Short answer: the Arendal Sound 1723 Monitor THX. It ranks #48 of 134 bookshelf speakers by sound quality, rated 4.2/5, at $2,400; the Paradigm Founder 40B ranks #56, 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.
Specifications Side By Side
| Arendal Sound 1723 Monitor THX | Paradigm Founder 40B | |
|---|---|---|
| Price | $2,400 per pair | $2,399.98 per pair |
| Ranked | #48 of 134 in Large Size Bookshelf Speakers | #56 of 134 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 |
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- KEF R3 Meta vs Arendal Sound 1723 Monitor THX
- KEF Q Concerto Meta vs Arendal Sound 1723 Monitor THX
- KEF R3 vs Arendal Sound 1723 Monitor THX
- Wharfedale Super Linton vs Arendal Sound 1723 Monitor THX
- ELAC Debut 3.0 DB63 vs Arendal Sound 1723 Monitor THX
Prices on this page were last checked September 30, 2026 at 2:57 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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The Two Speakers In Full
Arendal Sound 1723 Monitor THX: $2,400 per pair Arendal Sound eBay
Pros: 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. Its preference score rises from 5.16 to 7.30 with a subwoofer. Dual 8-inch woofers, a waveguided tweeter, robust HDF construction, and THX Ultra certification suit high-output rooms. Measured bass extension of 63Hz (-3dB).
Cons: 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. Bass reaches only 63Hz at -3dB despite the very large cabinet, and the 1.239 low-frequency Q indicates a pronounced alignment. At roughly 60 lb each, these require substantial stands and space.
Full Arendal Sound 1723 Monitor THX review and specifications →
| Bass Extension (-10dB) | approximately 37Hz (measured, spinorama.org) |
|---|---|
| Bass Extension (-3dB) | 63Hz (measured, spinorama.org) |
| Certification | THX Ultra |
| DIY Kit | No |
| Dimensions | 15.7”H x 10.8”W x 25”D (400 x 275 x 635 mm) |
| Drivers | Two 8-inch woofers; 28mm waveguided tweeter |
| Impedance | 4 ohms nominal |
| Sensitivity | 89dB (manufacturer specified, 2.83V/1m) |
| Spinorama Preference Score | 5.16 |
| Spinorama Preference Score with Perfect Sub | 7.30 |
| Weight | 58.9 lbs (26.7 kg) each |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Arendal Sound 1723 Monitor THX vs Power Sound Audio MT-110-M
- Arendal Sound 1723 Monitor THX vs ELAC Debut 3.0 DB63
- Arendal Sound 1723 Monitor THX vs Arendal Sound 1723 Monitor S THX
- Arendal Sound 1723 Monitor THX vs Wharfedale Super Linton
- Arendal Sound 1723 Monitor THX vs Klipsch RP-600M II
- Arendal Sound 1723 Monitor THX vs KEF R3
- Arendal Sound 1723 Monitor THX vs KEF Q Concerto Meta
- Arendal Sound 1723 Monitor THX vs KEF R3 Meta
Paradigm Founder 40B: $2,399.98 per pair Audio Advice eBay
Pros: 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. Toed in 30 degrees as Paradigm recommends, Erin’s Audio Corner measured an exceptionally even listening window, within a 1.7dB span from 300Hz to 5kHz, with low on-axis deviation (0.36) and wide horizontal dispersion averaging 60 degrees, for a preference score of 4.89 that rises to 7.11 with an ideal subwoofer. Sensitivity is a high 89dB anechoic. Measured bass extension of 69.6Hz (-3dB).
Cons: 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. It needs the recommended toe-in: measured straight on, its response is less even (preference score 4.58) and the tonal balance shifts. At about $2,400 a pair it is expensive for a 6-inch two-way.
Full Paradigm Founder 40B review and specifications →
| Bass Extension (-10dB) | 43.9Hz (measured, Erin’s Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 69.6Hz (measured, Erin’s Audio Corner) |
| DIY Kit | No |
| Dimensions | 14.5”H x 7.8”W x 12.6”D (368 x 197 x 320 mm) |
| Drivers | 6” AL-MAG woofer; 1” AL-MAC ceramic dome tweeter with waveguide |
| Frequency Response | 69Hz-23kHz ±2dB (manufacturer specified) |
| Impedance | Compatible with 8 ohms (manufacturer specified) |
| Sensitivity | 89dB anechoic, 92dB in-room (manufacturer specified) |
| Spinorama Preference Score | 4.89 |
| Spinorama Preference Score with Perfect Sub | 7.11 |
| Weight | 24.9 lbs (11.3 kg) each |
| Woofer Cabinet | ported |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons