Friday, October 28, 2011

Making Records in 1937...

If you have not seen this, it is not only interesting, it is useful for training in the modern studio.

My thoughts shortly...

Happy Tones!

Thursday, October 27, 2011

Speaking of "Loud" and Meters....

Since we're (I'm) talking about levels (as I was in last night's post), it occurs to me that I've noticed much confusion in folks over the years regarding perceived loudness and level metering.  People think that when they hit 0dB on their output converters their mix should be officially 'loud,' but are mystified by the fact that it still feels quiet.  The meters are solid in the red, but it just isn't kicking like it should.

Audio level meters, be they RMS or peak, show amplitude only.  They do NOT, however, tell you what frequencies make up this overall volume, or the shapes of those frequencies.  This is why the HPF I wrote about last night is so important.  It removes unwanted LF energy that pushes those meters up without giving you the benefit of perceived volume.

To demonstrate this point, take a signal generator, and make a 100Hz sine wave at any output level, and give it a listen.  Then switch to 1kHz at the same level -- a LOT more annoying, no?  It feels louder, but it's actual amplitude isn't any higher than the 100Hz tone.  Now, change that sine wave to a triangle wave and see which one feels louder.

What do we learn by doing this?  Simply that our perception of volume is based on the frequency and shape of the audio content as much as by actual output level being produced.

Ever watched late night TV and been blown away by how much louder than your show the shouting of your local used car salesman feels during the commercials?  There is a reason for this: there are FCC rules on how strong a broadcast signal can be (absolute amplitude), so in order to produce the highest perceived level the audio content is sent through a limiter before being broadcast.  This limiter isn't concerned so much with frequency content, just the level being transmitted.  The LF rumblings of traffic and ambient noise of the city in that detective show re-run uses up the available headroom during the show, but during the commercial there's nothing but the purely mid-range voice of the car salesman to assault your ears.  Same maximum amplitude for both (because of the station's limiter), but the frequency content is so vastly different that the perceived level is as well.

Your VU meters are critical in your work (more about metering in a future post), so keep using and trusting them, but in the quest for 'loudness' you must make sure to carve away any and all unwanted content to make room for what your really want your listeners to hear.

Happy Tones!

Wednesday, October 26, 2011

Making A Mix “Louder” Without Using Dynamics Processing

Ever wonder why your killer rock tune sounds big and huge while you're mixing it, but when you're finished you're shocked to discover it feels soft compared to other mixes, even though the meters are solidly lit?  Think the latest whiz-bang level maximizer plug-in will fix your problem?  Think again.  Could very well be that your problem isn't a dynamics issue at all.

Broad statement time:  the high-pass filter is your friend.  Your very good friend!  

I generally put a HPF on pretty much most tracks except those that really have business being represented in the LF range (bass and kick drum, perhaps some keyboard pads, and occasionally to allow the lower harmonics of a lead vocal).  Most everything else gets filtered. It's a simple as opening a 1-band EQ plugin (like EQ3 that comes with every ProTools system), set it to HFP with a 6dB/octave slope (for more subtle/general use), and sweep while listening to the solo'd track, starting at the lowest frequency, sweeping upward until you hear the timbre of the track change in a marked way.  Then back the frequency down a bit to restore the naturalness of the presentation, and move on to the next track (BTW sweep without looking at the screen... just use your ears.  You'd be shocked by what your eyes make you hear!).  There are a couple of reasons for using the HPF like this:

Firstly, low frequency (LF) content exists in tracks that one wouldn't consider particularly low in tone.  ALL electric guitar tracks have (often harmful) LF content, and they would benefit from being filtered this way.  Pretty much anything recorded up close with a cardioid microphone suffers similarly (as a result of proximity effect).  When a track is solo'd it may sound quite normal without the filtering, but when track after track of unfiltered 'midrange' instruments begin to play together, all of this non-offensive harmonic LF information begins to stack up and 1) robs your track of overall headroom (making the mix feel quiet even when you're maxing out the meters) and 2) the presence of this unneeded/unwanted LF content actually works against the proper presentation of tracks that should play a role in the LF content of the mix.  

By removing this unwarranted LF content you reduce the overall energy (amplitude) of your mix (there's a LOT of energy in low frequencies, even subtle ones). This decrease in level allows you to push the faders up overall to make use of the reclaimed headroom (which makes the mix feel louder to the listener.... of all the mistakes I have made in mixing over the years, this is probably my most egregious.  It wasn't until just a few of years ago that I fully understood the value of preserving the headroom of the mix in this fashion... it really does make for a louder sensation when listening back).

Also, by removing this information you will find that the true LF tracks (kick, bass, etc.) speak clearly and 'own' the low end, so to speak.  They aren't being muddied and smeared by the same frequencies represented in other tracks fighting, interacting and masking the important ones.  It makes for more articulation of elements within the mix... with less effort, no less!

You will even find that there are occasions where you can get away with robbing quite a lot of LF from midrange instruments (guitars, bgv's, etc.) to the point that the track will actually sound unnaturally thin when solo'd, but, because of the presence of those attenuated frequencies in other elements within the mix, the perception to the listener is that the filtered tracks still sound quite full within the overall presentation.  Again, the more LF you filter the 'louder' you can make your mix, because the less energy you have, the greater your headroom, the higher you can push your faders to reach the same level on the main L/R output meters.

Happy Tones!