Ha! That old "chestnut..."
 
Well, I'm sorry, but I still got a million and one questions about Mixing and it's doing my head in. I could carry on as I always have, doing what I think is right, and hardly anyone who bothers to listen to my music would know that I have "issues."
 
Those "issues" are currently being stirred up, in the nicest possible sense, by some recent topics on related subjects in the Techniques forum. I feel the need to take on board, as much as I can, everything that is being said by those much more experienced than me. So, I am going to raise some question in this topic, just to put stuff out there, and see what comes back, if anything.
 
And I am only talking about MIXING here. I rarely record any more, and if I do it's just my PRS DI'd via my MMP-2, and I'm experienced with that to know what I am doing. And Mastering is also a completely separate subject, which I do not wish to discuss here.
 
So, I'm currently trying to mix a project that has been made available as part of a mixing competition. There are a number of wave files plus some MIDI files, but I am only going to be discussing the wave files here. The wave files appear to be a combination of real recorded instruments and VST instruments, and it's not entirely clear to me which is what, but I guess it doesn't matter.
 
The first part I wish to deal with is causing me a couple of headaches.
 
Here is a screenshot of the wave file in SF10:-
 

 
In my opinion, this wave file peaks for too low. However, in Sonar, it doesn't sound too bad and I can use a number of ways to bring it up to a reasonable level.
 
If I leave the gain control at zero, and place an instance of SPAN in the FX bin, I get this:-
 

 
The wave peaks at -27.1 dBFS, with a RMS level of -53.7 and a Max Crest Factor of 9.5
 
CREST FACTOR
 
And it is at this point that I have to stop and ask a question about Crest Factor.
 
I thought that Crest Factor was the difference between the peak level and RMS level measured across the sample time. So the "math" doesn't appear to work (54 - 27 = 27, not 10), so I must be missing something. Perhaps I don't understand SPAN correctly, and I've searched the internet for more info about Crest Factor and SPAN but I can't find anything that helps.
 
Perhaps is has something to do with the fact that this is a percussive track and therefore I should not even be thinking of Crest Factor at this time. Should Crest Factor only be considered when dealing with a complete mix?
 
I'm going to hit "Submit Post" now because this is getting too long. I am going to add separate posts in this topic with more questions, rather that try to ask everything at once in the OP...
 
cheers, and thanks for your patience,
 
andy

USING SPAN AS AN INPUT METER
 
Another thing I want to ask about is metering. Much has been discussed about using VUMT, by Klanghelm, which I own. But I am having serious problems getting up to speed with interpreting what I see. I understand some of the simple basics, but I cannot, for the life of me, discern anything useful from a ballistic needle.
 
I need a quick fix, because, although I am not working at the moment, once the "market" picks up again, I will be back to my "day job" and therefore my musical endeavours will go back to being on an ad-hock basis. So I simply do not have the time to get up to speed with VU meters.
 
I've had SPAN for some time, and I have recently made an effort to learn more about this tool, which is more than just a Spectrum Analyser.
 
What I like about SPAN, is that, as well as graphs and meters, it gives me numbers, and I like/need numbers.
 
My question to the experienced chaps here is, am I going to do okay working like this, or am I heading for some unforeseen pitfalls?
 
Everything I need appears to be there... I can see the meters going up and down. The peak is held for a moment so I can see any momentary. And if I miss something there, there are numerical values for Peak and RMS levels that are held until reset.
 
I look forward to some feedback on the above, but in the meantime I am going to continue along this rocky path and try not to fall off the edge...
 
cheers
 
andy

Hi Andy...I'm not a "pro" I don't mix other peoples work...although I'd be happy too...if they would pay me...as The Beatles were asked on their first press conference in America: "Can you sing something?"..."We need money first" was their answer. But I will give you an answer as best to my ability.
 
Ok here is the crux the screen shot you posted...on looking at it I would say it's too quite but and here is why mixing is a dark art and every one will give you a myriad of answers if the part is suppose to be soft then it's probably fine...remember there is no supposed noise floor in digital...meaning if you have to turn the channel up so it's even with the rest of the mix then you can because there should be no hiss...in theory anyway.
 
I'm not sure what sort of track your mixing i.e. pop, rock dance ect...but there are many standards to adhere to when aiming for levels...for classical -18db RMS or even -20db...this is before mastering...rock -12 to -15 dance -12 so you can see what I am saying...yea??  So in setting up a mix...your trying to even out what your mixing...so if it's a soft track just keep the levels gentle -18db RMS...but lets say the track has over 20 tracks all playing at once...when it hits the master buss the accumulated sound would still go above 0DB peak on the master buss...I've got a little chart somewhere...I will try and find it...so how do you fit those 20 tracks in plus effects buss's ect.  The boffins would say turn the faders down till everything fits...that wave file you displayed then looks pretty good...doesn't it?  If your just going to turn everything down anyway but that's only half the story.
 
This is where it get's tricky...you see it took 40 years to understand how to record to analogue tape...it was just after 1945 when Les Paul and Bing Crosby using tape technology invented by the Germans created the first multi-track recorders 4 tracks mind you...Bing and Les invented home recording...but if you listen to anything recorded to about 1965...it all sounds pretty meh...IMO...it wasn't until The Beatles...Queen and Pink Floyd (Hendrix too) and their respective engineers and producers took the ideas of The Classical Avant Garde and transformed them into what we know as popular music...although the term had been coined to describe Bing and Frank 20 odd years before...my point the pinnacle of analogue recording art is probably Bohemian Rhapsody...so 40 years to get to there.  The first digital recording...was done one year later...if I remember correctly and was a classical piece...16 bit lol...I bet it sounded pretty ****e.
 
So what we have now is a lot of old school analogue engineers trying to fit analogue techniques into the digital realm...and in all fairness some of those techniques transfer but mixing in digital is a totally different beast...and even 15 years ago...when I started those old school analogue engineers were still right...the technology has come a long way...DSP was once a must...gone!! 32bit has morphed into 64bit and as I have mentioned in a previous post 64 bit is I think 192db dynamic range...massive.
 
Ok what does all this have to do with mixing?? Well for one it means once inside the box...in theory you have enough head room to clip internally and there is a lot of debate about this and also emulator plugs because in theory (you see I use the term theory a lot because that's my profession...I deal with theories) each plug has a sweet spot...some of those sweet spots were when the equipment was pushed into the red...hence why I say it does not matter about internal clipping of 4 or 5 db over...and again when you level the mix your only clipping internally in the plug...not the actual channel...yea??
 
So and I know this is the long way around...the file you posted a screen shot of could be fine or it may not...think of mixing like baking a cake or painting a picture...the "pros" wont like that...they prefer hard science...hence most music these days sounds boring...when you mix...your trying to even each channel, each buss and each effects buss so you don't have to move the fader to far...in theory...again...moving the fader (someone might need to correct me on this-I don't know everything lol) too far down effects the resolution...I think that's the theory.
 
So look at this way...if you want a big pounding mix in your face...like the stuff I've posted and please tell me if you think there is any problems with the mix...besides the tube crunch on the vocals...I know the mixes aren't perfect...but they are about where they need to be IMO but if you want a big pounding in your face mix...you mix hot, then you turn the gain stage down to fit the mix in.  This is why Sonar is such a great program...it acts like a real ****ing mixing desk...one of the things we were taught in Audio School albeit in the live course is don't touch the faders...use the trim...I think it had to do with resolution-it might have been something else (again correct me if I'm wrong)  but if you want a soft mix or a dynamic mix or a classical mix you set the gain stage up on the channels accordingly (hence the reason why your pic may be right it may be wrong) and I would still bet you would have to turn the gain stage down on the master buss but it would be a soft or gentle mix...you would not use huge amounts of compression or try and hit -12db RMS on the master, which all the mixes I've put up so far are...you could even have the master some what natural-as long as the mix was adhering to certain standards.
 
Ok have I answered your question Andy :)
 
Ben

BenMMusTech
Ok have I answered your question Andy :)

 
Hi Ben,
 
Thanks for all that.
 
Yes, you are answering some, and perhaps most things I am thinking about at the moment.
 
That sample is a shaker, so is high-ish frequency and I am panning it 40% left, with a similar instrument, tambourine, 40% to the right, so they are currently complementing each other.
 
What I have ended up doing is raising the gain knob to 14.4dB but then dropping the volume fader back by -7.4 dB. Which sounds a bit weird to me... I could have just raised the gain knob to 7 db and then moved the volume fader by much less. But that was just how it worked out.
 
I basically turned the gain knob to 14.4 dB in order to get a "reasonable" level at the first effects plug-in, which in this case is an EQ. The meter in the EQ plug is peaking at around -12 dB. Now, I'm only going off what I'm reading elsewhere, that you don't want a "hot" signal going into each plug-in, so I'm reckoning that -12 dB is okay.
 
But then that level going into the Master Buss is too high, when it is mixed with all the other bits and pieces. By ear that is... One thing I will say is, I still use my ears, as bad as they are, to judge how loud each element should be in the mix, and then I use SPAN to decide if the whole mix has too much bass or top end.
 
As for the project that has been causing me much angst... Well... I've finished it. As best I can anyway. There are issues, for sure. By the sounds of it, some of the other peeps are mentioning automation, which I am assuming is either clip gain, or volume fader automation. I'm not bothering with that at the moment... It's difficult enough getting to grips with all the gain staging stuff haha.
 
Once I have posted my efforts on the competition forum I will post a link here, if you are interested.
 
cheers, and thanks for you input Ben,
 
andy

To quote Span's user manual:

"The “Max Crest Factor” indicator shows maximum crest factor (difference) between the RMS and peak RMS values reached. Peak RMS value is not displayed anywhere on the user interface. 50 ms time window is used to estimate the peak RMS value. You may add the “RMS” and “Max Crest Factor” values together to obtain a peak RMS value."

It's perhaps a little misleading when it talks about crest factor being the "difference" between RMS and peak RMS. Crest factor is the peak amplitude of a waveform divided by the RMS value of the waveform. It's a measure of the ratio of peak to average (RMS) power expressed in dB.

In the real world it's something that can give you an idea of how much the RMS varies and therefore the perceived dynamics once the human ear/brain combination has done its stuff. In the really real world of music mixing and production it's pretty irrelevant for mixing purposes unless you consider mixing as an exercise in mathematics to make a mix match some arbitrary standard of what a mix should look like in Voxengo Span while ignoring what it sounds like.

Just use your ears.

As for gain staging, the input gain on a channel is used to do several things, and the use is similar in analogue mixers and DAW channels. Analogue circuitry and plugins alike tend to work best with an input signal of sufficient volume to place them in their operating range but without overloading them (unless you want to).

Audio tracks in a DAW can be thought of as an output from a virtual tape machine. The channel input gain is there to make sure the initial volume of the audio is where you want it as it enters the channel. The channel fader is there to set the level of the audio as it exits the channel.

Let's say you've decided to use a compressor. If the audio going into it is too low it will be difficult to get the compressor to do much at all because the signal won't exceed the compressor threshold sufficiently if at all. So the channel input gain can be turned up to boost the signal into the compressor. If you then left the faders alone and tried to mix purely by the channel gains in that kind of very common scenario every time you altered the gain the action of the compressor would change because the signal it is receiving is going up or down. So you'd end up continually having to reset every processor on every channel every time you tirned a channel up or down.

Hence the presence and usefulness of output faders.

For what it's worth I personally tend to use channel gain to make sure that following processing is working as I want while not pushing anything into the red. A final channel output of around 12-18dB with the fader at zero is fine unless you have very few tracks because once you start summing into sub-groups or the master bus if the channels are too hot you end up having to keep turning everything down to prevent the bus overloading.

As always the final decision should be to go with what sounds best.

i've been talking about 'crest factor' for a long time.
 
 
no body listens.
 
LOL

Hiya Tim,
 
Thank you for your words, I am reading them thoroughly and doing my best to take everything on board, as always 
 
Thanks for pointing out what the SPAN manual says. I had missed that.
 

tlw
It's perhaps a little misleading when it talks about crest factor being the "difference" between RMS and peak RMS. Crest factor is the peak amplitude of a waveform divided by the RMS value of the waveform. It's a measure of the ratio of peak to average (RMS) power expressed in dB.

Yeak, Tim, I found a wikipedia article about Crest Factor and it does say there that it is a ratio, which is what I expected it to be. But then I found other articles that talked about Crest Factor being a "difference." As per usual, the info on the interwebs can cause more confusion amongst noobs like me.
 
This SOS article is one I found that states Crest Factor is a "difference."
 
https://www.soundonsound.com/sos/sep11/articles/loudness.htm
 
By the way, you still say that it is expressed in dB, but if it is a ratio, shouldn't it be unit-less?
 

tlw
Just use your ears.

But this is the problem I have, in that, I cannot trust my ears any more. I use headphones to mix on, so that challenges my bass perception, and I am totally deaf to anything above 14kHz. So I use SPAN to compensate, and when I can, I listen to a mix on a hi-fi. Only on rare occasions am I able to dig out my Tannoy Reveal nearfield monitors.
 

tlw
Let's say you've decided to use a compressor. If the audio going into it is too low it will be difficult to get the compressor to do much at all because the signal won't exceed the compressor threshold sufficiently if at all. So the channel input gain can be turned up to boost the signal into the compressor.

Yep, Tim, I'm with that. I've found that some plug-ins have an input gain themselves, so I'm assuming you can use that control instead. But, as I mentioned in my last post, I'm now getting into the habit whereby I am boosting, or even cutting the channel input signal so that the next effect is getting around -12 dB peak. Perhaps that could go up to -6dB? 
 
Bottom line is, I think I'm getting there. Again... I thought I'd got all this sussed a couple of years ago, but my brain cells are deteriorating as I type 
 
Thanks again for your write-up there Tim, I appreciate the time you have put into that text 
 
cheers
 
andy

batsbrew
no body listens.

 
It's all your fault Rob, because I've been listening.
 
And I'd noticed the Crest Factor value in SPAN, so when I read one of your other posts I decided to look more into it.
 
So, thanks 

and here are some more things to blow your mind:
 
 
http://thewombforums.com/showthread.php?10454-An-Interesting-Excerpt-On-L-C-R-Mixing
 
 
 

That's a great article Rob. I've not read it yet, just scanned the first paragraph. 
 
I've bookmarked it for future 
 
Thanks for sticking your head into my Rather Protracted Discussion About MIXING, which is probably now not going to be quite so protracted, I hope...