Mazda 3 2019 focuses on refinement

Mazda says it has aimed to make its vital new small car, the fourth-generation Mazda3, more refined and upmarket than ever before.

In doing so, the levels of NVH - noise, vibration and harshness - have been a key focal point for company engineers such as Katsuya Shimizu.

Shimizu let us in on some of the ‘secret’s of the development of the new Mazda3 sedan and hatch, including a unique ‘damping bond’ integrated into the chassis that helps limit vibrations and noise entering the cabin. 

“The ideal state of NVH is not simple quietness,” he said, inferring that some level of noise is expected in any car - be it from the wind, the road or the engine. So he and his team didn’t attempt to silence the new 3 - instead, they moved to refine it.

Additional sound deadening elements and the new damping bond hidden in the frame of the car are said to make for “sound change that is linear and moderate, in line with the changing vibration energy input from the road, which realises comfortable quietness”.

Another way the car has become more serene inside is an emphasis on reducing panel gaps. According to Shimizu, "a gap of 1 per cent sees sound increase by 30 per cent”. But it isn’t incremental - a gap of 10 percent results in a 70 per cent increase in noise, he said. 

Additional sound deadening elements and the new damping bond hidden in the frame help make inside more serene.

“Gaps make great differences to sound isolation, so we focused on minimising gaps in Mazda3,” he said.

Other measures have been taken to improve the cabin ambience, with acoustics and audio expert Yoshihiro Teshima explaining that the audio system has seen a major overhaul in this generation of Mazda3.

“It’s hard to define ideal sound,” he said. “There are so many different and many brands of audio system. People have different tastes for sound. The perfect system has not been established yet.”

But Mazda has put forward a new eight-speaker stereo in the base model car that is designed so a driver is “able to listen to the sound at their preferred volume” and also “play music accurately” - as in, with no buzzing or contortion at higher volume.

“We examined the best speaker placement from scratch,” he said, before stating that Mazda studied the placement of the speakers before the chassis and engine layout was even finalised.

We expect the Bose system to be beefier in its bass compared to the standard speakers.

As such, Mazda’s engineers removed the lower speaker in the door, and instead used higher speakers in the tops of the doors because “sound pressure goes up easily” there, while the larger speakers are in the sides of the cowl panel. Where the previous door speaker was there’s no a steel plate to reduce the gaps present. 

With the NVH and audio teams working together, the result is claimed to see a reduction in cabin noise and an increase in the efficiency of sound from the stereo.

I can attest that the basic eight-speaker stereo is a vastly better offering than in the previous model, and as good - if not better - than a lot of stereo systems that luxury brands ask you to pay more for. We didn’t get to sample the up-spec Bose version with an additional centre speaker, subwoofer and twin rear satellite speakers (12 in total), but we expect it to be even beefier in its bass.

Are you an automotive audiophile? Tell us what you think in the comments below.