How we scoreBlogAdvertise
Amidioheadphones · speakers · earbuds
  1. Amidio
  2. Compare
  3. Onyx Studio 9 vs M18 SPEJSG2-0 Akku-Baustellenlautsprecher

Harman-Kardon Onyx Studio 9 vs Milwaukee M18 SPEJSG2-0 Akku-Baustellenlautsprecher

What Onyx Studio 9 does better (2) and where M18 SPEJSG2-0 Akku-Baustellenlautsprecher wins (0) — every spec side by side.

Harman-Kardon Onyx Studio 9
Harman-Kardon · 2025Onyx Studio 9
5.0Score
2 advantages≈ $160
Higher score
vs
Milwaukee M18 SPEJSG2-0 Akku-Baustellenlautsprecher
0 advantages≈ $110
6.4Sound6.5
Dimensions

Size comparison

Onyx Studio 9M18 SPEJSG2-0 Akku-Baustellenlautsprecher
389.2 × 387.5130145 × 333213
Onyx Studio 9M18 SPEJSG2-0 Akku-BaustellenlautsprecherDifference
Height387.5 mm333 mm+54.5 mm
Width389.2 mm145 mm+244.2 mm
Depth130 mm213 mm−83 mm
Weight3,300 g3,800 g−500 g

Drawn to the same scale from the official dimensions (front and side).

Why is Onyx Studio 9 better than M18 SPEJSG2-0 Akku-Baustellenlautsprecher?

  1. Output power50 W vs 44 W+14%
  2. Weight3,300 g vs 3,800 g+15%

Why is M18 SPEJSG2-0 Akku-Baustellenlautsprecher better than Onyx Studio 9?

M18 SPEJSG2-0 Akku-Baustellenlautsprecher has no measurable advantages in this pair.

Specifications

Side by side

Sound
Output power50 W44 W
Speaker channelsStereo2.0
Channel count—2
Lowest frequency50 Hz—
Highest frequency20,000 Hz—
StereoYesYes
Battery & charging
Battery life8 h—
Battery capacity4,722 mAh—
Charging time4 h—
Power bank functionYes—
Mains poweredNoNo
Battery powered (portable)YesYes
Connectivity
WirelessYesYes
Bluetooth version5.35.3
Bluetooth codecsSBCSBC
Hi-res codec (LDAC / aptX HD / LHDC)NoNo
aptXNoNo
LDACNoNo
AuracastYes—
USB-CYesYes
3.5 mm jack / AUXYes—
Design & build
Weight3,300 g3,800 g
Width389 mm145 mm
Height388 mm333 mm
Depth130 mm213 mm
ColoursBlack—
Features
Hands-free callsYes—
Party / stereo pairingYes—
To compare: 0up to 4 models
Compare