ω
- Sensitivity
- 84.4dB
- Low limit
- 50Hz
- Calculated sensitivity †
- 82.8dB
- High limit
- 6000Hz
- Manufacturer sensitivity
- 84.4dB
- Voice coil
- 26mm
- Diameter
- 101.6mm
02
Compare
Same-size drivers, compared with the 4SMP-8. Clear differences are green when better and red when worse.
This driver4SMP-8
Best price
£11.96
Fs
63 Hz
Qts
0.65
Vas
4 L
BL
4.2 T·m
Xmax
4 mm
Sensitivity
82.8 dB
Power
30 W
MonacorSPM-116/8
£13.40 · 12% more, worseFs75 Hz +19%, worse
Qts0.57 −12%, better
Vas4.5 L +13%, worse
BL4.2 T·m –
Xmax1.5 mm −63%, worse
Sensitivity85.7 dB +2.9, better
VisatonFR 10
£13.48 · 13% more, worseFs90 Hz +43%, worse
Qts0.67 +3%
Vas2.3 L −43%, better
BL4.6 T·m +10%
Xmax1.5 mm −63%, worse
Sensitivity84.5 dB +1.7
LavoceWSF030.70
£13.56 · 13% more, worseFs112 Hz +78%, worse
Qts0.61 −6%
Vas0.9 L −78%, better
BL4.7 T·m +11%, better
Xmax3.3 mm −18%, worse
Sensitivity84.5 dB +1.7
PeerlessGBS-85N25PR07-04
£14.59 · 22% more, worseFs130 Hz +106%, worse
Qts0.70 +8%
Vas0.47 L −88%, better
BL4.5 T·m +7%
Xmax3.0 mm −26%, worse
Sensitivity83.1 dB –
PRV Audio4MR60-4
£14.89 · 25% more, worseFs90 Hz +43%, worse
Qts0.68 +5%
Vas3.3 L −19%, better
BL3.4 T·m −19%, worse
Xmax2.9 mm −28%, worse
Sensitivity87 dB +4.2, better
VisatonSL 87 FE
£15.07 · 26% more, worseFs120 Hz +90%, worse
Qts0.65 –
Vas1.5 L −62%, better
BL4.0 T·m −6%
Xmax1.8 mm −56%, worse
Sensitivity87.1 dB +4.3, better
Dayton AudioPC105-8
£16.70 · 40% more, worseFs85 Hz +35%, worse
Qts0.64 –
Vas3.4 L −15%, better
BL4.1 T·m –
Xmax2 mm −50%, worse
Sensitivity85.7 dB +2.9, better
PeerlessGBS-115N25AL01-04
£21.32 · 78% more, worseFs90 Hz +43%, worse
Qts0.63 −3%
Vas1.8 L −55%, better
BL4.5 T·m +8%
Xmax4.8 mm +21%, better
Sensitivity84.3 dB +1.5
SB AcousticsSB12PFC25-8
£21.98 · 84% more, worseFs64 Hz –
Qts0.56 −14%, better
Vas4.3 L +7%
BL4.5 T·m +7%
Xmax5 mm +25%, better
Sensitivity84.4 dB +1.6
Dayton AudioDMA105-8
£22.10 · 85% more, worseFs72 Hz +14%, worse
Qts0.63 −3%
Vas4.2 L +6%
BL4.5 T·m +7%
Xmax2.5 mm −38%, worse
Sensitivity84.8 dB +2, better
CIAREHW129
£23.44 · 96% more, worseFs75 Hz +19%, worse
Qts0.55 −15%, better
Vas6.1 L +52%, worse
BL5.2 T·m +24%, better
Xmax3.9 mm –
Sensitivity87.3 dB +4.5, better
Dayton AudioND90-4
£25.04 · 109% more, worseFs90 Hz +43%, worse
Qts0.63 −3%
Vas1.1 L −74%, better
BL3.5 T·m −17%, worse
Xmax4 mm –
Sensitivity82.4 dB –
Dayton AudioND90-8
£25.87 · 116% more, worseFs71 Hz +12%, worse
Qts0.65 –
Vas1.8 L −56%, better
BL4.3 T·m –
Xmax4 mm –
Sensitivity81.2 dB −1.6
LavoceCSF051.21
£29.17 · 144% more, worseFs110 Hz +75%, worse
Qts0.64 –
Vas4.1 L –
BL5.9 T·m +41%, better
Xmax3.4 mm −15%, worse
Sensitivity90.7 dB +7.9, better
Dayton AudioRS100-8
£29.91 · 150% more, worseFs92 Hz +46%, worse
Qts0.58 −11%, better
Vas1.4 L −64%, better
BL4.2 T·m –
Xmax3.5 mm −13%, worse
Sensitivity83.7 dB +0.9
Dayton AudioRS100P-8
£29.91 · 150% more, worseFs96 Hz +52%, worse
Qts0.54 −17%, better
Vas1.8 L −54%, better
BL4.0 T·m −6%
Xmax3.7 mm −7%
Sensitivity85.5 dB +2.7, better
Dayton AudioND105-8
£30.48 · 155% more, worseFs67 Hz +6%
Qts0.66 –
Vas3.0 L −26%, better
BL5.4 T·m +30%, better
Xmax4 mm –
Sensitivity82.8 dB –
Dayton AudioND105-4
£30.48 · 155% more, worseFs79 Hz +25%, worse
Qts0.61 −6%
Vas2.0 L −51%, better
BL4.5 T·m +8%
Xmax4 mm –
Sensitivity83.7 dB +0.9
Dayton AudioRS125P-4
£37.39 · 213% more, worseFs70 Hz +11%, worse
Qts0.48 −26%, better
Vas4.0 L –
BL3.5 T·m −17%, worse
Xmax4 mm –
Sensitivity85.8 dB +3, better
CelestionAN3510
£41.86 · 250% more, worseFs113 Hz +80%, worse
Qts0.65 –
Vas1.9 L −53%, better
BL4.6 T·m +9%
Xmax2.3 mm −44%, worse
Sensitivity87.7 dB +4.9, better
CelestionTFX0412
£69.00 · 477% more, worseFs95 Hz +51%, worse
Qts0.59 −9%
Vas2.2 L −45%, better
BL5.4 T·m +29%, better
Xmax4 mm –
Sensitivity86.5 dB +3.7, better
VisatonB 80
£72.39 · 505% more, worseFs110 Hz +75%, worse
Qts0.63 −3%
Vas1.8 L −55%, better
BL4.2 T·m –
Xmax2.2 mm −45%, worse
Sensitivity87.4 dB +4.6, better
SEASH1304-08 MCA12RC
£76.51 · 540% more, worseFs68 Hz +8%
Qts0.56 −14%, better
Vas5 L +25%, worse
BL4.2 T·m –
Xmax0.9 mm −78%, worse
Sensitivity85.3 dB +2.5, better
Tang BandW3-1878
£125.60 · 950% more, worseFs75 Hz +19%, worse
Qts0.28 −57%, better
Vas3.1 L −23%, better
BL4.3 T·m –
Xmax4 mm –
Sensitivity87.9 dB +5.1, better
KartesianWIB120_VHE
No current priceFs68 Hz +8%
Qts0.56 −14%, better
Vas4.4 L +10%, worse
BL4.0 T·m −5%
Xmax4 mm –
Sensitivity86 dB +3.2, better
WavecorWF118OM02
No current priceFs61 Hz −3%
Qts0.65 –
Vas5.5 L +38%, worse
BL4.2 T·m –
Xmax1.9 mm −53%, worse
Sensitivity84.5 dB +1.7
WavecorWF120BD04
No current priceFs62 Hz –
Qts0.37 −43%, better
Vas4.3 L +6%
BL4.5 T·m +7%
Xmax4 mm –
Sensitivity86 dB +3.2, better
EminenceALPHA 4-4
No current priceFs120 Hz +90%, worse
Qts0.63 −3%
Vas1.8 L −56%, better
BL4.1 T·m –
Xmax2.6 mm −35%, worse
Sensitivity88.4 dB +5.6, better
PeerlessPLS-75F25AL02-08
No current priceFs100 Hz +59%, worse
Qts0.74 +14%, worse
Vas1.1 L −73%, better
BL3.6 T·m −15%, worse
Xmax3.4 mm −16%, worse
Sensitivity83.1 dB –
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 51 rating · 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 |
|---|---|---|---|---|
Parts Express Import VAT and duty may apply | £11.96, the lowest price | 115 in stock | Visit shop at Parts Express | |
SoundImports Import VAT and duty may apply | £16.70 | 40% above the lowest price | 4 in stock | Visit shop at SoundImports |
Best price over time
Tracked since 1 Apr