Human hearing ability
Human hearing ability is often mentioned to cover 20-20 000 Hz. One generally overlooked fact is that the hearing ability is not linear. The most precise hearing range is between 2000-5000 Hz, where ear is highly sensitive and even small sound variations are detected. The hearing ability diminishes gradually outside this region and dramatically towards both hearing thresholds.
Current crossover techniques and human hearing
Conventional crossover frequency range in 2-way speakers is 3000-4000 Hz and even up to 5000 Hz in 3-way speakers. Both are inside the most critical hearing range. In order to minimize the problems and achieve satisfactory results speaker designers are forced to come up with numerous complex crossover designs, use exotic materials or expensive special drivers. Even more problematic is the fact, that the critical frequencies are produced by the bass or the middle driver. Due to high mass drivers are not operating well in high frequency levels: lack of transient speed and uncontrolled vibrations are typical problems.
Amphion and human hearing
The crossover points in amphion models are between 1200-1800 Hz, which are well outside the critical hearing region. All the frequencies the ear is most critical towards are produced by the tweeter. As the moving mass of the tweeter is only about 1/50 of the woofer or even the middle, transients are faster and distortion lower. Added benefits are achieved in the bass region. As the woofer does not need to handle frequencies at the middle band, the bass production is cleaner, tauter and no ringing occurs.The highest crossover point in the amphion product range is 1800 Hz. The length of the sound wave at this frequency is about 19 cm i.e. much longer than the distance between the ears. This is of crucial importance as the ear is highly accurate in sensing the direction of sound at high frequencies i.e. when the length of the sound wave is less than the distance between human ear drums (about 12-14 cm). This improves reproduction of space information and produces pinpoint imaging.
Natural Amphion sound in your home environment
Home is generally not a good place for listening music, at least not in pure acoustical sense. It seems this fact has been overlooked by the world's audio community, who uses free field response as the most common loudspeaker evaluation method. As the free field response measures how the speaker behaves in anechoic chamber, it does not give much indication on how the speaker will sound in a real listening environment.Room reflections must be minimized to achieve similar results, which the free field response indicates. The most common way for minimizing room's effect is acoustical room treatment. This can be costly and be seldom done properly without having a separate room solely for listening purposes. Therefore most of the music in the world is listened in acoustically imperfect listening environments, were room reflections cause colourations to the sound.
Common speaker design and real listening environment
The most common dispersion pattern used in speaker design is omni-directional. The 360 degree dispersion pattern means, that furniture and room reflections take place through out the room marring the sound. Therefore omni-directional speakers suffer tremendously in most untreated listening rooms, especially in the bass and middle regions.To add to the problem all speakers tend to become more directive towards higher frequencies. This causes the dispersion patterns of different frequency areas to become uneven. The total frequency band gets distorted as middle and bass frequencies radiate spherically while treble becomes narrow, even beam like.
Amphion and Uniformly Directive Diffusion U/D/D
In order to minimize room reflections amphion has developed a new system called U/D/D - Uniformly Directive Diffusion. When moving towards off-axis the level of all frequency areas attenuate evenly. This unconventional system ensures that the direct sound from the speaker is not masked by room reflections. Despite strong directivity amphion loudspeakers still produce balanced, undistorted ambient information. Therefore speakers' free field response (anechoic chamber) and the energy response (real listening room) measured in wide variety of room types are surprisingly similar, sometimes even almost identical. This ensures that amphion loudspeakers sound extremely good even in acoustically challenging listening rooms.
Amphion loudspeakers ltd
Music Matters N.V.
Contact person: Sander Tinnemans