Short answer: the JBL Synthesis SCL-3. It ranks #13 of 28 in-wall speakers by sound quality, rated 3.7/5, at $7,259.90. The Miller & Kreisel IW150 ranks #17, rated 3.6/5, at $4,998, $2,261.90 cheaper, which does not close the gap in sound quality.
The JBL Synthesis SCL-3 is the more accurate, deeper-bass option. An in-wall or in-ceiling speaker with a horn tweeter, high sensitivity and bi-amp terminals for custom home theaters. Its measured preference score, a predictor of how neutral it sounds, is 3.80 against 2.88 for the Miller & Kreisel IW150. Its bass reaches about 72.4Hz before falling 3dB, against 95.2Hz for the Miller & Kreisel IW150. The tradeoff: Bass rolls off early, at 72.4Hz for -3dB and about 45.8Hz for -10dB in free air, so it needs a subwoofer.
The case for the Miller & Kreisel IW150: An in-wall speaker with three tweeters beside two woofers, designed to spread sound evenly across a room from one opening. The tradeoff: Bass is thin: measured -3dB is 95.2Hz and -6dB is 82.0Hz, and Miller & Kreisel rates it only to 80Hz, so a subwoofer is required, and even with a perfect subwoofer the score reaches only 6.32.
Buy the JBL Synthesis SCL-3. It is rated higher for sound quality, and saving $2,261.90 with the Miller & Kreisel IW150 does not make up for the sound-quality gap.
Still deciding? The full Passive Home rankings cover every ranked option.
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Specifications Side By Side
| JBL Synthesis SCL-3 | Miller & Kreisel IW150 | |
|---|---|---|
| Price | $7,259.90 per pair | $4,998 per pair |
| Ranked | #13 of 28 in In-Wall & In-Ceiling Speakers | #17 of 28 in In-Wall & In-Ceiling Speakers |
| Drivers | Two 5.25” aluminum matrix cone woofers, 1” 2409H compression driver on HDI horn (2-way) | 2x 5.25” polypropylene bass/midrange drivers, 3x 1” soft fabric dome tweeters |
| Enclosure | In-wall/in-ceiling, integrated MDF back box | In-wall |
| Dimensions | 16.5”H x 16.5”W x 6”D (418 x 418 x 153 mm) | 13.9”H x 12.2”W (354 x 311 mm) baffle (95mm mounting depth) |
| Weight | 24.3 lbs (11.02 kg) | 18.7 lbs (8.5 kg) |
| Sensitivity | 91dB (2.83V/1m) | 90dB |
| Impedance | 6 ohms | 4 ohms |
| Power Handling | 200W RMS maximum recommended amplifier power | 25-400W recommended amplifier power |
| Frequency Response | 65Hz-33kHz -6dB (manufacturer, on-axis) | 80Hz-20kHz +/-3dB (manufacturer) |
| Crossover Frequency | 1.3kHz | - |
| Bass Extension (-3dB) | 72.4Hz (measured, JBL data on spinorama.org) | 95.2Hz (measured, Erin’s Audio Corner) |
| Bass Extension (-10dB) | 45.8Hz (measured, JBL data on spinorama.org) | 68.7Hz (measured, Erin’s Audio Corner) |
| Spinorama Preference Score | 3.80 | 2.88 |
| Spinorama Preference Score with Perfect Sub | 6.42 | 6.32 |
| DIY Kit | No | No |
| Mounting Cutout | - | 288W x 331H mm |
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