Graphic Equaliser Levels

[ian hatch]

Hi all

Just got a new EQ unit, (BSS 960) and are little bit confused with it's output levels.

Running the EQ straight from the desk's main L&R inserts.

I set the levels for a background CD (0dB) on the meters to see if everything was working OK when I noticed strange outputs on the main meters.

When the EQ is off, the readings are "0" on the meters, but when the EQ is connected RIGHT is reading 6dB higher than the LEFT.

I checked the gains were set the same on the EQ and all the cableing is fine, as far as I know.

Is this normal or any ideas.

Cheers

Ian

[Stan Hope-Streeter]

...Just got a new EQ unit, (BSS 960) and are little bit confused with it's output levels.

Running the EQ straight from the desk's main L&R inserts.

When the EQ is off, the readings are "0" on the meters, but when the EQ is connected RIGHT is reading 6dB higher than the LEFT.

I checked the gains were set the same on the EQ and all the cableing is fine, as far as I know.

Is this normal or any ideas.

 

No it's not normal.

 

If your insert wiring is all correct, you should hear no difference in level when you unplug the insert jack (with the inserted equipment in bypass mode or all set to unity).

 

If there's a 6dB loss on one of the inserted channels, then you are missing one side of its balanced circuit.

 

Either your EQ has a duff output (check the connections between the circuit board and the XLR's for bad solder joints) or your TRS jack lead has a fault.

[dwright2104]

Run your graphics using balanced cables (ie XLR from desk L&R into graphics, then out to your pa) try not to use the main L&R inserts, you get all sorts of problems. if that dont fix it your cables or grpahics is duff.

[TimmyP1955]

Swap the insert cables at the back of the console. Does the problem stay on the same PA channel or switch? If it stays, it's the console. If it switches, see next.

 

Swap the insert cables at the backs of the EQs. Does the problem stay on the same PA channel or switch? If it switches, it's the EQ.

[ian hatch]

Swap the insert cables at the back of the console. Does the problem stay on the same PA channel or switch? If it stays, it's the console. If it switches, see next.

 

Swap the insert cables at the backs of the EQs. Does the problem stay on the same PA channel or switch? If it switches, it's the EQ.

Thanks for all the replies.

I have tried the swapping on the inserts on the desk, and the problem does switch.

I haven't tried switching at the EQ end, so I will give that a go.

I always thought it was best to run the EQ from the main inserts, because that way you can listen on cans to exactly whats going on.

The other way you get the mix pre EQ, I think?

So what are the pros and cons for the two methods.

Cheers

Ian

[dosxuk]

I always thought it was best to run the EQ from the main inserts, because that way you can listen on cans to exactly whats going on.

The other way you get the mix pre EQ, I think?

 

There was a thread on here about this exact topic the other week with several peoples viewpoints.

 

IMO it depends on what you're using the graphic for. If it's to make things sound as they should in that room (giving you a flat response from the PA), then you'll be wanting to hear it pre EQ. If you're using it for feedback supression / tailoring your sound (on an otherwise flat system), you'll want it post EQ.

[Stan Hope-Streeter]

I always thought it was best to run the EQ from the main inserts, because that way you can listen on cans to exactly whats going on.

The other way you get the mix pre EQ, I think?

There was a thread on here about this exact topic the other week with several peoples viewpoints.

 

On a monitor console, you always run the EQ's in the group inserts, so that bringing up a group AFL in the local (cue) wedge gives you the post-EQ sound that hte performer is hearing.

On an FOH desk you can do it either way. Generally I would prefer the master inserts (that's what they are there for).

 

However if you have a semi-pro or MI mixer, the choice depends on whether the line output amplifiers in the EQ are better than those in the mixer at driving a long multicore. You'd be surprised at how much this can affect the sound.

 

Oh, and to add to my previous message: another potential fault point is the connection bertween the insert jack on the mixer and the circuit board. The solder joints often fail due to the movement caused by frequent plugging.

[Trunker]

Have you got both sides on -10dB or both sides on +4dB or is Left set different to Right? Check out the switches on the back of the EQ

[Stan Hope-Streeter]

Have you got both sides on -10dB or both sides on +4dB or is Left set different to Right? Check out the switches on the back of the EQ

 

The FCS 960 doesn't have pro/domestic level switching. At least, none of mine have...

 

However they do have the XLR connectors wired directly to a PC board. This practice really should not be permitted in equipment that goes on the road or is frequently re-plugged. But like most manufacturers these days, BSS are now part of a conglomerate run by accountants.

 

Take the bottom panel off (6 small pozi screws, use a PZ1 screwdriver) and check the solder joints on the input and output XLR's. I've had to resolder a couple of mine over the years.

 

HTH

[ian hatch]

Have you got both sides on -10dB or both sides on +4dB or is Left set different to Right? Check out the switches on the back of the EQ

 

The FCS 960 doesn't have pro/domestic level switching. At least, none of mine have...

 

However they do have the XLR connectors wired directly to a PC board. This practice really should not be permitted in equipment that goes on the road or is frequently re-plugged. But like most manufacturers these days, BSS are now part of a conglomerate run by accountants.

 

Take the bottom panel off (6 small pozi screws, use a PZ1 screwdriver) and check the solder joints on the input and output XLR's. I've had to resolder a couple of mine over the years.

 

HTH

Cheers Stan

That could well be the problem, as the loom & desk has been double checked, and all is OK.

It will be disappointing if that is the case, as this unit is only 18 month old, got the original invoice from the chap I bought it off.

Sods law when he gave a demo on the unit, it worked fine.

As you say BSS are run like alot of companies by accountants dictating costs etc, even though the units haven't come down in price, but maybe the quality has?

[Stan Hope-Streeter]

That could well be the problem, as the loom & desk has been double checked, and all is OK.

It will be disappointing if that is the case, as this unit is only 18 month old, got the original invoice from the chap I bought it off.

Sods law when he gave a demo on the unit, it worked fine.

 

These faults are intermittent so they don't always show up on a quick test. But they are extremely common on equipment with in & out connectors soldered to the boards. Worth looking at your desk insert connectors, for the same reason.

 

If I buy any used audio gear I expect to give it a basic overhaul anyway. But that's easy for me because I have a fully equipped workshop.