Universal room treatments


I’d like to know if there are room treatments that almost all rooms need for optimum sound. I am moving a not picked out yet system into a dedicated room ( 14 x20 x 7 ft room) with carpeting , concrete floor and no windows. What treatments are essential even before I purchase any speakers etc. In other words, are there basic treatments I should do before any components are purchased? Than you in advance.
needlebrush
I like the whole free wheelin’ idea of equalizing pressure zones in the room using small tiny little bowl acoustic resonators. I sell some what people oft tell me are too strange for them Blue and Green dots for the room walls and ceiling respectively that address an esoteric problem involving the sense of perception of sound and the feeling of being enclosed in small spaces. 
Have a look at my system. https://systems.audiogon.com/systems/8367There’s nothing truly universal that all rooms need because the rooms are as different as the people and the systems. But the physics of sound is universal and so there are some general principles to keep in mind and use.

Walls that are parallel and unbroken will have slap or flutter echo. Sound bounces back and forth between them. Go in your empty room, stand a few feet from one wall, clap your hands, hear the sound echo back and forth so fast it seems to flutter.

You can break this up two ways. One is to scatter it off in different directions. That’s diffusion. Diffusors can be angled panels, or shapes of different heights. A bookshelf with all the books lined up perfectly straight is a wall. The same bookshelf with the books staggered is a diffusor. Look at my room. The equipment in between the speakers doesn’t harm the imaging because its all different heights and depths and down low. The same equipment on a rack would be like a wall and reflect and do a lot more harm. Just one example of there being more than one way to skin a cat.

Sound doesn’t just bounce off walls it also causes them to vibrate. Walls also reinforce sound. A horn is really just specially shaped walls. Where the walls meet can also be thought of as a not very well designed horn. Any sound originating in the corner will be reinforced as it travels along the wall. So a small amount of absorption in the corners has a large effect of control, without making the room sound overly damped.

Everything we’re talking about so far is midrange and treble. Bass is a separate issue. Learn fast that bass is a separate issue. Few things will screw you up more than thinking of bass the same as treble. Its sound, yes, but so much lower in frequency the wave lengths are so long its a whole different animal. Acoustic control of midrange can be done with cheap Owens Corning acoustic panels 1" thick. Acoustic control of low bass requires calculations to determine what frequency needs control, which tells you how big the trap needs to be, and the lower the bigger.

The good news with bass however is you can get truly superb bass response with four subs. So just do that and be free not trapped.

Read all the above and study. Now you know enough to simply walk around your room clapping and listening, figuring out where the problems are and what to do about them. Now you know to just go to the hardware store and buy a couple panels of OC and try them different places. You know if you have a problem it can be either absorbed or diffused. And you know how to tell which is better: by listening.

Last word, this is all the cheap easy low tech stuff to do. The low hanging fruit. Far more effective, unbelievably effective, are Synergistic Research HFT. Again, see my system. Those little dots are about a hundred times more effective and valuable than all the other stuff put together.

Good to hear that you’re thinking about room treatments from get go (for most people it’s an afterthought). I would contact GIK Acoustics for a free consultation.

Good luck with your room and system!
IMO any room for sound reproduction will improve dramatically with corner absorption (traps). Most basic I can think of. Also most cost effective