Steinberg CI2 + G4 Mac = clipping

Hello and sorry for the newbie post.

I am running two AT2020 large diaphragm condenser mics into a Steinberg CI2 USB interface, which is plugged into my old PowerBook G4 running 10.4.11. I can’t install the Cubase software that came with the interface b/c it isn’t compatible with my outdated system. I could, however, install the driver that came on a separate CD and which is compatible with 10.4.11.

My problem is that, while the mics are capturing the sound of my drums (as overheads) without clipping, Audacity clips even when the gain on both channels is set to the minimum. I have to turn the gain up to near the maximum to get the peak indicators to light on the CI2. Clearly, the clipping is occurring somewhere between the interface and the software, but I don’t know how to fix it. I should add that the mics are three feet away from my drums, and I’m a jazz musician who doesn’t play loud by any standard.

I do have the USB interface selected as the input as well as the output, both in Audacity and in the system software.

Any help is greatly appreciated!

Apple > System Preferences > Hardware > Sound > Input. Select the USB device and the blue ball sound meters should tell you the level you have – before the rest of the computer gets to it.

I’m guessing you ignore the Steinburg clipping lights and set the microphone levels so the Mac is happy. If the Systems Panel is happy, Audacity should be happy.


Hmm…the Sound panel is giving me comparable level readings, which I think are too high. Drummers routinely use these mics as overheads, yet I seem to be overwhelming them even with a light touch. They are rated to withstand 144dB! Are the preamps in the CI2 too aggressive?

When you say “Audacity is clipping”, are you seeing the red clip indicators on the input level meters?

Or instead is the waveform clipped without reaching the maximum level in the track?

If you are getting the red clip lights in the meters with the Audacity input slider set at minimum then the system is sending a much too loud signal to Audacity. This seems unlikely as you say the System Preferences Sound input panel shows good (not clipped) levels. So it seems likely that the clipping is occurring in the USB interface.

– Bill

Bill, because I’ve selected the interface as my input source, I have no control over Audacity’s input slider. It is grayed out. Mousing over it results in the message, “cannot control input volume; use system mixer.” I assume “system mixer” is the interface, but the gain on it is set to the minimum on both channels.

If I turn the gain way up, then the peak lights on the interface indicate clipping. But I’m not anywhere near this limit. However, I am seeing the red clipping indicators in the monitor, which is reflected in the waveform, too.

OK, we need to walk down the chain of devices and figure out what’s happening.

The mics go into the CI2, which has its gain set low and is not indicating clipping.

The CI2 goes directly into the USB port on the PowerBook. You have selected the USB Audio CODEC in System Preferences > Sound > Input and when you look at the input levels there they appear to be good - the blue input level meter does not light any of the top 3 “balls”. Also in System Preferences > Sound > Input the Input Volume slider is probably disabled.

You had to install an older driver for the CI2 to use with 10.4.11. Does that driver allow you to set bit depth and sample rate?

Despite seeing good levels at System Preferences > Sound > Input, the Audacity input meters show clipping.

Therefore there is some kind of glitch between the CI2 driver and Audacity.

Have a look at this page:

It sounds like you might be a candidate for using Audio MIDI Setup to explicitly set the bit depth and sample rate of the CI2. Scroll down on that page to “Using Audio MIDI Setup” and follow the instructions.

Let us know how you get on.

– Bill

Thanks for sticking with me on this.

I didn’t mean to cause confusion in my earlier post when I said the levels as read by the system were “comparable.” I was suggesting the opposite of your understanding, Bill: the readings I’m getting from the Sound panel match or are comparable to those in Audacity (i.e., they’re both too high, given that the gain is turned all the way down). You are correct, however, that I am trying to adjust the gain controls on the USB interface in order to make the system happy. Problem is I can’t turn the gain down any more than I have. Thus, the system isn’t happy, and neither is Audacity.

The driver I installed does allow me to set bit depth and sample rate. I have it set to 48000Hz + c2-bit float.

OK, that makes a lot more sense.

One point - the gain (in the System Sound panel) is not “turned down”, it is disabled. That actually means it is set to maximum (even though the slider may show as minimum). In other words, whatever digital audio stream is presented to the system via the USB connection is what is passed through. There is no opportunity to “scale it down”. This is actually a good thing, since you would simply be scaling down an already-clipped audio stream.

The odd thing is that the CI2 clip lights are not flashing, yet it seems to be sending clipped audio over the USB connection.

Try setting the interface, the connection in Audio MIDI setup, and the recording setting in Audacity all to 44100Hz 16-bit. That 32-bit float setting might be your downfall.

– Bill

It is odd that the peak indicators aren’t lighting up but the audio is getting clipped.

Now for another mystery. When I open the Audio/MIDI setup utility and select Steinberg CI2 as the device, I am given a choice between 48000Hz and 44100Hz, but only one option for bit-depth: 2ch-24bit. There’s no 16-bit option in the pull-down menu to select. So I’ve left the Audio/MIDI settings at 48000Hz/24-bit and changed Audacity’s default recording settings to match. The result: no change in output levels, which remain too high.

I’m beginning to think that the interface itself is putting out a signal that is too hot. Too bad it doesn’t have a pad to select–neither do the mics I purchased. Maybe I need to return the CI2 and get a different interface with a selectable pad.

The interface can’t put out a signal that is too hot. It’s putting out digital, and the absence of clip indicators on the analog portion would indicate this it should be putting out a digital stream that does not contain clipped samples. Since you are still seeing too-hot levels in the System Sound prefs panel, my guess is that the Mac system is not properly reading the stream of 24-bit samples, despite the settings in Audio MIDI Setup.

So, yes, a different interface might be the solution. You are using legacy drivers for 10.4.11 which may be part of the problem.

– Bill