In this review, we will be comparing RP-504C II and HDI-4500, two Passive Center Channel speakers from Klipsch and JBL.
Let's have a brief look at the main features
of Klipsch RP-504C II and JBL HDI-4500 first before getting into our more
detailed comparison.
| Key Specs | Klipsch RP-504C II | JBL HDI-4500 |
|---|
| Brand | Klipsch
United States · founded 1946 | JBL
United States · founded 1946 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Tractrix Horn | 1" horn-loaded high-frequency compression |
|---|
| Woofer | 4 x 5.25" Cerametallic cone | 4 x 5.25" Advanced Aluminum Matrix cone |
|---|
| Frequency response | 50-25k Hz | 50-30k Hz |
|---|
| Sensitivity | 96 dB | 90 dB |
|---|
| Impedance | 8 ohms | 4 ohms |
|---|
| Power range | up to 150 watts | 20-250 watts |
|---|
| Weight | 16.50kg / 36.3lbs | 20.15kg / 44.3lbs |
|---|
| Dimensions (H x W x D) | 6-15/16" x 32-3/16" x 15-1/8"
177.0 x 818.0 x 385.0mm | 7-3/4" x 33-1/8" x 12-3/16"
197.0 x 842.0 x 310.0mm |
|---|
What size room are the Klipsch RP-504C II and JBL HDI-4500 speakers good for?
The size of the room in which you are planning to use these loudspeakers is an important decision
factor. Here we have compared their suitability to various sizes of environments considering their size
and max power parameters:
| Listening Environment* |
Klipsch RP-504C II |
JBL HDI-4500 |
| Near-field |
Poor |
Poor |
| Small Room |
Average |
Poor |
| Mid-size Room |
Good |
Good |
| Large Room |
Average |
Good |
| Very Large Room |
Poor |
Average |
(* Approximate Room sizes: Small < 100sq. ft / 9 m2,
Mid-size: 100-220 sq. ft / 9-20 m2, Large 220-400 sq. ft / 20-36 m2, Very Large: >
400 sq. ft / 36 m2.
Average Floor Height: 9" / 2.7m. Typical room sizes differ from country to country, and the actual
listening experience changes depending on floor height, room shape, surface materials, listening
position, speaker locations, etc.)
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
Both RP-504C II and HDI-4500 are 2-way speakers.
Klipsch RP-504C IIJBL HDI-4500
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Klipsch RP-504C II |
JBL HDI-4500 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
4 x 5.25-inch
|
4 x 5.25-inch
|
RP-504C II features a 1" titanium Tractrix Horn Tweeter and 4 x 5.25" Cerametallic cone Woofer with a Crossover frequency at 1950 Hz. On the other hand, the HDI-4500 features a 1" horn-loaded high-frequency compression Tweeter and 4 x 5.25" Advanced Aluminum Matrix cone Woofer.
Frequency Response
RP-504C II has a frequency range of 50-25k Hz whereas HDI-4500 has a frequency range of 50-30k Hz.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Center Channel class in our database.
Low Frequency
Center Channel Speakers
Neither pair reaches down to 20Hz, the usual definition of full-range, which is normal for speakers of this size. If you want the bottom octave for movies or bass-heavy music, add a subwoofer to whichever you choose. Visit our Powered Subwoofers section to find out more about the available options.
Impedance and Sensitivity
RP-504C II is a 8 ohms speaker compared to the HDI-4500 which has a nominal impedance of 4 ohms. Lower impedance speakers, especially the ones that are rated at 4 ohms may put more pressure on the amplifier unit especially when played at high volume levels, so make sure the amp you pair with the HDI-4500 can provide this impedance level.
These two speakers also have different sensitivity levels. RP-504C II sensitivity is rated at 96 dB and the HDI-4500's is rated at 90 dB. This 6 dB difference makes the Klipsch RP-504C II a more sensitive speaker compared to JBL HDI-4500, hence will play louder with the same amount of watts.
Sensitivity
Center Channel Speakers
Power Range
Power
range is the range of input power in watts RMS that a loudspeaker is designed to handle. Staying
within that range gives nominal performance; driving the speaker beyond its maximum wattage can damage it.
HDI-4500 can handle a max power of 250 watts RMS, whereas RP-504C II has a max power handling value of 150 watts RMS, 100 watts less than the HDI-4500.
Note that higher power handling does not make a speaker louder: that depends mainly on
sensitivity and impedance. The calculator below shows how loud each of these actually plays
on a real amplifier.
Which plays louder on your amplifier?
Starting with a popular amplifier - change it to the one you own, or any you are
considering, and watch both numbers move.
Input Type and Bi-Amping / Bi-Wiring
RP-504C II features 5-Way post type posts and HDI-4500 has a 5-Way post type posts. None of these speakers feature bi-amping/bi-wiring.
Klipsch RP-504C II's Binding post terminals
JBL HDI-4500's 5-Way post terminals
Cabinet Type and Port Position
Both RP-504C II and HDI-4500 have rear firing ports. Rear ported speakers generally need more room between the backside of the speaker and the wall compared to sealed and front/bottom ported speakers. Placing the speakers too close to the walls may cause the bass to sound boomy.
If you are limited in space and can't get the speakers away from the backwall, check our Speakers with Front Firing Ports page.
Physical Specs
The size of a speaker can sometimes be an important decision factor due to space constraints or in some cases purely for esthetic reasons. In this section, we are going to compare Klipsch RP-504C II's and JBL HDI-4500's external dimensions. Klipsch RP-504C II has external dimensions of 177.0 x 818.0 x 385.0mm (6-15/16 x 32-3/16 x 15-1/8inch) whereas JBL HDI-4500 has external dimensions of 197.0 x 842.0 x 310.0mm (7-3/4 x 33-1/8 x 12-3/16inch).
Klipsch RP-504C II is 24mm narrower and 20mm shorter than JBL HDI-4500 but it is also 75mm deeper.
Base Surface Area Comparison
Base surface area of a loudspeaker may become a determining factor when the space in your room or desk is limited.
The base surface area of the Klipsch RP-504C II is approximately 3149.3cm2 / 488.1inch2 and base area of the JBL HDI-4500 is approximately 2610.2cm2 / 404.6inch2. The RP-504C II requires 21% more surface area than the HDI-4500 which gives it a small disadvantage on placement in tight spaces.
Weight Comparison The weight of a loudspeaker can become an important factor if you need to move and reposition the unit often. Weight of a speaker can also "sometimes" be an indicator of the rigidity of the enclosure and the quality of the internal components used. The Klipsch RP-504C II weighs 16.50kg / 36.3lbs and the JBL HDI-4500 weighs 20.15kg / 44.3lbs. This makes the HDI-4500 22% heavier than the RP-504C II.
Here is a comparison of how RP-504C II and HDI-4500's weights compare with the average, max and min weights in Passive Center Channel class.
Weight
All Center Channel Speakers
What's in the Box of Klipsch RP-504C II?
Here are the items that are included inside the box of RP-504C II:
- Center channel loudspeaker
- Grille
- User Manual
- Important Safety Instructions
- Warranty Information
What's in the Box of JBL HDI-4500?
Here are the items that come with the HDI-4500:
- Center-channel loudspeaker
- Grille
- 2 Jumper-straps (pre-installed)
- Owners Manual
 Sensitivity |
96 dB
vs
90 dB
|
Play louder with same amount of amplification power |
 Nominal Impedance |
8 ohms
vs
4 ohms
|
Less selective with amplifiers |
 Height |
177mm
vs
197mm
|
Easier to fit in smaller spaces |
 Price per pair* |
799USD
vs
1925USD
|
costs less (*prices may change depending on the seller, location and time) |
 Max Input Power |
250 watts
vs
150 watts
|
Handle more power from your amplifier |
 High Frequency Response |
30k Hz
vs
25k Hz
|
Generates higher frequency |
 Base Surface Area |
2610cm2
vs
3149cm2
|
Takes less floor space |
| General |
Klipsch Reference Premiere RP-504C II |
JBL HDI-4500 |
| Brand |
Klipsch |
JBL |
| Speaker Type |
Center channel speaker |
Center channel speaker |
| Power Range |
up to 150 watts |
20-250 watts |
| Sensitivity |
96 dB |
90 dB |
| Impedance |
8 ohms |
4 ohms |
| Frequency Response |
50-25k Hz |
50-30k Hz |
Drivers |
|
|
| Woofer Quantity |
4 |
4 |
| Woofer Size |
5.25" |
5.25" |
| Woofer Composition |
Cerametallic cone |
Advanced Aluminum Matrix cone |
| Woofer Surround Material |
Rubber |
n/a |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Tractrix Horn |
horn-loaded high-frequency compression |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
1950 Hz |
n/a |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
177.0mm (7") |
197.0mm (7.8") |
| Width |
818.0mm (32.2") |
842.0mm (33.1") |
| Depth |
385.0mm (15.2") |
310.0mm (12.2") |
| Weight |
16.50kg (36.3lbs) |
20.15kg (44.3lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
MDF/Wood-grain vinyl |
n/a |
| Available Colors |
Walnut, Black |
Walnut |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
No |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
These sit in different price classes - JBL HDI-4500 costs roughly 2.4x what Klipsch RP-504C II does. Expect it to lead on paper; the question is whether the gap is audible enough in your room to be worth it.
| Area | Better | Why |
|---|
| Bass | evenly matched | Much the same reach (50Hz vs 50Hz). |
| Amplifier needs | A | Klipsch RP-504C II is more sensitive (96dB vs 90dB), so it goes louder on the same amplifier. |
| Amplifier match | A | Klipsch RP-504C II is the easier load at 8 ohms; the other is 4 ohms and wants an amplifier rated for it. |
| Headroom | B | JBL HDI-4500 takes more power (250W vs 150W) - more in hand in a big room. |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Expandability | depends | Neither adds bi-amping, a sub output or height drivers. Klipsch RP-504C II sits in a wider range (10 models), so a matched surround system is easier later. |
| Price | A | Klipsch RP-504C II is cheaper - $799 against $1,925, about 58% less; arguably a different class. |
A Klipsch RP-504C II B JBL HDI-4500
depends neither is better in the abstract - it turns on your room, your system or how you will use them. Only specs published for both speakers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
Klipsch RP-504C II has the edge on paper, though the margin is not large. The rows marked "depends" may matter more to you than the score does. Match it to your room: we rate Klipsch RP-504C II the better fit for a small room, and JBL HDI-4500 for a large room and a very large room. If your amplifier is modest, vintage or valve-based, Klipsch RP-504C II is the safer partner - the other will want more current or more watts to sound its best.
And remember what a spec sheet cannot show: how each looks in your room and whether the finish suits it, what dealer support and warranty are like where you live, and how they actually sound to you. If you can hear them first - ideally with your own music - that will tell you more than any number above.