Acoustic enclosures

Most of high fidelity elements have good characteristics , whose we can not observe important hearing differences .

The significant difference situates on the acoustic enclosure . An enclosure has always a less balanced pass band than an amplifier .

What counts absolutely is to choose enclosures according to the size of the room where we listen , the place where they are placed , the distance of listening .

It is better to listen middle enclosures but adapted to evoked criteria above that good enclosures not adapted to conditions of listening .

Manufacturers of acoustic enclosures test their products in special great rooms with wall’s treatment ( having no resonances ) .

What create problem is the level of bass sounds regarding to the entire band pass Little Room > because it varies according to the enclosure near environment . Bass sounds are channeled by walls ( ground, ceiling ) what increases their relative level ( x2 to x4 ) . The worse places are corners of rooms. In general more speakers and enclosures are great , more the level of bass is strong . In an average home a bass speaker of 17cm seems a good choice . We can adjust the level of basses by distancing more or less enclosures by the walls or the ground ( feet ) .

The ideal point to listen a high fidelity ensemble is obtained when the place where is situated the listener and the enclosures form an equilateral triangle .

A good distances for the sides of this triangle is two meters . If we are far from enclosures , we hear the reverberation of the room much more.

Bass sounds are omnidirectionnal while treble sounds are directional . It is a better thing to direct enclosure towards the ears of the listener .

The ear does not hear bass sounds and trebles at the same manner , according to the volume of the sound . More the sound is strong more the ear hears

bass and trebles sounds . It is necessary to listen ( if possible ) at a volume corresponding to those of instruments or singers in the reality .

An important point is the output of speakers ( expressed in decibels ) . +3dB means acoustic power multiplied by two . Big Room >

An amplifier of 30 watts with an enclosure of output 90 dB has the same sounding level that an amplifier of 60 watts with an enclosure of 87 dB .

What counts for an amplifier is the continuous efficient power ( true RMS ) . Improper terms : musical power , admissible , maximum , PMPO .

To reproduce all the audible frequencies it is necessary and sufficient that an enclosure is equipped of two speakers ( two ways ) .

The impedance ( in general 8 ohms ) and the supported power of acoustic enclosures are not very precise values but rather reference values .