Computer Audio Asylum: RE: Ping Old Listener -- J.River Setup Question by Old Listener

> In J.River under "Tools - Options - Playback - Audio", there
> are several choices available.
> Under "Output Mode" I have:

> - Wave Out

This interface goes back to the early 90s and 16 bit Windows 3.x. It is functional for audio output. I've used it. It isn't low latency so it isn't great for recording. It doesn't have the features needed for good video game support either. You may also see this interface described as MME for Multi-media Extensions.

> - Direct Sound

So Microsoft developed DirectSound as part of the DirectX package for better game I/O. It wasn't much different than Wave Out for audio output.

Both these interfaces send audio through the entire Microsoft audio stack including the KMixer component that gets reviled by audiophiles. J. River's advice is to try one of these interfaces and if it doesn't work, try the other. That is a reasonable approach.

> - ASIO

If you wanted to use a Windows PC to record music, you needed a better interface. So Steinberg developed a driver interface ASIO and wrote ASIO output modules for their pro-audio products. Companies making Pro-Audio I/O PCI boards implemented ASIO drivers. The drivers had to be installed under Windows but they didn't use Microsoft's audio stack. The result was a short controlled path from the application program to the audio output hardware. It was possible to achieve low latency which allows you to do more recording work using PC s/w for more things. Low latency isn't necessary for audio output unless you want to synchronize multiple channels closely or synchronize audio with video.

Since an ASIO driver doesn't send audio through the Windows audio stack, you can avoid KMixer. For some audiophiles, avoiding KMixer made ASIO interesting for audio output. More recently, cics has advocated using ASIO with very minimal buffering (and low latency) as producing better sound than you get with more buffering.

Another reason to use ASIO is purely practical. Companies selling Pro-Audio PCI boards needed a functioning, low-latency driver to sell their hardware. In contrast, until recently two channel audio input and output were not high on Microsoft's priorities. It takes time, money and skill to develop driver software and time to get applications and drivers to work together seemlessly. ASIO is mature. That's good. Mature hardware is good too.

If your hardware comes with a good ASIO driver, try to use it.

> - Disk Writer

As the name says, what you play goes to a wav file on your hard drive.

If you run J. River MC under Vista, you should see another choice: WASAPI exclusive mode. Although Vista has been out for some time, adoption of this interface has been slow. Don't be surprised by glitches and incompatibilities. While the audio path is shorter for WASAPI exclusive mode than for regular WASAPI mode, it still involves some user mode code. ASIO may be a safer choice under Vista for a but longer.

My recommendations are my own based on experience working on drivers and inside operating systems. My conclusions are from that experience. You can use them or not.
--- Some extra info to fill out the whole picture.

I haven't said anything about the application side of the interface. J.River MC 13 comes with support for all these output choices. Some other players need a plug-in module from a 3rd party for ASIO or WASAPI exclusive mode output.

Most USB devices being sold now rely on USB audio drivers written by Microsoft. So you don't get an ASIO driver with your USB device. In the XP environment, some people installed ASIO4ALL which looks like an ASIO driver but sends output to a low level interface (kernel streaming) rather than to the audio hardware like a real ASIO driver. There are two practical reasons why this is less desirable than an actual ASIO driver: The ASIO4All module hasn't been tested with most audio devices that it will be used with. And the kernel streaming interface is far less tested as an entry point for the audio stream than Wave Out, DirectSound or ASIO. If you need to use ASIO4ALL, give it a try. If you don't need to use it, don't.

In general, the fewer 3rd party modules or plug-ins you need to use, the better your chances of trouble-free operation.

Ask more questions if I left some things unsaid.

Bill