Nov 03, 2010

OS X system-wide EQ with Soundflower and AU Lab

Entirely free. Requires XCode.

  1. Download and install Soundflower.

  2. Open Audio MIDI Setup.

  3. Create Aggregate Device (Audio -> Open aggregate device editor), constisting of:

    1. Built-in output (or whatever output you need)
    2. Soundflower
  4. Set default output to Soundflower.

  5. Start audio. At this point you should hear nothing.

  6. Open AU Lab (/Developer/Applications/Audio/AU

  7. Add 1 stereo input track, set Audio Device to "Aggregate device". Click "Done".

  8. Now you should hear sound and see level meters move.

  9. In either Audio 1 or Output 1 strip, click Effects drop-down and select Apple Graphic EQ, or whatever else you want!


Feb 21, 2010

Mastering an off-the-air recording (in Logic)

Preface: A few months ago I found an amazing device I should have found years ago — the amazing Zoom H2. Appropriately dubbed "a studio on a stick", it can produce amazing sounding location recordings. In the right hands, of course.


By "mastering" such a recording I mean simply making it listenable and enjoyable. The process is different from a conventional mix. On one hand, the material is taken care of and, if you're lucky enough to be listening to great musicians, already sounds very good. On the other hand, the only things you can really control is the mic position and your input gain level. Your task in post production, therefore, becomes correcting the things you could not change earlier.


This is a big one. During a performance levels can fluctuate wildly between sets, individual songs, solo sections, etc.. This works great when you are part of the setting, but listening to such a recording would be rather difficult, especially in less than ideal environment such as a car. You would have to keep adjusting the volume to hear the quiet parts over the noise and to keep the loud parts from blasting your ears.

We can avoid that by preemptively doing it for the listener: with volume automation curves and compressors. But take care not to destroy the dynamics entirely — the level changes must be subtle enough to keep the quiet parts perceptibly quiet and loud parts loud. Just enough to make the whole thing intelligible at a moderate and constant level.

To throw in a video analogy, there are webcams that show a static frame with a person moving about and then there are some webcams that constantly follow your face and fill the screen with it. You have to play the camera operator, zooming in and out when appropriate to produce a smooth and transparent viewing experience that does not get in the way of the story.

My processing chain

1. Levels

There is a gain plugin set to +6.8dB to bring the recording into a more useable range. The rest is just volume automation, some of it done riding a fader, but mostly just mouse drawing. I briefly toyed with a compressor but could not get it to sound right to my ears.

2. LinPhaseEq

The order of EQ and compression still puzzles me, but this placement is logical: it is there to correct the room/mic response. Where I was sitting it picked up hardly any bass and there was a pronounced honk around 400Hz. Also, I was very close to the drummer and the cymbals are just way too overpowering most of the time, so everything above 2.7kHz comes down about 5dB to keep them under control.

3. MultiPressor

Tricky to operate and very easy to make a total mess of your sound. I started off with a "Slow Attack 4-Band" preset and played with it to add some punch below 40Hz and to control the cymbals a bit more.

4. AdLimiter

Two of them, sharing the gain increase. They seem to adapt better this way.

Docutils System Messages

System Message: ERROR/3 (/home/dev/work.shared/unthingable/content/mastering-an-off-the-air-recording-in-logic.rst, line 14); backlink

Unknown target name: "|image0|".

Feb 10, 2010

G&L wiring and SC mod question

G&L L-series basses are Leo Fender's last creation. They are great. They feature two humbucking pickups and three configuration selector switches:

  • Pickup selector: neck/both/bridge
  • Series/parallel switch
  • Preamp: passive/active/active with treble boost

Original wiring: Notice the 0.1 uF caps on the pickups in series — those are "bass boost" caps present in the early L-2*00 models. Later they were removed, which is a shame, they sounded great.

Not only they are beasts in their stock configuration, they are quite mod-friendly. A popular mod adds a single coil option. Here is a variation:

#7 is what I'll probably do, with added DPDT push-pull switches. But there is one thing I don't get. Notice that the caps are present and how the neck cap is grounded, but the bridge cap connects to the bridge output. Why is that?

Feb 03, 2010

When I listen to Elsiane, this is what I see

Jan 21, 2010

Upgrading Poly Evoler (Rack) OS with Edirol PCR-M1

This was unexpected enough to warrant a mention: the PER hangs when it is sent any of the upgrade sysex'es (OS, DSP, Voice). It shows the "loading" message, but the countdown doesn't start.

The setup:

  • PER v2.0, upgrading to 2.1
  • Edirol PCR-M1 as a MIDI interface
  • 10.6 and 10.5 Macs, latest drivers for the respective OS'es
  • SysEx Librarian, PolyEvolver500 editor

So it appears the PCR-M1 is doing something of which Dave Smith does not approve. I would be curious to find out what.

For the meantime, UM-880 worked just fine.