Short answer: the Klipsch RP-504C II. It ranks #35 of 98 center channel speakers by sound quality, rated 3.8/5, at $499.99; the Polk Audio Reserve R350 ranks #40, rated 3.7/5, and costs $519, so there is not much of a tradeoff to weigh.
The Klipsch RP-504C II is the more accurate, deeper-bass pick. 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. Its measured preference score, a predictor of how neutral it sounds, is 4.58 against 3.97 for the Polk Audio Reserve R350. Its bass reaches about 71.8Hz before falling 3dB, against 85Hz for the Polk Audio Reserve R350. 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.
Why pick the Polk Audio Reserve R350: A slim sealed center, 141mm tall and 188mm deep, with a 1” Pinnacle ring radiator tweeter and four 4” Turbine cone woofers, designed to sit under a TV or mount on a wall. The catch: Bass rolls off at 85Hz (-3dB) and about 49Hz (-10dB), so a subwoofer is needed.
Buy the Klipsch RP-504C II. It is rated higher for sound quality than the Polk Audio Reserve R350 and costs less, which makes it the one to get unless you need something the other one does better.
Looking for alternatives? See the complete Passive Home rankings.
Specifications Side By Side
| Klipsch RP-504C II | Polk Audio Reserve R350 | |
|---|---|---|
| Price | $499.99 each | $519.00 each |
| Ranked | #35 of 98 in Center Channel Speakers | #40 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, 4x 4” Turbine cone woofers |
| Frequency Response | 50Hz-25kHz ±3dB (manufacturer specified) | 75Hz-35kHz -3dB (manufacturer specified) |
| Sensitivity | 96dB (2.83V/1m, manufacturer specified) | 87dB (2.83V/1m, manufacturer specified) |
| Impedance | 8 ohms nominal (manufacturer specified) | 3.9 ohms minimum, compatible with 4 to 8 ohm outputs (manufacturer specified) |
| Woofer Cabinet | ported (rear Tractrix ports) | sealed |
| Dimensions | 6.9”H x 32”W x 15.1”D (174 x 814 x 383 mm) | 5.6”H x 30”W x 7.4”D (141 x 762 x 188 mm) |
| Weight | 36.4 lbs (16.5 kg) | 19.8 lbs (9 kg) |
| Bass Extension (-3dB) | 71.8Hz (measured, Erin’s Audio Corner) | 85.0Hz (measured, Audio Science Review) |
| Bass Extension (-10dB) | about 43.4Hz (measured, Erin’s Audio Corner) | about 48.7Hz (measured, Audio Science Review) |
| Spinorama Preference Score | 4.58 | 3.97 |
| Spinorama Preference Score with Perfect Sub | 6.83 | 6.72 |
| DIY Kit | No | No |
Related Speaker Comparisons
More worthwhile head-to-heads for 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 R400
- 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.
As an eBay Partner, we may be compensated if you make a purchase.
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 Polk Audio Reserve R400
- Klipsch RP-504C II vs Klipsch RP-500C II
- Klipsch RP-504C II vs KEF Q6 Meta
- 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 R350: $519.00 each Amazon eBay
Pros: A slim sealed center, 141mm tall and 188mm deep, with a 1” Pinnacle ring radiator tweeter and four 4” Turbine cone woofers, designed to sit under a TV or mount on a wall. Audio Science Review measured a fairly flat on-axis response (0.31 average deviation), and the score rises to 6.72 with an ideal subwoofer. Measured bass extension of 85.0Hz (-3dB).
Cons: Bass rolls off at 85Hz (-3dB) and about 49Hz (-10dB), so a subwoofer is needed. The listening window spans 3.0dB from 300Hz to 5kHz, and the preference score without a subwoofer is a middling 3.97.
Full Polk Audio Reserve R350 review and specifications →
| Bass Extension (-10dB) | about 48.7Hz (measured, Audio Science Review) |
|---|---|
| Bass Extension (-3dB) | 85.0Hz (measured, Audio Science Review) |
| DIY Kit | No |
| Dimensions | 5.6”H x 30”W x 7.4”D (141 x 762 x 188 mm) |
| Drivers | 1” Pinnacle ring radiator tweeter, 4x 4” Turbine cone woofers |
| Frequency Response | 75Hz-35kHz -3dB (manufacturer specified) |
| Impedance | 3.9 ohms minimum, compatible with 4 to 8 ohm outputs (manufacturer specified) |
| Sensitivity | 87dB (2.83V/1m, manufacturer specified) |
| Spinorama Preference Score | 3.97 |
| Spinorama Preference Score with Perfect Sub | 6.72 |
| Weight | 19.8 lbs (9 kg) |
| Woofer Cabinet | sealed |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons