A SPECIAL "DO-IT-YOURSELF" ACOUSTIC CHALLENGE FROM SWEETWATER AND RPG For the past 14 years, no other acoustical company has introduced more acoustic innovation or been involved in more state-of-the-art recording studio projects than RPG Diffusor Systems. And Sweetwater is extremely proud to offer this remarkable acoustic technology to its customers. We have a lot of detailed product information that you need to check out in the RPG home page on our web site (www.sweetwater.com/products/rpg). Our relationship with the company and its founder, Dr. Peter D'Antonio has convinced us that once musicians are made aware of the negative effects of poor acoustics on their recording projects, they will make the modest investment to upgrade the acoustics of their own studios. Figure 1: You'll need a setup similar to this to complete our experiment. True, acoustic treatments don't have the sizzle of a new synth and you don't get that heady rush when opening a box of diffusors, but here's the reality: There is no more cost-effective addition to any studio than room treatment packages. Thanks to RPG, such treatments no longer cost an arm and a leg. To drive home the point, we are preparing a set of articles that will run over the course of the next several issues that illustrate why top audio professionals around the world pay so much attention to the sound of their control room. The key issue here is transferability. If you never want anyone outside your studio to hear your music, acoustics aren't an issue. But if you send a DAT or CD off to a friend, a record company, a mastering house, etc., each of these rooms are going to have a different acoustical signature and your music will sound different in each of them. The Problem: We're all familiar with electronic distortion and the need to control it. However, the effects of acoustic distortion are too often overlooked in most semi-pro and project studios. Acoustic interference is caused by interference between the direct sound and the early and late reflections in any room. This interference results in a variety of distortions, including room modes, speaker boundary interference, comb filtering and non-uniform diffusion. You may have heard all these terms before and Dr. D'Antonio has written numerous articles on the subject, but we wanted to present this information in our own unique way, so that each of you can experience the effects in your own studio. To help with this, Dr. D'Antonio has devised a series of equivalent circuits, using hardware that you probably already have in your studio, to simulate the effects of acoustic distortion. The Experiment: In Figure 1 we show an equivalent circuit consisting of a source (DAW, ADAT/console, etc.), a graphic equalizer, a multitap delay, amp and speaker. This will be used to simulate a wide range RPG's Bass TRaps are designed to help control modal distortion of acoustic distortions in this and other subsequent articles. The circuit simulates the effects of room mode emphasis at specific frequencies. Room modes build up due to the multiple reflections between room boundaries. For this example, we will consider only axial modes, which occur between two opposing room boundaries. For simplicity, we'll use a room with a width, length and height equal to eight feet as an example. Axial modes will occur at multiples of the speed of sound (1,130 ft/sec) divided by twice the room dimension. So to simulate this electronically, we boost the EQ at 71, 142, 213, 284Hz, etc. Signal flow will be from the source through the equalizer to the amp and into the speaker. Here's the challenge: We challenge you to mix a project in a room with an unknown acoustic signature and not hear a completely different mix in a room without that problem. Have an assistant help you by, without your knowledge, either switching in the equalizer or not. Then go ahead and mix a project. Now listen to the final mix with the equalizer in the opposite position than it was when you mixed. As soon as you hear the difference, we think you'll be calling your Sweetwater Sales Engineer for advice on all the RPG AcousticTools options available to you, like the Bass Trap and Abflector. The Solutions: RPG has addressed low frequency modal problems in two ways. Their soon-to-be-released Room Optimizer software will actually locate the optimum positions for both the listener and the studio monitors to minimize modal distortion and speaker-boundary interference. They also offer high efficiency bass traps to attenuate modal frequencies. We hope you go ahead and take this challenge, then call us and see just how inexpensive it can be to optimize your listening environment! Master Index | Sweet Notes Index | Home | Back Page | Next Page