Short answer: the Amphion Argon1. It ranks #42 of 160 bookshelf speakers by sound quality (rated 3.8/5) at $1,919 and is still sold new; the KEF Q150 ranks #49 (rated 3.7/5) and is discontinued, so it is only an option used. The KEF Q150’s replacement, the KEF Q1 Meta, is rated 3.6/5.
The case for the KEF Q150: 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.
What the Amphion Argon1 does well: A well-regarded Finnish audiophile design praised by What Hi-Fi?, HomeTheaterReview, Audiophilia and The Ear for reference-quality midrange and surprisingly deep bass for its size. The tradeoff: The independent measurement tells a rougher story than the reviews suggest: on-axis deviation of 0.896dB and on-axis smoothness of just 0.154, with a moderate -0.11dB per octave downward tilt, consistent with a deliberately voiced rather than neutral-flat tuning.
Buy the Amphion Argon1. It is rated higher for sound quality and still sold new, while the KEF Q150 is discontinued.
Want more options? Browse the full Passive Home rankings.
Specifications Side By Side
| KEF Q150 | Amphion Argon1 | |
|---|---|---|
| Price | $350 per pair Discontinued | $1,919 per pair |
| Ranked | #49 of 160 in Medium Size Bookshelf Speakers | #42 of 160 in Medium Size Bookshelf Speakers |
| Bass Extension (-10dB) | 44Hz (measured, Erin’s Audio Corner) | 41.2Hz (derived, log-interpolated between spinorama.org -9dB/-12dB points) |
| Bass Extension (-3dB) | 51Hz (measured, Erin’s Audio Corner) | 55.3Hz (measured, spinorama.org) |
| Dimensions | 11.9”H x 7.1”W x 10.9”D (303 x 180 x 278 mm) | 12.4”H x 6.3”W x 10.4”D (316 x 160 x 265 mm) |
| Impedance | 8 ohms nominal, about 4.7 ohms minimum (measured, Erin’s Audio Corner) | 8 ohms |
| Sensitivity | ~85dB (300Hz-3kHz on-axis, measured, Erin’s Audio Corner) | 86dB |
| Drivers | 130mm (5.25”) aluminium Uni-Q woofer, 25mm (1”) vented aluminium dome tweeter | 1” titanium dome tweeter, 5.25” aluminum woofer |
| Weight | 12.3 lbs (5.6 kg) each | 15.4 lbs (7 kg) each |
| Woofer Cabinet | ported, rear | - |
| Spinorama Preference Score | 4.86 | 4.79 |
| Spinorama Preference Score with Perfect Sub | 7.06 | 7.01 |
| DIY Kit | No | No |
| Enclosure | - | 2-way, ported |
| Frequency Response | - | 45-25,000Hz (-6dB) |
| Country | - | Finland |
Related Speaker Comparisons
How Amphion Argon1 compares with other leading options:
- KEF LS50 Meta vs Amphion Argon1
- Amphion Argon1 vs Tekton Troubadour
- KEF Q150 vs PMC twenty.21
- KEF Q150 vs Vandersteen VLR Wood
- KEF Q150 vs Monitor Audio Apex A10
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
Amphion Argon1: $1,919 per pair Amphion eBay
Pros: A well-regarded Finnish audiophile design praised by What Hi-Fi?, HomeTheaterReview, Audiophilia and The Ear for reference-quality midrange and surprisingly deep bass for its size. Compact at 7kg and 316mm tall, with a titanium tweeter and aluminum woofer in a two-way ported cabinet. Measured bass extension of 55.3Hz (-3dB).
Cons: The independent measurement tells a rougher story than the reviews suggest: on-axis deviation of 0.896dB and on-axis smoothness of just 0.154, with a moderate -0.11dB per octave downward tilt, consistent with a deliberately voiced rather than neutral-flat tuning. Directivity-index standard deviation of 3.33 and predicted in-room smoothness of 0.29 are both unremarkable, though a well-damped bass-alignment Q of 0.24, the tightest measured here, suggests a controlled low-end rolloff.
Full Amphion Argon1 review and specifications →
| Bass Extension (-10dB) | 41.2Hz (derived, log-interpolated between spinorama.org -9dB/-12dB points) |
|---|---|
| Bass Extension (-3dB) | 55.3Hz (measured, spinorama.org) |
| Country | Finland |
| DIY Kit | No |
| Dimensions | 12.4”H x 6.3”W x 10.4”D (316 x 160 x 265 mm) |
| Drivers | 1” titanium dome tweeter, 5.25” aluminum woofer |
| Enclosure | 2-way, ported |
| Frequency Response | 45-25,000Hz (-6dB) |
| Impedance | 8 ohms |
| Sensitivity | 86dB |
| Spinorama Preference Score | 4.79 |
| Spinorama Preference Score with Perfect Sub | 7.01 |
| Weight | 15.4 lbs (7 kg) each |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons