a few questions

[antispatula]

1. What's the point of checkering foam or fiberglass? (don't know which one is better.....)

2. What's the advanteges of deadening your room while still keeping some reflective surfaces? Is this good for mixing, or in booths?

[RICK FITZPATRICK]

What's the point of checkering foam or fiberglass?

Using patches of absorbant material in a checkerboard or similar pattern will INCREASE the absorption in SABINES due to diffraction at the edges, and exposed edges adds square footage to the overall square footage of exposed area. A 2'x4' panel of 4" thick rigid fiberglass has 576 sq inchs of exposed edge. That translates into 576/144= a whopping 4 square feet PER PANEL Thats equal to 1/2 of the face of the panel!! Which gives you 12 total square feet of absorption area per panel. Of course, incident angle has a bearing on the amount of absorption, but with edges exposed, you STILL get more absortion than if you didn't expose the edges, as in a support frame that covers the edges.

[antispatula]

woah....so checkering the foam or fiberglass works better than having it completely covered?

[RICK FITZPATRICK]

woah....so checkering the foam or fiberglass works better than having it completely covered?

It depends on what you mean by "better". You have to define the space. By completely covering all the surfaces in the room, you get a "dead" space, which you may or may not want, depending on the purpose of the space. A vocal booth should definetly be totally dead, as they are small, and you need to eliminate standing waves, and add ambience via electronics. A live room ....well, the name says it, but you want a balanced broadband absorption by checkering the walls and cieling with panels of various thickness, with lots of bass trapping in the CORNERS, and broad areas of diffusers if you have the wall space, as you are recording the ambience of the ROOM. . A control room...no, you don't want it dead. Checkering will provide a certain amount of diffusion, as you have reflective/absorbant surfaces. However, in a control room, you want to absorb the early reflections off of front, sidewalls and cieling at the engineering position to eliminate combfiltering which will smear your perception of the direct sound. However, there are all kinds of caveats, opinions, schools of thought etc etc, depending on the size room, geometry, height and length. During the 80's, DIFFUSERS were used on the rear wall of a LIVE END/DEAD END(LEDE) contro room design, with the front wall covered with absorbers. Splayed walls were used to reflect sound waves to the rear where they were reflected via diffusers. Then, bass trapping/broadband absorption techniques were used on the rear wall via Slat Absorbers, and Hemholz resonators..among others. Soffet mounting of speakers is another area of conflicting opinion. Man, I'm no expert, and have tried to garner a somewhat cohesive idea of a general design for home studio/control rooms, but to tell you the truth, it has become VERY confusing. However, broadabsorption via panels of rigid fiberglass/ and bass trapping via panels positioned across ALL corners OR diagonally cut SUPERCHUNKS of rigid fiberglass STACKED in the corners have become the norm for HR control rooms and recording spaces, and you can't go wrong with that. Diffusers are another animal all togeather. Some people are convinced that POLYCYLINDRICAL diffuser panals are just as good as multidepth QRD's(quadratic residue) or prime number type diffuser units. But along comes this new studio...and guess what? Just when people were convinced these things don't work...VOILA! A WHOLE CONTROL ROOM FULL!!........see it all here
http://recforums.prosoundweb.com/index.php/t/7454/0
BTW, if you REALLY want to learn about this stuff, here is some links to the real deal.

http://www.realtraps.com/
http://www.johnlsayers.com/HR/index1.htm
http://forum.studiotips.com/viewfor...b33d3226b7354d0
http://www.saecollege.de/reference_material/index.html
fitZ

[RICK FITZPATRICK]

BTW, if you do decide to venture into the rabbit hole, better leave a rope trail to trace your way out.