Three ways makers declare tiller noise
They cannot be ranked against each other: STIHL's KombiSystem table, a guaranteed sound power level under the EU noise directive, and a declaration under EN 709.
STIHL's KombiSystem table
The BF-KM mini-cultivator is an attachment that fits STIHL's KombiEngines. Its manual lists the sound pressure at the ear under ISO 11201 and the sound power under ISO 3744 for every approved engine, all measured one way: idling and rated maximum speed in a ratio of 1:6, with a K of 2.0 dB(A). That makes it the fairest comparison in the category.
| Engine with the BF-KM | Power | At the ear | Sound power |
|---|
| KMA 135 R | Battery | 74 dB(A) | 86 dB(A) |
| KMA 200 R | Battery | 74 dB(A) | 87 dB(A) |
| KMA 80 R | Battery | 76 dB(A) | 88 dB(A) |
| KMA 120 R | Battery | 76 dB(A) | 88 dB(A) |
| KM 94 R | Gas | 94 dB(A) | 106 dB(A) |
| KM 131 R | Gas | 99 dB(A) | 108 dB(A) |
Guaranteed sound power under 2000/14/EC
The EU noise directive covers tillers under the name motor hoes and requires a guaranteed sound power level, a ceiling the maker commits to. Three US-sold machines declare one: EGO's CTA9500 cultivator head at 91 dB(A), Honda's F220 at 92 and Honda's FG110 at 93.
That figure decides the order within this group. The ear figures sit beside it unranked, because each comes from a different method. EGO names none, while Honda cites prEN 1553 for the F220 and the machinery directive for the FG110.
EN 709, used by one machine
STIHL's MM 56 manual declares its BF-MM cultivator tines under EN 709, the European tiller safety standard, at 87 dB(A) for the person walking behind and 96 dB(A) of sound power. No other machine here declares under EN 709, so the MM 56 C-E stands in a group by itself.
Is a battery tiller quieter than a gas one?
Yes, by a wide margin. On STIHL's BF-KM table the gap at the ear between gas and battery is 20 to 25 dB(A), with nothing else changed.
That table isolates the engine. Same attachment, same tines, same method, same document. Fitted to the gas KM 94 R, the BF-KM reaches 94 dB(A) at the ear and 106 dB(A) of sound power, and on the gas KM 131 R, 99 and 108, while on the battery KMA 135 R it declares 74 and 86. Ten decibels is roughly a doubling of perceived loudness. A gap of 20 to 25 puts the battery machine in a different class altogether. The sound power gap, which is what the neighbors experience, is similar at 20 to 22 dB(A).
A bigger battery engine is not louder, either. The KMA 200 R, STIHL's most powerful KombiEngine, ties the KMA 135 R at the ear and sits one decibel above it in sound power. The KMA 80 R and KMA 120 R come in two decibels louder at the ear than either.
Which quiet tiller fits your garden?
For flower beds, borders and weeding between plants, a battery cultivator head wins on quiet by a wide margin. The STIHL KMA 135 R with the BF-KM has the lowest declared pair of any machine STIHL USA sells, and the KMA 80 R is the value version two decibels behind. EGO's CTA9500 suits owners already on EGO's 56 V batteries, with the lowest guaranteed sound power of the three guaranteed declarations.
A vegetable garden is different. A 9 inch cultivator would take all afternoon there, while the F220 is a real 21 inch tiller, and its guaranteed 92 dB(A) is the lowest of the gas machines that declare one. The FG110 is the small four stroke for raised beds beyond the reach of a cord.
One gas engine for cultivating, edging and trimming? That is the MM 56 C-E, STIHL's multi-tool, with a full EN 709 declaration. If edging is the bigger job, our lawn edger guide compares battery edgers and STIHL's KombiSystem edger attachments, which fit the same KombiEngines as the BF-KM.
Sun Joe's 93 has no weighting
The figure carries no A-weighting, does not say whether it is sound pressure or sound power, and names no distance or standard. Sun Joe's product pages include a spec row reading "Decibels (dB) 93" for the TJ600E, TJ603E and TJ604E, and the operator's manuals print nothing.
The same 93 appears on a 6.5 amp, a 12 amp and a 13.5 amp model. One number, it seems, reused across the range.
The three are listed under also considered so readers searching for them know why they are not ranked, and the 93 is compared with nothing else in this guide.
Greenworks shows none on its 40V and 80V cultivator pages, only the phrase "Low Noise". Champion Power Equipment's front tine and rear tine tiller pages and their English operator's manuals print none. Honda's US pages and US owner's manuals print none for any tiller, which is why the Honda figures here come from its European manuals, and Honda's larger US FC600 and FRC800 are left out because we did not match them to a European manual. Husqvarna's US tiller address no longer shows a tiller range, though its TF 224 has a US support page for parts and manuals. Worx showed no tiller on its US site when we looked. Without a figure, none of these brands has a tiller in the ranking.
On a machine you walk behind for an hour, what reaches the operator's ear is the number to read. Sound power is what the machine sends into the street, and the guaranteed value is the ceiling the maker commits to under EU law.
They are different quantities and never ranked against each other. Sound power vs sound pressure sets out what separates a tiller's two numbers, and the string trimmer guide uses the same approach for another garden tool.
Most people need about three decibels before they notice a difference easily. A one decibel gap between two cultivators is a tie in practice.
