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Harman JBL refuses to give spinorama and polar diagram information to prospective HT customers

TK750

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The one that promises 'Reference Series' performance (black and copper) is 10th generation.

The one that promises 'R Series' performance (white and silver) is 11th generation.

I honestly don't know what the difference between the two is, there are several white papers by KEF on both the R series and the Reference series to draw hints from (with spinoramas). I would check these out to draw some rough opinions on the differences.
Are you sure?

1642091226469.png
 
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sarumbear

sarumbear

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@sarumbear Correction! instead of 10th and 11th generation it's now 11th and 12th respectively. Oops.

Should not be a big deal.
So which one is newer generation, black/copper or white/silver?
 
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sarumbear

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Tom C

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I am considering changing my LCR speakers. I currently use three JBL Professional C222HP speakers. I am very happy with the sound but I am not happy with the viewing angle I now have. The speakers are almost 1.5m (59”) high and that forces the flat screen TV to be mounted too high in order to place the centre speaker below the screen.

@tuga suggested JBL Synthesis SCL-3, which I overlooked originally because they were not listed within the JBL Pro cinema range. I was wrongly expected all JBL cinema speakers to be under one roof. Anyway, within that range SCL-2 looked to be most fitting to my set-up, physically. I downloaded the documents and was pleasantly surprised to read the user manual, which said:



Here is the layout JBL suggests.

View attachment 178765

I could see that the horn is symmetrical but I could not understand how an MTM system can be rotated and still offer same polar diagram. I decided to email and ask JBL Synthesis, which you may know is part of Harman International, one of the largest audio companies in the world, and which is now part of Samsung, one of the largest electronic equipment manufacturers.

Furthermore, a single SCL-2 costs around US$9,000. I was enquiring for a purchase totalling US$27,000. On my email I said that I am planning to upgrade from C222HP. Three of them costs US$7,000. I was asking them information so that I can spend further US$20,000 with them.

This is what I received:



I now wonder what is the point of all that work done by those esteemed researchers if the company is not willing to part with basic information? Not to mention most likely offering bad advice in the case of the rotation of the centre speaker.

I feel pretty disillusioned with JBL Harman now...
Very disappointing. They must have the spins from the product development cycle, if not the final production model. Sounds like cliche corporate mentality: “We’ll charge you double; you’ll take what we give you, and like it!”
 

abdo123

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And it is four times cheaper!
Yes there is a tiny bit of speculation that they will soon upgrade their Reference line (copper and black) to the 13th generation (The same as the KEF LS50 meta) but it's just speculation at this point.
 

TK750

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Yes there is a tiny bit of speculation that they will soon upgrade their Reference line (copper and black) to the 13th generation (The same as the KEF LS50 meta) but it's just speculation at this point.
I swear I'm not trying to be 'that guy' haha but:

1642094654037.png
1642094673825.png


Seems like they are referring to it as 12th Gen with MAT
 

KSTR

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How does the 10% active MTM models work correctly as a centre speaker?
I was talking about 2.5-way aspect here with the 10% estimate. The cheap way of adding a 6dB or 12dB slope on the woofer doesn't work well once driver distances are signifcant vs wavelength as the phases do not track. To make them track, the midwoofers must have an allpass mimicking the phase of the lowpassed woofer. So it has the total phase response of a corresponding 3-way but the mids now also contribute to the bass.

Anyway, for a minimised vertical lobing concept (and thus minimal horizontal lobing for centers), see the landmark concept of the Horbach-Keele Crossover (DSP FIR).

Can't do that in passive or analog active but there are analog/passive solutions that reduce directivity errors, starting with the classic D'Appolito but not stopping there:
1642112450863.png


Good speaker design starts with a reasonable directivity target that creates the phase targets and then dialing in the magnitude response is peanuts but I would assume you know that.
 

BoredErica

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Sweetchaos made a thread on UNIQ generations.
 
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sarumbear

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I was talking about 2.5-way aspect here with the 10% estimate. The cheap way of adding a 6dB or 12dB slope on the woofer doesn't work well once driver distances are signifcant vs wavelength as the phases do not track. To make them track, the midwoofers must have an allpass mimicking the phase of the lowpassed woofer. So it has the total phase response of a corresponding 3-way but the mids now also contribute to the bass.

Anyway, for a minimised vertical lobing concept (and thus minimal horizontal lobing for centers), see the landmark concept of the Horbach-Keele Crossover (DSP FIR).

Can't do that in passive or analog active but there are analog/passive solutions that reduce directivity errors, starting with the classic D'Appolito but not stopping there:
View attachment 178877

Good speaker design starts with a reasonable directivity target that creates the phase targets and then dialing in the magnitude response is peanuts but I would assume you know that.
Thank you for the link. I read the paper and the part 2 which I purchased. The suggested design will work. However, there is a problem. Most tweeters require a crossover at around 2500Hz. That is 5.5” which means the driver pairs must cannot be further apart. That limits the each driver in the pair to be at most 4”. That in turn means you need a secondary pair outside in a 3-way setup, increasing the number of drivers to five. Include the amplifiers for each driver, you are talking about a very complex and expensive speaker. Not exactly an engineering solution.
 

KSTR

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Well, with perfection comes complexity and cost. No free lunch.

With slightly reduced target perfection things get managable. In the simplest case (with analog XO) just use a nice wideband driver for M/T duty and then blending in lower Mids/Woofers is much less of a problem. If ultra top-end is required then add a small super-tweeter. Or use a coaxial, or a shaded line source... many ways to get reasonable results here.

If ultimate fidelity and uniformity is the goal, I'd use three exact same speakers in same orientation and place them behind a transparent screen. And obviously, with full DRC.
 
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sarumbear

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Well, with perfection comes complexity and cost. No free lunch.

With slightly reduced target perfection things get managable. In the simplest case (with analog XO) just use a nice wideband driver for M/T duty and then blending in lower Mids/Woofers is much less of a problem. If ultra top-end is required then add a small super-tweeter. Or use a coaxial, or a shaded line source... many ways to get reasonable results here.
I have demonstrated you, using the paper you send that what you said above is not possible. If you want to argue more, I suggest do that with author of the paper.
If ultimate fidelity and uniformity is the goal, I'd use three exact same speakers in same orientation and place them behind a transparent screen. And obviously, with full DRC.
The author of the paper displayed that the Spinorama of the best option using their suggestion is as follows.

Fig. 8 shows the corresponding up/down frequency responses for the new linear-phase filter proposed in this paper applied to the pair-wise symmetric driver layout of Fig. 1. Except for some broadening in the 3 to 8 kHz range and narrowing at high frequencies, the response is very smooth and flat and exhibits perfect up/down symmetry.

Screenshot 2022-01-14 122113.png


I am afraid that here at ASR we have agreed that the above is not "ultimate fidelity". That is a compromise. Why compromise all three LCR.

Besides, why use a 5-way speaker with a 5-ch amplifier for all three channels. 15 drivers and 15 channels for LCR shouldn't even be a suggestion as far as I am concerned!
 

dasdoing

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note that the second crossover is pretty low at 1.3kHz, because compression drivers go lower.
not sure how this speaker is layed-out, but probably only the two lower drivers plays up to the crossover? maybe it's only one of the 3.
 

Chrise36

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Well, with perfection comes complexity and cost. No free lunch.

With slightly reduced target perfection things get managable. In the simplest case (with analog XO) just use a nice wideband driver for M/T duty and then blending in lower Mids/Woofers is much less of a problem. If ultra top-end is required then add a small super-tweeter. Or use a coaxial, or a shaded line source... many ways to get reasonable results here.

If ultimate fidelity and uniformity is the goal, I'd use three exact same speakers in same orientation and place them behind a transparent screen. And obviously, with full DRC.
What would be the downside of using two normal speakers in mono to the sides of the tv instead of the center? I use my tv speakers like this.
 
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sarumbear

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note that the second crossover is pretty low at 1.3kHz, because compression drivers go lower.
not sure how this speaker is layed-out, but probably only the two lower drivers plays up to the crossover? maybe it's only one of the 3.
1300Hz is 26cm, which is the distance allowed between the low frequency drivers' centres. The drivers used on that JBL are already 22cm in diameter.
 
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sarumbear

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What would be the downside of using two normal speakers in mono to the sides of the tv instead of the center? I use my tv speakers like this.
The centre image will move according to where you sit if you have a large TV. That is why almost a century ago they invented the centre speaker.
 

KSTR

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@sarumbear
You can't simply cherry-pick a graph to support your point... that is, I can do as well, from the same paper:
1642165495109.png


Exactly what I stated, perfection is possible but comes a at price. Besides that, that level of perfection is usesless when a center is located below the screen anyway.
I'm stopping this discussion now.
 
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