Short answer: the PSB Imagine B50, if you are buying new. The KEF Q150 measures as well as it (#49 vs #53 of 160 bookshelf speakers, 3.7/5 vs 3.7/5) but is discontinued, so only consider it used; the PSB Imagine B50 is still sold new at $999. The KEF Q150’s replacement, the KEF Q1 Meta, is rated 3.6/5.
The KEF Q150 is the deeper-bass option. 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. Its bass reaches about 51Hz before falling 3dB, against 69.6Hz for the PSB Imagine B50. 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 PSB Imagine B50: The standmount sibling to the PSB Imagine T65 tower, from PSB’s current 2023-refreshed Imagine line, using the same titanium-dome tweeter and woven-carbon-fiber woofer platform. Watch for: On-axis smoothness of just 0.235 and a deviation of 0.368dB are unremarkable for the price, with a +0.22dB per octave upward tilt giving it a brighter-leaning balance, a predicted in-room smoothness of just 0.35, and a Harman in-room bass extension estimate of only 49Hz.
Buy the PSB Imagine B50 new; the KEF Q150 is no longer sold new, so it only makes sense as a used find.
Looking for alternatives? See the complete Passive Home rankings.
Specifications Side By Side
| KEF Q150 | PSB Imagine B50 | |
|---|---|---|
| Price | $350 per pair Discontinued | $999 per pair |
| Ranked | #49 of 160 in Medium Size Bookshelf Speakers | #53 of 160 in Medium Size Bookshelf Speakers |
| Bass Extension (-10dB) | 44Hz (measured, Erin’s Audio Corner) | 44.4Hz (derived, log-interpolated between spinorama.org -9dB/-12dB points) |
| Bass Extension (-3dB) | 51Hz (measured, Erin’s Audio Corner) | 69.6Hz (measured, Erin’s Audio Corner via spinorama.org) |
| Dimensions | 11.9”H x 7.1”W x 10.9”D (303 x 180 x 278 mm) | 6.75W x 11.8H x 9.875D in |
| Impedance | 8 ohms nominal, about 4.7 ohms minimum (measured, Erin’s Audio Corner) | 8 ohms nominal, 4 ohms minimum |
| Sensitivity | ~85dB (300Hz-3kHz on-axis, measured, Erin’s Audio Corner) | 85dB anechoic / 87dB in-room |
| Drivers | 130mm (5.25”) aluminium Uni-Q woofer, 25mm (1”) vented aluminium dome tweeter | 1” titanium dome tweeter (ferrofluid neodymium magnet), 5.25” woven carbon-fiber woofer |
| Weight | 12.3 lbs (5.6 kg) each | approx. 11.2 lbs (5.1 kg) each |
| Woofer Cabinet | ported, rear | - |
| Spinorama Preference Score | 4.86 | 4.63 |
| Spinorama Preference Score with Perfect Sub | 7.06 | 6.92 |
| DIY Kit | No | No |
| Enclosure | - | 2-way, bass-reflex with rear slot port |
| Country | - | Canada (design) |
Related Speaker Comparisons
How KEF Q150 compares with other leading options:
- KEF Q150 vs Audio First Fidelia
- KEF Q150 vs Philharmonic Ceramic Mini
- Ascend Sierra 1 v2 vs KEF Q150
- KEF LS50 Meta vs KEF Q150
- KEF Q150 vs Ascend Acoustics Luna V2 Mini-Monitor Ribbon
Prices on this page were last checked October 9, 2026 at 8:01 AM UTC. Product prices and availability are accurate as of that date/time and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.
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The Two Speakers In Full
KEF Q150: $350 per pair Discontinued Amazon eBay
Newer model: the KEF Q1 Meta, ranked lower, rated 3.6/5.
Older model: the KEF Q100 (ranked lower, rated 2.4/5).
Same family: the KEF Q350 (larger bookshelf, rated 3/5), the KEF Q250c (smaller center, rated 3.9/5) and the KEF Q650c (larger center, rated 3.7/5).
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. Measured bass extension of 51Hz (-3dB), with a measured sensitivity of 85dB.
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) |
| DIY Kit | No |
| Dimensions | 11.9”H x 7.1”W x 10.9”D (303 x 180 x 278 mm) |
| 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) |
| Spinorama Preference Score | 4.86 |
| Spinorama Preference Score with Perfect Sub | 7.06 |
| Weight | 12.3 lbs (5.6 kg) each |
| Woofer Cabinet | ported, rear |
- Links
- Reviews, Comparisons and Sound Samples
- Erin’s Audio Corner: Kef’s Cheapest Bookshelf. Is the Q150 worth your money? More from Erin’s Audio Corner →
- Erin’s Audio Corner Website KEF Q150
- GR-Research: KEF Q150… can it get any BETTER? More from GR-Research →
- Erin’s Audio Corner: 5 AWESOME SPEAKERS Under $1000 You Won’t Regret
- Erin’s Audio Corner: Budget Stereo Systems You Will Love
- Erin’s Audio Corner Measurements (spinorama.org)
- Head-to-Head Comparisons
PSB Imagine B50: $999 per pair PSB Speakers eBay
Same family: the PSB Imagine T54 (smaller floorstanding, estimated 4.2/5) and the PSB Imagine T65 (larger floorstanding, rated 4.3/5).
Pros: The standmount sibling to the PSB Imagine T65 tower, from PSB’s current 2023-refreshed Imagine line, using the same titanium-dome tweeter and woven-carbon-fiber woofer platform. Measured bass extension of 69.6Hz (-3dB).
Cons: On-axis smoothness of just 0.235 and a deviation of 0.368dB are unremarkable for the price, with a +0.22dB per octave upward tilt giving it a brighter-leaning balance, a predicted in-room smoothness of just 0.35, and a Harman in-room bass extension estimate of only 49Hz. Current retail pricing ($999/pair) has risen well above the ~$700 figure recorded in the spinorama snapshot.
Full PSB Imagine B50 review and specifications →
| Bass Extension (-10dB) | 44.4Hz (derived, log-interpolated between spinorama.org -9dB/-12dB points) |
|---|---|
| Bass Extension (-3dB) | 69.6Hz (measured, Erin’s Audio Corner via spinorama.org) |
| Country | Canada (design) |
| DIY Kit | No |
| Dimensions | 6.75W x 11.8H x 9.875D in |
| Drivers | 1” titanium dome tweeter (ferrofluid neodymium magnet), 5.25” woven carbon-fiber woofer |
| Enclosure | 2-way, bass-reflex with rear slot port |
| Impedance | 8 ohms nominal, 4 ohms minimum |
| Sensitivity | 85dB anechoic / 87dB in-room |
| Spinorama Preference Score | 4.63 |
| Spinorama Preference Score with Perfect Sub | 6.92 |
| Weight | approx. 11.2 lbs (5.1 kg) each |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons