Short answer: both are discontinued, so this only matters if you are buying used. Used, the KEF Q150 is the better pick: it ranks #48 of 179 bookshelf speakers by sound quality (rated 3.7/5), against #119 (rated 2.9/5) for the Acoustic Energy AE100 Mk2. If you want one new, the KEF Q1 Meta replaces the KEF Q150 and is rated 3.6/5 at $399.99.
The KEF Q150 is the better-sounding, deeper-bass option. Compact bookshelf speakers with a tweeter set in the center of the woofer, usable ported or sealed and easy to correct with EQ. Its bass reaches about 51Hz before falling 3dB, against 63Hz for the Acoustic Energy AE100 Mk2. The tradeoff: A high-frequency lift in the estimated in-room response makes it sound noticeably brighter in an untreated room than in a heavily acoustically-treated one: a real preference factor depending on your room’s furnishings.
What the Acoustic Energy AE100 Mk2 does well: A nicely finished discontinued bookshelf speaker with wide dispersion and consistent off-axis sound that responds well to EQ. Watch for: High-frequency level runs noticeably too hot regardless of placement: the reviewer tried four different setups (near/far from wall, on-axis, 30° off-axis) at two listening distances and couldn’t get it to sound right at any of them.
Buy the KEF Q150 only if you find one used in good condition; both are discontinued, and it is the better rated of the two. For a new speaker, buy the KEF Q1 Meta, which replaces the KEF Q150.
Looking for alternatives? See the complete Passive Home rankings.
Measured Differences
- Close enough not to matter: bass extension (44 Hz vs 42 Hz, 10 dB down); preference score with a subwoofer (7.1 vs 7.2).
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Specifications Side By Side
| KEF Q150 | Acoustic Energy AE100 Mk2 | |
|---|---|---|
| Price | $350 per pair Discontinued | $399 per pair Discontinued |
| Ranked | #48 of 179 in Medium Size Bookshelf Speakers | #119 of 179 in Medium Size Bookshelf Speakers |
| Bass Extension (-10dB) | 44Hz (measured, Erin’s Audio Corner) | 42Hz (measured, Erin’s Audio Corner) |
| Bass Extension (-3dB) | 51Hz (measured, Erin’s Audio Corner) | 63Hz (measured, Erin’s Audio Corner) |
| Dimensions | 11.9”H x 7.1”W x 10.9”D (303 x 180 x 278 mm) | 11.4”H x 6.5”W x 9.8”D (290 x 165 x 250 mm) |
| Impedance | 8 ohms nominal, about 4.7 ohms minimum (measured, Erin’s Audio Corner) | 6 ohms nominal, 4.7 ohms minimum (measured, Erin’s Audio Corner) |
| Sensitivity | ~85dB (300Hz-3kHz on-axis, measured, Erin’s Audio Corner) | 84dB (measured average, Erin’s Audio Corner) |
| Drivers | 130mm (5.25”) aluminium Uni-Q woofer, 25mm (1”) vented aluminium dome tweeter | 5.25” midwoofer, 1” soft fabric dome tweeter with waveguide |
| Weight | 12.3 lbs (5.6 kg) each | 20.1 lbs (9.1 kg) each |
| Woofer Cabinet | ported, rear | ported, rear slot port |
| Spinorama Preference Score | 4.86 | 4.96 |
| Spinorama Preference Score with Perfect Sub | 7.06 | 7.18 |
| DIY Kit | No | No |
| Crossover Frequency | - | 2.9kHz |
Where the Ratings Come From
- KEF Q150: Spinorama.org measurements and reviews by Erin’s Audio Corner and GR-Research.
- Acoustic Energy AE100 Mk2: Spinorama.org measurements and reviews by Erin’s Audio Corner.
This comparison is generated from the ratings, specifications and measurements on each product’s own page, and it updates when that data changes. How we rank explains how each rating is decided.
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