Advice needed for iregular room treatment and speaker placement

[chichanes]

Hi, I just moved in to live/work in a new place which for my luck has a very spacious living room compared to what my previous place had, but the room is very irregular and I need to somehow make it work as a living room/listening room/studio.
I am attaching a few 3d renderings that I managed to put together so you could visualize what I have to work with.
My question is which of these options for speaker placement is worth considering in your opinion?
Currently, I have my speakers place the way they are shown on image #6
I have been thinking about it for some time now and for me, that would be one of the most optimal placement and use of space considering that it's a multipurpose space... the problem is that there is literally no right wall so side reflections are uneven. This is a place that I am renting so I cannot build walls but have no problem placing absorbers/diffusers.
My thinking was that I could try having a series of standalone absorbers/dif. as a right wall that can be placed when needed and moved when not.
Would that have a chance of working?
Second option I have been considering is having the speakers placed as they are on image #1, but from what I remember placing speakers that way is not a good practice (probably different in my case?) and there is the third option image #5 which is my least preferred way as it eats most of the space and it does not really solve the problem with the wall.
And some more details, my speakers are ATC SCM 100ASL, and the two long walls in the room are 7 meters long each.
Any ideas are welcome!
Thanks

 

[JStewart]

Second option I have been considering is having the speakers placed as they are on image #1, but from what I remember placing speakers that way is not a good practice (probably different in my case?

My very limited knowledge says jpg 1 looks to be a good choice. Speakers close to walls reduce SBIR (speaker boundary interference response). Sidewall reflections will be symmetrical. Sidewall reflections will be reduced (good or bad dependent on other factors and listener preference). I would try without panels.
The placement also worked for Floyd Toole. If Dr. Toole says it worked for him then you’re good to go. (Page 9)

https://www.harman.com/documents/LoudspeakersandRoomsPt1_0.pdf

 

[chichanes]

Thanks JStewart, I will give it a try and see how it works.

 

[FargateOne]

Image 1 or 7 (the difference seems to be the absorbtion?) because it is one of the FLoyd E Toole arragement in his first house and he claim a good SS&I

 

[Nordo]

Yeap, setup No.1.
Actually not having walls that are parallel is a good thing.
I am guessing that you are only listening in stereo, and also do not have a separate sub.
Also consider these guide lines :-

1. Consider bass traps in the corners (if your speakers have good reproduction below 80Hz).
2. Don't place the speakers too close to walls. The best sound is when they are de-coupled from the walls (say at least a metre away).
3. Your seating location looks pretty good.
4. Don't concentrate all your sound treatment on the front walls. Because of the configuration of the room you should not get too much reflection off your front walls. However, you will be getting quite strong reflections off your rear walls. especially the windows. In this room configuration, that is where I would be placing absorption panels - at least for a start. If you don't have heavy drapes on the windows, then treat yourself to some.
5. Use a favourite piece of music to test any changes/additions you do. Something with good clear vocals, broad frequency range, and some deep bass.
6. If you are unfamiliar with REW, then read up on this amazing program. Everything you need to know (including downloading the program) is on AV NIRVANA. It's a bit of a learning curve at the start, but this program will easily show you how your room/setup is performing, and help you to fine tune everything. And if you like it, be sure to donate a little to the developer.

 

[DanDan]

"2. Don't place the speakers too close to walls. The best sound is when they are de-coupled from the walls (say at least a metre away)."
Regretfully that is commonly stated, but it is a controversial. I guess anything with the world 'best' has to be.
But the acoustics/physics is clear:- Placing speaker a metre away from a wall places the woofers say 1.3M away from their nearest boundary. This will cause a massive SBIR dip. If the distances to the sides are similar, this will be compounded into a vast void in LF response. Your recommendation does take effect at much greater distances though. Genelec used to say greater than 2.2M or less than 0.2M

Speaker Placement 101: Is Speaker-Boundary Interference Killing Your Bass?

Not hearing enough bass through your monitors? The distance between your room boundaries and speakers has a huge impact on your bass performance. This tutorial will show you specific strategies for placing your speakers to get a balanced bass response.

arqen.com

 

[Nordo]

Hi Dan
I definitely was not insinuating that the mains be located out at 45deg. (i.e. equally from both adjacent walls).
There is information available on the internet suggesting using "golden ratio" and other ratios, regarding the distances from each wall.
I'm just not a big believer in using boundary reinforcement for mains (or centre, if you have one).
However, for the last 20 years, my system (home theatre) has always had a sub, with all other speakers crossed over around 100Hz (give or take).

Regarding SBIR, I spent hours shuffling my mains around and testing with REW.
The floor area where I was looking at, was covered in chalk crosses, but I eventually found what I thought was the sweet spot.
This was before I was fully aware of boundary interference, and before SBIR calculators, like you linked to (going to try it out).

 

[DanDan]

You have 2.1. Your 2 do not radiate much below 100Hz. The SBIR null for 1.3M is 66Hz.
The OP has serious full range speakers. Placing them away from the FW, presuming it is solid, will null as predicted.
The distance to the side wall may well be equal to the Front. Those two paths to the listener have different lengths.

 

[Nordo]

@DanDan
I know this is OT, but is there any way to get a working copy of that Wall Bounce SBIR Calculator 2D?
Following the link you posted, you can only download a Read-only copy.
I've been to Barefoot Sound's website, but there is no mention of it.

PS Oops, I missed the OP's note regarding his speaker model.

 

[DanDan]

PM me. I have a working copy. Also, I haven't played with it much, but this one seems very comprehensive. http://tripp.com.au/sbir.htm