Scope Mixers reducing input by 3db

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minipax
Posts: 128
Joined: Mon Dec 10, 2001 4:00 pm

Scope Mixers reducing input by 3db

Post by minipax »

Hi, i've noticed this problem for ages but have only tried to investigate now. I have run a few tests and I'm pretty sure the fault lies in STM 2448 (and all its variations, incl Big Mixer V2B).

Basically, If I send a signal (-10dB sine wave from the Control room device)to an input channel on a newly initialised STM device, it appears to be roughly 3db quieter (i.e. -13db )when it arrives at the Mix L/R (or CtrL/R) outputs (recording in wavelab).

If I perform the same test, but route the sine wave directly through to my Wave/ASIO2 destinations, I get the -10dB level from the outputs.
I get the same favourable (no attenuation) result sending the signal through a single 'Channel' mixer also.
So i am concluding the problem lies along the STM signal path.

Has anyone noticed this, and perhaps you could perform a quick test to verify it? I cannot think of a reason for this, I would expect an unaltered signal the whole way through...

Test steps.
1. Load a ControlRoom device, A Mixer and something for metering the level (I'm using LEVELMETER by ws design)
2. connect the test output of your ControlRoom to an input on the mixer.
3. Connect the Mix output on your mixer to your metering device.
4. As a control, connect the test output of the COntrolRoom directly to your metering input.

Any info on this would be appreciated (I know i can just up the master fader by 3db...but i'd like to know it's not just my setup)
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astroman
Posts: 8446
Joined: Fri Feb 08, 2002 4:00 pm
Location: Germany

Re: Scope Mixers reducing input by 3db

Post by astroman »

3 dB is always a highly suspective figure... ;)
if 1 mono signal is distributed to 2 output channels (a stereo pair) then it results in 3 dB less 'energy' for the whole mix :D

cheers, Tom
minipax
Posts: 128
Joined: Mon Dec 10, 2001 4:00 pm

Re: Scope Mixers reducing input by 3db

Post by minipax »

Ah OK, makes sense!
So how do I got about tracking in the most optimal way? Just add 3db gain to each mono track i guess?

Specifically, I would like to input a mono signal into channel one, and record that signal on mono cubase track transparently at the end of the mixer chain without attenuating the signal.I've tried multiple routes through the STM mixer but i'm still getting -3b when i record.
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astroman
Posts: 8446
Joined: Fri Feb 08, 2002 4:00 pm
Location: Germany

Re: Scope Mixers reducing input by 3db

Post by astroman »

I dunno your project and it's routing, but if you want that specific signal rather prominent in the mix, you can make it louder whereever you like. (I assume it's a synth signal or a sample already recorded)
Level in tracking matters only on the analog side of things before the conversion stage.
In that case the gear may have a specific way to react to a more or less 'hot' signal, but once it's digitized that doesn't matter anymore.
Everything is scaled proportionally - signal and noise.

cheers, Tom
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