Build My Own Room Treatments

Gentlepersons
I received my Owens Corning in the mail today.  I placed a few of the large rectangles around the room in spots I thought would make a difference.  I'll be damned!  I have been listening to a slight echo for 13 years and didn't realize it. the Corning pieces eliminated the reverb or echo, whatever you want to call it.  I am able to turn up the volume and hear a purer sound.  I am amazed!  This is like getting a new sound system!
Thank you all for your suggestions and guidance!!

Gentlemen
Thank you Dsper for your input.  A nice valuable tip on who I can enlist to cut those frames!  
audiophilenm - thank you for the lengthy response.  There is a lot of wisdom from someone who has a lot of experience with with absorption and disbursement of sound.
I've already ordered some Owens Corning acoustic panels that should arrive any day.  That will take care of some of the absorption.  I look forward to experimenting with them and see what positive differences I can create by proper placement.  Then, get into the aesthetic covering once that is established.
Chuck Miller - thanks again for that link you shared.  Great stuff in there!
This is a great site, with great people.  One day I hope to be able to  share my experiences with novices like myself to help them along as many of you have done with me.  Many thanks to those not specifically mentioned too.       

I've been using Owens Corning #703 and #705 rigid fiberglass panels for years. They're easy to hang on the wall, and you can make freestanding panels out of them, with an inexpensive wood frame, allowing you to move them whenever you like. I make these and use them as first reflection point absorbers when someone has a room with a wall on one side and an open wall on the other - nearly impossible to get good imaging in a system like that without those panels. You can cut bevel edge profiles on them, and once wrapped in acoustic fabric they look just like factory. BTW, for health reasons, you will want to cover them with acoustic fabric!!! But...

If you want to do this right, the first thing to do is figure out what frequencies you need to absorb, if any. The only way to do this properly is by measuring the system with a meter that displays some accurate version of an RTA or an FFT. You play a verified accurate pink noise signal through your system (as close to a reference signal as is practical) and you measure the frequency response at the listening position. The variation from a flat response curve will tell you what your electronics, speakers and room are doing to the reference signal. Armed with these facts you can make an informed choice.

If you want your system to sing, this is not a great time to slap whatever you can get your hands on onto the wall and see if it sounds "better". Egg crates, packing blankets, shag carpeting, etc. aren't acoustic treatments, though they will change the sound. These fiberglass panels are inexpensive, reliably consistent, and easy to work with.

If your speakers and electronics are above average, they shouldn't mangle things too much. Usually the worst component issues are speakers that are either too bright or not bright enough in the high frequencies. And bass problems, caused by either the room or the speakers, are a discussion for another day. But your room is almost guaranteed to be making a mess of things in one way or another. 
Once you know what frequencies you want to absorb, you want to look at the absorption characteristics of the various acoustic materials to find one that grabs those frequencies and little else. This can be hard to do, but it's always worth the effort! All things being equal, thicker absorbers will help with lower frequencies. If you just need to take the harshness off from 8kHz and up, you might be fine with a 1.5" thick absorber. If you need absorption from 2kHz-8kHz, you'll need a bit thicker treatment. The Owens Corning website gives acoustic absorption figures for their various density panels, so you can make a good choice.

Too much absorption and the room becomes acoustically "dead". Too little and you may have slap echo, comb filtering, excessive decay times, etc. that make your system sound jumbled and chaotic. It's possible that you don't need to absorb anything...that diffusion is what you need. Diffusion preserves the energy in the room, but scatters that energy, minimizing effects like slap echo and comb filtering without deadening the room. Only proper measurements can tell you if this is the case. I've measured hundreds of rooms, and a light touch has always been the key to proper absorption.
Also, don't neglect your listening chair; if it's back is at or above your ear level, is likely mucking things up, and absorbing lots of high and upper midrange frequencies. I swapped out a comfortable recliner for an IKEA low-back chair, and the improvement was dramatic. I never went back!

If absorption is required, the typical major offenders are the first reflection points at the front wall between the speakers, and at the side walls. The oldest trick in the room treatment book is to have a friend slide a mirror along those walls, tight to the wall. As soon as you can see the tweeters centered on the mirror while you're sitting in your listening position, that's likely where the treatment will be most effective. Also, centered behind the listening position is often a prime location. If done correctly, you'll find that the imaging becomes much more defined, even holographic, and it becomes much less fatiguing to listen to your system (i.e. you have to be physically torn away from listening). Because there's less chaos in a properly treated system, you'll find that you hear more into your music, even discovering things that you had never noticed in music you've heard a thousand times.

Final tweaking should always be done by critical listening, but evaluation, location and material choices should always be done by measuring. In my experience. Hope that helps!

Milercarbon speaks the truth.

Couple other hints:
Home Depot will cut lumber to your dimensions to make frames for absorption panels.
Joanne Fabrics sells inexpensive fabrics to cover the Owens Corning panels

After that it is just your time with a drill, screwdriver, and staple gun.

Thanks for listening,

Dsper

I made my own acoustic panels out of materials described by Miller. The panel thickness varied based on where I was placing the traps. Thinner on ceiling and thicker in first reflection corners.

Brownsfan
Nice to know who you would buy from in the event this turns out to be a project that is taking too long.  Thank you also for your experiences.

I have built my own using mostly Owens Corning 705 and 703.  I prefer to buy commercial products from GIK, because I don't save enough money to make it worthwhile making my own.  There is one notable exception.  There are back wall areas that I found needed treatment that were shapes and dimensions where  commercial products wouldn't fit or would leave too much exposed surface. 
It is pretty difficult to make bass traps.  Usually, specialized designs and technology is used for those products.  However, it isn't hard to make panels to address early reflection points that interfere with imaging. 

Sonicjoy is right.  Self education is the first step.

Millercarbon
BTW - I'm liking my Hyperian MK II cartridge.  Thank you for that referral.

Millercarbon
Wow!  Thank you for the step by step description of how to go about setting up room treatments.  It was very clear and I am looking forward to doing this. 
I remember reading guys talking about how expesive it was to buy room treatments.  I think I can handle making a frame that can house the material you suggested.  Heck, I even came up with a great idea how to my wife involved with selecting the cover material (porous of course).  I can probably use it gain agreement on my next targeted audio acquisition!!.   
I seriously appreciate your taking the time to lay all of this out for me to follow.  I was particularly blown away by your set up - long ago.  Most impressive.  You have been a serious "contenda" for a long time.  

Sonicjoy
Thanks for the response. I will check out the reference you have referred me to.  This should be a fun project.  Heck, I just thought of how I can get my wife involved in helping to pick the cover fabric (once I get there).  Understand, that is a very strategic move that has future value :)) 

Its not that hard. Learn a few very important but simple things and the rest you can DIY every bit as good as the pros.

One of the first things to learn is the frequency of the sound you want to control determines the wavelength which in turn determines the dimensions your acoustic treatment needs to have. That is why bass traps are great big tubes, while little 1" thick panels work fine for controlling midrange and treble. 

That's where you want to start and that will be all I will now talk about.

Owens Corning acoustic panel is the raw material inside a lot of expensive panels. Its affordable, readily available at hardware stores or Amazon, and cuts and shapes easily with a knife or razor blade. Get a few 1" thick 2' x 3' panels. You might need 3 to 5 for a room but just get a few to start.

Back in your room, first thing you do, put one up against a wall. Just lean it up there. At head height if you can but whatever. Stand a few feet in front of it and talk. Move sideways. Talk and listen. Hear how it muffles? Do you want your room to sound like that? So you just learned first hand: use sparingly!

Now continue experimenting with the full size bare panels. Place one on each side wall where they will block the first reflection. Play some music. Move them around. Get a feel for what they're doing.

Do the same with a panel anywhere you think might be a reflection you want to control. Directly to your sides. On the wall between the speakers. Just keep moving the same few panels around. Don't cut or mount or anything. Just experiment.

This is where the vast majority fail. For some reason they all think someone else can tell them what to do. As if. I can tell you how. No one can tell you what.

Now you have a better idea, next testing, cut into smaller pieces. Probably you want to cancel first reflections. For that you only need a panel about a foot square, two feet tops. Panel this small is so light you can stick it on the wall with Scotch tape, or little push pins. Not tacks. Push pins. Smaller, almost invisible hole. Can tell I've done this?

Picture of my room, long ago, sort of in the middle of going through the process I'm describing here. 
https://www.theanalogdept.com/c_miller.htm
This was way too much. All the uncovered panels are gone now. The corner tune panels though, those you can see are done and covered with fabric.

That's what you do next. First triangles to go in those corners. Then long rectangles to do the longer ones. Just like the picture. These are fantastic and accomplish a lot without damping the room too much.

Last thing- when you are ready to cover with fabric. The sound you heard in testing is without fabric. In order to have that same sound your fabric has to be fairly open weave, like speaker grill fabric. Otherwise the high frequencies will bounce off instead of being absorbed like you want. It'll still work. Its just the tone balance shifts. Letting you know because it surprised me when it happened. Even though I should have seen it coming.... anyway fabric obviously is one where you really balance how it looks with how it sounds.

I don't even want to think about how many thousands it would have cost to have a pro do this for me. Instead of a hundred bucks or so.

Still, an awful lot of guys rather pay through the nose than do a little honest work. As you will no doubt soon see.....

Before embarking on this journey some education is in order. Otherwise you will get so many conflicting ideas that you may end up more confused than when you asked this question. One of the best sources I have found is Acoustic Fields. They specialize in this very thing for recording studios audio listening rooms churches etc. They offer design work and have plans for DYI projects that you can build yourself. https://www.acousticfields.com/
Also check out Dennis's (the owner) video's where he will teach you all about room treatment. You really need to have a good understanding of what's involved and what it is you are really trying to achieve or you can waste lots of time and money.

https://www.acousticfields.com/videos/

Good luck!