JBL SCL-5 In-ceiling Speaker Review

[nick-v]

It is designed for use as a height channel or in-ceiling LCR or surround channel loudspeaker.

I sell and install them. They're used primarily as overhead channels in immersive audio systems.

 

[sarumbear]

I sell and install them. They're used primarily as overhead channels in immersive audio systems.

That’s one of their uses according to the manufacturer. Your market maybe for only one of the use cases.

 

[Dj7675]

JBL Synthesis, I think makes their focus quite clear on their front page of their website…
Of course their speakers can be used in a variety of scenarios, but immersive audio/home theater is the primary focus.

 

[TNT]

Missed the "usual" Matrona - JBL affiliation disclaimer and the "you may read any bias you want" statements

This one would have needed it - that kind of FR and distortion usually have a few quite hard comments written into the scharts ;-D

//

 

[Dj7675]

Thank you @amirm for doing the review. This require a lot of work for sure. Is there a way to calculate estimated in room response based on a 45 degree angle instead of on axis?

 

[amirm]

Missed the "usual" Matrona - JBL affiliation disclaimer and the "you may read any bias you want" statements

Why? It is in the intro section of the review:

Note: our company Madrona Digital is a dealer for Harman and as a result, JBL products. Above speaker was purchased through our company so feel free to read whatever bias you like in my commentary.

 

[amirm]

Thank you @amirm for doing the review. This require a lot of work for sure. Is there a way to calculate estimated in room response based on a 45 degree angle instead of on axis?

It is painful as it requires manual conversion of polar to cartesian coordinates. Last time I did that, it was kind of tricky to get it right. Let me think about it....

 

[amirm]

Harman's measurements with and without EQ applied:

Thanks. That's basically my measurements sans the trough at crossover point -- which I also showed with -40 degree curve.

 

[kencreten]

Very interesting. I first looked at the response and thought, "what?" But then instantly realized, "wait, this is built to a purpose." I have no knowledge about these kinds of speakers.

 

[ROOSKIE]

Yes, unfortunately.

would that distorsion peak even be there if meassured at -40 degrees?

The harmonic distortion would very likely be lower if the fundamental filled in.
It is a percentage of the fundamental.
So if it fills in on a different axis, then I would re-measure the harmonic distortion from that angle.

You can even see in the isolated tweeter responce which has no null at 1500hrz the HD is 40db down@1500hrz(1%).

It should also be noted the 3rd order distortion is extremely low.

The issue is 2nd order and many waveguide/compression combos seem to produce unusual 2nd order HD effects.

I don't think the tweeter is stressed at all.

 

[mcdn]

For all the posts about how this is designed for a specific purpose (mainly in-ceiling LCR and effects), I still don’t see how it’s any good at that purpose.

Sure, it has an angled direction of radiation above 1000Hz. Well done JBL. But that seems to be the only “good” thing about it. And that price!

 

[Vladimir Filevski]

The harmonic distortion would very likely be lower if the fundamental filled in.
It is a percentage of the fundamental.
So if it fills in on a different axis, then I would re-measure the harmonic distortion from that angle.
You can even see in the isolated tweeter responce which has no null at 1500hrz the HD is 40db down@1500hrz(1%).
It should also be noted the 3rd order distortion is extremely low.
The issue is 2nd order and many waveguide/compression combos seem to produce unusual 2nd order HD effects.
I don't think the tweeter is stressed at all.

If you are referring to this measurements

yes, 2nd harmonic is about -35 to -40 dB at around 1500 Hz - not the best effort from JBL, but thankfully without higher order harmonics. I would expect lower distortion for such a high price.
There is another interesting in-ceiling speaker from Bose:
https://pro.bose.com/en_us/products/loudspeakers/background_foreground/edgemax.html

 

[jhaider]

Interesting results. Admittedly I don’t know what to make of them: see post above with Dirac averages (which I have confirmed to my satisfaction are basically reliable and stable representations of the in-room response over the measured area) from @Dj7675.

Sadly there are very few suitable (I.e. angled, with driver configuration that could allow for smooth dispersion) ceiling speakers appropriate for immersive height channels. Off the top of my head, the whole universe consists of:

these newish JBLs, long ago discontinued (unfortunately, because they were as good as I've seen in the category to date) TAD/Pioneer models, a Klipsch THX model with angled horns, Tannoy 4” coax in a ball mount, and a couple 3-ways with rotatable coax from e.g. Monitor Audio and Sonance. There's also a Monoprice one styled after the old TAD/Pioneer ceiling speakers, but it's an odd duck - no isolation between coax and woofer!

That said, here the horn does seem a bit small for the highpass used. SCL-3 uses the same driver and only slightly lower highpass, but the horn is much larger. It could be bigger than it appears, though. How does the horn mouth size compare to, e.g. 705i/708i?

Interesting, "organic" design. It looks like the engineers took inspiration from another classic design (right) and deepened it.
View attachment 263050 View attachment 263052

More like these 1980s JBL 4660, but modernized with their latest computer-aided geometry, scaled down quite a bit, and designed for in ceiling mount:

That directed-pattern horn (I believe designed under the direction of Don Keele) was also used in an Everest model.

(Is anyone else thinking that might be a fun horn, if it were widely available today, to turn into a Unity horn with, tapped so the bandpass port fires in the same direction as the "on axis" pattern?)

 

[stevenswall]

There is another interesting in-ceiling speaker from Bose:
https://pro.bose.com/en_us/products/loudspeakers/background_foreground/edgemax.html
View attachment 263277

Man I'm seeing some clever ways to skirt around using a coaxial driver in this thread. Perhaps they are trying for wider dispersion with off the shelf parts than existing coaxial drivers offer?

Or perhaps this or the JBL SCL 5 can reach ear splitting levels that no coaxial could possibly touch?

I'm curious what a Kali UNF system would sound like mounted to the ceiling. (The stand is a separate peice). I wonder what Devialet and Genelec would do for in wall and in ceiling speakers, as it seems like KEF has the right designs and offers in ceilings without the wonkiness of the JBL.

 

[BinkieHuckerback]

Threw a wrench

 

[Dj7675]

I don't like to copy/paste from AVS, but I think it is good to have the info here, in this review thread, but a dealer (Rex from The Screening Room) received a reply from the designer of the speaker. In addition, posted some images. While it wouldbe better of course to have participation here directly, it is still relevant and interesting nonetheless. (LINK)

"Here is info (and more measurement data) re: ASR's review of the SCL-5 from the engineer who designed it:

We have 6 SCL-5's in the ceiling in a room at Harman, and my opinion is the height information is much better than in the Eargle Theater with SCL-3’s in the ceiling.

It’s really too bad that in our industry, where we design and sell pieces of equipment that are used in a subjective way, that the reviewers of that equipment can’t bother to actually set it up properly and experience it subjectively.

Re: ASR’s review of the SCL-5 and SCL-7, it involves me since I was the engineer on the SCL-5.

I notice we have made only subtle references to how this ceiling speaker should be used in the sales literature. It was designed to sum at 45° to the perpendicular from the mounting plane (ceiling). It was an idea based around making a better ceiling speaker using what we knew about ATMOS ceiling speaker requirements, but was not intended to get Dolby ATMOS certification.

To get a proper summation at 45°, it turns out that the HF compression driver must be inverted in polarity. If I remember correctly, it is actually a quadrature condition, so it could go either way with polarity for the SCL-5. However, when we listened to it in both configurations, we preferred the inverted polarity HF over the positive polarity. When the HF was in positive polarity, the image was right at the ceiling, whereas inverting the polarity resulted in an image down in the room as one would expect – with no change in frequency balance or smoothness of response at 45° off axis.

When you measure this on a 90° axis from the ceiling, you see a cancellation null at crossover. But this measurement doesn’t tell the correct story. You have to measure the SCL-5 (and the SCL-8 for that matter) at 45° off axis toward the woofer side (or more on axis with the horn throat). We note that the coverage angle is +/- 30° off of 45° to the ceiling, so I would think that someone looking to measure the speaker would take the measurement on the 45° axis.

But, I do not want to blame ASR exclusively for this. In our 2 pi chamber, we have a similar issue – the mic array is designed around the 90° axis to the floor (or, speaker’s ceiling mount), so we haven’t been able to generate a full spin yet. We were able to create a proper axial and listening window which I have attached. The axial is an average of our 40° and 50° mics, and the listening window was +/- 10° vertically and +/- 30° horizontally in 10° steps – so, pretty normal.

The great thing about this horn design is its coverage. I am also including an overlay of the vertical off axis curves, from 70° to the ceiling to 20° to the ceiling. You can see that it is pretty reasonable through that angle. You can also see how consistent it is across the range from -30° to +30° horizontally in the other curve.

As to the distortion: we had great concern over it, so we listened with music as well as sine wave at various levels, and discovered we couldn’t hear it since it was 2nd order. So the decision was made, based on the axial plus listening window measurement attached here, to leave it alone. Moving the crossover higher would damage the sound power response and color the speaker.

Re: the SCL-7 (I have measured it as well and received very similar results): the crossover area is not marked on axis by the dip ASR found. ASR’s nearfield approach likely allows some energy from the driver not being measured into the measurement, and agreed on the distortion comment. I note that for the nearfield measurements, if ASR reviewers can’t shut off the other driver, maybe they could use a Klippel QC station – it has two mics, one for room noise to cancel it out of the measurement, and this could be used to completely remove the other driver from the measurement.

Ultimately, I think we all need to realize that we listen to speakers, so the measurements should be looked at, but at the same time, people need to make the effort to visit The Screening Room or other retailers so they can listen and judge for themselves. They won’t be measuring their speakers every day, but they WILL be listening, so that should be the final arbiter."

 

[beaRA]

I don't like to copy/paste from AVS, but I think it is good to have the info here, in this review thread, but a dealer (Rex from The Screening Room) received a reply from the designer of the speaker. In addition, posted some images. While it wouldbe better of course to have participation here directly, it is still relevant and interesting nonetheless. (LINK)

"Here is info (and more measurement data) re: ASR's review of the SCL-5 from the engineer who designed it:

We have 6 SCL-5's in the ceiling in a room at Harman, and my opinion is the height information is much better than in the Eargle Theater with SCL-3’s in the ceiling.

It’s really too bad that in our industry, where we design and sell pieces of equipment that are used in a subjective way, that the reviewers of that equipment can’t bother to actually set it up properly and experience it subjectively.

Re: ASR’s review of the SCL-5 and SCL-7, it involves me since I was the engineer on the SCL-5.

I notice we have made only subtle references to how this ceiling speaker should be used in the sales literature. It was designed to sum at 45° to the perpendicular from the mounting plane (ceiling). It was an idea based around making a better ceiling speaker using what we knew about ATMOS ceiling speaker requirements, but was not intended to get Dolby ATMOS certification.

To get a proper summation at 45°, it turns out that the HF compression driver must be inverted in polarity. If I remember correctly, it is actually a quadrature condition, so it could go either way with polarity for the SCL-5. However, when we listened to it in both configurations, we preferred the inverted polarity HF over the positive polarity. When the HF was in positive polarity, the image was right at the ceiling, whereas inverting the polarity resulted in an image down in the room as one would expect – with no change in frequency balance or smoothness of response at 45° off axis.

When you measure this on a 90° axis from the ceiling, you see a cancellation null at crossover. But this measurement doesn’t tell the correct story. You have to measure the SCL-5 (and the SCL-8 for that matter) at 45° off axis toward the woofer side (or more on axis with the horn throat). We note that the coverage angle is +/- 30° off of 45° to the ceiling, so I would think that someone looking to measure the speaker would take the measurement on the 45° axis.

But, I do not want to blame ASR exclusively for this. In our 2 pi chamber, we have a similar issue – the mic array is designed around the 90° axis to the floor (or, speaker’s ceiling mount), so we haven’t been able to generate a full spin yet. We were able to create a proper axial and listening window which I have attached. The axial is an average of our 40° and 50° mics, and the listening window was +/- 10° vertically and +/- 30° horizontally in 10° steps – so, pretty normal.

The great thing about this horn design is its coverage. I am also including an overlay of the vertical off axis curves, from 70° to the ceiling to 20° to the ceiling. You can see that it is pretty reasonable through that angle. You can also see how consistent it is across the range from -30° to +30° horizontally in the other curve.

As to the distortion: we had great concern over it, so we listened with music as well as sine wave at various levels, and discovered we couldn’t hear it since it was 2nd order. So the decision was made, based on the axial plus listening window measurement attached here, to leave it alone. Moving the crossover higher would damage the sound power response and color the speaker.

Re: the SCL-7 (I have measured it as well and received very similar results): the crossover area is not marked on axis by the dip ASR found. ASR’s nearfield approach likely allows some energy from the driver not being measured into the measurement, and agreed on the distortion comment. I note that for the nearfield measurements, if ASR reviewers can’t shut off the other driver, maybe they could use a Klippel QC station – it has two mics, one for room noise to cancel it out of the measurement, and this could be used to completely remove the other driver from the measurement.

Ultimately, I think we all need to realize that we listen to speakers, so the measurements should be looked at, but at the same time, people need to make the effort to visit The Screening Room or other retailers so they can listen and judge for themselves. They won’t be measuring their speakers every day, but they WILL be listening, so that should be the final arbiter."

That's all good info for how we should interpret results, but the -45 degree axis measurement from the Klippel doesn't seem to match JBL. The dispersion also seems centered closer to -25 degrees than -45.

 

[mcdn]

So if we take the JBL designer at their word it's not meant for LCR duty at all. It's strictly for height duty in a fully compliant Atmos setup with DSP, and should be evaluated on its 45 degree performance (+- 15 degrees for different listening positions).

The engineering exercise as stated in the AVR conversation was "make an Atmos ceiling speaker with reasonable 45 degree response, but don't sweat the details on power/distortion/FR because we'll sort it with EQ". Later on it becomes part of a generic product line and acquires a $2200 price tag....

 

[amirm]

OK, I tried to recompute the response at 45 degrees but unfortunately it is not possible. This NFS capability is designed to measure a single driver and as such, subsamples the measurement points off-axis. That is, highest resolution response is only available at 0 degrees as I measured. If I skew the axis 45 degrees, it loses a ton of resolution and results become invalid above 1 kHz. Best I could do to maintain resolution (up to 10 kHz) was to skew it by 15 degrees. This gets us within the ±30 degrees Harman specifies. Here is that spin (accurate to about 10 kHz:

The dip is less deep but somewhat wider. Here is 0 degree vs 15:

Interestingly the high frequencies became smoother. The title down in that region is due to still being off-axis relative to tweeter response. If we were at 45 degrees, that would likely improve.

FYI the speaker is already shipped back to its owner (it was sitting here for a year!). I am measuring the Revel C763L as I type this so we get another bite at this apple.

 

[D!sco]

I can't picture spending $10-20k on these. They're already for people with fuck you money, but to build an effective surround system out of these takes more than just a dude with cash who wants in wall speakers. You're hiring a contractor to cut holes in your house. Tough sell.