Small monitors are often placed either horizontally or vertically on the mixing desk meter-bridge, which is better?
Firstly, positioning a monitor on the meter-bridge will cause the entire surface area of the mixing desk to vibrate when playing loud signals. This will affect the perceived sound quality as energy is transmitted through the mixing desk (or other control surfaces) causing blurring and strong midrange coloration of the direct sound.
To somehow reduce this mechanical coupling between the monitor cabinet and the mixing desk, the 8000 Series models are equipped with the Iso-Pod™ rubber foot.
In all cases, the better mounting method is to place the monitors on stands behind the mixing desk and sufficiently high so that the bass driver is not obscured.
Secondly, horizontally orientated monitors positioned on the meter-bridge of mixing desks may look nice but acoustically it is not a good idea for the following reasons:
Mounting the monitor vertically increases the distance and angle of the off-axis reflection from the console surface. This reduces the comb filtering caused by the reflection (usually between 1–2 kHz), as the reflected sound level will be lower in level.
Below is a real world example measured in a studio where the monitor was positioned horizontally on the meter bridge of a large mixing desk (red line). The comb filtering on the horizontally mounted monitor starts quite clearly at 1 kHz and extends nicely up to 7 kHz. This is caused by the reflection from the mixing desk surface and the resulting frequency response is clearly not acceptable.
The monitor was then simply rotated through 90° and placed in the same position back on the mixing console meter bridge. Nothing else was changed and the monitor was re-measured (green line). It can be seen that frequency response is much flatter due to the change in the angle of reflected sound. The response below 200 Hz is unaffected when rotating the monitor as the sound energy is omni-directional. The tolerance of this monitor's anechoic frequency response is ± 2.5 dB in the pass-band. Everything outside this tolerance range is an effect of placing the monitor into the room!
All spaced driver monitor solutions suffer from a notch in the frequency response when listening off-axis in the plane of the drivers. Positioning the monitor horizontally causes this notch to become audible when moving from left to right along the mixing desk. Positioning the monitor vertically removes this problem.