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QM 12MP
User Manual
User Manual Q Motion Series
QM 12MP
6
Speaker Placement for Maximum Stage Monitor Performance
The QM 12MP is primarily intended for use as a stage monitor in mirrored pairs or as single speaker
boxes. They can also be employed as single or small array front of house boxes for short throw
wide dispersion applications.
When two standard design fold-back monitors are placed in close proximity to each other and are
reproducing the same signal, “interference effect” between the speaker transducers will contribute
to uneven frequency response. This is called “comb filtering” and is impossible to correct with EQ
alone. The QM 12MP is designed to minimize this potential problem.
Two conventional monitors with top mounted HF horns. Regardless of where they are located,
the HF horns spill across each other and this causes “tangential interference” as the mid-high
frequency waves intersect and create both peaks and cancellations which will radically change the
frequency response in different areas of the sound field.
This is the source “hot zones” found as you move a microphone in an arc in front of a pair of
monitors.
The “mirror” design allows a monitor engineer to locate the HF horns at a greater distance apart
and lower the level of interference between the boxes.
If more low frequency output is required, moving the boxes closer together will increase the total
potential for more bass without causing excessive HF interference.
Technically, this box placement is called “coupling the bass drivers”. Placing two bass drivers next
to each other has the potential of increasing the low frequency response by at least 3dB.
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