Short answer: the Klipsch RP-504C II. Both are rated 3.8/5 for sound quality (#35 and #36 of 98 center channel speakers), and the Klipsch RP-504C II costs $499.99 against $559 for the Polk Audio Reserve R400, so with nothing between them on sound quality, price settles it.
Why pick the Klipsch RP-504C II: The largest Reference Premiere center puts four 5.25” Cerametallic woofers around a 1” titanium tweeter in a Tractrix horn, for a very high 96dB sensitivity. The catch: On-axis response is the least even of the Klipsch centers (1.13dB average deviation), and directivity varies strongly with frequency (4.27dB directivity index deviation), so the tone changes for off-center seats and in reflective rooms.
The case for the Polk Audio Reserve R400: Larger dual 6.5-inch Turbine cone drivers paired with Polk X-Port bass reflex design extend low frequencies down to 48Hz (-3dB). The tradeoff: Horizontal 2-way MTM driver layout narrows the ideal off-axis listening window for wide seating arrangements.
Buy the Klipsch RP-504C II. Both are rated the same for sound quality, and it costs $59.01 less than the Polk Audio Reserve R400.
Want more options? Browse the full Passive Home rankings.
Specifications Side By Side
| Klipsch RP-504C II | Polk Audio Reserve R400 | |
|---|---|---|
| Price | $499.99 each | $559.00 |
| Ranked | #35 of 98 in Center Channel Speakers | #36 of 98 in Center Channel Speakers |
| Drivers | 1” titanium LTS vented tweeter with Tractrix horn, 4x 5.25” Cerametallic woofers | 1” Pinnacle ring radiator tweeter, 2 x 6.5” Turbine cone woofers |
| Frequency Response | 50Hz-25kHz ±3dB (manufacturer specified) | 48Hz - 39kHz (-3dB) |
| Sensitivity | 96dB (2.83V/1m, manufacturer specified) | 89dB (2.83V/1m) |
| Impedance | 8 ohms nominal (manufacturer specified) | 8 ohms nominal (4.1 ohms minimum) |
| Woofer Cabinet | ported (rear Tractrix ports) | - |
| Dimensions | 6.9”H x 32”W x 15.1”D (174 x 814 x 383 mm) | 7.8”H x 24.2”W x 13.8”D (197 x 615 x 350 mm) |
| Weight | 36.4 lbs (16.5 kg) | 32.8 lbs (14.9 kg) |
| Bass Extension (-3dB) | 71.8Hz (measured, Erin’s Audio Corner) | - |
| Bass Extension (-10dB) | about 43.4Hz (measured, Erin’s Audio Corner) | - |
| Spinorama Preference Score | 4.58 | - |
| Spinorama Preference Score with Perfect Sub | 6.83 | - |
| DIY Kit | No | No |
Related Speaker Comparisons
More top alternatives to Klipsch RP-504C II:
- KEF Q6 Meta vs Klipsch RP-504C II
- Klipsch RP-500C II vs Klipsch RP-504C II
- Klipsch RP-504C II vs Polk Audio Reserve R350
- Klipsch RP-504C II vs Dynaudio Emit 25C
- Klipsch RP-504C II vs DALI Sonik Cinema
Prices on this page were last checked October 5, 2026 at 10:21 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
Klipsch RP-504C II: $499.99 each Amazon eBay
Pros: The largest Reference Premiere center puts four 5.25” Cerametallic woofers around a 1” titanium tweeter in a Tractrix horn, for a very high 96dB sensitivity. Erin’s Audio Corner measured the deepest bass of the Klipsch centers here, 71.8Hz (-3dB) and about 43Hz (-10dB), and a preference score of 4.58 without a subwoofer. Measured bass extension of 71.8Hz (-3dB).
Cons: On-axis response is the least even of the Klipsch centers (1.13dB average deviation), and directivity varies strongly with frequency (4.27dB directivity index deviation), so the tone changes for off-center seats and in reflective rooms. It is 814mm wide and 383mm deep, so check shelf depth before buying.
Full Klipsch RP-504C II review and specifications →
| Bass Extension (-10dB) | about 43.4Hz (measured, Erin’s Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 71.8Hz (measured, Erin’s Audio Corner) |
| DIY Kit | No |
| Dimensions | 6.9”H x 32”W x 15.1”D (174 x 814 x 383 mm) |
| Drivers | 1” titanium LTS vented tweeter with Tractrix horn, 4x 5.25” Cerametallic woofers |
| Frequency Response | 50Hz-25kHz ±3dB (manufacturer specified) |
| Impedance | 8 ohms nominal (manufacturer specified) |
| Sensitivity | 96dB (2.83V/1m, manufacturer specified) |
| Spinorama Preference Score | 4.58 |
| Spinorama Preference Score with Perfect Sub | 6.83 |
| Weight | 36.4 lbs (16.5 kg) |
| Woofer Cabinet | ported (rear Tractrix ports) |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Klipsch RP-504C II vs Klipsch RP-500C II
- Klipsch RP-504C II vs KEF Q6 Meta
- Klipsch RP-504C II vs Polk Audio Reserve R350
- Klipsch RP-504C II vs Dynaudio Emit 25C
- Klipsch RP-504C II vs DALI Sonik Cinema
- Klipsch RP-504C II vs Focal Theva Center
- Klipsch RP-504C II vs SVS Prime Center
- Klipsch RP-504C II vs Emotiva Airmotiv XC2
Polk Audio Reserve R400: $559.00 Estimated Amazon eBay
Pros: Larger dual 6.5-inch Turbine cone drivers paired with Polk X-Port bass reflex design extend low frequencies down to 48Hz (-3dB). Higher 89dB sensitivity and substantial dynamic output for large home theaters.
Cons: Horizontal 2-way MTM driver layout narrows the ideal off-axis listening window for wide seating arrangements. Rating estimated based on Reserve R200/R600 measurements.
Full Polk Audio Reserve R400 review and specifications →
| DIY Kit | No |
|---|---|
| Dimensions | 7.8”H x 24.2”W x 13.8”D (197 x 615 x 350 mm) |
| Drivers | 1” Pinnacle ring radiator tweeter, 2 x 6.5” Turbine cone woofers |
| Frequency Response | 48Hz - 39kHz (-3dB) |
| Impedance | 8 ohms nominal (4.1 ohms minimum) |
| Sensitivity | 89dB (2.83V/1m) |
| Weight | 32.8 lbs (14.9 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- No independent measurement review is linked for this model; it is ranked from hands-on listening and comparison against similarly priced speakers.
- Head-to-Head Comparisons