Short answer: both are discontinued, so this only matters if you are buying used. Used, the KEF Q150 is the better pick: it ranks #49 of 160 bookshelf speakers by sound quality (rated 3.7/5), against #111 (rated 2.8/5) for the Pioneer SP-BS22-LR (Philharmonic AAM Mod). 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. 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 78Hz for the Pioneer SP-BS22-LR (Philharmonic AAM Mod). 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.
Why pick the Pioneer SP-BS22-LR (Philharmonic AAM Mod): This is Dennis Murphy’s “Affordable Accuracy Monitor” (AAM) mod of the discontinued, budget Pioneer SP-BS22-LR: the stock tweeter is swapped for a Peerless BC25TG15 dome and a redesigned 3rd-order crossover is built to match it to the stock 4” woofer. The tradeoff: Some directivity error appears near the crossover frequency.
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.
Still deciding? The full Passive Home rankings cover every ranked option.
Specifications Side By Side
| KEF Q150 | Pioneer SP-BS22-LR (Philharmonic AAM Mod) | |
|---|---|---|
| Price | $350 per pair Discontinued | $168 per pair Discontinued |
| Ranked | #49 of 160 in Medium Size Bookshelf Speakers | #111 of 160 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) | 12.6”H x 7.1”W x 8.5”D (320.0 x 180.0 x 215.0 mm) |
| Impedance | 8 ohms nominal, about 4.7 ohms minimum (measured, Erin’s Audio Corner) | 8 ohms nominal (approx. 5 ohms minimum, measured by Audio Science Review) |
| Sensitivity | ~85dB (300Hz-3kHz on-axis, measured, Erin’s Audio Corner) | 83dB (2.83V/1m, measured by Audio Science Review) |
| Drivers | 130mm (5.25”) aluminium Uni-Q woofer, 25mm (1”) vented aluminium dome tweeter | 1x 4” curvilinear-cone woofer (stock Pioneer), 1x Peerless BC25TG15 1” silk dome tweeter (replacement) |
| Weight | 12.3 lbs (5.6 kg) each | 9 lbs (4.1 kg) |
| Woofer Cabinet | ported, rear | ported, rear |
| Spinorama Preference Score | 4.86 | 5.07 |
| Spinorama Preference Score with Perfect Sub | 7.06 | 7.82 |
| DIY Kit | No | Yes |
| Crossover Frequency | - | 3000Hz |
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- Ascend Sierra 1 v2 vs KEF Q150
- KEF LS50 Meta vs KEF Q150
- KEF Q150 vs Ascend Acoustics Luna V2 Mini-Monitor Ribbon
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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
Pioneer SP-BS22-LR (Philharmonic AAM Mod): $168 per pair Discontinued eBay
Pros: This is Dennis Murphy’s “Affordable Accuracy Monitor” (AAM) mod of the discontinued, budget Pioneer SP-BS22-LR: the stock tweeter is swapped for a Peerless BC25TG15 dome and a redesigned 3rd-order crossover is built to match it to the stock 4” woofer. CEA2034 spinorama shows only small variations from a flat on-axis response with some directivity error near the crossover, a marked improvement over the unmodified Pioneer, which the reviewer notes shows much more variation from flat. Distortion at 86dB SPL/1m is reasonably controlled above 200Hz, and tweeter distortion barely rises even at 96dB SPL/1m. Measured bass extension of 78Hz (-3dB), with a measured sensitivity of 83dB.
Cons: Some directivity error appears near the crossover frequency. Distortion climbs in the woofer’s range (below 200Hz) at both 86dB and 96dB SPL/1m. Minimum impedance dips to about 5 ohms with a couple of resonance peaks. This is a DIY project, not a finished retail product: Murphy sold ~$168 pre-built pairs for a while but no longer does, so it now requires sourcing a used/discontinued Pioneer SP-BS22-LR pair plus building the crossover and swapping the tweeter yourself. The mod itself is public domain, but there is no current turnkey way to buy this speaker.
Full Pioneer SP-BS22-LR (Philharmonic AAM Mod) review and specifications →
| Bass Extension (-10dB) | 60Hz (measured, Audio Science Review) |
|---|---|
| Bass Extension (-3dB) | 78Hz (measured, Audio Science Review) |
| Crossover Frequency | 3000Hz |
| DIY Kit | Yes |
| Dimensions | 12.6”H x 7.1”W x 8.5”D (320.0 x 180.0 x 215.0 mm) |
| Drivers | 1x 4” curvilinear-cone woofer (stock Pioneer), 1x Peerless BC25TG15 1” silk dome tweeter (replacement) |
| Impedance | 8 ohms nominal (approx. 5 ohms minimum, measured by Audio Science Review) |
| Sensitivity | 83dB (2.83V/1m, measured by Audio Science Review) |
| Spinorama Preference Score | 5.07 |
| Spinorama Preference Score with Perfect Sub | 7.82 |
| Weight | 9 lbs (4.1 kg) |
| Woofer Cabinet | ported, rear |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Pioneer SP-BS22-LR (Philharmonic AAM Mod) vs Dynaudio X14
- Pioneer SP-BS22-LR (Philharmonic AAM Mod) vs MartinLogan Motion 4i
- Pioneer SP-BS22-LR (Philharmonic AAM Mod) vs ELAC BS U5
- Pioneer SP-BS22-LR (Philharmonic AAM Mod) vs JBL L52 Classic
- Pioneer SP-BS22-LR (Philharmonic AAM Mod) vs Dynaudio Emit M10
- Pioneer SP-BS22-LR (Philharmonic AAM Mod) vs Parts Express Copperhead Desktop Kit
- Pioneer SP-BS22-LR (Philharmonic AAM Mod) vs JBL Stage A120
- Pioneer SP-BS22-LR (Philharmonic AAM Mod) vs ELAC Uni-Fi 2.0 UB52
- See all 36 comparisons