That Geddes book is a gold mine! If only I had known- and it had come out a dozen years earlier! Lol! Oh well at least I got the solid wood exterior door with weather seal!!
Showing 4 responses by millercarbon
So in the scientific view of acoustics we have a lot of different waves propagating back and forth across the room. Our scientific goal is to minimize the cancellations and reinforcements in order to hear the original signal as clear and undistorted as possible. Anechoic means no echo. Its a fact. You could look it up. Here, I’ll do it for you: https://en.wikipedia.org/wiki/Anechoic_chamberNo echo. No sounds going back and forth. Now what I said: "a lot of different waves propagating back and forth across the room." Literally the opposite of an anechoic measurement chamber. What you just described erik_squires is literally the opposite of what I said. You literally do not know the difference between echo and no echo. Now why am I not the least bit surprised by that..... |
Big problem. It’s not really science.Lol! Science. Clearly a stranger to you. Allow me to introduce you to the subject. Sound travels in waves. Like all waves when they encounter changes in density they reflect or refract. In other words sound bounces off walls just like light reflects off a mirror. Another thing waves do is cancel and reinforce. When two wave crests meet we get reinforcement and the resulting wave is greater= louder. When they cancel we have a null or dead spot. The length of a sound wave is related to its frequency. The higher the frequency the shorter the wavelength. The wavelength of sounds we can hear ranges from around 50 feet or more at the lowest bass to less than an inch at the highest treble. So in the scientific view of acoustics we have a lot of different waves propagating back and forth across the room. Our scientific goal is to minimize the cancellations and reinforcements in order to hear the original signal as clear and undistorted as possible. One way to do this is attenuation or absorption. We can do this with a medium such as a fiberglass panel. Sound waves move the fibers in the panel. This movement transfers the mechanical motion of the air into mechanical motion of the fibers according to Newton's Law, with the thickness of the panel determining the peak frequency of absorption. Because, remember, wavelength. Too much of this and the room sounds dead. If only there were some way of spreading the waves around, dispersing them more evenly, so we can keep that spacious sound without so much of the troublesome reinforcements and cancellations. Science to the rescue! Since we know sound is waves we can build panels to diffract the waves. They can be small flat surfaces of differing heights or large flat surfaces of differing angles. All these things audiophiles will have seen- and who knows maybe even you too. Now you know the science behind them. |
Actually trial and error is fast, cheap, and easy. Its what I did and highly recommended. Provided you do it the right way. Otherwise yes it can be incredibly expensive. Dweller nailed it on the slap echo. Here's how to do it methodically, cheap, and easy. Do what he said, with OC703. Owens Corning acoustic panels are industry standard. Thicker panels absorb lower frequencies but a couple 2'x3'x1" panels is probably all you will need. They are cheap and light and easy to cut with a box cutter. Here's a picture of my room from many years ago when I was still experimenting. https://www.theanalogdept.com/c_miller.htm Notice lots of yellow OC703 panels on the walls. They are temporarily held with push pins. That's how easy it can be. Notice the dark gray panels in the corners. Those are the same OC703 only cut to fit and covered in fabric. DIY acoustic treatment. Very effective but without making the room sound dead. Now here is more recent. https://systems.audiogon.com/systems/8367 No more big panels on the walls. Just the corner tunes. Much better! Its rare someone comes in my room and doesn't comment on the acoustics. Its not dead, not lively, but everything is crystal clear. Acoustic treatment is a balancing act. I don't need side panels to catch the first reflection, probably because my speakers are more than 4' from the side walls. If I did they would be as small as possible, no more than one to two feet square. But this is why you buy the panels and experiment with them like I did. Its so easy you can't believe it. That's the old school acoustic treatment method. Its great however only if DIY. Because the minute you talk about spending more than to buy a few cheap panels you'll get much better results going with something like Synergistic HFT. So start cheap, and build from there. |