Mix and Master: Fixing Flaws

[rocksure]

Got a few problems to Iron out in your mixes? Well you have come to the right place : " Tone's She'll be right mate, just give em earplugs" school of audio engineering, where we think the problem is all in the minds of the listener.
Nah seriously, no one wants their mixes to be substandard, so here are a few tips I hope will help to give them a bit of a hand up. Firstly, it's best if you don't have any flaws that need fixing by the time you get to the mixing and then mastering phase of your project. Avoid the "fix in the mix" attitude. A well recorded song is always going to sound better than a poorly recorded song, no matter how many "fixes" that you attempt to apply later. So try to use good quality equipment, good technique and good settings etc when you record. Aim to capture the full range of frequencies of a voice or instrument, as it is easier to attenuate them later than to try to add what is not there. Following that, if any problems do emerge, try to fix them on a track by track basis, rather than attempting to fix them once you have a 2-track mix. The earlier you can deal with things that are potential difficulties the better. I will have a bit of a run through a few of the potential hazards that might trip up all you well-meaning engineers.

DC Offset
Cheap soundcards or recorder inputs often add a DC voltage offset to a recorded sound. This is at 0 Hz, which we can't actually hear, but it offsets the wave so that it is centered above the zero line. This means you have less headroom before clipping occurs. Check out your tracks, and if they look like the wave is not centered around the zero, then you need to filter it. Or if when you were recording, the meters were reading even when you were not sending them any signal, that may be a giveaway. Most recording programmes have a function called something like "remove DC offset". Use it if the problem is evident. But do it prior to any compression or EQing. It should get rid of any offset.

Hums and Buzzes
It is very easy to get hums and buzzes in your audio, especially from things like guitar amps. Try to avoid them during the recording process. Check your cables, experiment with different proximities and angles of the guitar in relation to the amp. Use balanced cables where possible, and avoid long runs of unbalanced cables. Also try to avoid having power cables and transformers near audio cables. Keep them at least a foot (30 cm) apart, and if they must cross, try to do it at right anges, and better still sit the power cable on something above the audio cables so they don't touch. Hums can be dealt with by some programmes and plugins such as The Waves X-Hum, but it is very difficult to remove buzzes from a recording.

Hiss and white Noise
Hiss is often a result of incorrect gain settings when recording. Maybe you had too small a signal, and the gain set too high. Perhaps you just have a noisy piece of equipment. Whatever the cause, use your denoiser, dehisser or noise removal plugin, or programme function before you compress or otherwise tamper with the audio. If you compress before you use noise removal, you will likely be boosting the noise along with the signal, but if you remove the noise first, the compressor won't find any noise to boost! Higher settings on these programmes or gadgets often seriously mess with the signal and change the tone considerably. Try to avoid using them if at all possible, try mild settings first

Clicks and crackles
These problems can be a real bane of digital recordings at times. Some suggestions I can offer in avoiding them are as follows:
Defragment your hard drives to ensure the computer runs fast enough to keep up with the demands.
Adjust your programme's buffers to avoid clicks
Use the latest drivers for your software
Use crossfades at edit points
Avoid clipping any equipments inputs while recording
If you are unfortunate enough to get clicks in your mixes, use your programme's or plugin declicker, but try to get as close to the area of the waveform as possible by cutting the region either side of the problem area, and selecting just that small area of the region for processing. Sometimes you can manually remove clicks by re-drawing a wave, with the pencil tool supplied in the software.

Using a de-esser
Here is a useful tip I discovered a while back. Sometimes I found it hard to get enough headroom in my vocal recordings to cut through a mix. There would often be short unexpected transient peaks that would shoot way above the rest of the signal, and into the red zone. Now, I could have used a compressor or a brick wall limiter to squash these hard, but I discovered that they are often just centered around one frequency band, and most likely in the 6-8 khz range where the sibilance of an "S" sound resides. By using a de-esser, I not only made the "S" sounds less harsh, and more pleasing to the ear, but I found I now had much less problem with the transient peaks, and was able to boost the level of the vocals up more before clipping occurred. Kind of like killing two birds with one stone.
This technique is not only limited to vocals either, but frequency dependent compression using a side chain or a de-esser can also be applied the same way to such instruments as an acoustic guitar.
Well I hope these tips are of some use to you in the mix or master process, I am getting RSI from typing, so I might call it a day for now.

[brandondrury]

So try to use good quality equipment, good technique and good settings etc when you record.

This is technically correct, but I don't think it hits the point nearly hard enough. I prefer to say "There is no such thing as fixing". If you have to "fix" things in the mix, you completely screwed up while tracking. There is no reason why you can't get EXACTLY what you want while tracking.

Mixing is for creative purposes. If Mixing was the process of "fixing" tracks, they'd simply call it "Fixing" instead of "Mixing".

[richiebee]

Originally Posted by brandondrury

This is technically correct, but I don't think it hits the point nearly hard enough. I prefer to say "There is no such thing as fixing". If you have to "fix" things in the mix, you completely screwed up while tracking. There is no reason why you can't get EXACTLY what you want while tracking.

I don't agree with this. The limitation of your equipment, space or performer can be just as much at fault as your skills as a tracking engineer.

Is your boxy sounding drums because of poor mic placement or simply because your environment WON'T allow you to create a good sound?

We're not in multimillion dollar studios (even recording in my $1.8m concert hall is not without serious issues). We have to compensate after the fact.

[brandondrury]

Is your boxy sounding drums because of poor mic placement or simply because your environment WON'T allow you to create a good sound?

This is a legitmate issue. So how does one "fix" this in the mix? Granted, you can cut out 400-600Hz, but EQ isn't really the ideal cure. I usually end up cuting this frequency even when drums are recorded in great rooms. I'm of the opinion that if the room simply won't allow you to create a "good" sound (which we'll define as the sound the artist is after that best fits the song) then a person either has to settle for substandard results or take a more creative path in achieving it.

I'm convinced that I can not get the drums I want in the room I have in my home. So, I either use DFH or we go to a room that can get us what we want....or we don't do the record at all.

It's different for various instruments, but my favorite example of this is when recording rock and metal distorted electric guitars. There is no way to fix a crappy guitar sound that I've ever found. Ironically, if the amp sounds killer any idiot can slap up a 57 and it will sound great. Some of my best guitar tones have been recording live bands in the studio where I didn't have time to really mess with the amps or mics...we just had to hurry up and go for it.

We're not in multimillion dollar studios (even recording in my $1.8m concert hall is not without serious issues). We have to compensate after the fact.

"Compensate" is one thing...."fix" is another. I'm not sure what Webster's dictionary says, but "fix" implies that we can restore something broken back to acceptable states. I'm just not aware of a situation where this has ever happened to me. (Maybe others have gotten lucky).

In record to your huge concert hall, which you've mentioned in the past can get "out of control", are you better of using an EQ or compressor at mixdown or putting up a gobo?

I'm aware that there is a time where we all have to compromise. It takes a real badass to get what exactly what he wants each and every time. However, a person who understands that 99% of the sound of the recording is already determined long before the mic, preamp, compressor, etc are entered in to the equation is a person who stands a good chance of recording a kick ass record even with unideal circumstances. In unideal circumstances, this person is going to setup blankets, move absorbers, or move the musician around to deal with problems until he gets what he wants.

The other side of the coin is the guy who thinks that he can fix things in the mix ends up with substandard tones and really can't do anything about it but use EQ, compression, etc. There are no plugins for making a musician more proficient. There are no plugins that really remove acoustical problems. There are no plugins that fix crappy songs or poorly arranged songs.

When these tools come out, my point will be mute.

Brandon

[rocksure]

It is great when there are no things to have to "fix in the mix". That is what we should strive for when tracking, but in the real world sometimes we can find things are less than perfect and may need a bit of work later. I have had to try to fix some terrible sound issues recorded by other people who then ask me if I can "fix" things. If the performance was great but the sound is imperfect, I would rather try to improve what's there than get them to re-record something. Anyway sometimes that's just not possible and we have to use what's there because there is no other chance to redo it. Less than ideal for sure, but so is life in general.

[Baron]

Originally Posted by brandondrury

There are no plugins for making a musician more proficient. There are no plugins that really remove acoustical problems. There are no plugins that fix crappy songs or poorly arranged songs.

When these tools come out, my point will be mute.

Brandon

Sorry Brandon but you must learn to keep up with the times:
http://www.rane.com/pi14.html




Cheers
Baron

[brandondrury]

Not a bad unit, but it doesn't have what I need. I've had multiple bands ask me to "turn down the sucks and up the rocks". Maybe in time.