Short answer: the JBL Synthesis SCL-7. It ranks #14 of 28 in-wall speakers by sound quality, rated 3.7/5, at $2,419.90; the Miller & Kreisel IW150 ranks #17, rated 3.6/5, and costs $4,998, so there is little reason to consider the other one.
The JBL Synthesis SCL-7 is the more accurate, deeper-bass pick. An affordable way into a premium in-wall range, with a horn tweeter and consistent coverage across the room. Its measured preference score, a predictor of how neutral it sounds, is 3.46 against 2.88 for the Miller & Kreisel IW150. Its bass reaches about 67.4Hz before falling 3dB, against 95.2Hz for the Miller & Kreisel IW150. Watch for: The response sits in a wide 4.1dB reference band with 0.43dB average on-axis deviation, so tonal balance is less even than the JBL Synthesis SCL-6.
Why pick 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-7. It is rated higher for sound quality than the Miller & Kreisel IW150 and costs less, so it is the default pick unless a specific strength of the other one matters more to you.
Looking for alternatives? See the complete Passive Home rankings.
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Specifications Side By Side
| JBL Synthesis SCL-7 | Miller & Kreisel IW150 | |
|---|---|---|
| Price | $2,419.90 per pair | $4,998 per pair |
| Ranked | #14 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” 2410H-2 compression driver on HDI horn (2-way) | 2x 5.25” polypropylene bass/midrange drivers, 3x 1” soft fabric dome tweeters |
| Enclosure | In-wall, open back | In-wall |
| Mounting Cutout | 157 x 458mm (6.18 x 18.03 in) | 288W x 331H mm |
| Dimensions | 19.1”H x 7.3”W x 3.9”D (486 x 186 x 99 mm) (93mm mounting depth) | 13.9”H x 12.2”W (354 x 311 mm) baffle (95mm mounting depth) |
| Weight | 12.6 lbs (5.72 kg) | 18.7 lbs (8.5 kg) |
| Sensitivity | 88dB (2.83V/1m, 2pi anechoic) | 90dB |
| Impedance | 4 ohms | 4 ohms |
| Power Handling | 25-150W recommended amplifier power | 25-400W recommended amplifier power |
| Frequency Response | 55Hz-30kHz -6dB (manufacturer, 2pi) | 80Hz-20kHz +/-3dB (manufacturer) |
| Crossover Frequency | 2.0kHz | - |
| Bass Extension (-3dB) | 67.4Hz (measured, spinorama.org ASR data) | 95.2Hz (measured, Erin’s Audio Corner) |
| Bass Extension (-10dB) | 42.3Hz (measured, spinorama.org ASR data) | 68.7Hz (measured, Erin’s Audio Corner) |
| Spinorama Preference Score | 3.46 | 2.88 |
| Spinorama Preference Score with Perfect Sub | 6.21 | 6.32 |
| DIY Kit | No | No |
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