Short answer: the Arendal Sound 1723 Monitor THX. It ranks #56 of 222 bookshelf speakers by sound quality, rated 4.2/5, at $2,400; the Paradigm Founder 40B ranks #68, rated 4.1/5, at $2,399.98. Close enough in price that the sound-quality gap is the deciding factor.
Why pick the Arendal Sound 1723 Monitor THX: Independent ASR Klippel data shows a narrow 1.8dB reference band, 0.391 listening-window smoothness, and useful bass extension to 48.3Hz at -6dB. Watch for: The measured on-axis average absolute deviation is 0.979dB and the sound-power directivity-index standard deviation is 3.63, so its response and dispersion are less even than the best alternatives.
What the Paradigm Founder 40B does well: A 6-inch aluminum-magnesium woofer and a 1-inch ceramic dome tweeter in a deep waveguide, with Paradigm’s perforated phase-aligning lenses over both. The tradeoff: Bass rolls off early for a speaker this size, about 70Hz at -3dB and 44Hz at -10dB, so it works best with a subwoofer or close to a wall.
Buy the Arendal Sound 1723 Monitor THX. It is rated higher for sound quality, and saving $0.02 with the Paradigm Founder 40B does not make up for the sound-quality gap.
Looking for alternatives? See the complete Passive Home rankings.
Independent ASR Klippel data shows a narrow 1.8dB reference band, 0.391 listening-window smoothness, and useful bass extension to 48.3Hz at -6dB.
Arendal Sound $2,400 eBay
A 6-inch aluminum-magnesium woofer and a 1-inch ceramic dome tweeter in a deep waveguide, with Paradigm’s perforated phase-aligning lenses over both.
Audio Advice $1,199.99 eBayPrices on this page were last checked October 16, 2026 at 5:46 PM 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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Specifications Side By Side
| Arendal Sound 1723 Monitor THX | Paradigm Founder 40B | |
|---|---|---|
| Price | $2,400 per pair | $2,399.98 per pair |
| Ranked | #56 of 222 in Large Size Bookshelf Speakers | #68 of 222 in Large Size Bookshelf Speakers |
| Bass Extension (-3dB) | 63Hz (measured, spinorama.org) | 69.6Hz (measured, Erin’s Audio Corner) |
| Bass Extension (-10dB) | approximately 37Hz (measured, spinorama.org) | 43.9Hz (measured, Erin’s Audio Corner) |
| Drivers | Two 8-inch woofers; 28mm waveguided tweeter | 6” AL-MAG woofer; 1” AL-MAC ceramic dome tweeter with waveguide |
| Impedance | 4 ohms nominal | Compatible with 8 ohms (manufacturer specified) |
| Certification | THX Ultra | - |
| Spinorama Preference Score | 5.16 | 4.89 |
| Spinorama Preference Score with Perfect Sub | 7.30 | 7.11 |
| Sensitivity | 89dB (manufacturer specified, 2.83V/1m) | 89dB anechoic, 92dB in-room (manufacturer specified) |
| Dimensions | 15.7”H x 10.8”W x 25”D (400 x 275 x 635 mm) | 14.5”H x 7.8”W x 12.6”D (368 x 197 x 320 mm) |
| Weight | 58.9 lbs (26.7 kg) each | 24.9 lbs (11.3 kg) each |
| DIY Kit | No | No |
| Frequency Response | - | 69Hz-23kHz ±2dB (manufacturer specified) |
| Woofer Cabinet | - | ported |
Frequency Response Compared
Both speakers’ spinorama measurements, overlaid. A flatter line is more neutral: peaks sound forward or harsh, dips sound recessed. Each curve is shifted so its average from 300 Hz to 3 kHz sits at 0 dB, so loudness differences between the two are removed and only the shape is compared. The two were measured by different sources, so small differences, especially in the bass, can come from the measurement setup rather than the speakers.
Measurement data: Arendal Sound 1723 Monitor THX (measured by Audio Science Review) and Paradigm Founder 40B (measured by Erin’s Audio Corner), via spinorama.org.
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