Principles of good audio mixing
 

I am mixing down a live concert, sources are 2 house ambient mics, one house rear center (pa's and crowd), one house front pointed back at crowd, and two coming off the PA, one ducked down a little bit to prevent clipping if the mix got too hot.

I tried google-ing for a tutorial or more info but didnt have musch success. I guess what I am looking for is some pointers on EQ'ing and balance, a sort of primer of good mixing techniques. So far I've just kind of hacked away at them (both live concerts and other projects) until they sounded right, but I know that like video editing, there has to be some basic rules or guidelines hat can help you establish a decent mix.

Of course, in video editing, I break the rules when it works, I'm sure audio is the same way.

I am doing my mixdowns in Soundtrack Pro.

#1 - Accurate reference monitors in a good listening environment. Without this, you really don't know what you have recorded. Consumer speakers are designed to make anything sound good. Reference monitors are designed to reveal exactly what you're mixing.

Eg., many consumer monitors enhance bass and high freqs. If you dialed down your bass and high eq. you'd be compensating for the monitors, and would have a mix that emphasizes mid-range. Many television speakers enhance mid-range - your mix would sound too harsh. Some consumer monitors are light on the bass - your mix would sound as if it had none.

Search this forum, there are lots of posts on reference monitors. Maybe you've already got this covered.

#2 - as a general workflow for what you've recorded, I'd start with the board mix. Choose the hotter mix (if it didn't distort), and eq until it sounds right, with all instruments well represented.

Sometimes, especially in smaller venues, some instruments don't show up much in the board mix. For example, an electric guitar that has its own amp on stage. The bass drum that everyone hears without any reinforcement.

#3 - I think next you'd want to bring in the house rear center ambient mic to a level that sounds natural, that it gives you a proper sense of space. This may also help to fill in any holes in the board mix.

#4 - if at the end you're still missing some instruments, see if the house front ambient mic has anything useful. What kind of mic was this?

#5 - if there are still instruments you can't hear well enough there are some other ways to emphasize them. Narrow EQ. Multiband compression (this is advanced technique!).

#6 - if your editor has any mono-to-stereo tools, this is the time to try them out!

I need to get some reference Monitors.....in the meantime is it fairly safe to mix in some mdr-7506 headphones?

No. You can hear things your audience won't hear. Headphones can be useful for things like noise reduction where you want to hear everything. But for mixing they can get you in trouble.

I guess some maudio mx5a's are gonna get ordered from bh then!

Don't just get any monitors...they are not all the same. You should listen to different ones before making a purchase. Go to places like Guitar Center or Sam Ash if you have one close by to really hear the differences. In addition...studio monitors are not intended to sound like a hi speaker..The flatter the response the better. When I purchased mine I brought with me a cd that I knew with back of my hand and also made a cd with just sound effects because this way you can hear the differences when editing video as well as audio mixing.

I'll second Cary's advice. Monitors aren't just any speaker. You need to give some very careful auditioning of various models you're considering by A/B comparison listening to material that you are intimately familiar with and also to pay careful attention to the acoustic condition of your workspace. This is one of the areas where you simply cannot shop by price. Yes, we all have budgets but you have to look at other criteria in the decision making process. Start with some monitors that are absolutely beyond your price range and A/B them with the next step down. Keep going down the chain until you lose the ability to hear the details in the portions of the tracks that are of importance and the colouration introduced by the monitors starts to become apparent. For example, when I did that approach, I found some highly regarded KRK monitors were artificially harsh in the high end and had muddy bass while Mackie 8" didn't have anywhere near the ability to clearly detail different instruments in the mid-range as well as did some others from DynAudio and Adam (that were admittedly over double the price of the Mackies). Doing this patiently over several sessions will allow you to eventually narrow the search down to the monitors that will best let you evaluate the materials you are working with and still be within your budget. I've gone through this process personally over the last few months and eventually narrowed it down to a pair of JBLPRO LSR4328p's. Had settled on the 6" but got a deal on mint condition demo 8" that had only seen a couple of days service with the JBL sales rep in a demo 5.1 setup in a major studio's post facility and carried the full manufacturer's new speaker warrantee.

My experience with JBL LSR4328p's are as follows.
My mixes translate well into other studios and sound stages,
for less money then the Dynaudio BM-15A's I originally wanted.
They lack a little on the bottom end, so I added a sub to fill out the sound.
All in all a good monitor for the money.

1) Start by Normalizing your tracks and removing the DC offset.

2) Remove that which is bad. Use a spectrum analyzer and a good set of monitors to identify offending Frequencies. Don't over adjust an individual frequency +/-3db (phase problems). Use parametric EQ.

3) Enhance that which is good. Punch the EQ where it needs it. Mild compression...and reasonable amount of FX.

4) Listen to your final mix in different play-back invironments to hear how it translates.

I was thinking about getting the JBL LSR's pretty soon. Where did you find the best deal on them? Also are you using the SPDIF inputs or the analog inputs? If the SPDIF...do you control it with software or like any other digital output in your DAW? Does the Room Mode Correction make a huge difference to your ears? These are questions I've been pondering. Thanks for your input...pardon the pun.

I got mine at Resolution Pro Audio in Toronto - that won't help you much since I see you're down in the States. B&H and Full Compass both carry them. As to your other questions, I'm still setting them up - have to rearrage my workarea so I'll have to defer answering until I've had 'em in use for a while.

I'll look forward to hearing your review.

Something else to consider is the difference in phase of your various sources. The individual room mics and the mics on the stage (board feed) will have each captured the sound at slightly different intervals in time. The way these sources interact when mixed together may produce unwanted effects such as a reduction of certain frequencies or a boosting of others, as well as an overall smearing of the sound stage. Many times these phase differences aren't as obvious when listening in stereo, but become amazingly apparent in mono. If at all possible, the room mics should be used for crowd ambience only and the board feed used to supply the main mix. However, as a previous poster pointed out, if the venue was small, the board mix may be lacking some of the louder instruments as heard from the stage. If you need the room mics to accurately represent the performance, and you run into phasing problems there are a couple of things you could do, depending upon what app your using. Sliding a track forward or backward a few milliseconds will often help if you encounter phasing problems.

-John

Of course, knowing what rules you can break and when is what you are now learning. Please let us know how it comes out.

I had a guy stand over my sholder one night and I saw him taking notes, writing down something. Later, between acts, I asked what he was doing. "Writing down your EQ settings so I could use them later. Hope that's OK.", he said.

"No problem", I said. "Just don't expect them to work for you anywhere else and at any other point in time."

It's all fluid. Things change constantly in live sound. You have to be able to make sense out of it and apply the right solution.


Regards,

Ty Ford

Well, so far I learned that soundtrack 2 is very, very broken. Once I can finally export audio files I'll post a before and after excerpt.