Short answer: the Polk Reserve R100. It ranks #93 of 131 bookshelf speakers by sound quality, rated 3.4/5, at $699. The HSU Research MFL-6 ranks #96, rated 3.3/5, at $558, $141 cheaper, which does not close the gap in sound quality.
The case for the Polk Reserve R100: Compact cabinet, unusually useful bass for its size and well-controlled woofer breakup. Watch for: Erin measured only about 85dB sensitivity and the impedance reaches 3.6 ohms, so it is neither efficient nor an entirely benign AVR load.
What the HSU Research MFL-6 does well: A high-output 6.5-inch design with horn-loaded tweeter, strong measured sensitivity and flexible wall, stand or horizontal placement. The tradeoff: Its response deviation is substantial and the horn narrows dispersion, so tonal balance and seating coverage are less even than the best conventional monitors.
Buy the Polk Reserve R100. It is rated higher for sound quality, and the $141 you would save on the HSU Research MFL-6 does not close the gap.
Still deciding? The full Passive Home rankings cover every ranked option.
Specifications Side By Side
| Polk Reserve R100 | HSU Research MFL-6 | |
|---|---|---|
| Price | $699.00 per pair | $558 per pair |
| Ranked | #93 of 131 in Large Size Bookshelf Speakers | #96 of 131 in Large Size Bookshelf Speakers |
| Bass Extension (-3dB) | 68Hz (measured, Erin’s Audio Corner) | 77.6Hz (measured, spinorama.org) |
| Bass Extension (-10dB) | 49Hz (measured, Erin’s Audio Corner) | - |
| Sensitivity | 85dB/2.83V/1m (measured, Erin’s Audio Corner) | 85.6dB (measured average 300Hz-3kHz @ 2.83V/1m, spinorama.org) |
| Impedance | 3.6 ohms minimum (measured, Erin’s Audio Corner) | 8 ohms |
| Drivers | 1” Pinnacle ring-radiator tweeter; 5.25” Turbine Cone midwoofer | 1” horn-loaded tweeter, 6.5” paper-cone woofer |
| Dimensions | 12.8”H x 6.5”W x 10.2”D | 16H x 8W x 6.25-10.375D in |
| Weight | 12.1 lbs (5.5 kg) each | 13 lbs (5.9 kg) each |
| Woofer Cabinet | ported, rear X-Port | - |
| Spinorama Preference Score | 5.46 | 2.63 |
| Spinorama Preference Score with Perfect Sub | 7.93 | 4.77 |
| DIY Kit | No | No |
| Enclosure | - | 2-way bass reflex |
| Frequency Response | - | 60Hz-20kHz +/-2dB |
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Prices on this page were last checked September 26, 2026 at 11:14 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
Polk Reserve R100: $699.00 per pair Amazon Polk Audio eBay
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. Measured bass extension of 68Hz (-3dB), with a measured sensitivity of 85dB.
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) |
| DIY Kit | No |
| 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) |
| Spinorama Preference Score | 5.46 |
| Spinorama Preference Score with Perfect Sub | 7.93 |
| Weight | 12.1 lbs (5.5 kg) each |
| Woofer Cabinet | ported, rear X-Port |
- Links
- Reviews, Comparisons and Sound Samples
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HSU Research MFL-6: $558 per pair HSU Research eBay
Pros: A high-output 6.5-inch design with horn-loaded tweeter, strong measured sensitivity and flexible wall, stand or horizontal placement. The local Spinorama snapshot delivers a solid 2.63 raw score and 4.77 with a subwoofer, with controlled horizontal radiation and 45Hz extension. Measured bass extension of 77.6Hz (-3dB), with a measured sensitivity of 85.6dB.
Cons: Its response deviation is substantial and the horn narrows dispersion, so tonal balance and seating coverage are less even than the best conventional monitors. The trapezoidal cabinet and utilitarian finish are optimized for function rather than furniture-grade appearance.
Full HSU Research MFL-6 review and specifications →
| Bass Extension (-3dB) | 77.6Hz (measured, spinorama.org) |
|---|---|
| DIY Kit | No |
| Dimensions | 16H x 8W x 6.25-10.375D in |
| Drivers | 1” horn-loaded tweeter, 6.5” paper-cone woofer |
| Enclosure | 2-way bass reflex |
| Frequency Response | 60Hz-20kHz +/-2dB |
| Impedance | 8 ohms |
| Sensitivity | 85.6dB (measured average 300Hz-3kHz @ 2.83V/1m, spinorama.org) |
| Spinorama Preference Score | 2.63 |
| Spinorama Preference Score with Perfect Sub | 4.77 |
| Weight | 13 lbs (5.9 kg) each |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- HSU Research MFL-6 vs Polk R200
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