your speaker slightly forward into the room. What hap- pened to the bass response? What happened to the imaging? If the imaging is more open and spacious and the bass response is tightened, that is a superior posi- tion. Move the speakers back six inches from the initial setup position and again listen to the imaging and bass response. There will be a position where you will have pin- point imaging and good bass response. That position is the point of the optimal placement from the front wall.
Now experiment with placing the speakers farther apart. As the speakers are positioned farther apart, listen again, not so much for bass response but for stage width and good pinpoint focusing. Your ideal listening position and speaker position will be determined by:
•Tightness and extension of bass response
•Width of the stage
•Pinpoint focusing of imaging
Once you have determined the best of all three of these considerations, you will have your best speaker location.
The Extra “Tweak”
This extra “tweak” may be useful when your speakers are placed in a dedicated listening room. Use the following procedure and measurements for your speakers placement to see what can happen to your system’s performance. These formulas will help determine optimum placement of your speakers to minimize standing waves.
1Distance from the front wall (in front of the listening position) to the center of the curvilinear transducer: To determine distance from the front wall, measure the ceiling height (inches) and multiply the figure by 0.618 (i.e. ceiling height (inches) x 0.618 = the distance from the front wall to the center of the curvilinear transducer).
2Distance from the
Your Room
This is one of those areas that requires both a little back- ground to understand and some time and experimentation to obtain the best performance from your system.
Your room is actually a component and an important part of your system. It can dramatically add to, or subtract from, a great musical experience.
All sound is composed of waves. Each note has its own wave size, with the lower bass notes literally encompassing from 10’ feet to as much as 40’ feet. Your room partici- pates in this wave experience like a three dimensional pool with waves reflecting and becoming enhanced depending on the size of the room and the types of surfaces in the room. Remember, your audio system can literally generate all of the information required to recreate a musical event in time, space, and tonal balance. Ideally, your room should not contribute to that information. However, every room does con- tribute to the sound to some degree. Fortunately MartinLogan had designed the Source to minimize these anomalies
Terminology
Standing Waves
The parallel walls in your room will reinforce certain notes to the point that they will sound louder than the rest of the audio spectrum and cause “one note bass”, “boomy bass” or “bloated bass”. For instance, 100Hz represents a 10 feet wavelength. Your room will reinforce that specific frequency if one of the dominant dimensions is 10 feet. Large objects in the room such as cabinetry or furniture can help to minimize this potential problem. Some serious “audiophiles” will literally build a special room with no parallel walls just to help eliminate this phenomenon.
Reflective Surfaces (near-field reflections)
The hard surfaces of your room, particularly if close to your speaker system, will reflect some waves back into the room over and over again, confusing the clarity and imaging of your system. The smaller sound waves are mostly affected here, and occur in the mid and high frequencies. This is where voice and frequencies as high as the cymbals occur.
Resonant Surfaces and Objects
All of the surfaces and objects in your room are subject to the frequencies generated by your system. Much like an instrument, they will vibrate and “carry on” in syncopation with the music, and contribute in a negative way to the music. Ringing, boominess, and even brightness can occur simply because they are “singing along” with your music.
Resonant Cavities
Small alcoves or closet type areas in your room can be chambers that create their own “standing waves” and can drum their own “one note” sounds.
10 Placement & Room Acoustics
