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  .