JBL Stage 135C Review (Center Speaker)

[voodooless]

You don't need to measure them. One look is enough to know that they will not work. A d'Appolito design on its side will always create a narrow horisontal dispersion.

That really depends on the x-over frequency, doesn't it? For a 3-way with vertical TM and horizontal W alignment, you'll want to have the woofer X-over as low as possible, so that the TM mostly dictates the directivity. The Emotiva uses 550 Hz, probably still too high to fully mitigate the effect. But that 3" woofer might not handle much lower either.

 

[MZKM]

Strange that we haven't seen more of this budget center channels with a BMR center driver, eventually waveguided, plus cheap small format tweeter depending on the BMR ... seems a cheap and effective way to get much better directivity behavior in a much wider range and speech region in a low cost, low height enclosure, avoiding an expensive quality coax or a larger box to cram a bigger midrange+tweeter in the center.
Limited loudness probably depending on where you crossover too, but at the budget sector or smaller rooms that is a minor sin compared to this mess...

Well, for the ones that Dennis Murphy uses, the sensitivity is like 85dB, and Dennis stated they cannot be run dual to increase sensitivity, only to increase max power handling.

 

[sarumbear]

Can you share what makes or breaks such designs? Examples of successful ones maybe?

As I said, horizontally aligned tweeter and woofer/mid will always create a limited dispersion.

Find a d'Appolito type 2-way speaker, check its Spinorama in the vertical. Notice how narrow it is. Now turn that speaker 90 degrees in your head. The narrow dispersion is now in the horisontal.

 

[sarumbear]

That really depends on the x-over frequency, doesn't it? For a 3-way with vertical TM and horizontal W alignment, you'll want to have the woofer X-over as low as possible, so that the TM mostly dictates the directivity. The Emotiva uses 550 Hz, probably still too high to fully mitigate the effect. But that 3" woofer might not handle much lower either.

We are talking 2-way here. 3-way will always have the tweeter and mid range vertically aligned.

 

[sarumbear]

I agree with you. That's why all the posts acting shocked at these results are strange. It is clear from the driver layout that the A135C will have narrow horizontal dispersion. It does not follow logically that all center speakers suck and no center speaker can be designed to have good performance at a competitive price.

The problem is the height limitation. I can safely say that no correct centre speaker can be designed to fit into a 12-15cm height. The smallest tweeter will have at least 8cm height by itself.

 

[abdo123]

As I said, horizontally aligned tweeter and woofer/mid will always create a limited dispersion.

Find a d'Appolito type 2-way speaker, check its Spinorama in the vertical. Notice how narrow it is. Now turn that speaker 90 degrees in your head. The narrow dispersion is now in the horisontal.

when you say limited dispersion do you mean what we see here? or is it more controlled?

 

[sarumbear]

when you say limited dispersion do you mean what we see here? or is it more controlled?

Limited = narrow

 

[abdo123]

Limited = narrow

you mean like this

or like this

Because there is a big difference. I'm trying to figure out if ANY D'appolito design out there can be considered Hi-Fi or not.

 

[HooStat]

I have been meaning to put together a list of all of the "seemingly appropriately designed" center channels, including 3-way center channels and 2-way or 3way speakers that use concentric drivers. It isn't a long list, but it is bigger than one might think. KEF center channels plus most of their monitors, Monitor Audio, some Revel, Emotiva, SVS, Elac, Genelec Ones, Neumann KH310, Kali, some Dynaudio pro monitors, etc. I am sure there are a lot more.

 

[nick-v]

I despair...

But it can be done. Here is my secondary system.

View attachment 168830

I did the same thing in my master bedroom system.

Rather than hacking up the studs to install a "traditional" horizontal center channel, I installed a beefy 3-way vertically oriented center channel. Much higher performance!

 

[sarumbear]

you mean like this

or like this

Because there is a big difference. I'm trying to figure out if ANY D'appolito design out there can be considered Hi-Fi or not.

The top one has a smooth FR gradually narrowing but still flat for +/-50 degrees. On the bottom one FR changes dramatically between 1KHz and 3kHz when you move left and right.

 

[voodooless]

We are talking 2-way here. 3-way will always have the tweeter and mid range vertically aligned.

Are we? You were reacting to the Emotiva design, which is a 3-way with vertical TM.

There is a way though to have the 2-way MTM design work a bit better, either with a 2.5-way or by making one of the woofers a passive radiator.

 

[sarumbear]

Are we? You were reacting to the Emotiva design, which is a 3-way with vertical TM.

I am reacting to the review!

There is a way though to have the MTM design work a bit better, either with a 2.5-way or by making one of the woofers a passive radiator.

An MTM will never work for a centre speaker! Show us how if you have a way.

 

[beaRA]

The problem is the height limitation. I can safely say that no correct centre speaker can be designed to fit into a 12-15cm height. The smallest tweeter will have at least 8cm height by itself.

Yep. If you care about horizontal dispersion, then you better find a way to accommodate at least 18cm (7in) for something like the Kef Q150. Anything shorter than that and the customer cares more about the form factor than the performance. Clearly these big manufacturers consider that a valid market segment.

 

[sarumbear]

Yep. If you care about horizontal dispersion, then you better find a way to accommodate at least 18cm (7in) for something like the Kef Q150. Anything shorter than that and the customer cares more about the form factor than the performance. Clearly these big manufacturers consider that a valid market segment.

That is why I said Harman should be leading the industry. Otherwise, keep manufacturing a type of speaker that doesn't work is not dissimilar to selling audiphool products.

 

[voodooless]

I am reacting to the review!

That’s not what the post was about

An MTM will never work for a centre speaker! Show us how if you have a way.

I said a bit better. Trick is to not let the second woofer play the midrange. You’ll still have some directivity error to horizontal alignment, but it will be much better than a traditional MTM.

 

[KxDx]

I have been meaning to put together a list of all of the "seemingly appropriately designed" center channels, including 3-way center channels and 2-way or 3way speakers that use concentric drivers. It isn't a long list, but it is bigger than one might think. KEF center channels plus most of their monitors, Monitor Audio, some Revel, Emotiva, SVS, Elac, Genelec Ones, Neumann KH310, Kali, some Dynaudio pro monitors, etc. I am sure there are a lot more.

The HSU CC-8 could be used for a center, but it's a fairly big speaker at 10.5" on its side.

CCB-8 Speaker

It would also have to have the highs EQ'ed down for center use.

Hsu Research CCB-8 Bookshelf Speaker Measurements and Analysis

Hsu Research CCB-8 Bookshelf Speaker Measurements and Analysis

www.audioholics.com

 

[sarumbear]

I said a bit better. Trick is to not let the second woofer play the midrange. You’ll still have some directivity error to horizontal alignment, but it will be much better than a traditional MTM.

How do you choose who will be sitting at the good side next to you?

 

[phoenixdogfan]

If I get this as an Xmas present, I'm gonna re-gift it.

 

[voodooless]

How do you choose who will be sitting at the good side next to you?

Looks pretty symmetrical to me:

Not perfect, but pretty well.