Finding the right level, DBX286 gain staging

HomeRecordist

New member
I have the following setup:
Audio Technica BP40 --> DBX 286A --> Audient ID4 mk II
Due to various reasons, processing signal via software means is not feasible.

Plugging microphone directly into the interface, gain has to be set at maximum and even then I need to be within ~15-25cm from the mic to reliably hit -10db LED.
Currently I max-out DBX preamp (+60 gain) to saturate the compressor and have the last, "output" knob set to zero.

Afterwards, I amplify the signal in ID4 by having the gain knob set to approximately 11. Having it at 0 (line-in) results in clearly insufficient volume, so this step is not optional.

Questions:
  1. How do I reliably detect when signal coming from DBX into ID4 is too hot for the latter? I can hear the distortion well before Audient LEDs reach 0 level.
  2. Would the whole setup benefit from a preamp ("cloudlifter", etc.) before DBX so that it's not always at max gain?
  3. Anything else I might be missing?
Thank you.
 

Farview

Well-known member
How much reduction are you getting from the compressor? My guess is that you are overdriving the compressor, causing distortion and the gain staging goofiness later in the chain.
Also make sure your gate is wide open.

Bypass the processing and see what the gain situation is. 60db of gain should be plenty, especially when you are running it into another preamp.
 

HomeRecordist

New member
Bypass the processing and see what the gain situation is. 60db of gain should be plenty, especially when you are running it into another preamp.

Out of sheer interest done the sweeps. 20-20K, linear:

lin_sweep_src.png

DBX with gain knob at minimum (+10Db) and bypass ON:

lin_sweep_rerecorded_0knobs_dbx+10_bypass.png
 

drtechno

Member
I have the following setup:

Due to various reasons, processing signal via software means is not feasible.

Plugging microphone directly into the interface, gain has to be set at maximum and even then I need to be within ~15-25cm from the mic to reliably hit -10db LED.
Currently I max-out DBX preamp (+60 gain) to saturate the compressor and have the last, "output" knob set to zero.

Afterwards, I amplify the signal in ID4 by having the gain knob set to approximately 11. Having it at 0 (line-in) results in clearly insufficient volume, so this step is not optional.

Questions:
  1. How do I reliably detect when signal coming from DBX into ID4 is too hot for the latter? I can hear the distortion well before Audient LEDs reach 0 level.
  2. Would the whole setup benefit from a preamp ("cloudlifter", etc.) before DBX so that it's not always at max gain?
  3. Anything else I might be missing?
Thank you.
Had a similar experience with a 286A and sm7 setup, which I had two problems I fixed.
The weak signal input, I modded my SM7 and put a dynamic mic transformer in it and now its volage output is twice of what it is at an output z of 1K. It sounds better than stock sm7 compared side by side, as well as it can now plug into any mic pre w/o issuers. The second was my trs to xlr cable I was using on the output, as I discovered someone tied pin 3 and 1 together which cuts the signal in half and forces the connection in unbalanced mode which increased the noise floor.
 

BeGrody

Member
@HomeRecordist

I also have a DBX 286s and what you experienced really doesn't make any sense to me. Even with a passive ribbon mic there's enough gain in the DBX. Can you talk about how you actually wire things together? Unless you have a faulty unit, there should be nothing wrong with an Audient. They have a great reputation.

Here's what I do for good results. I plug the mic in with a quality balanced XLR mic cable into the XLR input of the DBX. I turn the unit on. If the mic needs phantom power, I engage the phantom power. I adjust the level on the "MIC PREAMP" up slowly until it sits at -10 on the LEVEL meter with the occasional 0 lighting up on peaks. Next I engage process bypass, and I move to the "OUTPUT" section. I set it 0. I activate the channel on my recording gear and watch the input level meter there while I adjust the input trim knob on my recording gear until the level is around -6 and doesn't activate the clip light except on occasional peaks. If I can't get there, then on the DBX 286s I will adjust the OUTPUT knob up or down accordingly. I make sure the "clip" light on the output section of the DBX 286s never engages.

Then I disengage the process bypass and mess with the compressor. You shouldn't see all LEDS on the meter on the compressor light all the way up. Adjust it to taste, but if they all light up that would mean you're squashing 30dB off your signal.

Hope it Helps
 
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