From the moment we started dreaming up what would eventually become the Arctis Pro gaming headset line there was a significant focus on sound quality. We asked ourselves how far could we push the envelope, could we make a gaming headset that we would truly consider high fidelity? Hi-Fi is one of those concepts and phrases that has long been used to describe great sounding audio products, but it doesn’t have an exact definition. I tend to think that high fidelity is a level of sound quality that you can’t always describe, you simply know it when you hear it. And once you’ve had the opportunity to really dive into high fidelity there’s really no going back.
Setting the target
The first step in crafting the sound of a headset is to establish some targets for what you want to achieve. In the case of Arctis Pro we knew that we wanted Hi-Res capability, so the headset had to be able to produce sound all the way out to 40 000 Hz, which is well beyond the original Arctis models and most gaming headsets which drop off beyond 22 000 Hz.
We also had to establish a target for the frequency response, the tonal balance of the headset. To do this we spent many hours listening to all sorts of high end headphones with various material including an assortment of games, music, and movies to see what worked and didn’t work on each. We also measured each of these headphones to build up a reference database of frequency response curves. This allowed us to refine and zero in on exactly what curve would deliver the high fidelity sound that was needed for Arctis Pro.
It starts with the speakers
Like choosing the right engine for a sports car, a high quality headset has to be built around the right speaker drivers. Choosing the right ones is no trivial process. There are a number of factors to consider like the frequency response, impedance, distortion characteristics, and of course having the right size to fit your design. (Contrary to what some companies’ marketing would have you believe, the size of the speaker in no way correlates to its sound quality). For Arctis Pro we evaluated a number of different options based on their specs and construction and eventually whittled it down to two.
Both drivers were chosen because of their larger magnet and voicecoil design, which allow the driver to produce frequencies out to 40 kHz, making them capable of Hi-Res audio applications, which was very much part of the plan. The design of the drivers also made them ideal to produce the very clear and detailed upper-midrange that would be key to the high fidelity sound we hoped to achieve with Arctis Pro.
The next step was to run a series of measurements on each driver and feed the data into a digital model that simulated how the final headset could perform with various design choices. The acoustic experts at Indy Acoustic Research ran these simulations and provided a great deal of data for our consideration. Armed with this extensive set of information we were able to analyze which driver would best achieve our target.
The tuning process
Tuning a headset is an interesting artform that requires some serious know-how. Ultimately it involves designing all of the pieces around the driver in such a way that will produce a frequency response that matches your target and achieves the lowest possible distortion. In practice though it’s a very iterative process. You start with an initial design, measure, and evaluate what needs to change to move towards the end goal.
Most tuning tweaks involve adding or removing leaks (holes!) between the front of the driver and the back enclosure or changing the amount of resistance on these leaks by choosing various acoustic fabrics. This allows you to tailor the balance between the lows, mids, and highs and to control any resonances (peaks in the response) that naturally occur.
In the case of Arctis Pro we were particularly focused on getting the bass response to be just right. We wanted a very strong bass extension, meaning that it would produce very low sounds down to 10 Hz, but without exaggerating the entire low end. Creating this effect without causing an unwanted bump in the low mids (around 150 Hz) is very tricky to do, and is often where many gaming headsets fail, leading to a woofy-sounding, distorted bass response. Done correctly, this design leads to a visceral bass sound that is almost felt more than it’s heard.
Again this is where we enlisted the help of Indy Acoustic Research to find the right solution. After running simulations, they constructed a 3D printed prototype speaker housing. They added a small, precisely calculated tube to create a leak between the back speaker housing and the earcup chamber, and covered it with an acoustic cloth that had the right amount of damping. This created the exact shape and extension of the bass that we had targeted.
The end result
As I said at the start, the goal with Arctis Pro was to create a gaming headset that produces truly high fidelity audio. With the powerful bass extension and well balanced midrange crafted by the tuning process coupled with the naturally clear brilliance of the speaker drivers we were able to squarely hit our target frequency response. Additionally we did it while keeping the distortion to an impressively low <1% at all frequencies (1 mW signal). So is Arctis Pro truly high fidelity? The only way to decide is to pick one up and have a listen.
