Audio level for recording guitar

MikeLV wrote on 2/6/2018, 4:40 PM

I am recording a guitar direct (not mic'd on an amp). The guitar (archtop) goes to a BlueTube DP v2. From there, it goes into a line input channel on a ZED10FX mixer. Main XLR out into my Canon XA10. Regarding audio recording level, the Canon manual says "adjust the audio recording level so that the audio level meter will go to the right of the -18dB mark only occasionally" When I do that, the resultant waveform in Vegas is practically flat, not much volume or life to it. I'm not a sound engineer, nowhere close, just have a job to get done. What is your best suggestion for getting the strongest, clearest signal from a guitar when recording direct in this manner?

If I'm going to normalize the audio, is there an ideal level that the raw audio should peak at?

Thanks for any suggestions on getting a better sound in this setup.

 

Comments

ChristoC wrote on 2/6/2018, 4:58 PM

> go to the right of the -18dB mark only occasionally

that seems a little conservative; I'd go up to around -3dB or so on the scale (maximum) to be safe but still have a healthy level...

MikeLV wrote on 2/6/2018, 5:15 PM

Is it better to record all the way up to -3dB, or record lower and apply normalization to the audio in Vegas?

Former user wrote on 2/6/2018, 5:17 PM

You really want to avoid normalization if possible. Try to get your max level recording. When you normalize you bring up all other noise as well, which will be more noticeable during quieter passages.

MikeLV wrote on 2/6/2018, 5:45 PM

I've just discovered if I apply the ExpressFX Dynamics effect, and choose the [Sys] Maximize volume (-12 dB limiter with gain compensation) preset, it greatly enhances the sound.

ddm wrote on 2/6/2018, 7:59 PM

>>>resultant waveform in Vegas is practically flat

Sounds like you might have the compression turned ON on the camera. Try turning that off, or put the Audio Levels in Manual instead of Auto, if that's the case.

MikeLV wrote on 2/6/2018, 8:46 PM

Just looked through whole manual and I could not find anything about compression in there??

JMacSTL wrote on 2/7/2018, 10:58 AM

Instead of looking for 'compression' in the manual, look for AGC (automatic gain control) or "limiter" or something similar. I agree with @ddm. Turn off anything inside the camera that might be altering the sound going to it. Also, make sure that your camera inputs and your mixer outputs are matched; i.e. mic level or line level. i also agree that you should aim for around -6 to -3db peaks on the recording level (both on the mixer and on the camera's meters...they should match). This gives you some additional headroom if you have a bigger peak, and gives you better signal to noise ratio (since you're recording analog audio into the camera).

Last changed by JMacSTL on 2/7/2018, 10:58 AM, changed a total of 1 times.

jmm in stl

Windows10 with Vegas 11 Pro (most recent build). Intel Core i7-3770 @ 3.40GHz 3.90 GHz, 32GB ram, separate audio and video disks. Also Vegas 17 Pro on same system. GPU: NVDIA GeForce RTX 2060 SUPER. Dynamic RAM preview=OFF.

rraud wrote on 2/7/2018, 1:38 PM

A flattened out waveform is often the result of AGC or too much compression and/or limiting. An over-driven preamp can also be the culprit and the waveform will often be flattened out a regardless of the record volume setting.. which BTW is difficult or impossible to fix after the fact. That said, the optimal record level is as high as possible whist leaving enough headroom so -0.0dBFS is never exceeded (clipping), so as was stated, -6.0 or 3.0 dBFS is a good target level for peaks

MikeLV wrote on 2/8/2018, 9:39 AM

The only AGC I could find on this camera has to do with picture, not sound. And I shoot in M (manual) mode, so that AGC control isn't even available in M mode. Why would Canon suggest shooting a a maximum of -18dB? For all inputs into the ZED, I use the correct level setting procedure (bring input gain up until adequate signal, then adjust output levels to the camera so that everything is where it needs to be). The where-it-needs-to-be part is what's throwing me in the Canon manual.

JMacSTL wrote on 2/8/2018, 11:08 AM

Ignore Canon's recommendation. It might be they are ultra conservative so that people don't end up with distorted audio. From p77 of the manual: talks about 'auto level control' but i see no way to disable that.

Last changed by JMacSTL on 2/8/2018, 11:13 AM, changed a total of 1 times.

jmm in stl

Windows10 with Vegas 11 Pro (most recent build). Intel Core i7-3770 @ 3.40GHz 3.90 GHz, 32GB ram, separate audio and video disks. Also Vegas 17 Pro on same system. GPU: NVDIA GeForce RTX 2060 SUPER. Dynamic RAM preview=OFF.

MikeLV wrote on 2/8/2018, 11:18 AM

Thanks for the clarification. I'll shoot for some higher recording levels from now on.

JMacSTL wrote on 2/8/2018, 11:21 AM

keep in mind that the 'auto level control' may fight you. Perhaps try recording the audio into a separate device and then synching it by hand in Vegas.

jmm in stl

Windows10 with Vegas 11 Pro (most recent build). Intel Core i7-3770 @ 3.40GHz 3.90 GHz, 32GB ram, separate audio and video disks. Also Vegas 17 Pro on same system. GPU: NVDIA GeForce RTX 2060 SUPER. Dynamic RAM preview=OFF.

MikeLV wrote on 2/8/2018, 11:32 AM

I could attempt to output directly from the mixer via USB and record the track into Vegas to see if that makes a difference. In the meantime, here's a snippet of the guitar without any fx processing in Vegas, exactly what was recorded to the camera:

And here's the same clip with that expressfx dynamics effect I found mentioned in my previous post added to it.

Alternative to this FX I found by exploring, based on your experience, what would you do to the unprocessed signal to give the guitar a better sound, more presence, etc, i.e. how you normally hear archtops recorded?

ddm wrote on 2/9/2018, 12:46 AM

http://eyemachines.sarigg.net/wp-content/uploads/2017/01/Audio-Settings-for-Canon-XA10.pdf

Audio settings for XA10, in mic settings, can be in Auto or Manual. Auto is Compressed. Also... -18 for digital audio (-20 really) is pretty standard.

MikeLV wrote on 2/9/2018, 11:05 AM

ddm, with the XLR inputs, i.e. external mic or other instrument, the only controls for the audio levels are the dials, so I'd interpret that to be a manual control. As you can see in the first audio clip I posted, those levels are actually higher than -18 and they're still lame. I'm going to do a test with bumping the level up much closer to -3 and see how it goes.

ddm wrote on 2/9/2018, 11:29 AM

According to the manual (I don't own this camera) the Auto/Manual setting is in the Menu "touch FUNC, touch MIC LEVEL touch A or M" for Auto or Manual. Pretty much ALL cameras have auto audio turned ON by default, so if you've never changed it, it's in AUTO.

MikeLV wrote on 2/9/2018, 11:34 AM

What you're missing is where it says "Using an Internal Microphone or Microphone Connected to the MIC terminal (1/8” jack on side of camera)" I'm not using the 1/8" jack, I'm using the XLR inputs. When you use the XLR inputs, that mic level option is grayed out, can't select it.

rraud wrote on 2/9/2018, 2:04 PM

Most all console's XLR output is +4dB (nominal) line level. (aside from the Mackies, many of which have a mic/line switch) .. so the cam's XLR input must be set to line as well. If the cam is set to mic, that would explain the flattened waveform (severe preamp distortion).

ryclark wrote on 2/10/2018, 6:51 AM

Your first example of the direct recording sounds pretty OK but, as you say, could possibly be a bit higher in level. You can always try turning on the Normalize switch on the audio track in Vegas to optimize the level though.