EQ III input and output gain

[AdamPT8]

On the EQ there is an input gain knob and an output gain knob. I had a flat EQ (so no change in signal) and I wanted to reduce the level of the audio by -10dB so I set the input gain knob to -10dB. The output signal was -10dB, good, but for some reason the input gain had gone down something like -20dB, surely this isn't right. What you reduce the input gain by should be exactly the same on the output meter if no changes have been made.

I set up a quick signal generator and took screen shots to show you what I mean. I set the signal generator at 0dB.

Here is the EQ with no changes, the input and the output meter are both hitting 0dB as it should be.




Here is with the input knob set to -10dB, notice how the input meter has gone down to -20dB whilst the output has gone down to -10dB.





Another strange think I noticed was that the master meter was showing -2.5dB on what the channel meter was showing... This is purely just the master channel and aux channel with the signal generator with no effects.




It seems that the master channel reduces the signal by -2.5dB for some reason...

[barismanco123]

It seems that the master channel reduces the signal by -2.5dB for some reason...

As for the last one above I am sure that it's because of the Pan Pot Law.

A MONO signal going to a Stereo output gets reduced by 2.5 dB in Pro Tools and by varying amounts on other DAWs and physical consoles aswell.

As for the others I will have a think before I get back as to make sure I'm correct.

[AdamPT8]

Originally Posted by barismanco123

As for the last one above I am sure that it's because of the Pan Pot Law.

A MONO signal going to a Stereo output gets reduced by 2.5 dB in Pro Tools and by varying amounts on other DAWs and physical consoles aswell.

As for the others I will have a think before I get back as to make sure I'm correct.

Congratuwelldone, I just did a test with a mono signal generator on a mono track and a multi-mono signal generator on a stereo track and on the stereo it was correct

[DrFord]

Adam... I don't know about your original EQ test but that's really trippy!!! Gunna try it myself.

[AdamPT8]

It's strange isn't it.

I came across it when I was using a bass loop sample that was at 0dB and I wanted to take it down to -10dB.

[barismanco123]

I'm still trying to get my head around this myself!

The gain knobs only go minus 20 down and upto plus 20 up so that 40dB of gain adjustment.

If you change the input gain knob by 10dB negative, then the output should be reduced by 10 dB like you said, but on the meters above the gain knobs it does show a reduction on the input meter of minus 20 dB, when it should show as minus 10dB also right????????????????????????

That's got me! Now I am very curious as to whats going on!

Anyone??????

[DrFord]

Adam, can you set it up, and then take a screen shot so we can see what the meters are doing on the faders holding the insert?

I am curious as to if this is just an internal visual only EQ bug or if the gain adjustment carries out towards the actual audio on the fader.

[AdamPT8]

I can't take a screenshot at this mo, I'm not at the mac with PT on it.

The gain knob is doing exactly what it should be doing, whatever I set the gain knob to affects the output correctly, but the meter reads wrong, it seems to read double what it should be.

So if I reduce the gain 10dB, the channel meter reflects this and shows that it has been reduced by the set amount, the only thing that is wrong is the input meter on the EQ.

Have you tried it on your setup?

[barismanco123]

I'm gonna try now.

[barismanco123]

So, here is the signal generator with no setting changed - it's flat, the EQ is flat too.

http://www.divshare.com/download/12280160-4eb

Now, I left the signal generator the same and only changed the EQ's input gain knob by -10dB.

http://www.divshare.com/download/12280161-622

You would think the EQ knob would be at the same level as the output know seeing as now processing and gain sctructure changes have taken place but that is now reflected on the levekl meters of the EQ's unput mter.