Turbosound TQ-440 user manual Choosing the best location

user manual

QLight series

Choosing the best location

It was stated earlier that the TQ-440’s tightly controlled directivity gives it essentially point and shoot qualities. Every room has its own unique set of characteristics that affect any sound introduced into the room. These include reverberation reflections and decay time, sound absorption of materials used, temperature and humidity, etc. A degree of experimentation with different locations (if possible) is best, especially if you are permanently installing the speaker and have particular requirements where you want to concentrate the sound into a specific area.

Any boundary like a wall or floor will lift certain frequencies. If you are fixing the unit to a wall, or in a corner then a lift at the bass end is to be expected and it may sound rather boomy. Either reduce the low end by means of a graphic equaliser or move the speaker.

Rooms with a lot of soft furnishings, curtains and drapes will absorb sound, especially at high frequencies. These rooms can sound rather dead and may appear to need more amplifier power to generate high SPL’s but have the advantage that the sound needs less equalisation and is easier to control. In this case the listener receives mainly direct sound, that is the sound emanating directly from the loudspeaker, with little reflected sound.

If the room has a lot of hard, exposed surfaces such as wooden floors, brick or plaster walls or glass windows, these will reflect the sound, causing it to bounce around the room and sounding over bright. These rooms also tend to have various resonances that will be excited by high SPL’s. Listening in the middle of the room you will hear a lot of reflected sound in comparison with the direct sound. Care is needed with speaker positioning, SPL’s and equalisation. If the room is large and very reverberant then bass roll-off below about 250 Hz may be required to ensure a reasonable level of intelligibility.

For long, narrow rooms the traditional left and right stacks (floor, wall mounted or flown) can suffice with good stereo imaging in the centre of the room. For multi-tier venues such as theatres, speakers should be flown or wall mounted to project into each tier. In highly reverberant rooms often a central cluster is the best option. This acts as a virtual point source with all the sound emanating from one point in the room, but path lengths should be carefully calculated.

The relationship between sound pressure level and distance is an “inverse square law” so remember that every time the distance from the sound source is doubled the sound level decreases by 6dB. For every 3dB increase of speaker output you need a doubling of input power and you can work out the Wattage input needed to give the required SPL levels at various distances from the loudspeaker(s).

When speakers are flown in free space then boundary effects are minimised. The result is a smooth frequency response without any boost at odd frequencies, but the bass end may appear subjectively light. In this case you will need floor mounted sub-bass, to bring the low end up.

TQ-440 manual page 13