Distorted Audio, Behringer XR18 to ProTools via USB, Windows Computer

[Michael Murray]

Attached is an audio sample of a live recording in a bar. I am using a USB to connect to a Behringer XR18. The music is being played through a PA system which does not exhibit any sort of distortion. I am a novice and would like help solving this issue, I appreciate any sort of advice in advance. Below is a link to the audio, the issue unpredictably occurs and then also unpredictably stops during recording.

https://www.youtube.com/watch?v=ERMQa_kfqfI

[Hugh Robjohns]

That's the sound of missing samples!

Possibly the computer's USB driver's buffer size is too small, or there is a clocking issue between the XR18 and DAW. Check which is selected as the master clock, and make sure the other one is slaved to it!

[Michael Murray]

Hugh, why would the issue resolve halfway through the clip and why do I have perfectly clean audio in many other examples?

I want to reiterate the fact that I am a novice/amateur and really have no idea what you are referring to in terms of clocking and buffer? I don't have intimate knowledge of sample size and the like. Thanks!

[Drew Stephenson]

If it resolves halfway through that might suggest that there was a background process running on the PC that was using up CPU. Once that task finished there was enough processing power to run at the selected sample rate and buffer size.

Here's some very quick reading on:
Clocking: https://www.soundonsound.com/glossary/clocking
Buffer size: https://www.soundonsound.com/glossary/buffer
Sample rate: https://www.soundonsound.com/glossary/sample-rate

Roughly speaking...*
For clocking the key thing is that everything connected is running off the same clock. It doesn't really matter which one's the master and which is the slave as long as they're both correctly set.

For buffer size, the smaller the buffer the more processing power it's going to need and the more chance of drop outs if the computer can't keep up.

For sample rate, a higher sample rate means more processing power is needed.

* Smarter people will correct me / extrapolate later.

[Michael Murray]

Very helpful Drew thank you. Is there any way to repair this audio if possible ?

[Drew Stephenson]

I suspect not unfortunately. You could try running something like Izotope's de-clip module and you might get a bit of improvement - but I wouldn't hold out a lot of hope I'm afraid.

[James Perrett]

Very helpful Drew thank you. Is there any way to repair this audio if possible ?

Only through very intricate editing of each individual section of good audio. There are thousands of sections that would need to be stretched and matched up which would take days (or weeks) of work. I don't think you could rescue it with standard de-click and de-crackle algorithms although they could improve it slightly.

Our lad has been playing around with frequency transforms in Snap! (vaguely similar to mp3 encoding) and the stuff I've heard him playing back has been remarkably good for such a relatively primitive process. So I'd maybe think about taking a Fourier transform of each section and then using those to synthesise a playback signal with the right timing.

However, if you value your time, it would certainly be cheaper and easier to re-record.

[Michael Murray]

Ok so I am going to simply try to reduce the buffer size and sample rate for my next recording session.

Right now I am using a laptop that has kind of just been laying about my house but going forward, I intend on purchasing something a little more robust to handle this issue while still capturing the highest quality audio. Should I just review the ProTools MAX system requirments, I didn't think it was a program which demanded much processing power and especially since I am not running any real time effects.

The other day I recorded a set where the musician had only one dynamic microphone and an acoustic guitar, the issue still occurred. I'm hoping if I just purchase a MAC or something of higher quality than I currently use, I can avoid this type of thing. I enjoy solving problems but I'm not terribly interested in devoting much more energy to this aspect of production.

[Wonks]

I think you meant 'increase', not 'reduce' the buffer size the buffer size.

If you are simply recording a complete live performance, and not recording whilst playing back to existing tracks, you don't need a small buffer size at all. Make it as large as it will go.

[The Elf]

Ok so I am going to simply try to reduce the buffer size and sample rate for my next recording session.

That would be *increase* the buffer size, hopefully!

Also make sure you're using the native ASIO driver (not ASIO4ALL, or similar).

[James Perrett]

Quite a few people in the business use Reaper for live recording rather than Pro Tools. It is very lightweight and even my 18 year old Windows XP laptop can record 24 tracks simultaneously all night without a glitch with Reaper.

[Michael Murray]

Quite a few people in the business use Reaper for live recording rather than Pro Tools. It is very lightweight and even my 18 year old Windows XP laptop can record 24 tracks simultaneously all night without a glitch with Reaper.

I had to purchase a new laptop for my business recently and as a result have got to try running a live recording into ProTools to see if the same result occured. It did.

The feedback issue is even worse this time, in fact it doesn't intermittently resolve so I cannot extract any usable audio.

James, could you provide a link to the Reaper software which you deem is reliable? I think I am a little off put (perhaps unjustifiably) by the appearance of the website I am looking at on my side of things. Maybe I have the wrong link.

[James Perrett]

James, could you provide a link to the Reaper software which you deem is reliable? I think I am a little off put (perhaps unjustifiably) by the appearance of the website I am looking at on my side of things. Maybe I have the wrong link.

You can download Reaper from

https://www.reaper.fm/download.php

Just choose the version that matches your operating system. I'm still on V6.63 but V6.64 should be reliable because it has been out for a relatively long time (for Reaper) - any bugs tend to be squashed pretty quickly by the developers.

I've not used it with an XR18 but I have used it a few times with an X32 for many hours at a stretch with no problems.

[Michael Murray]

James, could you provide a link to the Reaper software which you deem is reliable? I think I am a little off put (perhaps unjustifiably) by the appearance of the website I am looking at on my side of things. Maybe I have the wrong link.

You can download Reaper from

https://www.reaper.fm/download.php

Just choose the version that matches your operating system. I'm still on V6.63 but V6.64 should be reliable because it has been out for a relatively long time (for Reaper) - any bugs tend to be squashed pretty quickly by the developers.

I've not used it with an XR18 but I have used it a few times with an X32 for many hours at a stretch with no problems.

I am on the verge of being done with ProTools based on the amount of problems I regularly encounter that demand troubleshooting. In my mind I conceive of audio signal capturing as an essentially straightforward process but ProTools manages to make it hard for me , but this is what I learned to work with in college audio classes. For example , some of the solutions offered above regarding "clock timing" aren't accessible as the ProTools menu has changed and the solution isn't readily available on the internet...or I'm just not phrasing it correctly. When I attempt to change the clock settings via the session tab in ProTools , it is greyed out and refers me to "See Control Panel" . What control panel ? Windows ? A search within the application itself reveals no Control Panel . I hope that I can have reaper offer me a solution or perhaps Adobe audition , though the latter seems less used in the practice of live recording. Thanks for your assistance.

[James Perrett]

While I would suggest that it would be better to learn the standard Reaper, you can also download Reaper Themes that make it look more like Protools with the Protools keyboard shortcuts also available. It is worth watching a few of Kenny Gioia's videos from the Reaper Video page

https://www.reaper.fm/videos.php#DIuNcKfWx1o

.

[resistorman]

Most engineers I know use Reaper for live recording, particularly on Macs. You can download/ install it and hit record in a matter of minutes, we did it the other night when a band wanted to record off the house XR18 using an old Air.

[Michael Murray]

Most engineers I know use Reaper for live recording, particularly on Macs. You can download/ install it and hit record in a matter of minutes, we did it the other night when a band wanted to record off the house XR18 using an old Air.

Ok so now hear I am at the scene of where I intend to record , new computer and the distortion is even worse ...so it has to be the XR18 itself or a clocking issue ? Do I need any particular drivers installed for the 18 to work ? Because now I'm scrambling a bit and frustrated. I opened up Reaper and when I used the Scarlett at home...everything was fine! Now I'm at work and it is not even showing signal coming in. Again any help is greatly appreciated.

[James Perrett]

I'm wondering if you have set up the routing in the XR18 so that you have a feedback loop from the computer output back to the computer input? Reaper will automatically mute if the signal level goes too high due to a feedback loop.

[Hugh Robjohns]

Do I need any particular drivers installed for the 18 to work ?

No, if you're connecting to a Mac. Yes if its a Windows PC. The Windows USB/ASIO driver can be found in the Software section here:

https://www.behringer.com/product.html?modelCode=P0BI8

The setup is described in the manual (available in the Documentation section).

[Michael Murray]

Do I need any particular drivers installed for the 18 to work ?

No, if you're connecting to a Mac. Yes if its a Windows PC. The Windows USB/ASIO driver can be found in the Software section here:

https://www.behringer.com/product.html?modelCode=P0BI8

The setup is described in the manual (available in the Documentation section).

So this is precisely the link I went to and downloaded the USB driver option , not sure if it's going to work but certainly going to try... What a mess.