Calibration Input Problem

[Naio]

I am on OSX 10... with an RME UCX Fireface audio interface.
The problem is in the calibration set up that I so not get an input signal in the calibration set up of REW when setting up an output/input loop via a cable on one channel (right channel). I do hear the test tone and I do see the input/output signal on my internal mixer of the Fireface UCX GUI but I do not get a signal on the REW input channel.

Any advice?

 

[John Mulcahy]

Which OS X version? What input device and input selections have you made in REW?

 

[Naio]

Hi John,
Thanks for your reply.
As the input AND output device I have selected my UCX Fireface interface. See attached screenshot. The second screenshot shows my UCX Software mixer GUI when I can see that I have an input and output signal, bit again no input on the REW calibration.

 

[John Mulcahy]

I suspect you will need to configure something in Audio Midi setup to make the AN1/2 pair available to Java and hence to REW - since the only input label seems to be "Fireface UCX (23564485)" there must be some other way to determine which of the many available inputs those represent.

 

[Naio]

Makes sense, I will try to figure that out

 

[Naio]

I suspect you will need to configure something in Audio Midi setup to make the AN1/2 pair available to Java and hence to REW - since the only input label seems to be "Fireface UCX (23564485)" there must be some other way to determine which of the many available inputs those represent.

Hi John,
I am totally lost...normally I figure audio/routing stuff out but this time I have to clue. I did check all the option the RME Firefcae Mixer SW gives me but I can't get it done. Can can you please elaborate on the Java Part....where can I find those settings as I am not familiar with setting up any Java preferences....

 

[Naio]

Hi John,
I am totally lost...normally I figure audio/routing stuff out but this time I have to clue. I did check all the option the RME Firefcae Mixer SW gives me but I can't get it done. Can can you please elaborate on the Java Part....where can I find those settings as I am not familiar with setting up any Java preferences....

BTW I should mentioned that the calibration work when I use the internal AU engine from my Mac Pro and even the Display Audio of the Cinema display.

 

[John Mulcahy]

There's no configuration for Java as such, but Java is usually able to access the devices which appear in the input and output list in Audio Midi Setup. What appears there for the UCX?

 

[Naio]

There's no configuration for Java as such, but Java is usually able to access the devices which appear in the input and output list in Audio Midi Setup. What appears there for the UCX?

I guess you refer to the Audio MIDI set up of the Fireface, I can see the UCX there with port 1 and 2 to be selected as an input/output, respectively. See screenshot....What I don't get it why there is a connection between MIDI when we route audio...

 

[John Mulcahy]

No, of the Mac. Applications - Utilities - Audio Midi Setup.

 

[Naio]

No, of the Mac. Applications - Utilities - Audio Midi Setup.

OK got it, I have selected the UCX as the input and output device for all my 8 analog inputs/outputs. Problem now is that the volume sliders are inactive..I have pulled up all faders of the SW Mixer from the UCX to make sure nothing is off...but still, cannot move the volume sliders in the Audio/MIdi Setup

 

[John Mulcahy]

The volume sliders probably don't matter, but that selector which shows AN1-8 may control which group of inputs are made available. Also worth checking out what is offered in Configure speakers. What shows up in REW now on channel selection? There is also an option on the REW soundcard preferences to generate a debug file, could run that and attach the file for me to look at.

 

[Naio]

The volume sliders probably don't matter, but that selector which shows AN1-8 may control which group of inputs are made available. Also worth checking out what is offered in Configure speakers. What shows up in REW now on channel selection? There is also an option on the REW soundcard preferences to generate a debug file, could run that and attach the file for me to look at.

Under Configure Speakers it does not allow for much other than assigning the Analog 1-8 to the speakers, nothing on caning the input channels.
The REW channel selection still shows the same options, see screen shots on output and input selections.

I have attached the debit file. Hopefully that give us a clue.

 

[John Mulcahy]

Thanks, it looks like the file might not be complete but what I needed to see is in there. Good news and bad news really. Java on OS X is being smarter than I gave it credit for, it shows the Fireface as supporting either 1, 2 or 18 channels of audio data - the 18 would correspond to your full array of audio I/O. However, REW only copes with 2 channels for input and up to 8 channels for output, so it is only offering the 2-channel modes provided. Those should be the first two channels in your lists of inputs and output, which I think should be AN1 and AN2. If you run the REW signal generator can you produce an output signal on the Fireface? If so, on what channels does it appear? It is possible that the mapping for 2-channel inputs picks a different pair for output and/or input, you could open REW's Levels window to see the input meters and try applying a signal to each input in turn to see which registers.

Having said that, you could also just try the Mac's built-in audio input and output, you'll get perfectly good measurement results with those.

 

[Naio]

Hi John,
firs of all I want to thank you for taking the time to help me and go though all the details, I really appreciate your help and want to say thank you!
AN1 and AN2 are two of my hardware Outputs on the UXC they are not inputs. If I run the signal generator in REW I do hear the output signal on my monitors via AN1 and AN2. I also hear them when running the calibration and when running the measurements. The only problem I have is that when calibration REW does not get and input signal, no matter via which hardware input I loop back into the interface. I check out several tutorials on the Total Mix FX Mixer software that is provided with the UCX and you can essentially route any input to any output on the hardware side an do the same with all software outputs (e.g. from Logic and any DAW). They even offer a matrix to do that but it is quite complicated to unterstand, o I guess I could some how configure the SW Mixer from the UCX to only provide 2 input channels to comply with the RWE requirement of only 2 inputs.

I did run the signal generator in REW and pulled up the levels window and then connected the main HW output to every HW input available on the UCX to see if any input triggers the REW input, but no change, still no input signal on REW.

Some questions:
1. Is the calibration really necessary? I do understand that you want to avoid colouring of the UCX when measuring the room frequency response, but I am running a home studio and do not need a perfect result. So I guess my questions is how "bad" are measuring results without calibration?
2. You suggest to jus try the Mac's build in audio I/O and that works, so I do get an output and input signal in REW. So do you mean I should use the Mac's audio to measure my room? I have the Behringer ECM8000 mic and not input for that on the Mac. So, what if I just ignore calibrating the UCX and do the measurement with the UCX. I do need to place the mic at my listening position, right?

 

[John Mulcahy]

The main purpose of the calibration is to make sure there isn't an inadvertent feedback/monitoring loop active, which invalidates the measurements. It's fine to measure without doing that as long as you are sure no monitoring is active. I'm not clear how you would measure with the UCX if you can't get anything to register on any of the inputs though? Or does it work OK with the mic input you are using? Yes, mic goes at the listening position.

 

[Naio]

I don't have any input signal problems with my DAW or with the UCX mixer, they see them and work, its just with the input signal on REW when calibrating, mic inputs work and all my line inputs as well with equipment connected.

 

[Naio]

The main purpose of the calibration is to make sure there isn't an inadvertent feedback/monitoring loop active, which invalidates the measurements. It's fine to measure without doing that as long as you are sure no monitoring is active. I'm not clear how you would measure with the UCX if you can't get anything to register on any of the inputs though? Or does it work OK with the mic input you are using? Yes, mic goes at the listening position.

Hi John....stupid me...I started measuring and only then found out that REW can only read a signal from the mic when connected to my mic 2 input (XLR Line combo input). I then used that mic2 input as the line input for the calibration with a TRS/Line cable and voila, it worked....

Thanks again for your help

 

[John Mulcahy]

Phew! Got there in the end

 

[Naio]

I guess my mistake was not to have figured out from the beginning that my mic inputs can also be used as line jacks and mic1 and mic 2 are the first two numerical inputs of the UCX and those are the ones that REW looks for.

Once again, thanks for bearing with me here and your professional help!

Have a great day and greetings from Frankfurt Germany!