Near Field Monitoring
Near field monitoring is a way to sit closer to your monitors with the idea that sitting closer to the speakers say 3′- 4′, will reduce the sound of the room in the mix. Flooding the monitoring position with direct energy from the loudspeakers will reduce the impact from side wall reflections at the monitoring position. The more your ears hear the sound from the speakers directly, the more you hear the actual speaker as the speaker designer intended. Near field monitoring minimizes reflections from side walls but does not eliminate all room sound.
Side Wall Reflections
Reflections from side walls are just one room acoustic issue that needs to be addressed. Resonances from low frequency energy can be minimized if you position your speakers correctly. However, bass boom is not a resonance that can be eliminated because it can occur at any room position depending on the room dimensions themselves. Time delayed reflections from the back wall is another acoustical issue that will influence our mix. Even sitting near field will not stop this one from happening.
Speaker Positioning Geometry
Watch your geometry when positioning speakers. Stay away from room boundary surfaces. Use 3′ as a minimum distance to start for distance from speakers to side wall and distance of speakers to front wall. Do not position a speaker 5′ out from the back wall if the monitors on on 5 stands. With 5′ stands under our monitors, and 10′ ceilings, we have another geometric issue. Try to use unequal distances for front wall and back wall. One can also use unequal distances for the speakers to the side walls, but not by much. If we have a 4′ distance on one channel, we should have no more than a 3′- 3 1/2′ distance on the other channel.
Room symmetry is defined as equal distances in opposite room wall locations. If we use the center of our head and the middle distance between our ears as our starting guide point, then we can compare room symmetry issues. We must arrange our speakers or monitors to be in balance between left and right channels. The right channel set up must be a mirror image of the left channel speaker set up. Distances from the left channel speaker to the right channel speaker should be close in distance to the area from the left and right channel speaker to the listening or monitoring position. Make sure that side wall distances from both the left and right channels is very close in distance. It doesn’t have to be exact, but it should be close.
If we follow these basic rules, we will achieve a sound stage that is directly in front of us. Our sound stage will have a center stereo image that will contain our vocals and instruments. A good and centered stereo image can assist us in our mixing, but lets not get too carried away with a strong stereo image and lose site of our task as engineers. Don’t go crazy with this stereo image by trying to get it exactly centered in the middle of the speakers. Most consumers and some professionals will not hear or see the image at all. Make it musical first. Use the stereo image to add to the presentation, not be the primary focus of.
Watch out for room dimensions that are equally divisible by the same number. If you have a 10′ ceiling and a 20′ length, you want to be careful if your room width is 15. All of these numbers that represent the room dimensions and thus the room volume are equally divisible by 5. The worst room for sound is a square room where all dimensions are equal. Equal distances produce resonances in lower frequency waves and even middle frequency energy. Try for uneven distances with non parallel surfaces. One can even splay or cant the walls so reflections are redirected to other surfaces that are not in the direct path of the reflection.
Room volume is also critical. Small rooms have large acoustical issues especially with bass or low frequency energy. Try to keep your room volume above 2,500 cu. ft. room volume is calculated by multiplying room width x height x depth or length. Set up your speakers and monitoring position “triangle” in the first third section of a room that has a longer depth than width. Better yet, set up along the long dimension only if you have at least 4′ showing between your monitoring position and the back wall. If the room has alcoves and uneven dimensions, then seek a spot where resonances are at a minimum. Trial and error works best for this room type.
Choose a room that is large enough. Find one that has a volume of at least 2,500 cu. ft. Use vertical line symmetry to make sure all your critical distances are in line with your head and ears. A good strong stereo image is great, but don’t get carried away. Most will not notice it in the final mix. If you have a long room, set up on the long side. Do not set up in a corner. The corner of our rooms is where all the resonances of the room hang out together and party. We don’t want to be mixing in that acoustic soup.