Windows Driver Model and how it all works

[spthomas]

I'm using a Windows 7 64 bit system and a Tascam US122 interface for some home recording. for a lot of the quick and dirty work, or if I just need to dub something from tape to digital, I use Audacity. I have Sonar X1 but haven't spent the time yet to get real familiar with it.

I've noticed a bit of unacceptable latency with the US122. After prowling around on Google for a bit I have seen suggestions to update the drivers for the US122, maybe with something like ASIO4All. All well and good. I installed ASIO4All, but can't figure out how to get the US122 to recognize it (or Audacity either, for that matter.

It occurs to me I don't know nearly enough about how the drivers in Windows work. And what is ASIO vs WDM vs Windows Sound Direct vs???? Does anyone know of a good article that explains all this? I'm not sure exactly where the "driver" is (in a sound card, on the motherboard?) Since the US122 is a USB connected device, does it contain the sound card?? What is the sound chain from input device to the computer and out again?

I understand a lot about computers after all these years. But computer audio is fairly new to me. So if someone can point me to an intermediate-level explanation of all this I'll TRY not to ask a whole lot of dumb questions.

Steve

 

[somegeezer]

Download the official driver for it. See if that helps any.

 

[spthomas]

I have the official driver, and I downloaded the latest version. Still latency is an issue, and it still hangs the laptop if I power down without unplugging it first.

I have the driver that Tascam provides. But I've heard a lot about using ASIO drivers like ASIO4ALL to reduce latency and to overcome this hanging bug. But where does that fit. Does it REPLACE the TASCAM driver, or is it just the API that sits on top of the TASCAM driver? From what I have read the last day or so, it goes something like this:

HARDWARE -- Driver(like the TASCAM Driver) -- API (Like MM, ASIO, DirectX, etc.) -- Application (like Sonar or Audacity).

Where does an updated driver like ASIO4ALL fit in?

Steve

 

[JimmyS1969]

Using ASIO4All is a crutch for crappy devices/drivers that do not work. The Tascam drivers are solid and will be your best bet.

Your latency issue is most likely a buffer setting issue, or a CPU power or setup of you OS.

Throw out some specs and we can see if something stands out.

 

[spthomas]

Thanks. Here's what I know:

Laptop is an Intel CoreDuo T6600, 2.2GHZ processor, 4GB Ram

Windows 7 Home Premium 64-bit

US122 original (not Mk2) Driver version 3.4.2
Latency in the US122 control panel has options for 256, 512, 1024, 2048. Using the default 1024.
I believe it's using the 32-bit driver, but not sure. I don't think there is a 64 bit driver.

Audacity 1.3.13
Audio Host Windows DirectSound or MME (I've tried both)
Output Device US-122 Out (US-122 WDM)
Input Device US-122 A:B (US-122 WDM)
Audio Buffer 100ms, Latency Correction -130ms.


I also use Sonar X1 a little, but not enough to know if It's set up right or not. Here's the setup:
Also uses US-122 A:B and US-122 Out.
Driver bit depth: 16
Sampling rate: 44100
Buffers in Playback Queue: 2
Buffersize: 92.9msec, 4096 samples, sort of medium-fact on the slider.
Effective latency at 44khz/Stereo: 92.9msec.

Like I said, latency seems to be an issue with the US-122, plus the annoyance of having to unplug it before turning off the PC or it hangs.

 

[somegeezer]

Try it at a lower buffer setting, as Jimmy mentioned it could be.

 

[Mo Facta]

I'm using a Windows 7 64 bit system and a Tascam US122 interface for some home recording. for a lot of the quick and dirty work, or if I just need to dub something from tape to digital, I use Audacity. I have Sonar X1 but haven't spent the time yet to get real familiar with it.

Spend more time getting to know Sonar. It's a far superior program.

I've noticed a bit of unacceptable latency with the US122. After prowling around on Google for a bit I have seen suggestions to update the drivers for the US122, maybe with something like ASIO4All. All well and good. I installed ASIO4All, but can't figure out how to get the US122 to recognize it (or Audacity either, for that matter.

As Jimmy said, ASIO4all is not ideal although it's great if you want ASIO without the hardware, i.e when only using the onboard sound in your motherboard. I'll explain what it actually does shortly.

It occurs to me I don't know nearly enough about how the drivers in Windows work. And what is ASIO vs WDM vs Windows Sound Direct vs????

ASIO means Audio Stream Input Output. It was invented by Steinberg as a means to bus multichannel audio at low latencies in and out of a computer. It has become the de facto standard protocol in professional PC audio and is used by most audio interfaces, both prosumer and professional level. WDM means Windows Driver Model and is the stock standard driver protocol used by Windows for audio. I am not too familiar with how it works in W7 (I haven't made the leap yet!) but in XP the minimum latency you can get with WDM drivers is 64ms, which is unacceptable for professional audio applications. This is because WDM audio in Windows was never made for professional audio but was focused mainly on video and you get 64ms of latency to accommodate the pre-read required to buffer video. ASIO4all uses the WDM drivers of a given interface or onboard sound card and wraps it in the ASIO protocol, bypassing the 64ms latency barrier and providing low latency. What's handy about this is that by using ASIO4all you can run multiple audio devices at once, provided they have a WDM driver facility. This is not possible in ASIO, which is a shame as I know there are many people who would be very happy to see that happen, including myself. DirectSound is the DirectX sound driver that is can be used by some applications but it still runs on the WDM kernel. It is generally not used in professional audio.

So really the only option is to use ASIO if you are looking for multichannel low latency audio. Your Tascam will have ASIO drivers and they usually come on a disk that is supplied with the unit. If you don't have this software, you can download it here:

Product: US-122 | TASCAM

IDoes anyone know of a good article that explains all this? I'm not sure exactly where the "driver" is (in a sound card, on the motherboard?) Since the US122 is a USB connected device, does it contain the sound card?? What is the sound chain from input device to the computer and out again?

A driver is merely software that you install to enable the computer to "talk" to the sound card/audio interface. Think of it as the software that "drives" the bus. You can't move a bus without a "driver". Anyway, metaphors aside you should download the US122 driver and all documentation from that link above and read the installation guide. Sometimes there are specific steps that must be followed for the interface to work correctly. Reading the manual is always a good place to start.

Cheers