The centre-channel upgrade, in two very different boxes — which should you buy?
The short answer
Buy the Klipsch RP-504C II for a dedicated room with real space under the screen: four 5.25-inch woofers in a 32.1-inch cabinet, and the only qualified bass floor on this page at 50 Hz ±3 dB. Buy the Polk Audio Reserve R300 for a credenza, a soundbar-height shelf or a wall-mounted TV: 19 inches wide, 8.9 deep, sealed with no port to keep clear, and the only sheet here that publishes a minimum impedance.
As tracked by Home Theater Builder: the Klipsch RP-504C II tracks at $520; the Polk Audio Reserve R300 at $499.How we verify this data →
The first upgrade most people make after the front pair, and these two rows could hardly be less alike ($520 vs $499 as tracked today): a 32-inch-wide ported three-way against a 19-inch sealed two-way.
Specifications · side by side · per-field provenance
● SOURCE-TRACKED
Spec
Klipsch RP-504C II
Polk Audio Reserve R300
Price
$520
$499
Brand
Klipsch
Polk Audio
Speaker Type
center channel
center channel
Way Config
3-way
2-way
Woofer Count
4
2
Woofer Size Inches
5.25
5.25
Tweeter Size Inches
1
1
Impedance Nominal Ohms
8
not stated
Sensitivity DB 1w1m
96
86.5
Sensitivity Measurement Context
unstated
unstated
Freq Response Low HZ
50
65
Freq Response High HZ
25000
38000
Freq Response Tolerance
plus minus 3dB
unstated
Peak Power Handling W
600
not stated
Enclosure Type
bass reflex ported
sealed
Port Location
rear
none
Binding Posts
single wire
single wire
Grille Included
Yes
not stated
Height Inches
6.9
6.8
Width Inches
32.1
19
Depth Inches
15.1
8.9
Weight Lbs
36.3
16.8
Finish Options
Ebony, Walnut
Black, Walnut
Intended Roles
not stated
center
Impedance Minimum Ohms
not stated
3.8
Recommended Power Min W
not stated
30
Recommended Power Max W
not stated
200
Sold As
not stated
each
Shaded rows differ · green dot = lab-measured · amber = manufacturer-verified · blue = retailer/community-reported · grey = estimated · “not stated” means exactly that
Reading the numbers honestly
The impedance disclosure on this page is complementary rather than comparable: Klipsch states an 8Ω NOMINAL and no minimum; Polk states a 3.8Ω MINIMUM and no nominal. Neither sheet publishes the number the other publishes, so a load ranking cannot be made from what is stated — what can be said is that the Polk's published worst case is a genuinely demanding one, and the Klipsch's worst case is unknown rather than proven easy. Sensitivity: 96 dB (Klipsch) against 86.5 dB (Polk), both stored with an UNSTATED measurement context. Two unstated conventions are not one yardstick, and our rule is never to rank sensitivity across contexts, so the printed 9.5 dB gap is flagged here rather than scored. Bass: the Klipsch's 50 Hz floor is stated at ±3 dB while the Polk's 65 Hz carries an UNSTATED tolerance, so only one of the two claims is qualified. And the physical difference is the one most buyers hit first: 32.1 inches wide, 15.1 deep and 36.3 pounds, rear-ported, against 19 inches wide, 8.9 deep and 16.8 pounds, sealed with no port at all.
Compatibility · computed, not written
Checked against a popular budget receiver, the Denon AVR-X1800H (80W per channel into 8Ω): Denon AVR-X1800H
Will the Klipsch RP-504C II work with a receiver like the Denon AVR-X1800H?
Klipsch RP-504C II states 8Ω nominal with no published minimum — inside the Denon AVR-X1800H's stated 4Ω-minimum rating.
Will the Polk Audio Reserve R300 work with a receiver like the Denon AVR-X1800H?
Polk Audio Reserve R300 dips to a stated 3.8Ω minimum — below the Denon AVR-X1800H's stated 4Ω-minimum rating, so this pairing sits outside the receiver's published spec.
Computed from the catalog's normalized fields — the same fields the builder's compatibility engine reads. A missing field reads as "can't check", never as a pass.
Buy the Klipsch RP-504C II for a dedicated room with real space under the screen: four 5.25-inch woofers in a 32.1-inch cabinet, and the only qualified bass floor on this page at 50 Hz ±3 dB. Buy the Polk Audio Reserve R300 for a credenza, a soundbar-height shelf or a wall-mounted TV: 19 inches wide, 8.9 deep, sealed with no port to keep clear, and the only sheet here that publishes a minimum impedance.
A dedicated room with space under the screenKlipsch RP-504C II — Four 5.25-inch woofers in a 32.1-inch cabinet and a 50 Hz floor stated at ±3 dB — the only qualified bass claim on the page.
A credenza or a wall-mounted TVPolk Audio Reserve R300 — 19 inches wide, 8.9 deep and 16.8 pounds, sealed with no port — a little over half the width and no rear clearance to find.
Checking the amplifier loadPolk Audio Reserve R300 — Polk publishes a 3.8Ω minimum; Klipsch publishes only an 8Ω nominal, so the Klipsch's worst case is unknown rather than proven easy.
Reading the sensitivity figuresEither — 96 dB against 86.5 dB with BOTH measurement contexts UNSTATED — two brands' unstated conventions are not one yardstick, so this row is flagged rather than ranked.
Amplifier appetitePolk Audio Reserve R300 — Polk states a 30-200W recommended range a receiver's rating can be matched to; Klipsch states a 600W peak power handling, which is a different quantity.
Price todayEither — Whichever sits lower in the price row on the day — $520 vs $499 as tracked, the Polk lower by $21.
What our normalized data adds
NOT ON THE SPEC SHEETS
The impedance disclosure is complementary, not comparable: Klipsch states an 8Ω NOMINAL with no minimum; Polk states a 3.8Ω MINIMUM with no nominal. Neither sheet publishes the figure the other one does.
Only one bass claim on this page is qualified: 50 Hz stated at ±3 dB (Klipsch) against 65 Hz with tolerance UNSTATED (Polk).
96 dB against 86.5 dB with BOTH measurement contexts UNSTATED — neither sheet says what its figure was measured under, so the printed 9.5 dB gap is flagged as unrankable rather than repeated at face value or adjusted by a brand convention.
These two cabinets are not interchangeable furniture: 32.1 x 6.9 x 15.1 inches and 36.3 pounds, rear-ported, against 19 x 6.8 x 8.9 inches and 16.8 pounds, sealed with no port to keep clear.
The power figures are different quantities: a 30-200W recommended amplifier range (Polk) against a 600W peak power handling (Klipsch) — only the first can be matched to a receiver's rating.
Both are centre channels priced per unit in our catalog, so no pair doubling is applied to either side ($520 vs $499 as tracked today).
