Room improvement

Many of you speak of the importance a room plays in the ultimate sound . There must be be many variables to try. Where do you start?
In all things I always look for what's easiest and/or most important. Easy like get a couple sheets of Owens Corning fiberglass insulation, cut into 12" triangles, stick em up in the corners. Sound makes walls vibrate, the corners act like horns, and so stopping the sound at the corners has an outsize effect. Or if your speakers are close to a side wall then stopping that first reflection may be more important so try a piece on the wall there. Should hear a nice imaging improvement, again without using so much it makes the room feel overly damped.

Or if your room has a door it might benefit from some weather stripping to keep outside noises out. Cheap. Easy. 

Remember the biggest improvement is always to have the speaker placement dialed in to microscopic perfection. 

Those are the simple/cheap/effective tweaks. To get even more effective you are into Synergistic Research HFT for the walls, ceiling, speakers. HFT are a total system upgrade. The other stuff does make a difference but these, it is hard to believe how good they are.
Personally I think it’s the system’s responsibility to sound good in the room. Not the room’s responsibility to sound good in the system.
Contact GIK Acoustics. You can send them pics online of your room, and they will help you. Great advice, phenomenally high value products.
Personally I think it’s the system’s responsibility to sound good in the room. Not the room’s responsibility to sound good in the system.

Which limits you to speakers which interface well with the room. A good sounding room can accept a much broader range of speakers.  Small speakers sound huge, large speakers sound refined.

I strongly disagree with the opinion that the speakers are responsible for sounding good in your room. My advice is to find the speakers that sound best to you with your source and electronics, then perfect their placement in that room taking into account the dimensions, walls, and furniture. I recommend the Master Set Method. Only then can you perfect the reflections, Peaks and valleys. Imaging is a function of eliminating first reflections. At the first reflection point I use random books and CDs for diffraction. I also recommend corner absorbers as millercarbon says above. Further improvements can be made with specially designed products. Good luck.
As much more educated gents than me have pointed out, the amount of room treatment needed can vary a great deal by speaker, so the idea that one way or the other is more correct is not well supported.

Controlled narrow directivity can greatly enhance imaging and detail, reducing the need for room treatment. Line arrays, horns and panels (ESLs) can really help.

But a well treated room can take any of them and make them sound spectacular. A poor room will be much more speaker dependent.

The buyer's own preferences matter a great deal. Personally, I have to use a half and half approach. I used tweets with narrow dispersion, and add bass traps and room treatment.

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My room also functions as a home theater so there's lots of leather chairs and wall hangings plus a acoustic tile ceiling.  My speaker are Maggie 1.7is

I’ve read Erik’s advice many times. A month ago, I did as he suggested and used pillows and quilts to treat behind the speakers, first reflection points, etc. 

It made quite a difference in my system. I always thought treatments were used to tame bass, and of course it can be. However in my system, the treatments improved definition in the middle and highs, as well as tightened the bass. 

In an attempt to keep learning, I bought a studio worth of foam treatment from a local moving out of state. I understand foam has limited effectiveness, but some simple treatment in my bedroom system improved the clarity of instruments, and songs almost sounded new and more interesting to me. Movements in music that sounded homogenous berfore now have more definition and separateness. 

My plan is to experiment
and move to a more permanent, decor friendly solution if the changes are real- and not just my ears adjusting.

Thanks Erik! I should have listened to you earlier!

Audiomaze, fwiw, my listening position is a leather couch with a back above my ears. Placing a throw behind my head cleans things up a bit. In my case the leather seems to reflect sound and smear the details some. 
You are welcome, uncledemp, glad I could help you enjoy this hobby even more!
Thank you all for the sound suggestions. (No pun intended)
If your room sounds like crap with nothing in it, slap echo, hollow sounding, overdamped, reverberations, etc., why would you think an audio system will fix all of these issues. A good room will allow a good speaker to sound great whereas a bad room will make a great speaker sound like crap
Adjusting my ears to the speaker and room worked perfect and cost nothing. 
Adjusting my ears to the speaker and room worked perfect and cost nothing.

Oh, it does. It’s mentally fatiguing. At least for me. There are some interesting articles i keep meaning to pursue about the dual streams of information our brain perceives, and how much effort is involved in filtering out the room acoustics and noise.

I specifically use my stereo to relax my brain from this in-office sound brain fatigue. Can’t do it in a live room. But I know from talking and listening to many audiophiles that for a lot of them it's a non issue.

Audiomaze- start with the basics.  FIRST thing you need to do ( once the speakers are in place and with Maggies, that will take a LOT of experimentation) is to get a decent microphone and do some rudimentary analysis of the room with a test disc/cd.  Once you know what you have, then you can begin to level out the peaks with treatments/furnishings, etc.  As a basic, with Maggies, you want some diffusion on the wall behind the speakers and in your case, get a 4" foam cushion to sit on which (hopefully) will raise your ear height and eliminate the back of the couch reflections.  I would not try to "fix" problems that you can't identify from the tests- it is a waste of time and money.  Good Luck!

Another vote for GIK - fantastic company! 
Thanks Jwpstayman , very helpful info.I will work on those suggestions. 
Hi everyone, I am trying to optimize the sound in my room.
i have a pair of kef blade 2.
i talked to asc in Oregon and they r helping me with suggestions . We did a Matt test recording and they reviewed the acoustics in my room.
anyone has any experience with that company . Any recommendations appreciated 
For 41 years, my room was a 1100 sq ft area of a warehouse loft, with 9 ft tall brick walls, tin ceiling, hardwood floor, and 4 x 6 ft windows.

For about 9 months now, the room is an attic in a brownstone with a peaked roof, a gable, two dormers, 3 small windows, and hardwood floors. The walls are of varying height, from 3 ft to 12 ft, have 6” of rockwool stuffed in them. The ceilings have 17” of rockwool stuffed in them and are of various angles. Walls and ceiling are covered with fire resistant burlap.

The sound was dramatically improved. I’d say 35% to 40% improved.
You can have a $500,000 system and if your room is lacking, you will never realize the sound quality that you could have if your room was properly or at least semi-properly tuned.  It's like running regular fuel in a high performance motor.  The potential is there, but you're not letting the tiger out..  It will run like shat..
I’ll go along with "semi-properly" tuned. What I don’t like is a domestic room tuned so well that it sounds like a recording studio or theatre. You can’t hear the interaction between the recording and the room, which to me is the fascinating part of home audio. It’s in your home. To hear a cathedral in your living room is mindblowing. If your home sounds, looks and feels like a recording studio, it’s mundane.