Understanding Basics of LIne Array vs Point source

well the JBL's may not be the way to go but a well implemented array system would go a long way to achieve a "steerable" coverage pattern system but in the bass domain it may require more than 4 subs to create a directional array.

Looks, like I am either going to keep it simple with a point source system or get some consultation on the sound system process, as some more complicated techniques might achieve better results. Pity, cause its not my job and it will come out of my pay check(not that I am doing it for the money its more about reputation) but there is absolutely no point in all the effort of reducing reverberation times and getting a decent acoustics and adding a horrible sound system to it.Creating directional array with subs might also yield some good results in terms of reducing bass output in seated location. I'm not setting anything up from a sound system perspective just want the correct choice and implementation of system chosen so yeh its either simple set up or I get consultation.

decor always supersedes acoustic treatment unfortunately and that's truly the largest area where significant improvements to the acoustic space can be made but from the supplied pic's the hall appears to be close to the finishing stages.

Sorry I lost you, where can the most significant improvements be made? You mean generaly the large space of decor area that can be utilised...? I can add panels to the 3m ceiling and also the vaulted celing if thats what you mean. I can also make a dry wall on the back wall, there is a 30cm area next to the bricks, I can make some type of membrane absorber or just fill it with soft fluffy stuff.

and just to be clear the larger the space the worse room modes are!
i'm mentioning this because in post 35 your mention that " but it's small room acoustic problem" is false.

I get this, thanks for letting me know. I can easily work on this. If you can just tell me if we tackle general room modes the same in smaller rooms as we do with larger rooms? If so, I got the basic but this will also be difficult as placing sub woofers on opposite polarites of modes in the hall might not be aesthetic. So I might have to do with 2 subs, but might manage a sub or two on the ceiling to combat axial room modes. I might end up with just absorbtion to deal with the modes...
 
This room empty, assuming some curtains either at the stage or by the windows, with mostly plaster or other solid surfaces will have a reverb time of around 2.5 to 3.5 seconds. Desirable is 1.3 seconds when occupied.

Thanks for your input Simon, currently there are no curtains so possibly at the higher end of what you mention 3.5ms. And it would be great to get down to 1.3 ish but that is still a large amount of surface area covered, at least according to amacoustics calcualtor. Ultimately, I cover what I can and I don't think I can over do it. I think the only thing I can over do is over absorbing the upper frequencies rather than the lower and most important part between 60hz and 500hz which is the most difficult.

Normally you would put thick carpeting on the wall opposite the stage, the windows there rule that out. However once people enter the room the reverb will drop. At 300 people they should provide enough absorption to give the room just decent acoustics. However if there will be fewer people then heavy curtains along the wall surrounding the windows should be fine. I would not do any treatment to the ceiling. It is not parallel to the floor and has a number of features that will break up strong reflections.

Please refer to my reply to Bob4 above which outlines some of the concepts I will use and takes in consideration your input. But if you can please elaborate on your take regarding not adding absorbtion to the ceiling? I thought it would be the best place to add something to reduce reverberation times? Are you talking from a simplicity stand point or could it be detrimental in some way or another?

At the top of the window wall there is a bit of drywall or plaster, that is where I would use fabric stuffed with fiberglass to a 10 cm depth. Properly made panels will retain the architectural detail of the ironwork. As it is acoustically loaded with the ceiling and wall corner it will be the most effective place to treat. If not possible to use such panels, heavy lined drapes of 200% length up there should suffice.

There are a few areas I can use for implementing a drywall, back wall next to the bricks I have 30cm depth I can add fibreglass like you mention or aim for some membrane type absorber(I would say this is the only thing that I am uncofident about, is designing a membrane or diapghramatic absorber with plans online acoustic fileds has one for sale **** cheap). I also have inside the metal railings which I can just stuff with fiberglass and even put a perforated panel infront. The space you mention that is acoustically loaded with the corner is also a great area to use, and If I can I will add a dry wall there if not heavy lined drapes. The back glass will also have heavy lined drapes with an aim to absorb down to a decent point in the upper mid frequencies or whatever I can.
 
i was looking over the pictures of the space and a few things come to mind, reducing the amount of flat reflective surfaces with a combination of diffusers and absorbers would possibly go a long way.
235.2%2522+x+19.6%2522+Blocks+Brick+3D+Embossed+Plant+Fibres+Wall+Paneling+Off-White.jpg
problem is most of the ceiling is like that so treating those surfaces seems a must, the half way work around would be hanging diffusion "clouds"
whisperwave-ceiling-cloud-grey-new.jpg
a brick wall is better at reducing reflections than a drywall surface such as the raised wall panels.


at this point getting an acoustic consultant to come in and do an impulse response of the room to make a proper determination of how much and where in the frequency domain the greatest amount of RT60 lives would allow for a more targeted solution.
 
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For the orignal question of point source vs line array I think for your situation a point source system will be the better choice:
1) cost, line arrays involve buying lots of speakers which may be smaller but they aren't very cheap.
2) The room is not an arena the many 'sins' of line arrays would seem to outweigh any advantages. Particularly as any placement will have the audience acoustically close and far from the array.
 
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trdat wrote somewhere on "page 1" of this thread:

like I mentioned, I am purely doing the acoustics and warned the owner that choosing loudspeakers is up to the audio engineer
I suggest you stick with that plan.

Not to be confrontational, but sound reinforcement and acoustics in small and medium-size venues (primarily nighclubs, but also churches and auditoriums) were my forte back in the day. So, my observation is that you'd be in over your head if you're trying to do the room acoustics and sound system without a good academic education in those fields. I'd even venture that, given the questions you've been asking here, even doing the acoustics might be biting off too much to chew.

In any case, with a good acoustical environment, any good sound system, tuned by a good sound engineer, will sound good in it. Most problems arise from poor acoustics. Get the acoustics right, and the sound system will be comparatively easy.

Although, since you have a keen interest in this (which is great!), I suggest you find a qualified professional who might "take you under his wing" and give you some solid physics about acoustics and sound systems. I also suggest that you find and read these texts:

"Acoustical Designing In Architecture" by Vern Knudsen and Cyril Harris.
"Music, Acoustics & Architecture" by Leo Beranek.

These are both from the 1960s, written by leaders in the field. They are likely very hard to find, but I suspect that used copies and/or PDFs are available.

There are many others, but this is a good start.

Lastly, I'll quote myself. For years, I've said: "A good consultant doesn't have all the answers, but he knows where to find them." No doubt, there are professionals in your area who've "got this" with regard to your situation. Sure, they'll want to be paid, as anyone who knows what they're talking about. Hopefully, this isn't a problem for the facility owner, whom, I assume, wants to have a successful venue.
 
My goal is to match the acoustic treatment for the large venue I am working on with the intended speakers.
There are different aspects to acoustic treatment that you should probably separate into categories and not get needlessly mixed up. General room treatment stems from the idea that the speakers used are ideal, and so give the right spread without creating anything distinct.. and while there is an overlap, in theory you shouldn't have to know as much about the speakers flaws for that part.

The part about correcting for the speakers should probably look at where the speakers don't match the room entry geometrically. Strictly speaking, there is no such thing as a perfect acoustic source entry into a practical room and no speakers match. On the other hand many do the right thing well enough.. but if you have to contend with randomness then there are all sorts of things you might find.

It's generally not a bad thing to control around, beside and behind the sources.
The back is glass in the middle and on the sides concrete but I will fill up on that part of the back wall with heaps of absorbtion.
You mention this a number of times. As I was alluding to earlier, ensuring things spread well on their own before getting to the back wall, the more diffuse it will be. This reduces the intensity, reducing anything distinct and it allows the other room treatments to contribute.

Overall amounts of attenuation are one thing, but I've been presuming you'd measure and adjust as required.