• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

JBL Stage 135C Review (Center Speaker)

Rate this speaker:

  • 1. Poor (headless panther)

    Votes: 167 88.4%
  • 2. Not terrible (postman panther)

    Votes: 20 10.6%
  • 3. Fine (happy panther

    Votes: 2 1.1%
  • 4. Great (golfing panther)

    Votes: 0 0.0%

  • Total voters
    189

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
39,427
Likes
179,304
Location
Seattle Area
This is a review and detailed measurements of the JBL 135C center home theater speaker. It was kindly purchased new and drop shipped to me for testing. It is on sale now for US $170.

I really like the look of 135C:

JBL 135C Review Home Theater Center Speaker.jpg


This is a 2-way design and other brands we have tested of this kind have proved disappointing for center speaker usage. Will this be different? We will find out.

NOTE: our company, Madrona Digital is a dealer for Harman which includes JBL line. So feel free to read whatever level of bias you like in my subjective remarks.

Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise. Both of these factors enable testing in ordinary rooms yet results that can be more accurate than an anechoic chamber. In a nutshell, the measurements show the actual sound coming out of the speaker independent of the room.

Measurements are compliant with latest speaker research into what can predict the speaker preference and is standardized in CEA/CTA-2034 ANSI specifications. Likewise listening tests are performed per research that shows mono listening is much more revealing of differences between speakers than stereo or multichannel.

Reference axis was the center of the tweeter (aligned by eye). It is getting colder with the measurement room temp at 15 degrees C. Much more samples were taken for measurement of the 135C due to complex sound field created by the interference between all the drivers. Accuracy is better than 1% for most of the range but drops to 2% for part of the spectrum.

JBL 135C Measurements
Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker is and how it can be used in a room. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:

JBL 135C Measurements Frequency Response Home Theater Center Speaker.png


I must say, I was not ready for how ugly this looks. We have a bunch of flaws mixed in from lack of deep bass to resonances and directivity error. The only good news is high sensitivity to the tune of near 90 dB.

Due to directivity error which we will cover later, off-axis response is just as chewed up:

JBL 135C Measurements Early Window Frequency Response Home Theater Center Speaker.png


Somehow it becomes smoother when combined to predict the overall room response:

JBL 135C Measurements Predicted in-room Frequency Response Home Theater Center Speaker.png


The increase in energy at 200 Hz gives the sensation of bass to the unitiated but I find such sound tubby and undesirable. We also have some increase in high frequencies combining to present somewhat of a "showroom sound" for a small speaker.

Near-field measurements show some pronounced resonances:

JBL 135C Measurements near field Frequency Response Home Theater Center Speaker.png


The ports by the way are at each end of the speaker.

Now we get to the disappointing part: horizontal directivity and beam width:

JBL 135C Measurements Horizontal Beam width Home Theater Center Speaker.png


JBL 135C Measurements Horizontal directivity Home Theater Center Speaker.png


A center speaker needs to cover wide audience range and this is the opposite. The driver array has destructive cancellation that causes it to highly "beam" (narrow) in response from 300 Hz up to near 3 kHz. A lot of the vocal range falls in this area so voices are definitely going to be impacted.

While we don't need good vertical directivity, we have it here:
JBL 135C Measurements Vertical directivity Home Theater Center Speaker.png


One nice thing I have found with multiple drivers is that they handle power very well. Even though these drivers are small they still do an excellent job here:


JBL 135C Measurements THD Distortion Response Home Theater Center Speaker.png

JBL 135C Measurements Distortion Response Home Theater Center Speaker.png


Impedance is typical of speakers these days, dropping down to 4 ohms:

JBL 135C Measurements Impedance and Phase Response Home Theater Center Speaker.png


For fans of timing analysis, here are the waterfall and impulse responses:

JBL 135C Measurements CSD Waterfall Home Theater Center Speaker.png


JBL 135C Measurements Impulse Response Home Theater Center Speaker.png


JBL 135C Listening Tests and Equalization
I always listen on-axis to speakers which helped the 135C hide its horizontal directivity. Here, I found the sound as predicted, tubby depending on the track and a bit bright. Moving just half a seat horizontally, killed the clarity and openness of vocals. Figuring some don't need multi-seat coverage, I attempted to fix the high level flaws using equalization:

JBL 135C Equalization EQ Parametric Home Theater Center Speaker.png


I put in the filter at 200 Hz to get rid of overboosted response there. That got rid of the tubbiness but then highlighted the highs even more. So I dialed in the shelving filter on the right and got that fixed. Problem was, I now lost most of the bass response. I dialed in a quick and dirty low shelf and was surprised how well that worked. I had warmth and good bass now with no noticeable rise in distortion! Once there, as long as you sat on-axis, the sound was quite enjoyable with good ability to play loud.

Conclusions
JBL nails the price and looks of this speaker together with svelte form factor. Alas, it attempts to fight physics and loses on horizontal directivity. No doubt marketing and cost dictated this configuration as their competitors are guilty of the same. Fortunately it responded well to manual equalization (automatic may not work well). So if you want to listen alone, you should be fine. Note that you can't use it vertically due to the ports at each end unless you hang it on the wall.

I can't recommend the JBL 135C as a center speaker.

----------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 

Attachments

  • JBL 135C Frequency Response ASR.zip
    61.4 KB · Views: 59

spacevector

Addicted to Fun and Learning
Forum Donor
Joined
Dec 3, 2019
Messages
534
Likes
945
Location
Bayrea
Wow the harman/kardon streamer recently and now this JBL speaker. Both trashed. Must have taken some inner strength and courage amir - admirable. :p
 

MZKM

Major Contributor
Forum Donor
Joined
Dec 1, 2018
Messages
4,140
Likes
10,811
Location
Land O’ Lakes, FL
As for having six 3“ woofers, I assume that it is to make it similar to the size of a soundbar, allowing for flexibility with placement (e.g., on top an entertainment center, attached under a mounted tv, etc.), this goes along with having side ports over rear ones (a sealed design would have no bass in this case).

As for why a 2-way over a 2.5-way, I assume that is to keep sensitivity high and in line with most other center channels (89dB is about average for all center channels tested).

I find it odd that this is their only center channel offering for the line, I assumed there would have been also a 2-way version utilizing dual 5.25”.

Polk‘s Signature Elite line for reference:
image
 
Last edited:

MZKM

Major Contributor
Forum Donor
Joined
Dec 1, 2018
Messages
4,140
Likes
10,811
Location
Land O’ Lakes, FL
@MZKM they also have the A125C with 2x 5.25" Woofers.
1534851940_IMG_1050307.jpg
Hmm, it’s not on their main webpage, so I guess they discontinued it (maybe the market has spoken):

However, it is on this site:

However, on that same site they don’t have the normal Studio line of speakers, like the Studio 590 towers, they instead seem to have a variant of the HDI series, here is the Studio 690 for instance:
https://mm.jbl.com/loudspeakers/JBL+STUDIO+690.html
JBL_Studio690_No_Grill_Front34.png


Are these new models?

The center reminds me of the Array one with its narrow waveguide.
jbl-studio-665c-centre-speaker-01-1200x1200.jpg
 
Last edited:

respice finem

Major Contributor
Joined
Feb 1, 2021
Messages
1,508
Likes
2,850
Second thought: Considering the price, this one is likely to end up in a really cheap system, and perhaps wall-mounted, the remaining speakers being at a similar performance level. So maybe it's just good enough for this. That said, and for this scenario, a modern soundbar can be serious competition.
 

pierre

Addicted to Fun and Learning
Forum Donor
Joined
Jul 1, 2017
Messages
781
Likes
2,136
Location
Switzerland
Humm. Really bad speaker.

Score 0.8

Here is an EQ optimising things a bit starting at 120Hz, it will push the score to 3.1.

Code:
EQ for JBL Stage A135C computed from ASR data
Preference Score 0.8 with EQ 3.1
Generated from http://github.com/pierreaubert/spinorama/generate_peqs.py v0.14
Dated: 2021-11-29-08:57:42

Preamp: -0.6 dB

Filter  1: ON BP Fc   263 Hz Gain -3.60 dB Q 0.05
Filter  2: ON PK Fc   230 Hz Gain -4.30 dB Q 1.01
Filter  3: ON PK Fc  3925 Hz Gain -3.67 dB Q 1.40
Filter  4: ON PK Fc   948 Hz Gain +1.05 dB Q 4.00
Filter  5: ON PK Fc  1443 Hz Gain -0.50 dB Q 2.16
Filter  6: ON PK Fc   486 Hz Gain -0.61 dB Q 4.00
Filter  7: ON PK Fc   181 Hz Gain -0.50 dB Q 4.00

The EQ will cost you ~6dB.

filters_eq.png
filters_lw.png


filters_pir.png


filters_spin.png
 
Last edited:

YSC

Major Contributor
Joined
Dec 31, 2019
Messages
2,406
Likes
1,793
This is a review and detailed measurements of the JBL 135C center home theater speaker. It was kindly purchased new and drop shipped to me for testing. It is on sale now for US $170.

I really like the look of 135C:

View attachment 168762

This is a 2-way design and other brands we have tested of this kind have proved disappointing for center speaker usage. Will this be different? We will find out.

NOTE: our company, Madrona Digital is a dealer for Harman which includes JBL line. So feel free to read whatever level of bias you like in my subjective remarks.

Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise. Both of these factors enable testing in ordinary rooms yet results that can be more accurate than an anechoic chamber. In a nutshell, the measurements show the actual sound coming out of the speaker independent of the room.

Measurements are compliant with latest speaker research into what can predict the speaker preference and is standardized in CEA/CTA-2034 ANSI specifications. Likewise listening tests are performed per research that shows mono listening is much more revealing of differences between speakers than stereo or multichannel.

Reference axis was the center of AMT driver (aligned by eye). It is getting colder with the measurement room temp at 15 degrees C. Much more samples were taken for measurement of the 135C due to complex sound field created by the interference between all the drivers. Accuracy is better than 1% for most of the range but drops to 2% for part of the spectrum.

JBL 135C Measurements
Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker is and how it can be used in a room. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:

View attachment 168763

I must say, I was not ready for how ugly this looks. We have a bunch of flaws mixed in from lack of deep bass to resonances and directivity error. The only good news is high sensitivity to the tune of near 90 dB.

Due to directivity error which we will cover later, off-axis response is just as chewed up:

View attachment 168764

Somehow it becomes smoother when combined to predict the overall room response:

View attachment 168765

The increase in energy at 200 Hz gives the sensation of bass to the unitiated but I find such sound tubby and undesirable. We also have some increase in high frequencies combining to present somewhat of a "showroom sound" for a small speaker.

Near-field measurements show some pronounced resonances:

View attachment 168767

The ports by the way are at each end of the speaker.

Now we get to the disappointing part: horizontal directivity and beam width:

View attachment 168768

View attachment 168769

A center speaker needs to cover wide audience range and this is the opposite. The driver array has destructive cancellation that causes it to highly "beam" (narrow) in response from 300 Hz up to near 3 kHz. A lot of the vocal range falls in this area so voices are definitely going to be impacted.

While we don't need good vertical directivity, we have it here:
View attachment 168770

One nice thing I have found with multiple drivers is that they handle power very well. Even though these drivers are small they still do an excellent job here:


View attachment 168771
View attachment 168772

Impedance is typical of speakers these days, dropping down to 4 ohms:

View attachment 168773

For fans of timing analysis, here are the waterfall and impulse responses:

View attachment 168774

View attachment 168775

JBL 135C Listening Tests and Equalization
I always listen on-axis to speakers which helped the 135C hide its horizontal directivity. Here, I found the sound as predicted, tubby depending on the track and a bit bright. Moving just half a seat horizontally, killed the clarity and openness of vocals. Figuring some don't need multi-seat coverage, I attempted to fix the high level flaws using equalization:

View attachment 168776

I put in the filter at 200 Hz to get rid of overboosted response there. That got rid of the tubbiness but then highlighted the highs even more. So I dialed in the shelving filter on the right and got that fixed. Problem was, I now lost most of the bass response. I dialed in a quick and dirty low shelf and was surprised how well that worked. I had warmth and good bass now with no noticeable rise in distortion! Once there, as long as you sat on-axis, the sound was quite enjoyable with good ability to play loud.

Conclusions
JBL nails the price and looks of this speaker together with svelte form factor. Alas, it attempts to fight physics and loses on horizontal directivity. No doubt marketing and cost dictated this configuration as their competitors are guilty of the same. Fortunately it responded well to manual equalization (automatic may not work well). So if you want to listen alone, you should be fine. Note that you can't use it vertically due to the ports at each end unless you hang it on the wall.

I can't recommend the JBL 135C as a center speaker.

----------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
This is real bad… especially from a brand with so much research backing it…

Cost is on cheap side but I can’t imagine ppl buying this in a multi channel setup for better sound yet get all these
 

H-713

Senior Member
Joined
Jan 24, 2021
Messages
365
Likes
609
Headless for being almost useless with that beam width. I get the sense that this was designed to look a certain way, not perform a certain way. Of course, at this pricepoint, looks is what sells.
 

LearningToSmile

Active Member
Joined
Jun 29, 2020
Messages
255
Likes
416
Good timing with the review since the JBL Stage series seems to have finally become available in Europe recently. Unfortunately disappointing result, even comparing to other 2-way center speakers.

@amirm any other JBL Stage speakers in the pipeline? I'm not expecting much from them anymore, but it would still be nice to see the towers measured, particularly the A190.
 

ROOSKIE

Major Contributor
Joined
Feb 27, 2020
Messages
1,446
Likes
2,512
Location
Minneapolis
Yikes.

Get a three way or no way.

The 3way Polk L400 is on sale right now.
$1449

I also believe accessories4less is expecting more Polk LSIM706c's soon for $399. Crazy good price for those. Both Black and Cherry should be in stock again soon. My Old Polk LSIM703's performed extremely well.

Airmotiv C2+ and SVS Prime are also $399, wonder how these perform?
 

Blumlein 88

Grand Contributor
Forum Donor
Joined
Feb 23, 2016
Messages
16,378
Likes
28,171
And another one bites the dust... Making a good measuring horzontal center seems to be almost impossible, let alone a low profile one.
Yes it does. So hopefully a few more measurements and that format will be abandoned. If you use a projection screen, you would have the option of getting an acoustically transparent screen and putting a conventional well designed floor stander in for the center.
 

voodooless

Master Contributor
Forum Donor
Joined
Jun 16, 2020
Messages
5,660
Likes
9,306
Location
Netherlands
Yes it does. So hopefully a few more measurements and that format will be abandoned. If you use a projection screen, you would have the option of getting an acoustically transparent screen and putting a conventional well designed floor stander in for the center.
Well, tell that to the spot underneath my TV... I only have room for a small thingy. But since even most big ones suck, it doesn't really matter that much. I did try to come up with an alternative with my Bessel Array topic, but in the end, it seems it will not yield enough HF directivity and you have to sit too far away to make it properly work. The only thing that I can think of now besides a small Coax (with limited output as a consequence) is a horizontal CBT array, however, that needs lots of drivers and a rounded shape and/or a boatload of DSP channels.
 

dasdoing

Major Contributor
Joined
May 20, 2020
Messages
2,801
Likes
1,587
Location
Salvador-Bahia-Brasil
Making a good measuring horzontal center seems to be almost impossible, let alone a low profile one

the woofers need to be isolated, so the lobing ocures above the crossover, like done in line array modules:

007_HDL-6-A_open.jpg


now these are obviously produced for big distances, I am still curious how this would behave. sitting on the left you would be totaly isolated from the right woofer, for example
 
Top Bottom