Silent Computer for Audio Recording

DigitalNathan
Old case fans and new case fans.
Old case fans and new case fans.

Ambient noise can be a huge issue when trying to record and mix. It can wreck great takes and mask tricky mix decisions. Having a separate isolated place to put your computer like a dedicated machine room or iso-cabinet will solve the problem, but for many it isn’t an option. The whizzing of fans, and buzzing and knocking of hard drives must be tackled at the source. When it comes to a silent computer for audio recording, the quieter the better!

We investigated a variety of options for our 2 year old custom built PC. It runs as a HD3 Accel Pro Tools rig using OSX. While it is not the fastest machine by modern standards, it has been reliable and stable even with the abuse it cops from being thrown around in a 3-unit road case from venue to venue, and studio to studio. Over the past week I took the opportunity to breathe a little extra life into it and silence it up a little more with some carefully selected components.

Tips for silencing a PC

The motherboard with i7 870 & stock heat sink, plus the peripherals. GPU, Pro Tools HD3 Accel, Wifi card and the new CPU fan.
The motherboard with i7 870 & stock heat sink, plus the peripherals. GPU, Pro Tools HD3 Accel, Wifi card and the new CPU fan.
  • Heat equals noise. It sounds odd, but a lot of moving components in your computer are there to remove heat. The hotter your computer operates, the harder those moving parts need to work to cool it down. Heat critical components like CPU’s usually list in their specifications the thermal design power (TDP). This is the amount of power in watts that a CPU can continuously draw while maintaining a stable thermal state as it operates standard software. If you can choose an Intel processor that has a TDP of 95 watts or less, or an AMD processor with a TDP of 65 watts or less, you will be on good ground for creating a quiet recording PC. Over the last few years we have seen some great leaps in CPU efficiency with some current 4th Gen Intel i3 processors putting out just 35w of heat.
The build up of dust in the fan outlets.
The build up of dust in the fan outlets.
  • Dust increases heat. Heat sinks rely on fans and airflow to dissipate heat. So to keep your system as cool as possible you need to ensure it is as dust free as possible. Periodically you will have to open it up and give it a blast with some compressed air and a vacuum to remove the dust they will be inclined to build up between the fins of heat sinks and within the frames of fans. It is a simple, yet necessary job.
  • Moving parts make noise. So try and consolidate them with your component selection. You most likely will always need a case fan or two. You will find it hard to avoid a CPU fan on a powerful PC build as well. When it comes to the graphics processing unit (GPU) and the power supply unit (PSU) it is possible to select components that have no additional moving parts to cool it. Using onboard GPU’s, or fanless GPU’s and PSU’s will keep your PC much quieter while relying on the natural airflow created by your case fans for cooling.
Old case fans and new case fans.
Old case fans and new case fans.
  • Forget water cooling. On paper it sounds like a quiet way of keeping things cool. In reality, a water cooled system relies on the coolant being pumped between the hot components and the radiator that cools the water down. The water pump that keeps the coolant flowing is much noisier than standard air cooling.
  • SSD’s and 2.5 inch HDD. Standard 3.5 inch hard disk drives can be noisy. Very noisy. Running solid state drives for your applications and operating system, and using 2.5 inch hard drives for your audio and sample drives will help keep the sound of spinning platters to a minimum. An SSD will give you a great performance increase as well.
  • PWM & Temp Monitoring. Most aftermarket fan manufacturers offer low noise adaptors and PWM fan control. Using temperature monitoring software such as Temperature Monitor or iStat Menus, you can experiment to your hearts content with low noise adaptors and case fan locations. Even swapping your case fan connections between system fan 1 and system fan 2 motherboard plugs can result in lower fan speeds while maintaining case temperature levels. Don’t forget that your fans will move faster as your system works harder. Geekbench 3 will put your system through some strenuous tests to give you an idea of how hot it will run under heavy loads.
Motherboard mounted with new heat sink and fan.
Motherboard mounted with new heat sink and fan.
  • Rattles and Vibration. A common cause of noise in a computer system is the rattle and vibration that they can cause. Tightening up loose bolts and screws and using the supplied rubber grommets and spacers with cooling fans is a good start to minimising these rattles. You can also utilise PVA tape to pack out any aspects of the case that aren’t tight fitting like the case access panel. A few select strips of PVA tape in the right spot will make the panel fit so much more snug and rattle free.

Suggested Components

You will have to check for compatibility with your specific system. Here is a list of silent or quiet components ideal for use in recording computers. Quite often replacing an entire component will yield lower ambient noise than just updating the fan attached to it.

Fanless GPUs

Fanless PSUs

Case Fans

CPU Fans & Heat Sinks

HDDs & SSDs

 

[wpsgallery]