Audio recording tops at -11 dB?

Cubase
1

I normally use Cubase with VSTis, rarely with audio files. Today, just for my own amusement, I recorded myself practicing cello. I only have two XLR mics, one is a Shure SM58 with almost no gain because it’s for singing with your mouth 1 mm from it, and a directional Audio Technica AT875R, which is a mic intended for video, but it sounds great regardless. My audio interface is a Behringer UMC404HD.

During recording, I noticed a strange thing, and I don’t know if it’s a restriction in Cubase or in the interface. I noticed that no matter how loud I played, or even yelled into the mic, it would top at -11 dB. Adjusting the gain for the input I was using in the interface didn’t change this, it only made it distort quite a lot but at -11 dB. The only way to raise that top level was to raise the fader for the input track in Cubase.

This is not a huge problem because since it’s XLR it has almost no noise, so raising the gain in the audio file gives me a perfect result. I’m just curious if this -11 dB top is a restriction in my audio interface (which so far I couldn’t find anything on that topic), or Cubase. I mean, I thought that the level went up as high as I wanted it to go.

By the way, this is a very simple project, just a default project, created an audio track, and recorded. Later I added more tracks and a couple of FX buses, but I saw that -11 dB thing as soon as I started recording since the gain in the Behringer was a bit high.

2

When I’m setting levels while the talent is doing mic checks, it’s easy to pin the Cubase meters into the red if I raise the preamp gain too high.

I can’t speak to your interface as I’m not familiar with it, but I’d be genuinely surprised if it topped out at -11dB.

3

Yeah, but if you say that you can go into the red in the Cubase meters when raising the gain in the interface too much, it seems more likely than my Behringer has some kind of feature to cut it at -11 dB, or that it’s a feature that I somehow enabled. I’ll have to check the manual.

I also have a smaller Focusrite 2i2 interface, I’m going to find it later and see if that’s the case.

4

If the Behringer is overloading at input but only outputting -11 to Cubase (presumably recording with a clipped waveform) either it’s broken or you have the input channel in Cubase turned down 11db.

5

No, the channels are at the default levels every project starts with, which depending on the inspector it says that it’s 0 dB, but on the faders it shows as something between -6 and -12, I guess they are different types of meters.

6

Not sure the input channels show in the inspector as they don’t appear in tcp and may also be hidden in the mixer. I think you’re talking about track channels not the input channels?

7

Sorry, you’re right, I was looking at an audio track, not the input bus channel.

But I solved the mystery. This interface has 4 channels, and I realized that channels 1 and 2 are full range, meaning that even at the default input level when you start a new project, if I yell next to the mic it will go up to the 0 in the channel meter in the mixer, but inputs 3 and 4 are capped at 11 dB for some reason.

All inputs from 1 to 4 are set to the middle, meaning almost exactly the same gain, and other than that, each channel has a toggle button to select between line or instrument (which at least for mics doesn’t seem to change anything), and a “Pad” toggle, than when turned on brings down the level several dB. However, this is not on on channels 3 and 4, in fact if I turn it on, it brings down the levels a lot. But plugging in the mic with the same cable, one XLR input at a time, it’s clear that 1 and 2 are unconstrained but 3 and 4, you can have a train next to you and it won’t send out a digitized audio signal of more than -11 dB or thereabouts. I assume there’s some good reason for that, I’ll have to check.

When I recorded myself yesterday, I used a different longer XLR cable that I plugged in input 4, and in Cubase I created a Mono input bus with that channel, hence the -11 dB top. I guess next time I want to record myself and pretend I’m Yo-Yo Ma when I’m just Yo-Yo Not, I’ll just have to connect to input 2.

8

I had a look at the manual which, while a little difficult to interpret (the same manual covers nultiple models), doesn’t appear to make any distinction between channels 1-2 vs. 3-4 on this model. My understanding from the manual is that all input channels share the same specs. So I think @Grim still has a point that your unit may have a fault.

Building a unit where two of the four channels have a -11 dB cap just doesn’t make a sense to me.

9

Is the pad button engaged?

10

To me either, but if two inputs have a fault, wouldn’t they just stop working, or have weird noises? It’s strange to me that the defectiveness consists of two inputs being capped at -11 dB.

As I said, no. I did engage them to see if it made any difference, and it does, making the gain much lower. But when I tried the mic with the same cable in each input, all four of them had the padding disabled and had the gain knob as close as I could make them to half way.

11

Hi,

You have got two different kinds of mics: The SM 58 is a dynamic mic and requires no phantom power. The AT875R is a condenser mic and it requires phantom power for operation (there’s a switch at the back of your audiointerface which needs to be turned on).

Have you tried testing the SM 58 on all inputs of the audiointerface? Same result?

Have you tried testing the AT with phantom power switched on at the back on all 4 inputs as well?
Maybe the phantom power is broken on channel 3 and 4?

12

Well, you taught me something new today. I evidently need to learn a bit more about mics, because to me it was always very simple: if the mic requires a battery and has a switch, it doesn’t need phantom power; if it doesn’t need a battery, it needs phantom power to get the power from somewhere.

Since I assumed both of these needed phantom power, the switch is on all the time, with the Audio Technica being my regular microphone for whatever.

I’ll do those tests you mention with the SM 58, but I can tell you that when I tried both of them with input 4, it was remarkable how little gain the Shure had. While the AT topped at -11 dB, if I yelled close to it, it would get to that mark and distort quite a bit; but the SM 58, I was yelling with my mouth 1 mm away, and it barely pushed the meter up.

Just to clarify, in this interface, you don’t get individual phantom power, it’s either on or off for all channels. And I know it’s on because it’s an amber light on the front when it is.

Regardless, this is not a problem for me. Honestly, I bought this interface because it has both XLR outputs and RCA line outputs. So the XLR ones go to my Sansui G-5700 receiver, and the line outputs go to my Pioneer VSX-935 receiver, which has a Dolby Atmos setup, and does a great job of turning stereo into a fake Dolby Atmos. The only problem is that the line output has a rather low volume, but not terribly low.

Obviously if I had the space I would buy a pair of those Adam audio studio speakers that most people have for their home studio, but I simply have no space for them in my current desk layout.

But to me, if I have those two channels at full range, that’s all I need, because if I record myself playing cello, violin or whatever, it’s always going to be a long XLR cable, and the one connected to the mic a short cable, so as long as I have two XLR inputs I’m fine.

1 Like