June 30, 2008

It's getting Hot in Here - When to record hot, and when to pull back

I've been hearing a lot of people say that you should record as loud as you can as long as it doesn't clip, otherwise you're not using all the bits (and therefore not getting the highest quality possible).

It's true that if you record quieter, you're not using all the bits available... but it just doesn't matter.

Every additional bit added doubles to possible amplitude you can record, that is, it increases the dynamic range by 6 dB. I don't want to get to involved in the way people perceive sound, but if you're interested just leave a comment and I'll be happy to explain further.

Too hot!

Anyway, CD's are encoded in 16 bit. So if you're recording at 24 bit - and you should be - that means at least 24 dB of dynamic range are going to be dropped when you finally encode your music onto a CD. So don't worry about getting those input levels so hot, it opens the door for lots of other problems, like distorting plug-ins that aren't equipped to handle such hot input. Distorting plug-ins aren't usually the sound you're going for.

I don't want you to think I'm saying you should record really quiet either, just leave yourself 8 to 10 dB of headroom; you should be able to see the waveform whenever you hear sound, but on the other hand, it shouldn't ever look like it's in danger of touching the edges of the track (clipping).

If you want to be loud, you can always throw a mastering limiter on the output bus and boost the levels up to 0 dB there.

edit: I accidentally switched up 3dB and 6dB at the doubling of amplitude part of the post. A Doubling is power is 3db. A doubling in amplitude is 6dB... sorry about that. It's fixed now :)

correct me if I'm wrong, but I believe this is because doubling in amplitude doubles the size of the waveform in both directions (up and down from 0dB)

June 26, 2008

Makes music interesting

Music is only interesting when there's contrast. Here's a few ways you can create contrast in your music:
  • Dynamics
    Loud vs. soft

  • Sound vs Silence
    This is really just an extension of dynamics, but in practice it's quite different

  • Texture
    The tone and mix of all the instruments together

  • Timbre
    The way a specific instrument sounds

  • Arrangement
    Which instruments play which parts.

  • Rhythmic
    Pretty self explanatory. Use different rhythms, time signatures, etc.

  • Dissonance
    The difference between consonant and dissonant notes/chords

  • Envelope
    The volume of each note over time. For instance, a drum has a very fast attack (the pop) with a fast decay and a very quiet sustain that lasts a second or so. On the other hand, the human voice has a long attack that sounds almost like a fade in. You can vary the envelope using dynamics processors like compressors.

There are also a few ways to create additional contrast that you can add in post production.
  • Panning
    Moving the sound from left to right. This is a HUGE thing in mixing. One of the most common things amateur musicians do wrong when mixing their own music is leaving everything panned center, or very close to center.

  • Stereo Width
    How far the tracks are panned on average, from a plain mono sum of all the tracks, to an ultra-wide mix with nearly every track panned all the way to one side or the other.

  • EQ
    The balance of frequencies.

That all being said, keep in mind that repetition is what makes music memorable, and familiar. For a few ideas on how to create lots of contract and still have repetition just listen to your favorite song. If it didn't have both of those things, you wouldn't like it (I can't say for sure since I probably don't know you, but if you're like every single person I've ever met it's true *wink*)

All in all what makes music interesting is contrast and repetition. weird huh?

June 23, 2008

Make your own Stackable Gobos!

Hello everyone! As promised, Here is the article on how to make your own gobos (a gobo? what the heck is that?)

Well here's what we'll be building in a youtube video:

Recipie for 2 Gobos:
cost: about $40 per gobo

Each step covers what to do for one gobo. You need to do the instructions from step 3 - 12 twice to complete both gobos.

  • 16 feet of 1x12 lumber
  • 12 feet of 2x4 lumber
  • 2 - handles (I used cabinet handles)
  • Box of 2" wood screws
  • Fiberglass insulation
  • 2 - 2' x 2' pieces of 1/4" plywood
  • A cover for the absorptive side of the gobo

I used pegboard for my absorptive side. I evens out the frequency response a bit, if you're not sure what that means, my advice is to use pegboard. If you want your gobo to absorb lots of high frequencies the you can staple canvas around the open side of the gobo instead.

You can also make see through gobo's by removing the plywood, fiberglass, and absorptive side cover from the list. Use 2 - 2' x 2' pieces of plexiglas on both sides instead of plywood and an absorptive cover.

See through gobos are useful when you need several gobos to block the sound and you want to stack them without breaking the musician's eye contact.

  • Circular Saw
  • Drill (with a 3/32" bit; A screwdriver bit would also be useful)
  • Measuring Tape
  • Screwdrivers
  • Pencils
  • T - Square
  • Boxcutter

Step 1: Cut the pieces you'll need
I labeled the dimensions of each piece as I cut it:
  • (2x) 2x2 1/4" plywood
  • (2x) 2x2 pegboard
  • (4x) 2' long 1x12
  • (4x) 1' 9" long 1x12
  • (4x) 2' long 2x4
  • (4x) 8" long 2x4

Step 2: Mark the 2' long 1x12's 2.5" from each end. These marks show you where to drill later on.

Step 3: Set up the 4 sides of the box on a flat surface and tape them together. The 2' long sides are shown on the left and right in the picture, and the 1'9" sides are shown on the top and bottom in the picture below.

Step 4: Drill at the places you marked, and try to make sure that the you get the bit centered by the width of the 1'9" pieces. You should end up with 8 holes (2 on each corner). Put a screw in each hole.

The four pieces should make a perfect square with 90 degree corners. Use the T - Square to check this is the case as you go.

Step 5: Put the 2' x 2' piece of plywood over it (it should line up with the edges of the box you've built so far). I didn't need to drill holes before putting in these screws, but if you're worries about it, or using really fat/long screws, it may be a good idea.

Step 6: Now that the box is strong and stable, you can pull off the tape we put on in Step 3

Step 7: Attach the handle. You want to center the handle so that it'll fit nice later on. The end goal is to have it fit between the feet of the gobo above it so that they can be stacked easily.

In this picture, the long 2x4's on either side of the center row (the one with the handle and the shorter 2x4's) represent the positions of the feet of another gobo. Don't attach these long pieces, they're just to help you understand.

Before you attach the handle mark where the holes need to be drilled by putting the handle on it's side. Drill from top to bottom through the marks you just made. Then it's a piece of cake to attach the handle using the screws that come with it (all the handles at Loews came with screws)

Step 8: Cut the fiberglass insulation into 22" segments. If you used 15" wide RC-13 like me, you'll need six segments per gobo.

Cut 2 of the 6 segments in half (as pictured). Only cut 2 of them in half.

Here's what all your cut fiberglass should look like:

Step 9: Put the fiberglass segments in the gobo facing out (each layer facing out, though it doesn't matter a whole lot which way the individual pieces are facing).

Step 10: Attach your cover. I used pegboard because of it's flatter frequency response. You can use canvas if you'd like to tame those higher frequencies, or if you just want to block sound with minimal absorption just put plywood on this side as well.

note: there is no insulation in the picture. This is just because I'm dumb and took the picture at the wrong time ;). Don't take the fiberglass back out of the box.

Step 11: Attach the feet. The feet are necessary to make the gobo's stackable. Again, I didn't need to drill before putting in these screws. However I did need to put the screw in, take it out halfway, and put it in again (to get a tighter fit).

Whatever you do, just make sure you put the screws in far enough that they're somewhat inset into the 2x4. You don't want the screw sticking out, or else it'll be wobbly and also scratch wood and tile floors.

Keep in mind that these need to be all the way to the edges, because the handle and alignment 2x4's need to fit in between them.

Step 12: Attach the alignment 2x4's on the top.

Sorry to use the same picture twice, but this one is the best shot to illustrate the point. You want to attach these alignment 2x4's so that they're in line with the handle with space for the feet of the next gobo, which would be on top of it.

Steps 13 - 15: Admire your handiwork!

I hope you found this howto guide useful! I've also created an instructable of this guide.

June 17, 2008

Finding the sweet spot

Hello everyone,

This good morning I'll keep my update brief since I've been up all night.

Whenever you put a microphone on anything, you should try to put your ear in the exact spot the microphone's diaphragm will be. This is the best taste you'll get of how the track will actually sound, and it'll help you find the elusive sweet spot much quicker. Be careful with amps though...

PS - I was GOING to post an article on how to make your own gobos, but my drill broke and I couldn't get the example gobos built fast enough, maybe for tomorrow though ;)

June 9, 2008

What the heck is a Gobo? It's just baffling!

Ok, first and foremost, I apologize for the terrible pun in the title. Gobos are really useful things especially if you're working in a sub-par recording environment (ie. your living room). So what exactly is a Gobo?
Baffle - A physical object that absorbs or otherwise reduces the volume of sound which passes through it, or is reflected by it.

Gobo - see Baffle.
In other words, It absorbs or blocks sound. Those are the 2 main ways this effect can be achieved:
  1. Absorbing the sound (converting it to heat via friction) - this is what foam, cloth, and other porous materials do.
  2. Reflecting the sound (bouncing it back where it came from) - this is what concrete, and other non-porous materials do.
Of course it's a sliding scale (there are degrees of porosity), but the main thing you need to know is that you'll mainly want to absorb sound if you're trying to reduce the amount reverb in a room. Which is what you usually want to do in a crappy room so that you can apply digital reverb at a later point.

You can also use a gobo between 2 microphones to keep the two sounds from bleeding into each other's microphones. For example if you're recording two guitar players in the same room together.

And if that isn't enough uses for you here's another! You can use large gobos to simulate a wall making the room effectively a different size (or shape). Which can come in handy if there's a note that seems to resonate in the room and sounds bad.

So how do we know what types of acoustical properties things have? Well the long answer involves measuring and anechoic chambers, but luckily physicists have invented something called an absorption coefficient. This coefficient is basically just a proportion of the energy which is absorbed by a given material.

For instance, a coefficient of 0.5 would absorb half of the energy thereby reducing the volume of the sound by 3 dB (and a coefficient of .9 would absorb 90% of the sound reducing the volume by 10dB). Unfortunately the absorption coefficient changes with frequency. So here's a few charts to help you out.

June 6, 2008

About metronomes... (plus a comic)

Metronomes may drive people crazy, but they're also useful tools when you're dealing with midi (or bad drummers) but when is the right time to use a metronome? Lets go over the pros and cons of using a metronome during tracking.

  • Keeps your musicians in sync with the computer's tempo track
  • Makes editing easier
  • Allows midi/audio quantization and other
  • Allows you to use beat detective if you want
  • Makes editing harder
  • Makes you (and especially your drummer) crazy
  • Takes more time
  • Can sometimes make the song feel lifeless
    (It removes the subtle, natural tempo fluctuations characteristic of live music)
  • Metronome Bleed

First, I'll clarify the "Makes editing easier/harder" part. It makes it easier to fix tempo problems and drag/drop sections etc. because you can just snap your regions to the beginning of measures and know they'll be in time.

However, it's harder to rearrange songs, create spaces, and other things that involve changing the structure of the song. Especially when you have multiple time signatures in a song.

Which brings me to "It takes more time." You have to spend time setting it up (which can take a long time if the song changes tempo or time signature). You have to spend time getting takes that sync up with the metronome, which is just one more complication in the recording process. You have to spend time redoing tracks that were otherwise OK except for the metronome bleed.

Metronome Bleed - When the sound of the metronome in the headphones gets picked up by the microphones and is audible in the audio tracks.

I can personally attest to the annoyance of metronome bleed.

Let's talk about some of the things that make metronomes useful. If you're working with a weak drummer using beat detective is possibly the only way you have of getting usable drum takes. If you want to use beat detective, you really need to use a metronome. I'm sure someone will disagree in the comments but the fact of the matter is: beat detective is much easier to use if you recorded to a metronome. You almost can't use it if you didn't.

Next up is that you can quantize midi, as well as enabling tempo sensitive arpeggiators, and effects (like delay). This is really useful.

I'll admit that I rarely use a metronome when I record a song unless I'm specifically planning on utilizing one of the pros I've mentioned here. They're usually just a lot of trouble for not much return.

Whatever decision you make, just know that there are people who are avid members of both camps so be polite if someone does or doesn't want to use one.

And here is the Friday comic I promised:

Dedicated to mike!

So I know my drawing ability isn't great, but I'll work on it I might also grab one of those sick wacom tablet things to make it faster and possibly vector as well.

June 5, 2008

New theme! (guest authors, comics and bears oh my! wait bears?)

Hello all, check out the new look! Let me know if you like it, if there are any problems, etc.

I'll be writing a post in the morning about the Pros and Cons of using a metronome to while tracking.

In other news, my friend Matt will be writing a few articles on reason for this blog. Hopefully those will be up soon. On the topic of guest authors, If anyone is familiar with ableton live let me know.

Also, I'm considering doing a comic every Friday on this blog, what do you think?

June 2, 2008

Howto wiki

Quick update... I've put together a long list of things I'd like to write about, so I should be updating regularly now.

Also, since I usually use Cubase, Waves plug-ins, and Reason in my howto articles, I created a wiki so people can share how they accomplish the same things in other programs (like ableton live, garageband, protools, etc). I will try to at least add the protools version to all of the more popular howtos myself, but I'll be relying on comunity support for pretty much all other software.

The wiki could also cover alternate plug-ins if a given tutorial (like the one on drum comression) pictures a specific plug-in.

The wiki is brand new and currently empty but feel free to add to it!
Death By Protools wiki: http://deathbyprotools.wetpaint.com

© 2008 Jim Robert