TOA Electronics 8D, 6D MID and High EQ Settings, Installing and Positioning, Surround Monitoring

MID AND HIGH EQ SETTINGS

RT60 Decay Time: An estimation of the RT60 decay time above 1kHz within the monitoring environment will help to set the mid and high frequency equalisation. Hard surfaces in general and particularly if close to the speakers will increase the amount of reverberent energy to direct energy above 1kHz (RT60 above 500mS) and may justify setting the mid or high EQ (or both) to -1dB. Absorbent surfaces in general and particularly if close to the speakers (RT60 below 200mS) will reduce the reverberant to direct energy and may justify setting the mid or high (or both) EQ to +1dB. In both cases the LF-Q may be adjusted to compensate the overall balance. If the monitor environment is well designed with a flat RT60 time of around 200 to 250mS then no LF-Q, mid or high EQ should be required.

Source Material: For prolonged sessions working on bright, forward or difficult news/location material where the content of material is being edited rather than control of the sound quality the full range of mid and high EQ can be used to prevent fatigue. This is a matter of individual taste and the EQ can be set accordingly. Alternatively, boosting mid and high frequencies can make decisions during editing easier with limited bandwidth material.

+10dB
0dB re 2.8v
@ 1 metre
-10dB									1 1 1 0 0 0
							1 1 0 0		0 1 1 0 0 0
							0 1 0 0		0 0 1 0 0 0
				1 1 1 0	1 1 1 0	0 0	0 0 0 0		0 0 0 0 0 0
							0 0 1 0		0 0 0 1 0 0
							0 0 1 1		0 0 0 1 1 0
									0 0 0 1 1 1
10Hz	20Hz	50Hz	100Hz	200Hz	500Hz	1Khz	2kHz	5kHz	10kHz	20kHz

6.0: INSTALLING AND POSITIONING

When choosing a suitable location for the monitors, bear in mind that the physical mounting of loudspeakers can have a large influence on performance. For best results the monitors should be mounted on a rigid structure, supported on four pads making contacts with the laminated panel. The use of soft pads (rubber, Sorbothane, or Blu-Tak) is recommended.

Ensure that the console position does not obscure the direct sound radiation from the loudspeakers when sitting down. The engineer and producer should have a clear, uninterrupted view of the monitor loudspeakers.

6.1: 5.1 SURROUND MONITORING

In order to ensure a uniform acoustical environment, the room should be symmetrical about the centre loudspeaker axis; room treatments should be applied symmetrically throughout the room. Mixed "Live end/Dead end" environments should be avoided. If the lateral speakers are positioned close to walls then the constitution of the wall surfaces should be identical.

When using either Precision 6D or 8D as the main effects speaker for the front soundstage, placement is a critical factor for good performance.

In all cases the centre channel speaker should be placed as close to the viewing screen as possible. The viewing position when seated determines the ideal mounting height, but in all cases this should be as close as possible to ear height, if this is not possible the monitor should be tilted towards ear height in the mix position. The centre speaker should be positioned along the centre axis of the picture and the left/right monitors just outside the picture, ideally the three front effects speakers would be placed with the front baffles in line with the screen surface. If an acoustically transparent screen is used, the left/right monitors should be placed just inside the edges of the picture. The surround speakers should be positioned at the same distance to the mix position as the main front speakers. As the subwoofer/LFE channel only produces low frequencies it is difficult to localise its position by ear. As a result it could effectively be situated anywhere in the room, though optimum performance will be gained by placing the subwoofer in the same plane as the main front speakers. The LFE channel is set at a level 10dB higher than the other channels when mixing therefore it is important to apply the same in any playback situation.

6.2: SPEAKER MOUNTING

You’ve probably got your monitors delicately balanced on your console meter bridge, or sitting on a counter top beside your hard disc editor. Find some music with some real solid low end that you know well. Try listening to this music with the speaker sitting directly on the mounting surface and then with it sitting on a thin piece of rubber pad. Hear a difference? Which one sounds more like the recording should? Does one get tubby, or muddy? Depending on the type of mounting surface, you may find it beneficial to use a thin layer of flexible material (i.e. Bluetack) beneath the enclosure. This not only absorbs some vibration,but will help prevent the monitor from vibrating off of its mounting surface.

6.3: BASS PORTS

The Precision D monitor’s bass port is located on the back panel. You should keep the back panels at least 150mm (6") away from the nearest wall surface to avoid an overblown bass sound. If you cannot avoid being close to the wall or if you’re using a separate subwoofer, you may want to consider plugging the port tubes on your near-fields with a closed cell foam-rubber plug, friction fit for a full seal. Because the ports aren’t needed if the monitor speakers are being used with a high pass filter, you won’t be losing any bass performance and you can improve the mid-bass response by plugging the ports.

7.0: PERFORMANCE DATA

PRECISION 6D

PRECISION 8D

14 15