Short answer: the Yamaha HS8. It ranks #15 of 66 powered bookshelf speakers by sound quality at $678.28; the PSI Audio A21-M ranks #24 and costs $3720, so there is not much of a tradeoff to weigh.
What the Yamaha HS8 offers: ASR’s Klippel measurements show a notably neutral predicted in-room response, smooth horizontal directivity, and strong bass extension for a studio monitor: about 44Hz at -3dB and 35Hz at -10dB. Its Spinorama preference score rises from 4.95 full-range to 6.68 with a subwoofer, and the rear room-control switches provide some placement adjustment. Watch for: There is still some midrange unevenness and the vertical listening window is much narrower than the horizontal one, so ear height matters. The rear port and cabinet depth complicate close-wall placement, there is no DSP or automatic room correction, and the price is per speaker rather than per pair.
What the PSI Audio A21-M offers: PSI Audio deliberately skips DSP entirely, using a proprietary Coherent Phase Response analog circuit to keep phase alignment accurate without adding conversion stages, tracing its design back to the Studer A3 studio monitor. The sound power directivity index tracks tightly (standard deviation 3.39) and on axis deviation measures a moderate 0.375dB average, and it reaches a measured 39.6Hz extension point with a wide 80 degree horizontal by 30 degree vertical dispersion pattern. Watch for: The bass alignment measures a Q of 0.96, close to the point where a port tuned system starts to show a mild peak rather than a clean rolloff, worth knowing if placed near a wall. Sold as a single unit rather than a pair, a stereo set runs roughly $6,000 to $7,800 depending on retailer and finish. With no DSP or room correction on board, getting the most from it depends more on room treatment and placement than with a comparable DSP equipped monitor.
Buy the Yamaha HS8. It ranks higher for sound quality than the PSI Audio A21-M and costs less, so there is no real case for the other one.
Specifications Side By Side
| Yamaha HS8 | PSI Audio A21-M | |
|---|---|---|
| Price | $678.28 | $3,720 each |
| Ranked | #15 of 66 in Large Size Powered Bookshelf Speakers | #24 of 66 in Large Size Powered Bookshelf Speakers |
| Dimensions | 15.4"H x 9.8"W x 13.1"D (391.2 x 248.9 x 332.7 mm) | 9.8"H x 15.7"W x 11.8"D (250 x 400 x 300 mm) (9.9 x 15.8 x 11.9 in) |
| Frequency Response | 47Hz - 24kHz (-3dB) (Manufacturer specified) | 38Hz-23kHz -6dB |
| Bass Extension (-3dB) | 43.9Hz (measured, Audio Science Review) | 39.6Hz (measured, Audio Science Review) |
| Bass Extension (-10dB) | 34.7Hz (measured, Audio Science Review) | 33.2Hz (measured, Audio Science Review) |
| Inputs | XLR | - |
| Weight | 22.5 lbs / 10.2 kg | 28.2 lbs / 12.8 kg (28.2 lbs) each |
| Drivers | 8" woofer, 1" dome tweeter | 27mm handmade dome tweeter, 172mm cone woofer |
| App | No | - |
| Bluetooth | No | - |
| EQ | Yes (Room adjustment) | - |
| DSP | No | - |
| Output Power | 120w Per Speaker | - |
| Enclosure | - | ported |
| Power Output (Watts) | - | 335W total (280W woofer, 55W tweeter, Class A/B) |
| Max SPL | - | 110dB short term, 121dB peak |
| Crossover Points | - | 2.4kHz |
| Warranty | - | 5+1 years |
| Country | - | Switzerland |
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Prices on this page were last checked August 25, 2026 at 6:19 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
Yamaha HS8: $678.28 Amazon eBay
Pros: ASR’s Klippel measurements show a notably neutral predicted in-room response, smooth horizontal directivity, and strong bass extension for a studio monitor: about 44Hz at -3dB and 35Hz at -10dB. Its Spinorama preference score rises from 4.95 full-range to 6.68 with a subwoofer, and the rear room-control switches provide some placement adjustment.
Cons: There is still some midrange unevenness and the vertical listening window is much narrower than the horizontal one, so ear height matters. The rear port and cabinet depth complicate close-wall placement, there is no DSP or automatic room correction, and the price is per speaker rather than per pair.
Full Yamaha HS8 review and specifications →
| App | No |
|---|---|
| Bass Extension (-10dB) | 34.7Hz (measured, Audio Science Review) |
| Bass Extension (-3dB) | 43.9Hz (measured, Audio Science Review) |
| Bluetooth | No |
| DSP | No |
| Dimensions | 15.4"H x 9.8"W x 13.1"D (391.2 x 248.9 x 332.7 mm) |
| Drivers | 8" woofer, 1" dome tweeter |
| EQ | Yes (Room adjustment) |
| Frequency Response | 47Hz - 24kHz (-3dB) (Manufacturer specified) |
| Inputs | XLR |
| Output Power | 120w Per Speaker |
| Weight | 22.5 lbs / 10.2 kg |
- Links
- Reviews, Comparisons and Sound Samples
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- DSAUDIO.review: Genelec 8020D vs Yamaha HS8 Sound & Frequency Response Comparison
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- Audio Science Review Measurements (spinorama.org)
- Reddit Search for Yamaha HS8 Review
- Head-to-Head Comparisons
PSI Audio A21-M: $3,720 each B&H Photo eBay
Pros: PSI Audio deliberately skips DSP entirely, using a proprietary Coherent Phase Response analog circuit to keep phase alignment accurate without adding conversion stages, tracing its design back to the Studer A3 studio monitor. The sound power directivity index tracks tightly (standard deviation 3.39) and on axis deviation measures a moderate 0.375dB average, and it reaches a measured 39.6Hz extension point with a wide 80 degree horizontal by 30 degree vertical dispersion pattern.
Cons: The bass alignment measures a Q of 0.96, close to the point where a port tuned system starts to show a mild peak rather than a clean rolloff, worth knowing if placed near a wall. Sold as a single unit rather than a pair, a stereo set runs roughly $6,000 to $7,800 depending on retailer and finish. With no DSP or room correction on board, getting the most from it depends more on room treatment and placement than with a comparable DSP equipped monitor.
Full PSI Audio A21-M review and specifications →
| Bass Extension (-10dB) | 33.2Hz (measured, Audio Science Review) |
|---|---|
| Bass Extension (-3dB) | 39.6Hz (measured, Audio Science Review) |
| Country | Switzerland |
| Crossover Points | 2.4kHz |
| Dimensions | 9.8"H x 15.7"W x 11.8"D (250 x 400 x 300 mm) (9.9 x 15.8 x 11.9 in) |
| Drivers | 27mm handmade dome tweeter, 172mm cone woofer |
| Enclosure | ported |
| Frequency Response | 38Hz-23kHz -6dB |
| Max SPL | 110dB short term, 121dB peak |
| Power Output (Watts) | 335W total (280W woofer, 55W tweeter, Class A/B) |
| Warranty | 5+1 years |
| Weight | 28.2 lbs / 12.8 kg (28.2 lbs) each |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons