Bobby Owsinski talks about 3 quick things a band can do as a group to improve quickly. He talks about dynamics, attack and releases, and turnarounds. All three of these have application for bands but they are also applicable for room acoustics.
Dynamics is the difference between the loud and soft passages in your music. If you play softly and then loudly, that difference is your dynamic range, if you will, as a band. Variable loudness playing can allow your vocals to be heard more when you are playing softly and then can allow for more emphasize when you need to convey more emotion by raising your vocal loudness level. If you start soft, you have more “headroom” with dynamic range. If you start loud then you must get louder for dynamic impact or stay at the same volume. Neither is welcome for good quality sound recording.
Dynamics in room acoustics works in a similar way. Your room should allow for dynamics to be represented completely. Quiet passages must be heard. Over absorption can smother quiet passages. Too much diffusion can produce a separation in vocals and instruments that can be confusing. Comb filtering can blur and smear any difference in volume between quiet and louder passages. Our room must be able to hear both quiet and loud passages with the same clarity.
Proper sound isolation techniques employed in your room, will make lower noise levels within the room, so that quiet passages and lower volumes can be heard. Barrier technology is not cheap, but quiet rooms are a great joy. There is no substitute for the quiet in a room that is measuring between 35 – 40 SPL. I was in a room once that was at 28 SPL continually. There were 4 SPL meters that had LED displays that one could read easily. They would move back and forth with 28 SPL as a low. I can still “hear” that room. I will never forget it.
Can you imagine playing a soft passage in this room and then a louder one. With a start point in SPL of 28, a loud passage would appear at say, 38 SPL. This would be real room dynamics with a range more conducive to human hearing. Start your car and let the motor idle. Do not move the car. Listen to music with the engine running. Turn the engine off. Listen to the same music. Now you hear what I mean. If we lower the noise floor, we allow for more headroom.
Low Frequency Control
Low frequency control is another part of dynamics that must be dealt with. There is a lot of important sound energy from 30 – 60 cycles. Your room must provide the necessary acoustic “room” for acoustic and electric bass notes. Both of these instruments represent dynamic ranges from soft to loud. Within those two domains are layers of energy that your room low frequency absorption must be able to differentiate. Your room must allow for the dynamics of each low frequency layer of frequencies to be heard in its entirety. High sound pressure areas in the room must be treated with low frequency absorption that addresses not only the pressure’s level but it must also absorb this excess low frequency energy at a high rate.
Attack And Release
Attack and release are another live sound area that can be related to a band and a room. Bobby tells us that a bands ability to begin a phrase and end it is critical to producing a good sounding recording. Vocals must begin and end with the proper phrasing. Instruments must begin and release correctly and on time in a regular and predictable time. Bobby cites the Eagle’s Hotel California as a good example of attack and release, especially with the guitars.
Attack And Decay
Attack and release in room acoustics translates to attack and decay with musical sound energy within our room. Attack must be defined. We must have low SPL levels within our room using barrier technology in order to hear every attack note at its certain pressure level. We must also have a room that has the correct balance of rigidity in room wall construction and surface materials on these walls. Sound energy takes on the characteristics of the surface it strikes. Strike glass, receive glass in your room sound. With these two conditions in place, it is possible to hear the attack of a note and the following decay without it getting smothered by another attack and decay sequence.
The room must have the necessary rate and level of absorption at all frequencies to maintain a balance between attack and decay energy requirements. Sound absorption technology used within the room must be smooth in absorption rate so that there is no over absorption occurring at any frequency. Middle and high frequencies must have proper spectral balance between reflections and direct sound. Low frequency absorption rates and levels must be in place to provide enough absorption levels and rates for attacks to occur and then decay on their own volition.
Turnarounds are that few bars between each part of the song you are playing. Bobby cites the area between the “verse and chorus, chorus and verse, verse and outro, and chorus and bridge.” it is a critical part because it is played differently from the rest of the song. A drummer can begin a roll and end segueing into the next section. Other band players may continue to play over the roll. If everyone has their start place and end place, all can be heard in the song.
In room acoustics, all sound absorbing and diffusing technology must be placed in the proper place or surface area within our room, so that the room’s turnaround is predictable, tight, and consistent. Location of different technologies in different room positions will produce different “sounds” within the room. One can produce a wide and deep sound stage by using sound diffusion technology on the front and rear walls of a listening room. In a control room, diffusion on the rear wall can negate the delay in our signal from the rear wall to our monitoring position.
Diffusion both horizontal and vertical can add sound stage depth and height in a playback environment. Small room playback environments need to create an acoustical space within a small amount of square footage and room volume. Diffusion, and in particular quadratic diffusion, can give us the sensation of a larger room by front and rear wall placement. Side wall absorption, provided it is done at the correct rates and levels, can contribute to vocal and instrument separtion along with increased definition.
Dynamics – Attack – Release
Dynamics, attack and release, and turnarounds are three things Bobby Owsinski tells us will help a band show immediate improvement if followed. These three variables can also be applied to the science of room acoustics. In room acoustics, attack and release becomes attack and decay. Turnarounds become the predictable and consistent room acoustic behavior.
Limp mass material types can never achieve the proper rates of absorption that music and voice require.
Actually, fiberglass is more effective at absorbing bass frequencies than rockwool is, as long as it is thick enough. Denser…
Thanks, for this.
What are the frequency and amplitudes of your noise issues.