I'm investigating the acoustics of my room. I have been doing REW scans and analyzing them with the help of a member here. I've played with sub and speaker positioning and settings to see how this affects measurement and what it sounds like. I've reached out to GIK Acoustics to get their advice.
But, because I wanted to just try some experiments before (possibly) spending a lot with GIK and/or other companies, I bought 6 OC 703 panels (2" x 24" x 48") to try, temporarily around my room, singly or in combination. I might even make my own panels if that seems worthwhile.
My question is: What are some useful experiments to do with the panels and where in the measurements might I see some changes?
Again, this is not to replace getting expert help; this is a way for me to start to learn by interactive experience how my room is affecting the sound. So, good things to try?
You have the gift of room volume/ space. No level of acoustic treatment can make up for lack of room volume. Experimenting is a means to an end. Enjoy the journey. Yes, set expectations accordingly, but don't settle for less than what you think is possible.
Your system seems to appreciate more side room/ width to breath. I really think your room is pretty good as is. Again, I think a few diffusion and/ or absorption panels well placed is the right call, but no need to get to deep in the weeds with it. No need to cover larger amounts of your room. Don't forget the ceiling as you work through it. Again, be surgical in your use and placement. Address what can be addressed before you hit the threshold of diminishing returns. Also, consider adding a bass array setup to help address low frequency modal issues, if needed. It really helped my room. Google (bass array) Earl Geddes - using multiple subwoofers, if you want.
Yes, I will try a few well placed panels and not go too crazy. I placed a couple panels at the floor just beneath the ceiling and really heard a difference, so I know the effort to put at least one or two up on the ceiling will be worth it. Also, there’s a lot of bass energy at the front wall.
Raise the ceiling in my bungalow. Er, um, hmm.... I hope to move into a larger unfinished basement room next to this one, 12 foot ceilings -- a blank canvas.
I somehow deleted a long post. I'll try again but keep it short.
6 x OC 703 panels will help but not all that noticeable. Buy a bunch more as they will not go to waste.
For the biggest impact look at taming bass frequencies which creates acoustic havoc in any domestic room. Make 2 stacks of 3 panels placed on either side of your system. Set these up lying horizontally at 45 degrees straddling the floor/wall corner. If you get more panels do the same in other corners. The more you have the easier it will be to see the result on REW.
The best advice I can give you is to become comfortable with REW, especially regarding the CSD (waterfall) plots. Once you begin to absorb the lower frequencies which are, because of combining either constructively or destructively, creating peaks and nulls. It is difficult to appreciate the harm done by these peaks and nulls or partial nulls. Consider that a null has nothing to contribute to the sound, it's music that's missing. Gone.
Bass can be well smoothed by using a DBA but will still need cognisance taken of the decay time. Using acoustic smoothing in the modal region in addition to the multi-sub approach will optimise what can be done. This double attack on the bass gives stunning results.
I see @
tomic601
is the only one who wisely mentioned RT60. This mysterious quantity is simply the time it takes for the sound to decay by 60dB which for the average domestic room is about 400ms. The target then is to have the full spectrum decay within 0.4 secs. REW's CSD plots provide this info.
Expect a correct RT60 to provide bass info previously missing or partially missing depending on the depth of null and more control and bass detail. It appears poor @
shalommorgan
did not go this route and required 5 iterations to get things sorted. Using REW or HolmImpulse (as used by Geddes), get the table off the net for RT60 for your size room and have fun.
The result of a correctly treated room is difficult to conceptualise but it is a bigger move to believable, rewarding and immersive sound than an expensive component upgrade. True story.
@lemonhaze Thank you for taking the time to articulate the important things, in useful form. As the diagram on my system page will show (and which my measurements confirm) the corners are not that problematic.
Given that, would you suggest 2 stacks of 3 panels somewhere else? Where the bass frequencies are the loudest? Or somewhere else?
I'm getting help with REW and learning these additional plots. I've been looking a lot at RT60 since tomic601 said that. I'll look at the things you suggest.
Posts on this site have convinced me that I'm done thinking about gear. (And I just put a system together.) So now I'm looking for a correctly treated room, or at least the path which leads there. Thanks again.
There is so much great info on the net regarding acoustics and seeing that it is the acoustics of your room that is going to be the final say on what you will hear that I once again encourage you to delve deeper into this fascinating aspect of optimising the speakers into your chosen room.
It's of course possible to get a professional company to supply and fit the treatment but without an understanding of 'what and why' you will find yourself needing to hire them again at great expense to analyse and fit out the next room you decide to use for system. Also appreciate the fact that you, armed with the knowledge and REW, can design a huge bass trap to sort out a specific problem. Acoustics companies are reluctant to design and provide custom service. They have standard designs which in knock-down form can be couriered easily and a few of them tend to oversell.
This brings up another point which is if you have REW sussed out you can measure any treatment fitted by the pro's and tell them to stop when RT60 is where you want it. A friend of mine had to remove a bunch of panels that rendered his room too dead.
@mitch2 A/V Room Service EVPs are made with/of: "The EVP core is a matrix of precisely compressed high-density molded glass fibers, which allows controlled air movement through the fibers." (from his web site specs) They work well for isolating equipment.
Brief update. I did some critical listening with one interesting variation: (a) the entire box of panels against the front wall with the front face of it OPEN or (b) with the cardboard flaps closed. Very, very noticeable difference in what it did to the bass. When open and absorbing (and not even ideally), it sucked in enough energy to render the bass much crisper, located, defined. No muddiness even when the string bass in the jazz I was listening to went to the lowest notes; I could hear fretting and very distinct notes. Closed up again, and the muddiness came right back to the low bass notes.
FWIW, a noticeable difference. I didn’t focus on much except the bass region, so I have no idea if it was over-absorbing or disrupting upper balance. But it helped the bass a lot.
Hilde45 “Posts on this site have convinced me that I'm done thinking about gear. (And I just put a system together.). So now I'm looking for a correctly treated room, or at least the path which leads there”
I am at the same juncture, Hilde45. While I have been interested in utilizing REW for a few years, the perceived learning curve has kept me from even attempting it. Hopefully that changes now, thanks to your thread and some of the very helpful posts from many including Lemonhaze, Tomic601, Shalommorgan.
Like many in the hobby, I have been working on my tweaking my room set-up for years. Implementing several tips in Jim Smith’s book, Get Better Sound, improved my SQ. Then I paid Jim a very reasonable consultation fee for room-specific guidance aimed at finding the all-important (according to Jim and others) ideal place for one’s chair. Called the anchor spot or chair, IIRC. I sent photos and dimensions of my room. Using the RTA app on my phone I took readings of white or pink noise (forget which it was right now) playing as I moved my chair further from the front wall. Did 6 readings. He identified the two best spots and my chair has been at one of them for close to 2 years now.
Why my interest in REW, then? Because we took no readings of corners, center of front wall (between speakers) or anything else. And, I also wonder how much better REW and a microphone may be compared with an RTA phone app.
My room sounds more than “quite good”. It really does. However, I have felt that way many times and then found ways to make it better. There is sheetrock bump-out that houses an HVAC chase that has discouraged me from moving my speakers further into the room because the left speaker will eventually be so close to it the SQ will suffer—I presume. The other “deterrent” is that my speakers are on DIY adjustable platforms that make moving the speakers and resetting them with OCD symmetry a bit “involved”. However, last nite I DID move my speakers further into the room by almost 3 inches and thus also reduced the distance to my ears by the same. I fine-tuned toe-in and assessed the closer triangle. While I do believe in assessing over at least multiple sessions over time, Wow. I should have done this sooner. One key improvement seems to be dynamics, but there are others. Doing the “ears cupped by hands” test, the impact of my hands is vastly decreased. Does anyone know if that is an indication of improved dynamics, per se?
I like my equipment, believe it is well engineered and have even improved it by employing the services of a very gifted mod-er here on AG. Like the OP and others who’ve posted, I wish to address my room’s SQ-robbing deficiencies a bit more methodically now because I suspect I’ve still not heard my rig at its best.
Thanks, rc22. I continue to use REW and have benefited from help from numerous nice people and also from videos online. I think some of those videos can help push you further toward more measuring, and if I can tell you anything useful, please P.M. me. We could chat.
Hilde, I went the 703 route and tuned by ear as well. For aesthetics, you can frame with wood; or in my case, I just wrapped them like Christmas presents in fabric and used a 3M spray adhesive to secure fabric to fiberglass. I am definitely not a DIY-inclined person, and somehow they came out good enough to satisfy my wife for placement in the living room. You can see details on my system page. https://systems.audiogon.com/systems/4844#&gid=1&pid=8
@cymbop I love your fabric choice! Groovy, a la 1968! And a great system and room. I have just wrapped mine in fabric, too, and they are quite sturdy. I'm not going to bother with wood frames, yet. We'll see if they sag as bad as I'm sagging.
UPDATE: I've had great success with some DIY OC 703 panels that I made into 2" and 4" panels. Thing is, they cost nearly $110 to buy (6 of them) and shipping was 40% of the cost! I was in Home Depot yesterday, and they don't carry these panels.
I'm wondering if anyone has had luck procuring these or similar acoustic-oriented panels locally and avoided the shipping surcharge?
Funny this is your most recent post. Because 2 days ago on 2.27 I was in Home Depot looking for 703. I will try Lowes next and then other local building suppliers. Will let you know if I find it at a lower price than online. I just thought of a guy in the insulation business that I can call.
When I was building panels for my room, I had contacted GIK and they suggested I go with the Knauf Insulation. This is what they use in their panels as well and is brown in color. 2 feet by 4 feet. They have a DIY section on their website and you can buy it from there.
That's about what I paid. I think the best deal I've found since then is to find a local insulation company that sells it and just go pick it up with my car. It comes in around $65 for 6 two-inch by 4 ft by 2 ft sheets.
Unfortunately, the only OC dealer in my area who was sells the 703 panels does so by the square ft., not by the carton. He quoted me $2.86/sq.ft., six of the 2’ x 4’ panels (48 sq.ft.) then coming in at $137.28!
I went with the 6pc carton from Buy Insulation Products.com. Bought a 2’ x 4’ piece of birch ply, cut it into four equal pieces 6" wide, and made a 4’ x 4’ x 6" frame. The six 2’ x 4’ x 2" OC703 panels perfectly fill the frame: two side-by-side, three deep. Wrapped the frame with grill cloth, set the frame on a pair of 3’ tall ASC tube traps against the wall behind my listening chair.
That sounds great! Please let us know how things change with the new construction! I created 4 units with mine -- two were single panel sized and two were double panel sized and that gave me flexibility to move them to different places around the room, including the ceiling.
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