What is ASIO and why it’s good

To answer what is ASIO it’s best to start with what it stands for. ASIO stands for Audio Steam Input output. It is an audio transfer protocol for computer sound cards, designed to work across lots of different operating systems. Steinberg, the music software pioneer came up with it to improve the awful way that Windows handled audio.

Steinberg was a German company that basically invented computer music software. I can remember back in 1987, Pro24 on the Atari ST thoroughly blew me away with its capabilities.

Basically, like a lot of the things Windows does, it does audio particularly badly. Audio processing gets mixed up with everything else so you get problems with audio latency.

What is audio latency?

This is where audio gets delayed when being processed through microprocessors. It’s a particular problem with music because it obviously affects the timing. You’ll know exactly what I mean if you have encountered a laptop trying to use a DAW music program using Windows direct sound audio drivers. You play a note on your synthesizer VST and you hear it later than you would want.

Delays of over 20ms are noticeable when it comes to playing musical instruments and 10ms is basically a pipe dream on a Windows audio driver. So things weren’t great for music and Windows.

How audio latency can affect your music and mixing?

Ideally, you don’t want any latency. You don’t get it when you play an acoustic instrument. I can remember when I first got an OSCar synthesizer. Although it was and still is a fantastic synthesizer I did notice that it didn’t seem quite as fast-acting as some other mono synths that I had. I’m not absolutely sure whether this was down to the microprocessors that controlled the OSCar. It could have been the speed that it took to scan the keyboard and trigger the envelope generators or the actual speed of the envelope generators themselves. Either way, it wasn’t as fast as my other synths but when you played it live, you compensated by playing slightly early.

It was more apparent when you sequenced it. With small latency times, you unknowingly compensate by playing early.

It’s when it gets over 20 milliseconds that it starts to become musically unacceptable.

That’s when you’re playing and recording.

If you are mixing and everything is on the hard drive, PC latency shouldn’t be such a problem as when you are altering levels. A 10ms delay won’t cause problems. You’ll only start to notice problems when you are mixing live stuff in as well.

In the picture above you can see the ASIO driver installed for the Behringer UMC204HD sound interface. This hardware, together with its ASIO driver is an excellent choice for a home studio sound interface choice. With its ASIO driver, you can easily get latency timings down to 10ms.

Ways to reduce latency and audio problems

Since most people using Apple Macs won’t have this problem. This article is mainly aimed at users running the Windows operating system.

Firstly you want to have as much of your processing power available to produce your music. For this reason, I have a laptop that is entirely dedicated to making music.

This enables me to do away with an internet connection. Then with no internet connection, there’s no need for an antivirus program and updates and other internet-checking software has nothing to download in the background.

This leaves more processing power for your digital audio workstation (DAW). The lack of internet also has another advantage. You don’t get distracted by Emails and social media because you can’t access them.

Low latency

When you use real time audio in a computer system you want low latency. Low latency is considered below 10ms if you get to 5ms you are doing well. There are some professional systems around that can get as low as 3ms allegedly.

You can adjust the latency on your system. It alters things like buffer size but it is a bit of a juggling act as the lower you reduce latency the more likely you are to get audio artefacts like clicks and crackles. Again not something you want.

Multiple inputs and outputs

Microsoft direct sound audio drivers only supported stereo input and outputs. ASIO supports multiple inputs and outputs. If your sound interface has more than that, you should be able to route them with the software to set things up how you want in a much more flexible way.

If you have more inputs on your sound card you should be able to route them to record on all of them at once. This is one of the most useful applications, to enable multichannel recording.

Alternatives to manufacturers ASIO drivers

You may have heard of ASIO4all. If you haven’t have a look at my ASIO4all explanation and guide to setting it up .

FlexASIO is a similar application.

You can use either of these if there is no ASIO driver written for your particular hardware. If you are using a laptop’s built-in sound card you may struggle to find an ASIO driver written for your hardware. Then you won’t have many options other than to use ASIO4all or FlexASIO.

If there is an ASIO driver for your hardware, you are better off using that. ASIO4all can cause some other issues but it’s pretty good when you consider it has to work with multiple operating systems and hardware.

USB sound interfaces

If you have a laptop that you use for music, you may be better off getting a USB external sound interface.

These aim more at music production so most of them will have ASIO drivers written for them. For more information on exactly how good these are have a look at my article on how sound interfaces are necessities for music production.

Sound quality

Incidentally, you also get better sound quality with ASIO as there are no resampling or compression techniques used.

A final thought on what is ASIO

As you can see latency in music systems is particularly problematic. Delay in any sort of processing isn’t great but it is particularly bad for music which requires precise timing.

Asio enabled Windows to use music software properly.

Although there are several programs like ASIO4all and equivalents, they do have to work with generic hardware so they are compatible with as wide a range of hardware as possible.

It’s a lot better to use specific ASIO drivers for your hardware and operating system if they have been written. Luckily if you are interested in music production on your PC or laptop you will probably have a decent sound interface. Almost all of the newer decent sound interfaces are well geared up for professional or near-professional sound and that includes the ASIO drivers.

The ongoing problem though is that the more you reduce latency by shrinking the buffer size the harder your microprocessor has to work and the more chance you get of clicks and crackles. As microprocessors get faster they can process audio quicker but then audio software manufacturers write plug-ins to take advantage of that power.

In the end, ASIO and latency are a juggling act.