Connecting FM9 with FX II XL via SPDIF

E

extawu

Member
I have 2 problems connecting FM9 with FX II XL via SPDIF.

Problem 1. I can clearly hear clipping (not pleasant) when using any presets on my FX II XL with FM9 and still all leds are green (INs/OUTs). Mostly with overdriven presets but sometimes with clean presets.
Found the parameter SPDIF-level in FM9, defaults to 0.0, and when I lowered it to about -5.0 the clipping disappears. So, why does it clip if all leds are green and should it work this way?

Problem 2. With this configuration the tuner is 6-8 cents lower on my FM9 and when not using this configuration the tuner is OK.
Should it work this way?

Both devices are locked to 48 kHz and can't be changed. I have alternated FM9/FX II XL to be master/slave and still the same behavior.

When I use analog INs/OUTs it works as is should.
System parameters have been reset on both devices except for Digital Input Source SPDIF, SPDIF Out Source OUTPUT2, Input 2 Source DIGITAL, Display Offset 1, AC Line Frequency 50 Hz and MIDI Channel 2 & 3.

Preset on FM9: IN1 - OUT2(SPDIF) - IN2(SPDIF) - OUT1
 
That just means you have the level in your output block too high. Usually you fix that by turning down the level on your amp block. Don't change the spdif output level. The LEDs are showing you the level at the DAC, not the level at the float-to-int digital conversion, which is what matters for spdif output. In othe words, ignore the LEDs and use the output block meter.

See the recording guide for some additional info:

https://forum.fractalaudio.com/threads/axe-fx-for-the-recording-musician.177592/
 
So you mean all the presets on my FX II XL are too hot when I use the SPDIF but not when I use the analog output? I have no problem using the presets with the analog output, they are all accurately equalized.

One other thing, I have not changed the spdif output level on my FX II XL, I said I had to lower the SPDIF input level in FM9 to not clip.
 
The whole point of using digital I/O is to make the two devices act like a single device. But that means you'll have to be careful to adjust the outputs to not exceed digital PCM zero, especially when using output blocks 1 and 2, which add 18 dB of gain. If you have the levels adjusted correctly there will be no need to adjust the spdif level. The meters page on the main screen and the output block meters can help with that adjustment. The analog outputs and the LED meters aren't relevant for that connection.
 
So, there is a difference between the analog and the digital domain regarding sound levels? I can handle it for the moment - I was just curious about it and maybe do something else to handle it.

Problem 2 is more important to me than problem 1. What do I have to change so the tuner in FM9 tunes correctly when connecting my FM9 to my FX II XL via SPDIF? If I shut down my FX II XL the tuner is back and tunes correctly.

I must thank you for trying to help me with this problem. Maybe others have some suggestions that can help me.
 
extawu said:
Problem 2 is more important to me than problem 1. What do I have to change so the tuner in FM9 tunes correctly when connecting my FM9 to my FX II XL via SPDIF? If I shut down my FX II XL the tuner is back and tunes correctly.
Click to expand...
What is your FM9 clock source currently set to?

If you're using the SPDIF input on the Axe-FX II, it can't be master and will only slave to the incoming signal. If you had the FM9 clock source set to SPDIF and still heard sound, it was only because the two devices were in a phase-locked loop, which means the samplerate could drift and affect tuner readings. So, make sure the FM9 is set for internal clock source.
 
extawu said:
So, there is a difference between the analog and the digital domain regarding sound levels? I can handle it for the moment - I was just curious about it and maybe do something else to handle it.
Click to expand...
I would put it this way: If your levels are adjusted correctly, then nothing needs to be handled. If your levels are not adjusted correctly, the consequences will differ for digital and analog.
 
Bakerman said:
What is your FM9 clock source currently set to?

If you're using the SPDIF input on the Axe-FX II, it can't be master and will only slave to the incoming signal. If you had the FM9 clock source set to SPDIF and still heard sound, it was only because the two devices were in a phase-locked loop, which means the samplerate could drift and affect tuner readings. So, make sure the FM9 is set for internal clock source.
Click to expand...
As I said earlier I have tried to set my FM9 as master clock and also tried to set the FX II XL as a master and still the same wrong behavior.
I will try again tomorrow and I will be very precise about this. Thanks!
 
Made some tweaks today that solved problem 1 and 2.

I had to reset the system parameters twice on my FM9 and lower the GLOBAL EQ OUT1 to -6.00 on my FX II XL because the INPUT2 lights on the FM9 kept turning red.
Don't like having to reset twice and lower GLOBAL OUT1 because now all my presets on the FX II XL are too low when I use the analog OUTPUT1.
 
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