Short answer: the Amphion Argon1 for better sound quality, the KEF Q150 for the lower price. The Amphion Argon1 ranks #25 of 87 bookshelf speakers at $1919. The KEF Q150 ranks #26 at $350, $1569 cheaper.
What the KEF Q150 offers: 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. Watch for: 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.
What the Amphion Argon1 offers: 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. Watch for: 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.
Buy the KEF Q150 if the price matters more than sound quality. Buy the Amphion Argon1 if sound quality matters more than the price.
Specifications Side By Side
| KEF Q150 | Amphion Argon1 | |
|---|---|---|
| Price | $350 Discontinued | $1,919/pair |
| Ranked | #26 of 87 in Medium Size Bookshelf Speakers | #25 of 87 in Medium Size Bookshelf Speakers |
| 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) | 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 |
| Discontinued | Yes | - |
| Weight | 12.3 lbs / 5.6 kg each | 15.4 lbs / 7 kg each |
| Woofer Cabinet | ported, rear | - |
| Enclosure | - | 2-way, ported |
| Frequency Response | - | 45-25,000Hz (-6dB) |
| Country | - | Finland |
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The Two Speakers In Full
KEF Q150: $350 Discontinued Amazon eBay
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 |
- 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)
- Reddit Search for KEF Q150 Review
- Head-to-Head Comparisons
Amphion Argon1: $1,919/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.
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 →
| Country | Finland |
|---|---|
| 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 |
| Weight | 15.4 lbs / 7 kg each |
- Links
- Reviews, Comparisons and Sound Samples