This guide will explain, in detail, how to use the SSL 611EQ units (the EQ units that are installed in the 500 series slot at the top of the XL). Before following this guide, follow the ‘Routing to the SSL 611 EQ Units’ guide to route track(s) to the 500 series units.
Using the Shelves on the EQ:
1. The High Frequency and Low Frequency bands on the EQ unit are shelving EQ responses. To change these to a bell response, press the ‘BELL’ button.
2. A shelving EQ boots or cuts frequencies above or below the cutoff point. In this case, the cutoff point is selected using the ‘kHz’ dial on the EQ.
3. The level by which it is boosted or cut by is specified by the ‘dB’ dial.
4. When the ‘dB’ dial is at 12 o’clock, there is no difference to the level of the EQ band.
5. When the ‘dB’ dial is turned clockwise, towards the '+' symbol, the signal is boosted at all frequencies above (for the High Frequency section) or below (for the Low Frequency section) the cutoff point.
6. When the ‘dB’ dial is turned anticlockwise, towards the '-' symbol, the signal is cut at all frequencies above or below the cutoff point.
Setting the Q on the Parametric EQ Bands:
1. The Q factor controls the width of the band of frequencies that will be affected by the EQ.
2. When the ‘Q’ dial is turned anticlockwise, the Q will be narrower and therefore fewer frequencies will be affected.
3. This will make the EQ more specific and would be used for surgical EQ.
This image shows a graph recorded using a D-Scope with the ‘Q’ dial turned all the way anticlockwise in the HMF section, the ‘dB’ dial turned all the way right and the ‘kHz’ dial at 4.5kHz.
4. When the ‘Q’ dial is turned clockwise, the Q will be wider and therefore more frequencies will be affected.
5. This will make the EQ broader and would be used more for creative EQ.
This image shows a graph recorded using a D-Scope with the ‘Q’ dial turned all the way clockwise in the HMF section, the ‘dB’ dial turned all the way right and the ‘kHz’ dial at 4.5kHz.
High Frequency EQ Band:
1. The top section of the EQ unit includes two red dials and a ‘BELL’ button. This is the High Frequency (HF) section.
2. As explained previously in this guide, the HF section uses a shelving EQ response.
This image shows a graph recorded using a D-Scope with the ‘dB’ dial turned all the way to the right in the HF section and the ‘kHz’ dial at 10kHz.
3. To set the cutoff point, turn the ‘kHz’ dial to the value you require.
4. Use the ‘dB’ dial to boost or cut the signal above the cutoff point.
5. To change the EQ response from a shelving EQ to a bell parametric EQ response, press the ‘BELL’ button.
High Mid Frequency EQ Band:
1. The green dials on the EQ unit are the High Mid Frequency (HMF) section.
2. The ‘dB’ dial is used to boost or cut the signal around the frequency selected.
3. To select the frequency, use the ‘kHz’ dial.
4. As explained earlier, using the ‘Q’ dial sets the Q factor.
Low Mid Frequency EQ Band:
1. The Low Mid Frequency (LMF) band on the EQ unit works the same as the HMF band and includes the blue dials.
2. As with the HMF band, there is a ‘dB’ dial to boost or cut the signal around the selected frequency.
3. There is also a ‘kHz’ dial to set the frequency.
4. The ‘Q’ dial is used to set the Q factor.
Low Frequency EQ Band:
1. The Low Frequency (LF) band works the same as the HF band and includes the brown dials on the EQ unit.
2. The ‘dB’ dial is used to boost or cut the signal below the cutoff point.
3. The cutoff point is selected using the ‘Hz’ dial.
4. The ‘BELL’ button is used to change the EQ response from a shelving EQ to a bell EQ response.
Selecting the EQ Type:
1. The “BLK” button above the ‘IN’ button switches the EQ between the “Black-242″ and the “Brown-02″ EQ. The two EQ types have a subtle difference in tone and response curves.
2. The image shows the difference the BLK button makes on a Low Pass Filter with the Low Frequency dB dial on max and the Frequency dial on 450Hz. The purple line shows the response with the BLK button pressed in and the yellow line with the BLK button not pressed.
This was tested using a –50dBu sine sweep from a D-Scope.
3. The image presents the difference the BLK button makes on a High Mid Frequency boost with the Low Frequency dB dial on max and the Frequency dial on 4.5kHz. The purple line shows the response with the BLK button pressed in and the yellow line with the BLK button not pressed.
This was also tested using a –50dBu sine sweep from a D-Scope.
