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Script for Finding the Best WiFi Channel

When running a wifi router in a public space, the least congested channel will offer the best performance. Use this script for Apple computers to help you find that channel fast.

For live sound events I often use wifi to interact with computers and digital devices that control audio, video, and lighting. Having dedicated, reliable wifi is critical for successful productions, so I bring my own router with me to live events. This is the model I own and recommend.

image of TP-Link router

All your [wifi] base belong to us.

WiFi is has become nearly ubiquitous. Networks are everywhere. The increasing number of public, private, commercial, and consumer grade broadcasts mean that the designated wifi spectrum is growing more crowded. Like lanes on a highway, there are a limited number of wifi channels to choose from. Car drivers try to avoid traffic and choose the least crowded lane on the road. Likewise, you will get the best wifi experience by “driving” in the least congested wifi channel.

icon for Wireless Diagnostics application

Also available by Option-clicking on the WiFi icon in the menu bar and choosing Open Wireless Diagnostics…

Apple computers have a built in Wireless Diagnostics service with a sub program that recommends the best wifi channel. It’s hidden away in the system folder and I have a hard time remembering the exact clicks and keystrokes to find it. So I wrote an AppleScript that runs inside an Automator Service to make the exact window pop up when I need it.

screenshot of Automator workflow

This is how I wrote the script in Automator. Can you make it better?

This is the easiest way to get it in the right place:

  1. Download this ZIP file: Find-Best-Wireless-Channel.workflow.zip
  2. Double-click the ZIP file to unzip it.
  3. While still in the Finder, click Go to Folder… under the Go menubar item. Alternatively, press the key combination ⇧⌘G (Shift-Command-G).
  4. In the little window that drops down, type the following: ~/Library/Services
  5. Hit the (Return) key. The Finder will navigate directly to that folder.
  6. Copy or move the Find-Best-Wireless-Channel.workflow file to that folder.
    screenshot of folder location in Finder window

    This is place the file should be put.

Once you’ve put the workflow file into that folder, look for it under Finder > Services > General.

screenshot of Finder Services menu items

Mine has a key command assigned to it. See the note at the bottom about how to set that up.

When you click on the “Find Best Wireless Channel” service item the workflow will run and a you should be left with a window named “Scan” opened. The wireless networks that your Mac has found will be listed on the right. Look at the panel on the left.

screenshot of Wireless Diagnostics Scan Summary panel

The red circle is provided to direct your eyeballs where to look.

The best wifi channels will be listed at the bottom. Use these numbers to set your router’s wifi channel. Good luck!

Notes

OS Compatibility

This Automator service works on macOS Sierra. Depending on your current OS and any future OS updates, YMMV.

No Library?

If you can’t see your Library folder, follow the directions found here to unhide your Library.

Roll Your Own

For those of you that like to DIY, here’s the raw script.

tell application "Wireless Diagnostics"
	activate
	# opens Scan Window
	tell application "System Events" to keystroke "4" using {command down, option down}
	# brings Assistant Window to the front and closes it
	tell application "System Events" to keystroke "1" using {command down, option down}
	tell application "System Events" to keystroke "w" using {command down}
end tell

Keystroke Combo Power-Ups!

If you want to assign a key command to this workflow service like I did, open up  > System Preferences… > Keyboard > Shortcuts. In the left panel select Services and scroll down to the bottom of the right panel. Next to “Find Best Wireless Channel” click the word “none” and then the “Add Shortcut” button that appears. Press the combination of keys you want to trigger the workflow. Voilà!

screenshot of Keyboard Shortcuts in System Preferences

Assign whatever key combination you like.

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GEQgen Creates StudioLive Graphic EQ Presets Offline

GEQgen is a web application for editing PreSonus StudioLive GEQ presets offline.

I made a web application called GEQgen (short for Graphic EQualizer generator, pronounced: “geek-jin”). It was designed for easy creation of GEQ presets that the first generation PreSonus StudioLive audio mixing consoles read/write/share within the original Universal Control software.

screenshot of GEQgen graph and input fields

GEQgen provides a visual graph for reference.

The older Universal Control software (not the newer UC AI version, which only works with StudioLive AI devices) permits editing only when a StudioLive device is connected. The dB values of the 31-band EQ can only be adjusted by clicking and dragging the sliders, which is kind of tedious.

screenshot of original Universal Control software splash screen

Universal Control requires a StudioLive console to be connected to the computer in order to function properly.

GEQgen allows offline creation of GEQ presets (convenience!) and for the dB values to be typed in or incremented up and down with the arrow keys. The result is plain text formatted in valid XML that can be saved as a preset and uploaded to first generation StudioLive mixing consoles.

screenshot of XML code

GEQgen outputs valid XML which can be saved as a GEQ preset.

Why does this matter? Well, sometimes I like to create “flattened” GEQ presets based on the frequency response graph that manufacturers provide with their products. Having a flatter EQ response means that the output of various mains speakers, monitor wedges, and headphones are more consistent with each other. Doing this task was tough in the old Universal Control software. With this new GEQgen tool I can simply look at the graphs, guesstimate the values, and type in what I want. It’s much faster and easier.

screenshot of many frequency response graphs

Graphs like these can be used as reference to create GEQ presets which can flatten the response of loudspeaker output.

Maybe you will find this tool useful. I’ve posted it on a new Tools page here on my site. I suspect I will be making more things like this in the future. Let me know what you think.

Also, if you like coding for the web, maybe check out GEQgen on Github. Thanks!

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How to Wire or Choose the Correct Audio Cable

This isn’t as easy as it seems.

December 10th, 2015 | Technology | , , , , , , , | Comments: 0
the joke is in the image

Do you know The Secret? It’s not really a secret, just science.

Nearly every audio problem can be traced back to bad practice. Whether that’s a musician not being prepared or an engineer not using gear correctly, almost every problem encountered in the making of music can be attributed to one of these two camps. For the musician, the answer is simply more (and better) practice. For the engineer, it’s more (and better) knowledge.

A pair open letters:

Dear Musician,

Practice, so that we might enjoy your performance.

With gratitude,

Everyone in the Entire World

Dear Engineer,

Know thy shtuff. Don’t assume that you do.

Hesitantly,

Everyone Who Has Had to Endure a Show

With that in mind, musicians, please excuse yourselves to go practice. Engineers, let’s talk.

Topic: Cables.

Cables are crucial to everything you do. They connect every piece of equipment you use. But do you know—and I mean really know—how to hook all of them up correctly? Even if you think you do, chances are that you could be reminded of a few things. I could.

An audio engineer is a technical professional that manipulates electrical signals under the pretense that we are ultimately providing auditory pleasure (or at bare minimum, tolerability) for an audience, whomever they shall be.

Good sound doesn’t happen by accident. It is the engineer’s duty to use audio equipment properly. Connecting the many pieces of gear together to make a show happen arguably is the engineer’s most basic of tasks and yet the most often screwed up.

I’ve found no better resource for how cables should be wired for the various scenarios than this article from the folks at Rane called Sound System Interconnection. Bookmark it, study it, refer to it every time you think you know the answer. They provide a way to connect anything to anything else an engineer might need to connect.

screenshot of image from Rane

Click for knowledge.

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Haas Effect Panning

A little history plus a free download of plug-in settings for Haas Effect panning.

History

A smart guy named Helmut Haas discovered a bunch of cool things about the way our human brains decode the sounds we hear to determine the direction of where those sounds originate.

Back in 1949, Mr. Haas found that early reflections of sounds help our brains decipher where the sounds came from. We can tell a noise came from the left not simply because we hear it in our left ear, but also because the sound bounces off a wall to our right and hits our right ear a very short time after it hit our left ear. Almost instantaneously, the brain detects the short time between the two signals and tells us, “Hey, that sound you just heard came from your left. Better turn your head to see what it was!” This happens so quickly that we don’t really even think about it. We just “know” it came from the left.

Haas also recognized that early reflections are basically copies of the initial sound that are delayed slightly. He started messing with people’s heads. He pointed speakers at them and firing sounds with very short delay differences. Then he asked the test subjects which direction the sound seemed to come from.

His conclusion: Not only is it fun to play with sounds, but also 40 ms (milliseconds) is some kind of magic point for our brains. If an echo is more than 40 ms after the initial sound, then we hear the sounds as separate instances. But if the delays happen within 40 ms or less of each other, then we perceive them together as merely directionality cues of a single sound.

For example, if a sound hits our right ear and the same sound hits our left ear 0.3 ms later, we don’t hear two sounds, we only hear one sound coming from approximately our 1 o’clock position.

And so the Haas effect was named after him.

Panning

Engineers have implemented the Haas effect as an alternative to panning. Most of the time panning works just fine, but it does have limits.

Sometimes panning leaves the location of the audio feeling indeterminate, smeared, mono, or one dimensional. This is why a lot of engineers skip the pan knob altogether and mix LCR.

To effectively localize a track in a stereo field using the Haas effect, engineers have to do a couple things. They duplicate the track, pan the two tracks hard left and right, and then apply a delay to only one of the sides. The delay is applied to the side opposite of the side from which the sound is intended to perceived as originating.

Typical delay times for this technique are increments of 0.1 ms from 0.1 to 0.7 ms. This yields linear movement across the stereo field. You can think of it like this chart shows.

diagram of pan knob and delay times in ms

Example: Want the sound to come from 9 o’clock on the left? Delay the right side by about 0.4 or 0.5 ms.

Download

After researching the Haas Effect, I decided I wanted to try it out in a mix. Since the settings must be very exact, setting it up correctly can be a bit confusing. Presets to the rescue!

I made these presets for the stock Digidesign Mod Delay II plug-in. These presets only work for this specific plug-in and Pro Tools. If there’s interest, maybe I’ll make more presets for other DAWs in the future.

Installation

Download this ZIP file, unzip it, and drop the folder and included presets in the Mod Delay II folder in the Plug-in Settings folder. On a Mac it’s probably located at Library / Application Support / Digidesign / Plug-In Settings / Mod Delay II, but may be in a different location on your system.

Setting up the tracks

Insert an instance of the Mod Delay II (mono/stereo) plug-in on the mono track you want to Haas-ify. Select the preset you want. No need to duplicate tracks. Bingo.

Haas Effect Panning

screenshot of Pro Tools session

Digging Deeper

Understanding how to use the Haas effect properly means you need to understand and pay attention to things like stereo-to-mono compatibility and comb filtering, as well as other stereo field mixing techniques. As with all effects, have fun but be careful not to over do it. Experiment and do your homework. Then let me know if you find learn or discover anything cool. Here’s a cool video that got me thinking about the Haas effect. This video no longer available.

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The Secret to Mixing

Maybe there are no secrets.

Mixing audio is not easy. I’m no expert, but something just struck me…

Maybe making a great mix simply comes down to listening to a song a thousand times and removing all the little things that annoy you until there’s nothing left to dislike. Hopefully the subtraction leaves you with enough material to reveal the goodness of the song. I bet great mixing engineers can get there in fewer than a 1000 listens. Maybe there’s more to it. Just a thought.

Got any mixing secrets?

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