In this review, we will be comparing Monitor XT35 and A135C, two Passive Center Channel speakers from Polk Audio and JBL.
Let's have a brief look at the main features
of Polk XT35 and JBL Stage A135C first before getting into our more
detailed comparison.
| Key Specs | Polk XT35 | JBL Stage A135C |
|---|
| Brand | Polk Audio
United States · founded 1972 | JBL
United States · founded 1946 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" High-res dome | 1" dome with HDI (High Definition Imaging) waveguide technology |
|---|
| Woofer | 4 x 3" bi-laminate paper cone | 6 x 3" polycellulose |
|---|
| Frequency response | 57-40k Hz | 75-40k Hz |
|---|
| Sensitivity | 87 dB | 90 dB |
|---|
| Impedance | 8 ohms | 6 ohms |
|---|
| Power range | 25-200 watts | 20-150 watts |
|---|
| Weight | 6.36kg / 14lbs | 7.46kg / 16.4lbs |
|---|
| Dimensions (H x W x D) | 4-3/16" x 24-7/16" x 5-9/16"
107.0 x 621.0 x 142.0mm | 4-1/8" x 29-3/8" x 7-5/16"
105.0 x 747.0 x 186.0mm |
|---|
What size room are the Polk XT35 and JBL Stage A135C 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* |
Polk XT35 |
JBL Stage A135C |
| Near-field |
Poor |
Poor |
| Small Room |
Average |
Average |
| Mid-size Room |
Good |
Good |
| Large Room |
Average |
Average |
| Very Large Room |
Poor |
Poor |
(* 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 Monitor XT35 and A135C are 2-way speakers.
Polk XT35JBL Stage A135C
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Polk XT35 |
JBL Stage A135C |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
4 x 3-inch
|
6 x 3-inch
|
Monitor XT35 features a 1" Terylene High-res dome Tweeter and 4 x 3" bi-laminate paper cone Woofer. On the other hand, the A135C features a 1" aluminum dome with HDI (High Definition Imaging) waveguide technology Tweeter and 6 x 3" polycellulose Woofer.
Frequency Response
Monitor XT35 has a frequency range of 57-40k Hz whereas A135C has a frequency range of 75-40k Hz. With a minimum frequency of 57Hz, the Monitor XT35 can go significantly deeper on the low side and provide stronger bass compared to the A135C's min frequency of 75Hz.
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
Monitor XT35 is a 8 ohms speaker compared to the A135C which has a nominal impedance of 6 ohms.
These two speakers also have different sensitivity levels. Monitor XT35 sensitivity is rated at 87 dB and the A135C's is rated at 90 dB. This 3 dB difference makes the JBL Stage A135C a more sensitive speaker compared to Polk XT35, 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.
Monitor XT35 can handle a max power of 200 watts RMS, whereas A135C has a max power handling value of 150 watts RMS, 50 watts less than the Monitor XT35.
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
Monitor XT35 features 5-way post type posts and A135C has a 5-way post type posts. None of these speakers feature bi-amping/bi-wiring.
Polk XT35's 5-Way post terminals
Cabinet Type and Port Position
Monitor XT35 has a rear firing port whereas A135C has a side firing ports.
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 Polk XT35's and JBL Stage A135C's external dimensions. Polk XT35 has external dimensions of 107.0 x 621.0 x 142.0mm (4-3/16 x 24-7/16 x 5-9/16inch) whereas JBL Stage A135C has external dimensions of 105.0 x 747.0 x 186.0mm (4-1/8 x 29-3/8 x 7-5/16inch).
Polk XT35 is 126mm narrower and 44mm less deeper than JBL Stage A135C but it is also 2mm taller.
Below you can see the front view size comparison of Polk XT35 and JBL Stage A135C in scale.
Comparison image of Polk XT35 and JBL Stage A135C Size and External Dimensions
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 Polk XT35 is approximately 881.8cm2 / 136.7inch2 and base area of the JBL Stage A135C is approximately 1389.4cm2 / 215.4inch2. The Monitor XT35 requires 37% less surface area than the A135C which gives it a small advantage 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 Polk XT35 weighs 6.36kg / 14lbs and the JBL Stage A135C weighs 7.46kg / 16.4lbs. This makes the A135C 17% heavier than the Monitor XT35.
Here is a comparison of how Monitor XT35 and A135C'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 Polk XT35?
Here are the items that are included inside the box of Monitor XT35:
- Center-channel loudspeaker
- Grille (attached)
- 4 Self-adhesive rubber feet
- Owners Manual
- Online Product Registration
- Wall-Mount Template
What's in the Box of JBL Stage A135C?
Here are the items that come with the A135C:
- Center-channel loudspeaker
- Grille
- 4 Leveling feet
- 4 Rubber feet
- Owners Manual
- Warranty Card
 Max Input Power |
200 watts
vs
150 watts
|
Handle more power from your amplifier |
 Nominal Impedance |
8 ohms
vs
6 ohms
|
Less selective with amplifiers |
 Low Frequency Response |
57 Hz
vs
75 Hz
|
Generates deeper bass |
 Base Surface Area |
881cm2
vs
1389cm2
|
Takes less floor space |
 Price per pair* |
299USD
vs
300USD
|
costs less (*prices may change depending on the seller, location and time) |
 Sensitivity |
90 dB
vs
87 dB
|
Play louder with same amount of amplification power |
|
Number of Woofers |
6
vs
4
|
More woofers |
 Height |
105mm
vs
107mm
|
Easier to fit in smaller spaces |
| General |
Polk Audio Monitor XT35 |
JBL Stage A135C |
| Brand |
Polk Audio |
JBL |
| Speaker Type |
Low-profile center channel speaker |
Low-profile center channel speaker |
| Power Range |
25-200 watts |
20-150 watts |
| Sensitivity |
87 dB |
90 dB |
| Impedance |
8 ohms |
6 ohms |
| Frequency Response |
57-40k Hz |
75-40k Hz |
Drivers |
|
|
| Woofer Quantity |
4 |
6 |
| Woofer Size |
3" |
3" |
| Woofer Composition |
bi-laminate paper cone |
polycellulose |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
High-res dome |
dome with HDI (High Definition Imaging) waveguide technology |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
rear |
side |
Physical Specs |
|
|
| Height |
107.0mm (4.2") |
105.0mm (4.1") |
| Width |
621.0mm (24.4") |
747.0mm (29.4") |
| Depth |
142.0mm (5.6") |
186.0mm (7.3") |
| Weight |
6.36kg (14lbs) |
7.46kg (16.4lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Available Colors |
Black |
Black |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
n/a |
No |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
No single best speaker here - they are built to different priorities, and the right one depends on your room, your amplifier and what you listen to.
| Area | Better | Why |
|---|
| Bass | A | Polk XT35 digs deeper - 57Hz against 75Hz. |
| Amplifier needs | B | JBL Stage A135C is more sensitive (90dB vs 87dB), so it goes louder on the same amplifier. |
| Amplifier match | A | Polk XT35 is the easier load at 8 ohms. |
| Headroom | A | Polk XT35 takes more power (200W vs 150W) - more in hand in a big room. |
| Size | depends | Polk XT35 is easier to place; JBL Stage A135C is bigger, which usually goes with fuller bass. Your room decides. |
| Price | evenly matched | Much the same money ($299 vs $300 a pair). |
A Polk XT35 B JBL Stage A135C
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?
Polk XT35 has the edge on paper, though the margin is not large. The rows marked "depends" may matter more to you than the score does. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 75Hz anyway, so judge these on the other rows instead. In a large or open-plan room, JBL Stage A135C has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Polk XT35 is the easier speaker to get right.
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.