What's wrong with your system that you are trying to fix?
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I am also wondering what exactly your room treatments are trying to fix? There are some holy books out there now. I forget the title but it's something like "Get Better Sound Now" ..??? not sure but you see it mentioned all the time with his advice to get your components out from between your speakers. Did you try to search for old threads on the topic, that may prove useful.
FWIW, while I too would like to hear what you think can be changed or improved by the use of room treatments, I think that the photos of your set up suggest (to me anyway) that one of your problems may be related to side wall reflections which might just be cured by toeing in your speakers until the axis of your speakers cross in front of the listeners chair.
I might also mentioned that the rooms dimensions could easily cause substantial nodes/nulls which could be avoided to some degree by careful speaker and listening position changes. You might consider getting a SPL meter and a frequency test disc which will help you identify the nulls and nodes which need to be addressed.
Room acoustics is 90% science and 10% the "black arts". You need to measure your room to understand what is going on and what needs to be addressed. You must take a scientific and pratical approach to treating a room. It takes time with a lot measuring and remeasuring, listening and relistening, the proper treatments with an understanding what they do, trial and error, and a ton of patience.
Hi, You use room treatment to solve certain issues that will not be altered by your equipment selection. Can you describe your actual issues? Are you having problems with imaging, low frequency buildup, etc? It is hard to know what to recommend without knowing what you are trying to improve. The first thing I notice is that your room is exactly twice as long as it is wide. That is going to give you some really nasty standing waves at certain lower frequencies and their harmonics. I would expect that to not sound so good. I just googled to find a reference for you and found this link:
The fundamental frequency of concern is going to be more effected by room geometry than surface treatments. Can you angle any of the walls? This can be done in small pieces, perhaps four feet long so that you do not lose too much floorspace.
Another typical problem in a room is the first order reflections. These are much easier to reduce, but using absorptive treatment won't do much below 100 Hz.
An easy way for you to find those is to use a mirror. Sit in your normal listening position. Have someone move the mirror around flush to the side walls and the ceiling. If you see the tweeter in the mirror, then that is an area of a first reflection. Those points will all be somewhere between the speakers and you on the side walls and ceiling. This happens on the floor as well, so just put a rug in between you and the speakers, you can use the mirror to see where the rug wants to go as well. The material that you use for the absorption matters as well.
There is a lot more to this than what I am pointing out here, but these are the items that typically cause issues in a rectangular listening room. I would need a lot more info to actually suggest more. Hope that helps.
The book Mechans refers to is "Get Better Sound" by Jim Smith, highly recommended. He has also done a video, though it's more of a video version of the book. He's currently working on a more in depth product, but progress has been slow. The ultimate solution to your problem is to have an acoustician come and evaluate your room, but that is a relatively expensive solution ($2000+ for the evaluation only).
One more thing. Anyone who has Sonex anywhere in the room is advised to remove it poste hasten even in small amounts Sonex does something unfavorable to the sound, maybe it's the open cell construction, who knows, making it sound phasey and unpleasant. Try taking all Sonex out of the room and see what you think. Sonex is one of the most insidious, sonically disastrous products ever perpetrated on naive and gullible audiophiles. And it looks so cool, just like an anechoic chamber. Lol
Nope, not the OP just someone following this thread. I do own a RS sound pressure meter and a frequency test CD. I like the sound of my room however think with further exploration might be better tuned. As stated above, it takes time and effort. Part of the fun!
Thanks Shawnlh for the opportunity to share your thread.
I see mentions of the RS SPL meter. I suggest getting the Studio Six apps for your I/O device. It is waaaay more flexible and accurate. It does so much more than just SPL. I even grab it for professional use, even though we own really expensive B&k instruments. It is just so convenient and well thought out. I am going to be carrying one tomorrow at a show I am working at.
Also, while looking at frequency info is certainly useful, combining that with the time domain gives you a much better picture of what is going on in a room. You really need to look at both to analyze a room. Pretty cheap to do these days with Studio Six!
I have gone so far as to reading Master Handbook of Acoustics, watching lectures and doing room measurements. For the novice, like you and me, it takes trial and error. The initial big deal seems like speaker positioning, then addition of acoustic treatments. Its important to keep in mind that acoustics behavior changes a lot depending on frequency. Simplified, treating high frequencies, which behave more like rays reflecting off boundaries is easier and very different from low frequencies which are subject to room modes, while "middle" frequencies act like waves. Acoustic management also has to be split up in both frequency and time domains, which are interrelated.
I'm with Richz (of course he is an expert and I am not) and also somewhat disagree about the SPL meter alone. Acoustic software like Room EQ wizard with microphone, and usb audio interface yields more precise, more accurate and more user-friendly results along with reverberation time information. IMO well worth the relatively modest extra cost.
You can look at bobgolds (online) room acoustic calculator to get some idea what you are dealing with but its not going to be perfectly accurate.
First thing I recommend is with only the things that have to be in the room play and finalize speaker position. You cannot position speakers in a room with room treatment. You will find that when you get the best overall sound the room will have the least negative effect on the sound. Then one by one you can bring in acoustical treatment to fine tune the sound.
You want to be very careful what materials you use to control the rooms reflections so it does not not over damp the room and worse cause comb filtering effects ( large peaks and valleys in the frequency response). Most absorptive material will absorb at certain frequencys and reflect at others. I use very light material to only delay reflections and not to absorb them.
Defuser's are also a good thing to use, so as not to absorb sound but to eliminate slap echoes.
I believe in keeping the front wall reflective, NO absorption, defuser's are ok, with very slight absorption on the back wall. Side wall reflections are again best addresses with defuser's.
I suggest installing one at a time so you can hear what each one is doing and where it is taking you acoustically, until you get the desired results you prefer.
It takes time and patience
As far as bass modes, those are very difficult to address. Your room dimensions show bad ratios and will have many bass mode issues. At 50hz, 75 hz, 101hz, and 150hz. Bass draps do little to nothing. Only two options is alter the room dimensions ( build a room with in the room) or helmholtz resonators. These must be built and tuned specifically to the rooms modes.speaker placement will definitely effect this too, so make sure you do that first to try and minimize those room modes. Any other questions feel free to ask. A good size area rug or simply carpet on the floor is also recommended to treat floor to ceiling reflections.
There has been a lot of good suggestions. Every room is going to have issues. Are your speakers set up using the 1/3 or 1/5 model? For example are the speakers about a 1/3 into the room and your listening position about a 1/3 from the back wall? The corner traps are probably OK but I would remove the absorption panels from the front wall. We can't see the sidewalls but at the first reflection points diffusers may work better than absorption. The back wall would benefit from some diffusers but we can't see any pictures. Also as mentioned some toe in of the speakers may help perhaps with a focus a couple of feet behind your listening position to start. It's a trial an error process. Get the bass right by moving the speakers around and then focus on the soundstage and image by the distance between the speakers and toe in.