Topic: UFX with Reaper hiss

Hello,

This is probably something simple but I am not able to figure it out so I thought I will ask here.

When I turn monitoring on in Reaper, I get a loud hissing noise.

I have unplugged all microphones - hissing persists.
The noise gets louder as I increase the volume of my main output.
When I turn off the monitoring the noise disappears.
The noise gets recorded on the track, even though no microphone (or any other hardware input) is connected.

Please let me know if this sounds like Reaper issue so I can take this up on their forum.

Thank you for your time and help,
Wojt

2 (edited by wojt33 2022-06-29 05:34:14)

Re: UFX with Reaper hiss

The hiss is caused by the amount of gain. Even at 30 with no source connected the amount of hiss is very high. Is this normal?

I have changed output level on headphones to low, and now noise is more manageable.

Re: UFX with Reaper hiss

What's the input noise level shown in Totalmix with gain at 0, 30, and all the way up?

Regards
Daniel Fuchs
RME

Re: UFX with Reaper hiss

I assume this is on your monitors? what does it sound like on headphones? (be careful with your hearing!)

I'm wondering if your monitor gains are set too high, not with software but the actual hardware gain.

Re: UFX with Reaper hiss

Hi Daniel, thank you very much for your response.

At gain 0, the input signal with no source connected is 97.6, at gain 30 the input signal is 87.9, all the way up the input signal (audible hiss) is around 50.

I am monitoring using headphones Sennheiser HD25. I am on location so headphones are my only way of monitoring. I had my headphones level set to low. At high, the noise is a lot more noticeable. All of this was done at fader at 0.0 at the Mic 9 input, with nothing connected to the input.

The strange thing is that as I was checking for the information you have requested, at first I could hear a clear difference in the amount of noise when using the gain knob on mic 9. Now, moving the gain all the way up or down has no influence on the noise level at all.

My apologies that this is so confusing.

Thank you for your help.
Wojciech

Re: UFX with Reaper hiss

Sbcrikey, thank you for your response. I think my headphone levels are ok. I have tried going all the way up and down. At low levels, I cannot hear any noise.

I am trying to record at low levels due to the noisy environment. I want to avoid the outside street noise by using a directional microphone and setting levels low.

7 (edited by ramses 2022-06-30 09:16:43)

Re: UFX with Reaper hiss

wojt33 wrote:

[...] All of this was done at fader at 0.0 at the Mic 9 input, with nothing connected to the input. [...]

AFAIR Invalid procedure, you might need to connect something to a (combo) input before making such tests.
Otherwise the input is not in a defined state.

This has been mentioned by MC/RME in this forum some time ago, e.g. this
https://forum.rme-audio.de/viewtopic.ph … 09#p132109

Not 100% sure whether this applies fully to your case, but I would do it this way.

I also remember that I had to mute an unused Instr input with nothing connected to it and with higher gain settings on my UFX+.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14