Short answer: the KEF Q150. It ranks #17 of 56 bookshelf speakers by sound quality at $350; the ELAC BS U5 ranks #29 and costs $856, so there is not much of a tradeoff to weigh.
What the KEF Q150 gets right: Two-way coaxial (Uni-Q) design with a 1” dome tweeter and 5.25” mid-range time-aligned in a single driver assembly, available in ported or sealed configuration. The catch: 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.
The case for the ELAC BS U5: This slim three-way coaxial design (an Andrew Jones creation) shows a fairly even on-axis response up to 3kHz, with off-axis behavior notably smoother than the on-axis curve. The tradeoff: Distortion is very high right at both crossover points - around 270Hz (mid-range) and 2700Hz (tweeter) - at both 86dB and 96dB SPL/1m, exceeding 3% at the mid-range crossover.
Buy the KEF Q150. It ranks higher for sound quality than the ELAC BS U5 and costs less, so there is no real case for the other one.
Specifications Side By Side
| KEF Q150 | ELAC BS U5 | |
|---|---|---|
| Price | $350 Discontinued | $856 Discontinued |
| Ranked | #17 of 56 in Medium Size Bookshelf Speakers | #29 of 56 in Medium Size Bookshelf Speakers |
| Bass Extension (-10dB) | 44Hz (measured, Erin’s Audio Corner) | 60Hz (measured, Audio Science Review) |
| Bass Extension (-3dB) | 51Hz (measured, Erin’s Audio Corner) | 78Hz (measured, Audio Science Review) |
| Dimensions | 11.9"H x 7.1"W x 10.9"D (303 x 180 x 278 mm) | 13.4"H x 7"W x 11.5"D (339.1 x 178.0 x 293.1 mm) |
| Impedance | 8 ohms nominal, about 4.7 ohms minimum (measured, Erin’s Audio Corner) | 4 ohms nominal (3.4 ohms minimum) |
| Sensitivity | ~85dB (300Hz-3kHz on-axis, measured, Erin’s Audio Corner) | 83dB (2.83V/1m, measured, Audio Science Review) |
| Drivers | 130mm (5.25") aluminium Uni-Q woofer, 25mm (1") vented aluminium dome tweeter | 1" tweeter + 5.25" woofer |
| Discontinued | Yes | Yes |
| Weight | 12.3 lbs / 5.6 kg each | 13.2 lbs / 6 kg |
| Woofer Cabinet | ported, rear | ported, rear |
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- ELAC BS U5 vs JBL Stage 2 250B
The Two Speakers In Full
KEF Q150: $350 Discontinued Amazon
Pros: Two-way coaxial (Uni-Q) design with a 1” dome tweeter and 5.25” mid-range time-aligned in a single driver assembly, available in ported or sealed configuration. Exceptional soundstage depth, a hallmark of KEF’s coaxial designs that the reviewer says few other speakers match. Bass extension reaches into kick-drum territory, respectable for a compact bookshelf speaker. Resonances present in measurements are consistent across on- and off-axis readings, meaning they can be effectively corrected with EQ. Distortion profile is essentially the same whether run sealed or ported, since a subwoofer crossover point sits above where the differences would matter anyway. At its sale price (around $300, sometimes seen at $400), the reviewer considers it a clear step up from his previous budget favorite in this range, the Emotiva B1+, mainly due to the superior soundstage depth.
Cons: 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. A mild dip in the 1-2kHz region reduces vocal fullness somewhat. Unexplained resonances appear in measurements and persist in both sealed and ported configurations, pointing to enclosure or panel vibration rather than the port. Horizontal radiation is narrower than the reviewer generally prefers from KEF’s lineup, with directivity that widens somewhat around 1.2kHz (near a resonance) and again above about 5kHz. Compression testing at high output (102dB) shows significant nonlinearity, especially at lower frequencies - noticeably worse than a comparable Arendal bookshelf speaker costing over twice as much, which held up better until 80Hz. Not intended for loud listening without a subwoofer - the woofer will over-exert itself without a high-pass filter, and the reviewer recommends crossing over at 80-120Hz. At full retail price (around $600/pair), the value proposition is far less certain than at sale pricing. Discontinued.
Full KEF Q150 review and specifications →
| Bass Extension (-10dB) | 44Hz (measured, Erin's Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 51Hz (measured, Erin's Audio Corner) |
| Dimensions | 11.9"H x 7.1"W x 10.9"D (303 x 180 x 278 mm) |
| Discontinued | Yes |
| Drivers | 130mm (5.25") aluminium Uni-Q woofer, 25mm (1") vented aluminium dome tweeter |
| Impedance | 8 ohms nominal, about 4.7 ohms minimum (measured, Erin's Audio Corner) |
| Sensitivity | ~85dB (300Hz-3kHz on-axis, measured, Erin's Audio Corner) |
| Weight | 12.3 lbs / 5.6 kg each |
| Woofer Cabinet | ported, rear |
As an eBay Partner, we may be compensated if you make a purchase.
- Links
- Reviews, Comparisons and Sound Samples
- Erin’s Audio Corner: Kef’s Cheapest Bookshelf. Is the Q150 worth your money?
- Erin’s Audio Corner Website KEF Q150
- GR-Research: KEF Q150… can it get any BETTER?
- Erin’s Audio Corner: 5 AWESOME SPEAKERS Under $1000 You Won’t Regret
- Erin’s Audio Corner: Budget Stereo Systems You Will Love
- Reddit Search for KEF Q150 Review
- Head-to-Head Comparisons
ELAC BS U5: $856 Discontinued
Pros: This slim three-way coaxial design (an Andrew Jones creation) shows a fairly even on-axis response up to 3kHz, with off-axis behavior notably smoother than the on-axis curve. Predicted in-room response looks like it should give good tonality. Vertical directivity is better than average, a benefit of the coaxial layout.
Cons: Distortion is very high right at both crossover points - around 270Hz (mid-range) and 2700Hz (tweeter) - at both 86dB and 96dB SPL/1m, exceeding 3% at the mid-range crossover. Minimum impedance dips to 3.4 ohms with a possible resonance around 500Hz visible in the impedance/phase curve. Discontinued.
Full ELAC BS U5 review and specifications →
| Bass Extension (-10dB) | 60Hz (measured, Audio Science Review) |
|---|---|
| Bass Extension (-3dB) | 78Hz (measured, Audio Science Review) |
| Dimensions | 13.4"H x 7"W x 11.5"D (339.1 x 178.0 x 293.1 mm) |
| Discontinued | Yes |
| Drivers | 1" tweeter + 5.25" woofer |
| Impedance | 4 ohms nominal (3.4 ohms minimum) |
| Sensitivity | 83dB (2.83V/1m, measured, Audio Science Review) |
| Weight | 13.2 lbs / 6 kg |
| Woofer Cabinet | ported, rear |
As an eBay Partner, we may be compensated if you make a purchase.
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