Hi,

Been ITB forever, just breaking out - very happy with the results.

So, say i run a signal out of Nuendo into a Stereo Compressor (TK Audio BCS1, since you ask).

On my soundcard (Audient ID22, since you ask, though many are like this), the two 'inputs' act and indeed are independent of each other.

This means, one of the 'gains' can be higher or lower than the other, leading to the newly recorded stereo signal to be uneven - ie. Left channel may be recorded louder or quieter than Right channel.

The soundcard provides no information about this (barring the physical 'position' of the gain pots), and Nuendo has small meters at best. I'm using my ears but obviously this is a big deal to screw up!

So what techniques can i use to ensure i'm capturing a totally identical L and R signal (in terms of the overall gain)?

Thanks for your help/ input!

Run a mono test signal through both channels, using a splitter, and calibrate accordingly, using meters. I had to do it with my own interface. Even that won't guarantee perfection, but it's better than just using your ears.

Thanks for that

What sort of meter is it that you're referring to?

How do 'proper' studios do this - it would be a stereo-linked pair of gains on a soundcard? I guess 'stepped gain' pots would also do the trick.

This must be an issue for lots more people than just me - both my soundcards have had this same problem?

Input meters in your DAW will do, or meters on your interface if they are accurate enough.

Thanks - they're a bit small for such an important job perhaps, but yes. It's a bit like, i've spent tens of hours making something really carefully, and at the last minute saying 'oh **** it, who cares about a 0.3db difference' - when all the way through the production process you're caring about tiny tiny differences, of course.

For info; Setting Input Levels

^ following those instructions will configure all meters to show 'input' (in Cubase/ Nuendo)

Keep in mind that changing gain in the digital domain will have no effect on the analog level hitting the A/D.
In other words, check how high the levels are coming into the digital domain and if needed adjust it in the analog domain.

if you are recording a truly stereo source - let's say an acoustic piano, or a mix, the natural musical differences inherent in the right and left hand sides of the signal will exceed your '.3db' tolerance by an order of magnitude at least.

Music is not standing still. The meters will be jumping back and forth up and down as the drummer hits a tom, the piano player fingers a high chord, etc etc. The more accurate your meters, the more of this you will see. What matters is what you hear. Even if your calibration is a tiny bit off, you would presumably be adjusting your mix by what it sounds like.

I agree, but IMO the tiny tiny differences you should be most concerned about are the tiny tiny musical differences.

Let's say I have an electric guitar on the right and an acoustic guitar on the left. I have no problem at all letting one of them read higher on the meter as long as subjectively they "feel" the same on both sides. One way to keep yourself "honest" is to have a switch that will flip the right and left channels on your speakers. If you have a personal bias, or an acoustical anomaly in your space, (or your ears are out of calibration!) you will notice it right away.

Poinzy's method for calibrating your inputs will do just fine. You should include your compressor in the path, as the circuits in that may not be 100% identical either. If I have one of those meters that is just a 'ladder' of a handful of LED lights, one thing I do is gradually sneak it up to find the point where it just 'changes' from four lights to five - for example. IOW they are more sensitive than you might think at first.

The part which worried me most is where I’m using mono signals. Bass and kick drum. The more unbalanced the signal I’m recording, you begin to lose that solid mono feel. Plus you send it to be mastered and the mastering engineer is wondering why one channel is louder than the other. Plus if you limited the unbalanced signal or processed it further, it’s just getting worse...

The rest I’ve probably panned and i just want to protect what I’ve created. I make careful decisions and the idea of replacing this with a shonky accidentally misbalanced stereo mix is not ideal!

Thanks for the input

Not quite?

The signal output from Nuendo is totally balanced. A mono signal would be deadly equal - I think.

Then the compressor is using some stereo circuit to produce/ output the signal.

It’s the input back into the DAW (recording) that worries me, so I’m not sure what you mean? It’s the capture of the signal of using the analogue gains into the DAW?

Thanks for the input - perhaps we’re saying the same thing in different ways

I am still a little vague on your process. Are you running a final mix through a hardware compressor, once, or are you reamping individual instruments through the hardware?

I am not really sure what you mean.

BTW do you have the "link" button engaged in your compressor? A peak on either side should trigger compression on both sides.

Your DAW meters show you the digital level, after A/D.
Changing this in the digital domain (software) does nothing to the signal level coming in.
To adjust the signal level hitting the A/D you need to use the analog adjusters (gain knob on your interface).

Yep, all agreed!

Yes, just processing a stereo signal through a stereo compressor.

If there is an imbalance in the capture this means the left channel would be louder than the right - the advice has been good; just be careful and do the best you can to make sure you capture the channels at the same levels - I would say stepped gain pots would be a good idea but not sure why this isn’t something more prevalent - I got in touch with audient and they don’t offer this at all, preferring to permit any values

Anyway!

It adds to the cost. The UAD Apollo has the ability to link a pair of channels so they will turn up and down together. (It is a virtual knob). I haven't tested it, but OTOH, I have never found it to be noticeably "off". Seems to work perfectly.

You are more likely to encounter stepped pots on the analog devices, such as compressors. I would suggest that after running your test tone to calibrate your inputs, you mark them with a grease pencil.
but are they? After you run your mono test tone and match the left and right channels are they wildly different positions on the knobs? Are you experiencing mixes where the vocals, kick and bass are shifted out of the center and towards one side? Or are you just worried that this might be happening?

You seem to be quite certain that this would be a very strong and obvious effect. If that is the case, then the chances of such an effect "sneaking past" you would be minimal. I would say calibrate your inputs as described above and take comfort in the fact that you have done your due diligence.

Hey - yes, the reason I posted was because I noticed exactly this, and then thought, I haven’t really considered this as a possible production mistake. For example I had a limiter on the recorded track and of course, one side was being uh limited more than the other; just exacerbating every error!

Thanks for your input. Some of your tone and use of bold and your attitude seems a little passive aggressive btw - I’ve got tracks on YouTube with some good numbers (all ITB haha) so it doesn’t mean anything to me, couldn’t care less, but when I was less experienced I disliked it when people took that kind of attitude - looking at your other posts I can see it’s nothing personal but it probably puts other people’s backs up too

Thanks again man - also the Apollo tip