Streaming audio between two Macs

Macs can share video, so that you can use a Mac from a remote Mac, as if you were sitting in front of it. The Share Screen feature makes remote access to another computer incredibly easy. You can use a Mac’s display, keyboard, mouse or trackpad from the controlled Mac. You can even access all the peripherals connected to that other Mac.

But you can’t hear the sound from it. Audio is not shared. A commercial solution to this missing feature is Rogue Amoeba’s Airfoil. A free one, that you might already have in your computers, is Skype, together with Soundflower or Rogue Amoeba’s Loopback.

First of all, install Soundflower in your controlled Mac. You can download it for free from the developer’s site (Matt Ingalls). Once it is installed in your Mac, you get a virtual audio stream between applications. An application sending audio via Soundflower can be recorded by an application that has Soundflower as its audio input. It is like a virtual cable running between applications.

In the controlled Mac’s System Preferences > Audio control panel, choose Soundflower (2ch) as the audio output. You can do the same from the audio icon on the right side of the Mac menu, if you have checked the relevant option. At this point, the Mac is outputting stereo audio via Soundflower.

Then, go to Skype’s Audio and Video settings, and choose Soundflower (2ch) as the audio input device. This makes Skype listen audio from Soundflower, instead of the microphone. Any application sending audio to the Mac’s audio output (that is now Soundflower) will send audio to Skype.

From the controlling Mac, log into Skype with a different account. Call the local Mac from the other Mac. When you answer your own call, you can listen on the controlling Mac the audio generated by the controlled Mac.

Please keep in mind that, depending on the speed of the connection, audio may be delayed. Skype should choose to connect via the LAN, and not via the internet, but its audio stream will not be in realtime. Lip-synching, for example, may not be perfect. However, this should be enough to prelisten to a score or an edited sound.

Switching to a bigger computer monitor

So, you are thinking of switching to a bigger monitor, because you want to see your orchestral score in full size. Great idea! Accustomed to using pen or pencil on huge A3 music sheets, this seems the best thing we orchestral composers can do.

With the huge number of 4K – also known as Ultra High Definition (UHD) – computer monitors on the market, you may go right with one of them. Only to find that maybe they make everything look too small. At 3840 x 2160 pixels, things go in the micro dimension.

The old standard video definition on the Mac was 110 points per inch (ppi), and 96 it was on Windows. Hi-Definition mode (HiDPI), or Retina in Apple's jargon, has upped it to 220 ppi. To do it, they simply use twice the pixels per side (that is, four pixels for a single older pixel), and make everything look smoother.

So, on a 27" monitor, if you keep the original maximum definition you end up with about 160 ppi. This makes everything look too small. If you go Retina, you get too big text and icons, and a video definition that might be equal – or even lower – than your older monitor. That is, a typical 1920 x 1080 pixels, or the old Full HD 1080p.

Both Mac and Windows have a way to scale what you see in their preferences. Typically, on a 27" monitor you will want 2560 x 1440, that is the equivalent of the aged Quadruple High Definition (QHD). The effect of the scaling is not as good as with Retina, but good enough.

If you have an old Mac or PC, however, you might not immediately get UHD. To get it, on a Mac you can install the cheap and excellent shareware SwitchResX, and choose the preferred resolution. Be sure to never use "lower resolution" modes, because they would force the display to switch to a real resolution that is not native, and look fuzzy. With SwitchResX you can also automatically switch resolution depending on the foreground app – for example, a lower resolution when jockeying with files in the Finder, QHD for working with orchestral scores, and full UHD for watching movies.

With older computers you might end up with a 4K resolution, but only at 30 instead of 60 Hz. This is a slow frequency, that might make mouse and windows movements, scrolling and video not totally smooth. Speech can appear a fraction of a second too late. If you can stand it, it works. If you can't, either you switch to a low resolution from the display, or get a better video card or Mac. (As for my experience: I can barely notice it with video, and only occasionally; not a major issue for me).

And yes, I got an HP Z27, and am using it with an old Mac a 30 Hz, with software scaling to QHD. The picture is a bit small, but there is a lot of room for my orchestral scores. And if I want things bigger, I can just magnify them with Ctrl-Up, or momentarily switch to the lower, gorgeous, Retina resolution.

Better yet, since I find the user interface elements (text, icons, menus) too small, I can lower the scaled resolution to 2304 x 1296, that is a close approximation to what a 24" display looks like at Full HD.