Fixing Phase problems


Recently I have noticed that there have been a growing number of searches coming to my blog that relate to fixing phase problems. Although I have mentioned the importance of phase in recording I do not believe that I addressed fixing phase problems.

Ok let’s get started.  You have a multitrack recording and somewhere there seem to be phase problems. Are you sure? Probably not.  Let’s review for a second.

Phase is caused by two or more microphones being used on one item that you are recording. In some cases the varying distances between the mic cause the sound waves to line up peak to trough and this means they are out of phase.  If you are in the process of recording this sound then you fix the problem by moving the mics around until the sound falls into phase.  Also it should be noted that EQ adds phase problems to any signal it is used on. This is an absolute as far as I am concerned although I have been corrected by engineers on this point they are wrong and I am right damn it. If you add EQ it adds some phaseyness. Usually this is acceptable and part of the sound. Sometimes too much EQ makes a thin phasey mix.  How do you fix this problem? Drop all of the EQ it’s that simple.

The most common situation for phase problems is recording multiple tracks of one particular instrument on one pass. When do you do this? Every time you cut drum tracks. So let’s assume that you cut four simultaneous tracks of drums last night and know it’s time to mix and damn it sounds out of phase.

The first thing you do is prove it to yourself. Drop every track except one. Now listen carefully. Does the track sound fat? Does it have bottom? It does, ok move on to the next track. Most likely all of the individual tracks will sound fat and have bottom. Now start putting up combinations of tracks two at a time. One you happen upon one combo that sounds thin, phasey and has no bottom mark it down and move on.  There may be multiple problems. Sometimes, but not usually the problems may be between two tracks recorded at different times.  Remember listen closely.  You are looking for thin sound with no bottom. If you are unsure what phase problems sound like put up a track and then switch the positive and negative wires on your studio monitors. Step back away from the speakers and play the track. That’s the sound of a phase problem.

So now you know what phase sounds like and you have two or more tracks that are definitely out of phase with each other. Can you rerecord? No ok then let’s fix it.

In all likelihood the sounds are not perfectly 180 degrees out of phase. They rarely are.  It doesn’t matter. If it is enough of a problem to be heard as out of phase correcting the phase will help.  In short what you need to do is reverse the phase on one track and then listen. Does your board or software have a phase switch? If it does you are all set. Switch the phase on one track , it doesn’t matter which, and then listen to the offending tracks. When it comes into phase you will hear much more bottom and the thin wavy quality will disappear. If you have more than two tracks at issue you may need to mess around with various combos of phase switching in order to find the best phase situation.

What do you do if you don’t have a phase switch, which is common with many boards. Does the board have an insert section with paired plug ins/outs? In this case you take a cable open one end up and cut the two or three wires. Switches the connections on the positive negative. Now use this cable to flip the phase on the individual channels. Use the same process I outlined above.

What do you do if you have a board with no phase switch and no insert section? Shot yourself? No, calm down.  Try doing the same trick with a basic guitar cable. Then send the sound out of one channel and record it on the next open track with the phase reversed.

Now I will address the more complex method since someone that thinks they are smart will certainly post a comment about it. I may even decide to approve said comment if it contains a good joke or the new home phone number of my high school girlfriend.

There are phase relationship altering outboard and inboard equipment. They allow you to dial the phase around 180 degrees. They are magic. Let an engineer run them, preferably an engineer that would never record two tracks out of phase.

Finally I’ll talk about phasing in a mix. A depressingly common problem is a mix that sounds shitty. It sounds muddy, or phasey or both. How do you fix this? Well if you are trying to fix a mix that is done and is a stereo master than take it to a good mastering house. If you are trying to fix a mix that you are working on then there is still hope.

Let’s say you have a home studio. You do a mix. The next day you take the CD of the mix and pop it into your car stereo and, jeez, does it sound like shit. Don’t worry everyone does shitty mixes. It’s only a problem if you release it  to the world.

Ok try this. Put up the mix. Eliminate every EQ that is engaged. This alone may solve your problem. After you remove the EQ’s the sound may very well clear up. Try running a mix with no EQ on anything just rebalance the tracks and call it a mix. No compare the two. Which one sounds better? The most common problem I have seen in mixes is too much EQ. If this doesn’t help the mix try adding the tracks one at a time listening specifically for the phase problem to appear. When you find the offending track strip it down to the basic track without effects. How’s that?  If it isn’t caused by some kind of outboard effect then the most likely problem is that the offending track(s) sound too good. What!!??? That’s right. A common problem with recordings is that every single track is recorded as if it the only track on the recording, that is to say tons of bottom, tons of mids tons of top. If you do this on every track then the mix will sound like shit. Remix engineers make great money taking multitrack tapes and removing various frequencies in order to make them sound clearer.  Try removing a little bottom from a few tracks with the eq. Try cutting some of the mids. EQs are much more beneficial when used to remove frequencies then when they are used to add frequencies……..

© Brad Morrison/Billiken Media 2013

How to create a final mix (pt 2)


So now we move on to adding the effects, compression and fader moves to your mix. I am assuming that you have read and understood part one. You have your mix up and running and it sounds completely balanced with drums, bass, guitars and vox. Now it’s time to add in all of the other ear candy such as background vocals or car crashes – whatever is left. As you do add elements find their proper position in the stereo field first, then find their level. This is important. If you set level first and then pan it somewhere it will be very hard to achieve balance.

This is the point where you sit back and think about the mix. Does it feel right?  Too dry? What does it need? This is the point where you may decide to add effects to instruments to achieve particular colors or atmospheres. Don’t add reverb to the vocals because all vocals have reverb. First this isn’t actually true and second it should be added in an attempt to achieve something particular.  Over the years I have spent endless hours screwing around with effects at the demand of musicians, all of that time was wasted. It rarely comes out better. On the other hand when a musician has something in mind you can quickly move towards a better mix. For example the singer might say “the vocal needs to sound more lonely”. Well that might seem vague but it gives you somewhere to go. You might add a small room reverb and pan the instruments slightly away from the vocal so it seems like it’s by itself.  By contrast the guitarist might say “the solo needs to sound grand, like a choir or something” . This leads you to push it back in the mix and add big church reverb. Most musicians understand how things should feel. They all use different terms to describe these variables. You need to take the time to understand what they mean by “it needs punch” or “it has to rock more”. Everyone seems to use these kind of terms differently. if, on the other hand, the drummer says, “I wanna sound like Bonham on When the Levee Breaks remind him that he plays like a pussy, Bonham was no pussy and that he still owes 9 bucks for last night’s food. In short ignore him.

Now is the time to think about EQ changes. Does the bass lack bottom? Is the vocal dull? When you identify a problem like these two attempt, at first, to remove things from the mix to see if the problem goes away. The most common problem that I have seen in mixing is caused by each individual element having too much top, bottom and mids. When you put it all together it makes mud.  THIS IDEA IS IMPORTANT. LEARN TO THINK ABOUT IT!

All of the great remix engineers spend most of their time removing frequencies from tracks to achieve clarity. Muddy mix? Take things out.

Now this doesn’t mean you need to lose the guitars. Instead you may need to EQ them and remove some well-defined frequencies. As you rebalance the mix and add in effects be careful to carefully remove bits and pieces of the different tracks frequency spectrums to allow other elements to shine. If you follow the rookie system of adding top and bottom to every track as it enters the mix you will end up with mud that smells of shit. I guarantee it.

Another important point about effects. Less is more and whenever you add reverb to a track it makes that track LOUDER. That means you must lower the dry track and add the reverb return track. Then rebalance the two elements, then rebalance the whole damn mix. If you put effects on everything then the mix will become an insoluble rubic’s cube. So don’t do that.

Next element to consider is compression. I am a big fan of compression. It makes tracks flatter dynamically and as a result adds detail which makes them stand out in the mix. It also controls big jumps in volume (very useful on vocals). This allows you to get a balance that continues throughout the whole mix. Again, if you compress a track you need to rebalance the mix.

Often I will run the mix through matched compressors to flatten the whole mix and make it all sound louder.  In this case both compressors must be the same with one unit “slaved” to the other so that only one set of controls runs both units. If you know how to do this and have two nice matching compressors give it a try. If not it’s best to leave this to the mastering engineer.

One final comment – always listen to the mix on as many different stereos as possible before deciding it is done. Play it in the car. Play it on your iPod through your girlfriend’s clock radio, play it on your kid brother’s karaoke box, play it anywhere that is a challenge. This will show you what needs to be changed and will show you how it will be listened to by your fans. Remember, no one is going to listen to your mixes on a studio rig so get used to it and mix it so it sounds good on ANY system……….

©Copyright 2011 Brad Morrison/Billiken Media