Friday, February 24, 2012

Gear Talk -- Perhaps THE Most Critical Piece of Gear In Your Studio...

It's always touchy trying to claim one piece of gear the most important piece in the studio.  After all, there are many critical pieces of gear -- monitors (your gotta be able to hear what you're recording and mixing!), microphones (first link in the chain), converters, recording platform, acoustic treatment, etc... all important to getting great results.  Of course there are the artistes of the engineering world who will always interrupt such conversations with the obligatory, "your ears are the most important piece of gear in the studio," or some other such truthful, yet completely off-topic comment to show the richness of the depth of their experience and wisdom.  Psshh.

I'm talking about gear here -- stuff you purchase.  Everyone with a recording program wants to know what gear they need to get great results, and with that ever-present question in mind I will venture an opinion -- one developed over many years of observation.

What is the most important piece of gear in a studio (i.e. where should you commit your dollars)?  The microphone preamp.

Not monitors?  Nope.  Every single day folks all over the planet do great work on modest monitors (NS10s anyone?).  They don't have to be full-bandwidth, killer, high-dollar, self-powered client impressors.  They just have to be familiar to you.  You need to be so familiar with their response that you can trust what you're hearing from them, so you can make mixing decisions with confidence.

What about the mic?  It's the first part of the chain.  Yes, your choice of mic is critical, but now, more than ever, there are tons of solid-performing, reasonably-priced mics on the market, from tube and solid-state condensers to dynamics and ribbons.  Most folks can assemble and impressive mic cabinet without too much difficulty or expense.  And I'd much rather record a modest microphone with a killer mic preamp than a killer mic through a modest preamp.  "Why," you ask?

Professional microphones produce a balanced, low level output signal.  For this signal to be useful it must first be amplified a LOT to feed the input of a balanced, line-level signal processor or recorder input.  Most any microphone signal will see a minimum of 20dB of gain to be useful.  That's a 10x increase over the mic's output.  If you require 30dB of gain, that is a 31.6x increase.  40dB is 100x.  And any signal that requires 60dB of gain has to be increased 1000x!  That's a lot of amplification, and the manner in which it is accomplished has everything to do with determining the quality of your signal when it moves to the next device in line. 

Comparatively, an inexpensive line-level device (such as a compressor) has both line level inputs and outputs (essentially a unity gain device).  If your gain reduction is around 10dB (which is a lot, actually), then the compressor's output stage has to produce only just over a 3x increase in signal to produce the same level of output on louder passages... a much simpler task that can be done well with even modest circuits.  But the mic preamp.... your microphone's low-level output, no matter how pristine it may be, will require such gain before it becomes useable that it is literally at the mercy of your preamp.  Skimp here and your $3000 tube mic could lose much of its pricey luster.  And once the damage is done there is no whiz-bang device that will restore what has been lost.  Nothing.

A quality mic preamp will produce a solid, focused, fully intact signal ready for recording or further processing.  Some designs produce solid, but accurate signals (sometimes referred to as a 'straight wire with gain').  Being a rock dog I'm personally a fan of preamps that bring a little sex to the party, and give the signal not only a solid focus, but some rich color as well to add some visceral spice.  For these reasons I'm a fan of older style designs with transformers that saturate, round transients, and generally thicken the whole affair in a glorious way. 

Mmmmm...... transformers....  (Okay, I'm getting off topic...)

Like I say, I'd rather record a modest mic through a killer preamp than a killer mic through a modest preamp.  Ideally both would be killer, but if I gotta choose one I'm going with the preamp.  It'll improve my results with every mic I plug into it.

Thanks for reading!

Friday, February 10, 2012

Mixing Drums - Processing Overheads (2 of 2)

In this video I process the overheads with EQ:

Thanks for watching!

Mixing Drums - Processing Overheads (1 of 2)

In this video I process overheads with compression:

Thanks for watching!

Tracking Tip - Gain Setting and Compression

Occasionally a thought will enter my mind of something that I think might be useful for other engineers.  Even the most experienced engineers make silly mistakes at times, so even a simple tip can sometimes have profound impact.  With this in mind I have decided to make posts of such thoughts when they occur (assuming I remember them when I get to my computer!).  This is the first such post.

A few years ago a friend of mine bought one of my JC1272 preamps and then called me a few weeks later asking if the distortion he was getting from it was normal.  The input meter on the track he was recording to wasn't hitting red, yet he was getting audible distortion on louder passages.

Now this dude is a talented musician and producer, but not the most at home turning knobs (as he will freely admit), so I began to ask questions to try to help determine what was causing the problem.  Basically, it came down to this:  he was setting gain for the mic preamp with a compressor engaged between the preamp output and the A/D input.  When I asked him to bypass the compressor his level pegged the meter -- clearly the thing was putting out a great deal of level (as it turns out he was actually overloading the signal path of the compressor, not the mic preamp).  Yet with the compressor engaged it was reducing the level (as a compressor does), and its output was below the headroom of the converter, so it looked to him like he had plenty of headroom.

Don't laugh, we've all been guilty of goofy stuff like this, but, FWIW, make sure you set your gain with no dynamics processing engaged, or you simply may not know what's actually happening with respect to your levels.  In fact, I prefer not to have a physical processor in line at all between the mic preamp and A/D input until I've got my levels.  Then I'll physically insert a compressor (or EQ) and adjust it as desired.  Some processors (such as Urei's much beloved 1176) can be 'bypassed', yet the input/output controls still affect the signal.  With level manipulation happening in other areas of your signal path it is rather pointless to try to set optimum gain at the mic preamp, so remove all that other stuff, get your gain settings happening, and then insert and set your processing.  Doing so will result in distortion-free audio and a lower noise floor.

More drum stuff coming shortly...

Thanks for reading!

Monday, February 6, 2012

Friday, February 3, 2012

A Good, General Approach to Equalization...

I'm about to post some video entries on processing drums that include my use of equalization (EQ).  I have a love/hate relationship with EQ (extreme on both sides), and I thought that is might be a good time (before I post those videos) to ramble briefly about my overall approach to EQ.  With regard to EQ while tracking, please see my earlier post on the subject.

Regarding EQ in general, I take a subtractive approach first.  This is pretty much what it sounds like -- subtracting (removing) frequencies that I don't want, rather than adding (boosting) the ones I do want.

Acoustic energy (anything you'd use a microphone to capture) is often very complex, formed from multiple fundamental and harmonic frequencies that interact dynamically to create each voice's unique timbre.  Almost no instrument can be radically shaped by manipulating a few frequencies -- that is, by tweaking a few bands on an EQ, even a very nice and expensive EQ, you're not going to convince a listener that an acoustic guitar is really an electric guitar.  It will just sound like an acoustic guitar with some EQ (even if the curve is so dramatic that it now sounds like a weird acoustic guitar).  You're not likely to affect enough harmonic content and interaction of the multiple, complex frequencies of the instrument to betray the fact that it is, indeed, an acoustic guitar.

Similarly, if an instrument is a bad-sounding instrument, you're not going to be able to manipulate a few frequencies with a quality EQ and convince people that it is a nice sounding instrument.  In this respect EQ is quite limited in its ability to 'fix' things in a mix.  This is why it is so important to record the best instruments you can, well maintained and tuned, and hopefully played by a competent musician.  Then, using a good-quality microphone that is an appropriate choice for the instrument, along with careful mic placement, capture the sound of the instrument as best you can.  Then, when you reach for EQ it will be to massage the frequency spectrum to better place the instrument within its spot in the overall soundscape of the mix -- not to 'fix it.'

If you ever hear an engineer say, "we'll fix it in the mix," it might be time to rethink things...

So the overall character of a signal is captured with proper instrument selection, tuning, mic selection and mic placement (yes, gain staging is uber critical too, but I'm this is a blurb on EQ, so I'll save my lecture on gain staging for a future post).  EQ will not change the overall character of the sound, but rather just the tonal balance of the instrument (remember, an acoustic guitar stills sounds like an acoustic even with EQ).  Therefore.... subtractive EQ makes a great deal of sense as a primary EQ approach.  

EQ's main strength is in helping you blend multiple signals together into a cohesive, balanced final mix -- featuring the frequency spectrums (spectra?) you desire in a given signal and attenuating others.  Since the basic character (timbre and 'quality') of an instrument is captured apart from EQ, an additive approach to EQ only serves to accentuate a portion of the signal you like.... but there is so much more spectrum information critical to the signal than that one section you wish to emphasize!  With a primarily additive approach, boosting frequencies ranges of signals throughout your mix, you will notice that while you 'hear' everything (once you've balanced the faders), you're not really getting the full timbre of the tracks, leaving the final mix feeling somehow incomplete or hollow.  Unfortunately, this trait is often blamed on bad converters or plug-ins, or 'recording to digital' in general (often stated by twenty-somethings who have, themselves, never spooled a single reel on an analogue multi-track!  But I digress...).  This isn't something to blame on digital.  Rather, it is squarely the result of poor engineering.

Subtractive EQ processing, however, tames the frequency ranges you don't want, leaving the whole of the rest of the signal, timbre and all, translating naturally within the balance of the mix.  

Another benefit of subtractive EQ is that while it leaves the timbre of a given signal relatively intact, it is actually removing amplitude from the signal, increasing that track's headroom.  When mixing I find that I remove LOTS of low and low-mid content from tracks that simply don't benefit from it.  These lower frequencies have a lot of power in them.  Removing them not only makes room for the tracks that are intended to own the bottom of the frequency spectrum (kick drum, bass, etc.), it also drops the power of all signals that are so processed.  After awhile I find that I can push up the levels of everything much more to use up the newly available headroom, which makes the mix 'feel' louder, even though it may be hitting the same level on your meters as a version of the mix done with an additive approach.  

The 'subtractive' mix will feel louder and more natural.

So I recommend subtractive EQ highly.  It's not as obviously sexy as pushing up the frequencies you want to hear, but in the end your mixes will sound more balanced, more complete, more natural, and LOUDER (without resorting to any dynamics processing).  That's a win, win, win, WIN!

Thanks for reading.