Short answer: the Dynaudio Special Forty for better sound quality, the Polk Reserve R100 for the lower price. The Dynaudio Special Forty ranks #66 of 105 bookshelf speakers at $3600. The Polk Reserve R100 ranks #75 at $649, $2951 cheaper.
What the Dynaudio Special Forty offers: Smooth, “buttery” overall tonal character consistent with Dynaudio’s house sound. Watch for: A glaring, sometimes sibilant quality around 3-4kHz was the most noticeable issue in listening, the one thing the reviewer would want notched out with EQ.
What the Polk Reserve R100 gets right: Compact cabinet, unusually useful bass for its size and well-controlled woofer breakup. Set against that: Erin measured only about 85dB sensitivity and the impedance reaches 3.6 ohms, so it is neither efficient nor an entirely benign AVR load.
Buy the Dynaudio Special Forty if sound quality matters more than the price. Buy the Polk Reserve R100 if the price matters more than sound quality.
Specifications Side By Side
| Dynaudio Special Forty | Polk Reserve R100 | |
|---|---|---|
| Price | $3600 | $649/pair |
| Ranked | #66 of 105 in Large Size Bookshelf Speakers | #75 of 105 in Large Size Bookshelf Speakers |
| Bass Extension (-10dB) | 39Hz (measured, Erin’s Audio Corner) | 49Hz (measured, Erin’s Audio Corner) |
| Bass Extension (-3dB) | 54Hz (measured, Erin’s Audio Corner) | 68Hz (measured, Erin’s Audio Corner) |
| Dimensions | 14.1"H x 7.7"W x 12.1"D (358.1 x 195.6 x 307.3 mm) | 12.8"H x 6.5"W x 10.2"D |
| Impedance | 6 ohms nominal (4.9 ohms minimum above 80Hz, measured, Erin’s Audio Corner) | 3.6 ohms minimum (measured, Erin’s Audio Corner) |
| Sensitivity | 83.5dB (measured, Erin’s Audio Corner; 86dB manufacturer specified) | 85dB/2.83V/1m (measured, Erin’s Audio Corner) |
| Drivers | 5.9" MSP (Magnesium Silicate Polymer) cone woofer, 1" Esotar soft dome tweeter | 1" Pinnacle ring-radiator tweeter; 5.25" Turbine Cone midwoofer |
| Weight | 17.9 lbs / 8.1 kg each | 12.2 lb each |
| Woofer Cabinet | ported | ported, rear X-Port |
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- Polk R200 vs Sonus Faber Sonetto II G2
- JTR Noesis 210HT vs McIntosh XR50
- ELAC Debut 2.0 B6.2 vs GR-Research NX-Studio
- Dynaudio Special Forty vs Revel Performa M22
- JBL Studio 630 vs Dynaudio Special Forty
The Two Speakers In Full
Dynaudio Special Forty: $3600 Safeandsoundhq
Pros: Smooth, “buttery” overall tonal character consistent with Dynaudio’s house sound. Surprisingly precise, focused imaging despite wide horizontal radiation (about ±70°) - atypical, since wide-radiating speakers usually sacrifice some image precision in reflective rooms. Strong output capability: reached 100-101dB average at 3.5 meters with no audible distortion or woofer distress, and compression testing at 102dB shows the cabinet holding up mechanically well at extreme output. Bass reaches a genuine 50Hz (potentially 40Hz) in most rooms from a rear-ported design. Distortion stays below 1% at 86dB and doesn’t cross 3% THD until about 50Hz even at 96dB. Extra weight and impact on snares and percussion around 700-800Hz that the reviewer found appealing on many tracks.
Cons: A glaring, sometimes sibilant quality around 3-4kHz was the most noticeable issue in listening, the one thing the reviewer would want notched out with EQ. Multiple enclosure resonances appear between 500Hz-1kHz across on-axis, listening window, early-reflections, and sound-power measurements, corroborated by independent third-party CSD data showing similar 500-800Hz cabinet resonances. A dip around 1.2kHz traces to a cone-edge-to-surround compliance mismatch in the driver itself (confirmed by testing the bare driver’s impedance) - a known artifact common to many similarly-sized drivers across several manufacturers, contributing to elevated second-order distortion in that region. A somewhat laid-back, recessed 1-2kHz character (sometimes described as a “BBC dip”) gives an overall subdued quality that isn’t overtly problematic but shapes the tonal balance. Impedance drops below 3 ohms in the 100-200Hz region, requiring a genuinely 4-ohm-stable amplifier rather than an AVR. Rear port means it can’t be placed directly against a wall.
Full Dynaudio Special Forty review and specifications →
| Bass Extension (-10dB) | 39Hz (measured, Erin's Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 54Hz (measured, Erin's Audio Corner) |
| Dimensions | 14.1"H x 7.7"W x 12.1"D (358.1 x 195.6 x 307.3 mm) |
| Drivers | 5.9" MSP (Magnesium Silicate Polymer) cone woofer, 1" Esotar soft dome tweeter |
| Impedance | 6 ohms nominal (4.9 ohms minimum above 80Hz, measured, Erin's Audio Corner) |
| Sensitivity | 83.5dB (measured, Erin's Audio Corner; 86dB manufacturer specified) |
| Weight | 17.9 lbs / 8.1 kg each |
| Woofer Cabinet | ported |
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- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Dynaudio Special Forty vs ELAC Debut 2.0 B6.2
- Dynaudio Special Forty vs SVS Prime Bookshelf
- Dynaudio Special Forty vs Infinity IL10
- Dynaudio Special Forty vs KEF Q3 Meta
- Dynaudio Special Forty vs Polk Monitor XT20
- Dynaudio Special Forty vs Behringer B2030P
- Dynaudio Special Forty vs Sonus Faber Lumina II
- Dynaudio Special Forty vs JBL Studio 630
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Polk Reserve R100: $649/pair Amazon Polk Audio
Pros: Compact cabinet, unusually useful bass for its size and well-controlled woofer breakup. Erin measured F3/F10 points of 68Hz/49Hz, and the X-Port vent avoids much of the chuffing and pipe resonance common to budget rear ports. The 5.25-inch Turbine Cone woofer and 1-inch Pinnacle ring-radiator tweeter produce good detail at moderate levels, while listening roughly 20° off-axis reduces part of the elevated top octave.
Cons: Erin measured only about 85dB sensitivity and the impedance reaches 3.6 ohms, so it is neither efficient nor an entirely benign AVR load. The treble runs roughly 3dB above the midrange and becomes aggressive above about 85dB SPL. A directivity discontinuity through the woofer/tweeter crossover means EQ cannot fully repair the power response, and a 400Hz impedance feature plus 500Hz-1kHz response irregularity suggests a cabinet or system resonance. Substantial low-frequency compression at higher playback levels limits clean dynamics.
Full Polk Reserve R100 review and specifications →
| Bass Extension (-10dB) | 49Hz (measured, Erin's Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 68Hz (measured, Erin's Audio Corner) |
| Dimensions | 12.8"H x 6.5"W x 10.2"D |
| Drivers | 1" Pinnacle ring-radiator tweeter; 5.25" Turbine Cone midwoofer |
| Impedance | 3.6 ohms minimum (measured, Erin's Audio Corner) |
| Sensitivity | 85dB/2.83V/1m (measured, Erin's Audio Corner) |
| Weight | 12.2 lb each |
| Woofer Cabinet | ported, rear X-Port |
As an eBay Partner, we may be compensated if you make a purchase.
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Polk Reserve R100 vs Polk R200
- Polk Reserve R100 vs JBL XPL-90
- Polk Reserve R100 vs Emotiva Airmotiv B2+
- Polk Reserve R100 vs Revel Performa M22
- Polk Reserve R100 vs Focal Aria 906
- Polk Reserve R100 vs Sonus Faber Lumina II
- Polk Reserve R100 vs Sonus Faber Sonetto II G2
- Polk Reserve R100 vs Polk Monitor XT20
- See all 16 comparisons