why do center speakers fail horizontly if line array speakers can do it?

[dasdoing]

could one use one of these for example? https://commercial.presonus.com/products/WorxAudio-V5M
has anybody ever meassured something like this?

 

[pozz]

could one use one of these for example? https://commercial.presonus.com/products/WorxAudio-V5M
has anybody ever meassured something like this?

These typically have narrow horizontal and extremely narrow vertical directivity.

Line-Array-Test: dB Technologies VIO L208 und S118R | Production Partner

test des L208, mit dem der italienische Hersteller dB Technologies seine aktuelle Spitzenserie VIO um ein kompaktes 2 × 8"-Line-Array erweitert

www.production-partner.de

Line-Array-Test: Seeburg acoustic line Galeo C | Production Partner

Im Test: Das voll aktive Line-Array Seeburg Galeo C bietet neben sehr guter Performance und hoher Entwicklungstiefe hor. Coverage von 70° oder 100°

www.production-partner.de

 

[dasdoing]

narrow horizontal

looks like spected (100 degrees; why would you need more?)

note that -6dB in this graph includes orange colour.

also note that it is controled down to 500Hz, better than a Genelec 8050 for example (controlled only to 1000Hz)

compare that to a center speaker like this

note also that you examples are 8" woofers, a 6" is even more controlled, like this brazilian product (cheaper than the smallest Genelec here)
* is factory meassurement, though
(http://markaudio.com.br/downloads/manuais/MANUAL TÉCNICO LMK6.pdf)

extremely narrow vertical directivity

while this is the case, I think you stay in you seat while watching movies. it will also reduce floor and ceiling bounce (cancelations)

 

[fineMen]

could one use one of these for example? https://commercial.presonus.com/products/WorxAudio-V5M
has anybody ever meassured something like this?

You showed the measurements already. As they are cross-checked with professional users, You might argue that the data is correct. So, what's Your decision, give it a try? Please, in case report.

 

[dasdoing]

You showed the measurements already. As they are cross-checked with professional users, You might argue that the data is correct. So, what's Your decision, give it a try? Please, in case report.

my descisions usually take a long time. I am even considering this vertical module for mains: http://markaudio.com.br/downloads/manuais/MANUAL DE OPERACAO HMK6.pdf

 

[pozz]

The real problem is that PA speakers tend to have somewhat ragged on axis and a bunch of resonances. The 1/3 octave resolution in the Mark Audio measurements will hide that.

I think for horizontal directivity to be wide, it should be >100°, but otherwise I don't disagree. On vertical I disagree heavily. I cannot stands how much sound changes with head movement.

Try them out and report back.

 

[dasdoing]

The 1/3 octave resolution in the Mark Audio measurements will hide that

I am aware. they are FIR corrected though in FR and phase. So while I expect some uglyness, it wont be the typical one

On vertical I disagree heavily. I cannot stands how much sound changes with head movement.

with 20 degrees of dispersion in vertical, and sitting 2 meters apart, you get a range of 70cm: https://www.calculator.net/triangle...&vx=2&vy=2&va=&vz=&vb=&angleunits=d&x=64&y=28
I don't think you move your head up and down like that

 

[ernestcarl]

These aren’t cheap to just try out and later return (assuming it’s possible):

~$2-3k for the dual 5-inch models
~$5k for the dual 8-inch

I thought they’d be cheaper since the (re)brand is “Presonus” — but nope!

I’ve never heard of anyone using this type of speaker at home. It would be interesting if anyone with experience would chime in… in all practicality these are meant for very high-SPL playback positioned distantly.

 

[dasdoing]

These aren’t cheap to just try out and later return (assuming it’s possible):

~$2-3k for the dual 5-inch models
~$5k for the dual 8-inch

I thought they’d be cheaper since the (re)brand is “Presonus” — but nope!

I’ve never heard of anyone using this type of speaker at home. It would be interesting if anyone with experience would chime in… in all practicality these are meant for very high-SPL playback positioned distantly.

first, let's not forget they use compression drivers, which are never cheap.

but here in Brazil the ultra-compacts are cheaper,

I can think of 3 reasons:

1) they don't use the complicated guide layout:

but put the woofers together so lobing does not ocure before the crossover; which is around 1Khz for arrays (I still didn't give up on the crossoverless midrange lol):

2) the brazilian market for small arrays is huge because you have a pentacostal church on every corner. internationaly they are more niche (= they charge whatever they like because of lack of concurrence)

3) the brazilian layout type is outdated and has serious problems not visible in the graphs I have seen

 

[ernestcarl]

It seems that the designs and price vary quite a bit… the more robust and internally “powered” (esp. cardioid) ones are more expensive.

Annoying that Worxaudio/Presonus aren’t providing easily accessible or complete spec sheets with graph data — there are many variants for each model and it’s not very clear what all the differences are… And while I was able to open the provided GLL data files, I haven’t been able to figure out yet how to display the FR properly yet.

Fulcrum Acoustic’s only line array design looks a bit different, but at least the most relevant information is provided clearly:

FL283T Dual 8" Subcardioid Line Array Module | Fulcrum Acoustic

The FL283T is a subcardioid line array module intended for portable or permanent installation applications in a wide range of venues. It includes dual 8-inch horn-loaded woofers and three 1.4-inch compression drivers in a compact enclosure. The enclosure is shaped to accommodate up to 20 degrees...

www.fulcrum-acoustic.com

 

[dasdoing]

It seems that the designs and price vary quite a bit

yep

here are many variants for each model and it’s not very clear what all the differences are

true, too

And while I was able to open the provided GLL data files, I haven’t been able to figure out yet how to display the FR properly yet.

you have to put a microphone (most right symbol):

the software doesn't seams to be realy usefull for a small room

Fulcrum Acoustic’s only line array design looks a bit different, but at least the most relevant information is provided clearly

hmmm. dispersion controled from 600-9000 only.
and the vertical gets crazy narrow.

 

[ernestcarl]

dispersion controled from 600-9000 only.
and the vertical gets crazy narrow.

Fulcrum’s is also subcardioid (also in a horn-loaded bass configuration) so it shouldn’t be… why do think it’s effective only in that range? The narrow dispersion we already kind of fully expected since an array is to be used with multiple units supposedly — disregarding the single unit for home use proposed.

*Not sure if it’s the same software you are using in your images that I used, but I’ll try testing this more later. Hopefully, I can figure it out.

 

[Duke]

could one use one of these for example? https://commercial.presonus.com/products/WorxAudio-V5M

The vertical directivity is quite narrow and may not provide adequate coverage in some applications, but imo the biggest issue is the technique used to achieve relatively wide horizontal coverage: The compression driver's output is funneled through a diffraction slot. To the extent that diffraction results in audible coloration the result will presumably be colored, because you cannot fix diffraction with EQ.

Thus far I have yet to hear a line array or J-array composed of such elements that actually sounded good to me. This might be in part because of the different arrival times, but as the SPL goes up the ones I have heard sounded increasingly harsh to me, which is one of the artifacts of diffraction slots predicted by Earl Geddes' research into the perception of distortion.

Not that I've tried to figure out the best way to get wide, uniform dispersion with high output and low coloration in a practical center-channel speaker, but I'd be surprised if a diffraction slot was part of the answer.

 

[dasdoing]

why do think it’s effective only in that range?

no clue, I never studied horns before. It seams to use a more traditional style of horn (3 of them), while other array modules use very specific waveguides.
(the control down to 600Hz is still better than all but one speaker reviewed on ASR)

The narrow dispersion we already kind of fully expected

compare this vertical (Mark Audio from above):

to this from the Fulcrum

The vertical directivity is quite narrow and may not provide adequate coverage in some applications

as I allready said, in my opinion 20 degrees is enough. it shouldn't be too extreme though (like the Fulcrum).
they are also verticly controlled, on contrary to all normal speakers which have a strong narrowing
It depends on the user though, some might like the ability to listen to music standing, or sitting/lying on the floor

The compression driver's output is funneled through a diffraction slot. To the extent that diffraction results in audible coloration the result will presumably be colored, because you cannot fix diffraction with EQ.

I am wondering about the implications. what type of coloration would you expect which is not EQable?

in the time-domain there are some small resonances down 20 dB in this example:

but how audible is that?

or is there more distorsion?

Thus far I have yet to hear a line array or J-array composed of such elements that actually sounded good to me.

I don't think you can judge the sound of one of those modules by listening to a full array of them. even if they try to control dispersion, there will be a lot of interference between them

 

[dasdoing]

@ernestcarl
now I remebered you actualy have a horn-speaker with your Sceptre, though it is crossed way higher than these modules. how does the range above the crossover sound to you compared to your Neumann?

 

[Duke]

as I allready said, in my opinion 20 degrees is enough. it shouldn't be too extreme though (like the Fulcrum).
they are also verticly controlled, on contrary to all normal speakers which have a strong narrowing

The average vertical coverage might be 20 degrees, but the actual pattern shape is more complicated. Here is the vertical polar map of a 1" throat diffraction slot "waveguide" like those we see in line array modules:

Here's the horizontal polar map, probably better than most center-channel speakers. The stated horizontal pattern width is "140 degrees", and that looks about like the average width up to 6 kHz or so:

I am wondering about the implications. what type of coloration would you expect which is not EQable?

Diffraction is an acoustic phenomenon. The sound that comes out of the sharp-edged diffraction slot is inherently subjected to it, no matter what EQ was applied in advance. So EQ cannot fix it.

Diffraction produces an artifact which arrives later in time than the original signal and therefore is not perceptually masked by the original signal. The ear/brain system has a non-linear response to this type of distortion, meaning that as the SPL increases, diffraction becomes increasingly audible and objectionable. This according to the research of Earl Geddes and Lydia Lee:

http://www.gedlee.com/Papers/AES06Gedlee_ll.pdf (see the "Conclusion" in this paper if nothing else)

http://www.gedlee.com/Papers/Distortion_AES_I.pdf

http://www.gedlee.com/Papers/Distortion_AES_II.pdf

 

[ernestcarl]

Can’t really say the wider — albeit maybe more uneven — Mark Audio vertical polar plot dispersion showed is desirable or better for its original intended application.

Whether either would work “well enough” for actual use as a home centre channel speaker is still an open question. In most cases, it may not be practical. I think there are better, if not cheaper, alternatives to consider — the coax Sceptre, for example, seems suited for the job already — driver can also be rotated if desired.

With regards to the sound of the Sceptre S8 and KH120... The Neumann is “smoother” yet more “metallic” or harsh (relatively speaking) to my ears. The Sceptre is brighter and probably a bit uneven, yet surprisingly less harsh — also more “realistic” in many instruments that are heavy in HF transients. Listening directly on-axis in the nearfield both could use some shelving.

While neither is superior over the other to me personally — again, they’re qualitatively very different — I seem to prefer the “coloration” I get from the Sceptre’s imperfect horn-loaded design more often than not. The Neumann is admittedly more natural with most vocals, though. I know some people believe the latter is absolutely paramount…As for “Live” concert recordings, I find myself preferring the Sceptres overall.

My experience is limited* so take my word with a grain of salt.

*In regard to the number of speakers and speaker types I’ve personally heard.

 

[abdo123]

I think for horizontal directivity to be wide, it should be >100°

I rather keep the wall exactly behind the speakers free of early reflections. for me a controlled wide directivity speaker is only forward firing (90°) like the Philharmonic BMR.

Hopefully someone in the future can make a similar design but with controlled directivity going even lower. for me that's the best experience possible in audio.

the sound power can still slope down along-side the on-axis response, i don't mind.

 

[dasdoing]

And while I was able to open the provided GLL data files, I haven’t been able to figure out yet how to display the FR properly yet.

GLL Viewer can show all kind of graphs with the GLLs: https://www.audiosciencereview.com/...ant-beam-transducer.21469/page-13#post-998343