Short answer: the KEF LS50 Meta. It ranks #4 of 160 bookshelf speakers by sound quality (rated 4.5/5) at $1,599 and is still sold new; the Pioneer SP-BS22-LR (Philharmonic AAM Mod) ranks #111 (rated 2.8/5) and is discontinued, so it is only an option used.
The KEF LS50 Meta is the more accurate, deeper-bass pick. Uni-Q concentric driver mounts a 1” vented aluminum dome tweeter at the center of a 5.25” aluminum cone woofer, rated 79Hz-20kHz+. Its measured preference score, a predictor of how neutral it sounds, is 5.74 against 5.07 for the Pioneer SP-BS22-LR (Philharmonic AAM Mod). Its bass reaches about 68Hz before falling 3dB, against 78Hz for the Pioneer SP-BS22-LR (Philharmonic AAM Mod). The catch: F3 of 67Hz and F10 of 42Hz mean it doesn’t get much below 50Hz in-room; a subwoofer is recommended for real bass.
The case for 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 LS50 Meta. It is rated higher for sound quality; the Pioneer SP-BS22-LR (Philharmonic AAM Mod) is no longer sold new.
Want more options? Browse the full Passive Home rankings.
Specifications Side By Side
| KEF LS50 Meta | Pioneer SP-BS22-LR (Philharmonic AAM Mod) | |
|---|---|---|
| Price | $1,599.00 per pair | $168 per pair Discontinued |
| Ranked | #4 of 160 in Medium Size Bookshelf Speakers | #111 of 160 in Medium Size Bookshelf Speakers |
| Bass Extension (-10dB) | 43Hz (measured, Erin’s Audio Corner) | 60Hz (measured, Audio Science Review) |
| Bass Extension (-3dB) | 68Hz (measured, Erin’s Audio Corner) | 78Hz (measured, Audio Science Review) |
| Dimensions | 11.9”H x 7.9”W x 11”D (302 x 200 x 280.5 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 (3.7 ohms minimum above 80Hz, measured by Erin’s Audio Corner) | 8 ohms nominal (approx. 5 ohms minimum, measured by Audio Science Review) |
| Sensitivity | 83dB (measured average, Erin’s Audio Corner; 85dB manufacturer specified) | 83dB (2.83V/1m, measured by Audio Science Review) |
| Drivers | 130 mm (5.25 in.) aluminium cone woofer, 25 mm (1 in.) vented aluminium dome with Metamaterial Absorption tweeter | 1x 4” curvilinear-cone woofer (stock Pioneer), 1x Peerless BC25TG15 1” silk dome tweeter (replacement) |
| Weight | 17.2 lbs (7.8 kg) each | 9 lbs (4.1 kg) |
| Woofer Cabinet | ported, rear | ported, rear |
| Spinorama Preference Score | 5.74 | 5.07 |
| Spinorama Preference Score with Perfect Sub | 7.88 | 7.82 |
| DIY Kit | No | Yes |
| Crossover Frequency | - | 3000Hz |
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- KEF LS50 Meta vs Philharmonic Ceramic Mini
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The Two Speakers In Full
KEF LS50 Meta: $1,599.00 per pair Amazon Crutchfield eBay
Older model: the KEF LS50 (ranked lower, rated 3.9/5).
Pros: Uni-Q concentric driver mounts a 1” vented aluminum dome tweeter at the center of a 5.25” aluminum cone woofer, rated 79Hz-20kHz+. Speaker-to-speaker matching measured tight at roughly 0.5dB deviation between the pair tested, versus 2-3dB seen on some other speakers: likely why imaging stayed so precise. Imaging stays tight and focused even toed out, unlike most coincident designs where toe-out typically diffuses the image, giving more of an oval-shaped soundstage than a hard rectangular boundary. Horizontal and vertical directivity both hold to about ±50° at the -6dB point, so tonality stays consistent across roughly a 100° listening cone. The extended bass shelf is deliberately tuned for near-wall/boundary placement rather than the usual “pull it 3 feet into the room” advice, playing lower without excess boominess when placed close to a wall. At its frequent sale price, well below list, called a no-brainer for a compact stand-mount speaker. Independent ASR Klippel measurements corroborate this: very good directivity with the on- and off-axis curves tracking closely, and a predicted in-room response the reviewer called “very close to ideal.”. Measured bass extension of 68Hz (-3dB), with a measured sensitivity of 83dB.
Cons: F3 of 67Hz and F10 of 42Hz mean it doesn’t get much below 50Hz in-room; a subwoofer is recommended for real bass. A 2-3dB scoop around 2-4kHz shows up in both the listening window and sound power measurements, matching a subjectively noticed lack of attack and vocal clarity that the reviewer wanted to correct with about 2dB of EQ. An on-axis diffraction dip around 8kHz smooths out with about 15° of toe-out (typical for concentric designs, but still present at 0°). Distortion is elevated at low frequencies since the single 5.25” cone shares surface area with the tweeter housing, reducing effective radiating area; multitone distortion crosses the 3% threshold at 96dB/1m, making roughly 88dB or below the safer output ceiling. Moderate sensitivity (~83dB average) needed 2-3dB more amplifier gain than typical in testing. Adding a subwoofer at an 80Hz crossover only helps lower-midrange distortion, not the elevated distortion in the 1-2kHz and above-5kHz regions. ASR’s own Klippel testing found the same pattern in starker terms: THD is very good at 86dB SPL/1m but climbs past 100% in the bass at 96dB SPL/1m, confirming this is not a near-field speaker for high-output bass-heavy material. Cumulative spectral decay (waterfall) also shows a couple of resonances lingering in the 1-2kHz region.
Full KEF LS50 Meta review and specifications →
| Bass Extension (-10dB) | 43Hz (measured, Erin’s Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 68Hz (measured, Erin’s Audio Corner) |
| DIY Kit | No |
| Dimensions | 11.9”H x 7.9”W x 11”D (302 x 200 x 280.5 mm) |
| Drivers | 130 mm (5.25 in.) aluminium cone woofer, 25 mm (1 in.) vented aluminium dome with Metamaterial Absorption tweeter |
| Impedance | 8 ohms nominal (3.7 ohms minimum above 80Hz, measured by Erin’s Audio Corner) |
| Sensitivity | 83dB (measured average, Erin’s Audio Corner; 85dB manufacturer specified) |
| Spinorama Preference Score | 5.74 |
| Spinorama Preference Score with Perfect Sub | 7.88 |
| Weight | 17.2 lbs (7.8 kg) each |
| Woofer Cabinet | ported, rear |
- Links
- Reviews, Comparisons and Sound Samples
- Erin’s Audio Corner: Unveiling the KEF LS50 Meta: The Truth Behind the Hype More from Erin’s Audio Corner →
- Erin’s Audio Corner Website KEF LS50 Meta
- Audio Science Review KEF LS50 Meta More from Audio Science Review →
- GR-Research: KEF LS50 Meta! Worthy of HYPE? More from GR-Research →
- Erin’s Audio Corner: My Top Picks of 2023: Must-Haves Under $3000
- Erin’s Audio Corner Measurements (spinorama.org)
- Head-to-Head Comparisons
- KEF LS50 Meta vs Ascend Sierra 1 v2
- KEF LS50 Meta vs Ascend Acoustics Luna V2 Mini-Monitor Ribbon
- KEF LS50 Meta vs Philharmonic Ceramic Mini
- KEF LS50 Meta vs XMechanik Mechano23 DIY
- KEF LS50 Meta vs Audio First Fidelia
- KEF LS50 Meta vs Ascend Acoustics HTM-200SE2
- KEF LS50 Meta vs Arendal 1961 Monitor
- KEF LS50 Meta vs SunAudio Purified 4
- See all 84 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
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