Optimization for PC Audio: Part Two

Last month we showed you a dozen easy ways to optimize your PC for audio recording and playback. Here are eleven more ways to manipulate your BIOS (Basic Input Output System) to get the most out of your computer.

1. Assign a separate IRQ to your M-Audio sound card.

If you have too many devices on one IRQ, you can overload your system. You can, however, reassign the IRQs to optimize performance.

Take note of what PCI slot your M-Audio card is in. Then go back to the Device Manager (right-click on My Computer, then select Properties | Hardware | Device Manager). Look for an unused port that you can disable in order to use the IRQ it's assigned to. In most cases, the COM1 or COM2 ports work the best.

Once you find an unused port, take note of what IRQ it's on. Right-click on it, select Properties, and choose "Disable in this device profile." Then reboot your computer.

While the computer is rebooting, tap the F1 key and the Delete key back and forth until your system BIOS pop up.* Go to “Advanced,” then “PCI Configuration.” This will show you the PCI slots and their IRQ assignments. Simply go to the Slot Number that your M-Audio card is in, and change it’s IRQ number to the newly available one. Choose "Exit and save changes." Your computer will restart and boot up normally.

Now go back to the Start menu, select Run and type "msinfo32". Then click OK | Hardware Resources | IRQs. Confirm that the M-Audio card is on it's own IRQ.

*NOTE: Not every BIOS will allow you to make IRQ assignments by PCI slot. Please review your motherboard documentation for details.

2. Load Bus Master driver.

If you are running a newer (P4) Intel Chip set, load the particular chip set driver (Intel PCI Bus Master IDE controller) for that motherboard in order to prevent the OS from loading a generic “Ultra ATA Storage Driver” hard disk controller.

With the ATA controller, there are always distinct peaks in the CPU usage when audio applications access the hard drive. These peaks result in noticeable clicks in your audio. These clicks will disappear when using this Bus Master driver. Similarly, the peaks in the CPU usage display will also be eliminated. The Bus Master driver will also prevent pops or clicks from occurring when you activate or deactivate audio playback through the keyboard. As an added bonus, it relies less on the CPU.

3. Monitor system resources.

Make sure that your system resources are not being maxed out. You may need more RAM system memory.

Too many applications running in Windows will quickly use up system resources. Hold down the "Ctrl" and "Alt" keys, then press “Delete.” Aside from “Explorer” and “Systray,” all the programs that pop up are non-Windows OS programs and are using up system resources. Close the unnecessary applications.

4. Monitor USB devices.

USB mice can generate pops and clicks when the USB host controller is sharing an IRQ with other devices. A USB hub located alongside an audio cable that is connected to the sound card can generate noise. The noise induced through the cable can be especially great at a sample rate of 96kHz.

5. Disable unneeded USB.

If you do not use any USB devices, disable USB completely in the BIOS.

6. Properly ground all electrical components.

Poor grounding of electrical components can result in unwanted pops and clicks. This can include electrical components that are inside the computer, as well as external elements such as air conditioners, fans, heaters, and microwaves. Please take the necessary steps to ground such items.

7. Reinstall sound card drivers.

Restart computer into "Safe Mode" by tapping the F8 key while your computer is booting up. Go to Device Manager | Sound Video Game Controller and locate all listings of the Delta card. Try removing all such listings and re-boot the system, allowing Windows to reinstall the drivers automatically. This has been proven to significantly increase the quality of audio during recording and playback.

8. Reset DMA buffer size.

Try setting the DMA buffer size to 1056. This option can be found in the Delta Control Panel under the Hardware Settings tab.

9. Adjust sample rate settings.

Uncheck "Reset Rate When Idle" under the Codec Sample Rate section of the Delta Control Panel Hardware settings tab.

10. Select the proper BIOS setting for your hard drive.

Wrong BIOS settings for a UDMA Hard Drive can cause unwanted noises. If you have a UDMA hard drive but have the BIOS set to IDE, pops and clicks will occur. Right-click on My Computer. Enter Properties | Hardware | Device Manager and click the “+” sign next to Disk Drives. Right-click on GENERIC IDE DISK TYPE. Select Properties/Settings and check DMA. Click OK.

Now go back and do this with the second GENERIC IDE DISK TYPE. Right-click on Properties/Settings and check DMA. Click OK and restart your computer.

11. Use the USB expansion bracket.

On the Asus CUSL-2 motherboard, it is important to install and use the two-port USB expansion bracket. This plugs directly into the motherboard, and does not use the same system resources as the two on-board ports, thereby increasing audio quality.