Focal Hi-fi Tonal balance, Example, User manual

4		Hi-fi
	User manual

Obviously these are only guidelines because in normal situations there may be prevailing conditions which will not permit significant alterations. You sould simply take these criteria into account in order to assist you in determining the best location for you speakers. Their accurate positioning will give the best possible tonal balance, an aspect which will be discussed in detail hereunder.

• Tonal balance

This parameter is directly related to the linearity of restitution of your listening room.

The various frequency registers must be reproduced at the same level so that the tonal color of the individual instruments will be respected. For instance, a swollen bass range will mask the treble range and the tones will be dull and weak. A stressed midrange and treble will result in harsh tonal colors which lack fullness thus producing an unpleasant listining experience.

The purpose of the positioning is to maintain the response primarily in the bass range. Your JMlab speakers have been designed with great accuracy and on the basis of extreme neutrality.

Because of the important wavelengths in the bass range, the sound will be amplified in this frequency area by reflection from adjacent wall and/or floors if the base driver is situated as follows:

•Quite close to a wall, such as a floor, the bass range will be amplified by 3dB (doubled).

•Quite close to two walls, such as the floor and the wall opposed to the listener, the bass range will be amplified by 6dB (quadrupled).

•Quite close to three walls, such as a corner, the bass range will be amplified by 9dB.

Consequently, it is well-advised to situate the speakers away from the walls and the floor as much as possible so as to not alter the response because of unduly swollen bass frequencies.

These easy rules will help steer you in the right direction :

•The center plane of the speaker (between the bass driver and tweeter in a two-way system or between the midrange driver and tweeter in three-way or four-way system) should be at approximately the same height as the listener’s ear ; i.e. between 60cm and 120cm

(24” and 48”) high. Stands should be selected accordingly for smaller speakers and floor-standing columns should be on cones or spikes.

•The clearance with respect to the wall behind the speaker and the closest side wall depends on the size and configuration of the listening room. The smaller the room the less the speaker can be cleared away from the rear and side walls but the furniture arrangement may place restraints on your positioning manoeuvres. Suffice it to say that 20cm (8”) is a minimal distance

(no less) with respect to the wall behind the speakers especially if there is a vent at the rear. The closest side wall should be at least 40cm (16”) away. Identical distances from the rear and side wall should be avoided. The bigger the speaker, the more these clearances should be increased.

To please the perfectionists, we shall give an optimum positioning formula :

if A is the distance from the boomer centre to the closest wall (floor or wall), B the intermediate distance and C the longest distance (A<B<C), the relation B2=AC determines the ideal position of the speakers.

•Example 1 :

The boomer centre is 60cm (24”) from the floor (B=60cm) (mini speaker on a foot),

standing 50cm (20”) from the back wall (A=50cm), the side wall will be ideally 72cm (28”) (C=B2⁄A=72cm).

•Example 2 :

The boomer centre is 30cm (12”) from the floor (column speaker) (A=30cm), 1m (39”) from the back wall (C=1m), the clearance with respect to the side walls will be B= AC=54.7cm (22”).

You are now in possession of the knowledge vital to the successful installation of your JMlab speakers.

Last but not least, following are the accessories which will allow optimization of your sound system.

Correct height positioning is critical to quality restitution.

A < B < C