Using the SSL 611EQ 500 Series Units

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.