Hi,
Say I want to sum 48 input channels using a standard virtual earth summer.
I don't care about 0dB channel in being equal to 0dB summer out.
Assuming all 48 channels are feeding the bus, and containing somewhat uncorrelated signals, the output of the summing bus could be up to 16dB hotter than each individual channel's input level.
Is there any penalty in running the summer at a closed loop gain smaller than 1? Say I want to lose 12dB in the summer, make Rfeedback 2.5K with all Rinputs being 10K?
Assuming the above does not cause major concerns, what would be the most elegant way to make the summer's gain adjustable? Making Rfeedback a 7.5K pot in series with a fixed 2.5K to set the gain anywhere between -12dB and 0dB?
I do realise that designers tend to choose a fixed gain as to have fixed operating conditions all the time; still I'd like to find out what audible influence the flexible gain would have.
My main concern is headroom in the summer stage without having to run the inputs at too low a level.
Many thanks,
Best Rogy
Say I want to sum 48 input channels using a standard virtual earth summer.
I don't care about 0dB channel in being equal to 0dB summer out.
Assuming all 48 channels are feeding the bus, and containing somewhat uncorrelated signals, the output of the summing bus could be up to 16dB hotter than each individual channel's input level.
Is there any penalty in running the summer at a closed loop gain smaller than 1? Say I want to lose 12dB in the summer, make Rfeedback 2.5K with all Rinputs being 10K?
Assuming the above does not cause major concerns, what would be the most elegant way to make the summer's gain adjustable? Making Rfeedback a 7.5K pot in series with a fixed 2.5K to set the gain anywhere between -12dB and 0dB?
I do realise that designers tend to choose a fixed gain as to have fixed operating conditions all the time; still I'd like to find out what audible influence the flexible gain would have.
My main concern is headroom in the summer stage without having to run the inputs at too low a level.
Many thanks,
Best Rogy