Be honest with yourself. Why did you buy a BMW? To own a discreet car perfect for Sunday trips to church?
Nope. You bought it for the roar in the suburbs.
Nothing brings satisfaction like catching the stares around you each time your unleashed V8 screams under the hood – well, apart from the dynamic thump on the highway with your Sport Mode turned on – yet, unfortunately, not all modern BMWs can bring out that engine growl.
Since most of them come with quieter exhaust systems and are getting progressively more sound-isolated, you can barely hear their distinct motors, which makes you think... you might as well have bought a Honda ¯\_(ツ)_/¯
And here’s where the Active Sound Design (ASD) steps in. For some – the saviour filling the void of the Bavarian brand’s missing sporty experience. For others – a complete failure faking the authentic roar of the engine. Depending on your taste, Active Sound Design may be a fun acoustic feature to play with, or something to immediately get rid of your in system. Whatever way you choose, we’ll tell you how to do both.
This is how we got here – in the face of environmental restrictions and a demand for enhanced fuel economy, BMW started to produce smaller engine subsystems that reduced the original sound and replaced the distinct deep whirr with a quieter high pitched noise. Since this decision sparked cravings for a more desirable interior and exterior sound, the automotive manufacturers introduced a new acoustic technology concept – Active Sound Design.
In a nutshell, it’s technology using a vehicle's audio system to allow drivers to experience the manufacturer's preset engine sound. Active Sound Design operating within the audio amplifier either alters, reduces or enhances the sound inside and outside of the vehicle. Using active noise control and acoustic enhancement techniques, it delivers a synthesized engine sound that’s (debatably) supposed to improve the car's reception.
Delving into the technicalities, to improve the effects of ASD manufacturers may use Active Noise Cancelling (ANC), which eliminates undesirable noise within the interior of a car via the vehicle’s infotainment hardware. This filtering technique is called a harmonic order reduction. On the other hand, Engine Sound Enhancement (ESE), just as the name suggests, enhances engine sounds with synthetic noise based on various engine parameters, such as torque, throttle and RPM (revolutions per minute). Such synthetically composed sound is further delivered through interior or exterior speakers to enhance perceived engine power without making any mechanical alterations.
There are a few ways the ASD may work. As we’ve already covered, the Active Sound Design takes inputs from continually updated engine parameters, exhaust noise and vehicle speed, which are then filtered by a DSP to produce the desired outputs. Depending on the type of ASD, it can use one or multiple of these variables to produce a brand new sound inside and out of the vehicle. The variations come as follows:
If you wonder how to know which cars have Active Sound Design, it’s best to look at the BMW model type. Fake engine noise can be found most commonly on M performance models – like the BMW M240i or BMW M235i. Nowadays, almost all newer performance focused BMWs come with car sounds simulators. For instance, you can find ASD in the BMW i8, BMW M5 F10, BMW X3 M40i, BMW X4 M40i or BMW X6 50i SUVs.
Before BMW introduced Active Sound Design to its range of vehicles, it was in fact a petrol-powered MINI Cooper S prototype demonstrated in 2009 that was first equipped with the module. Never before had a four four-cylinder engine sounded like a straight-six or even V8, which actually… seemed a bit disconcerting.
Soon after, the Bavarian company used BMW Active Sound Design on a diesel car – the 635d – to demonstrate the engine sound enhancement that was to be applied to most of the future M-type and i-type BMWs.
Why EVs though? As it turns out, the lack of an internal combustion engine has its gains and losses.
Electric vehicles may have been hailed for their environmental progress, but in fact, because electric car noise is much quieter than its gas-powered counterpart, it induces a particular risk for pedestrians and animals.
According to research, EVs and hybrid cars have a 40 percent higher chance of being involved in an accident causing injury to road users, especially those who are blind or visually impaired. Due to this, legislation has been enacted. In 2019 European Union imposed an obligation for all 2019+ electric and hybrid vehicles to come equipped with an acoustic vehicle alert system (AVAS) from the factory, and by July 2021 all existing EVs used in the European Union will be bound to have it.
The fake engine sound generator won’t have to be on at all times though. It’s supposed to produce an internal-combustion-engine–like sound when the vehicle is reversing or driving below 12 mph, just to give pedestrians an idea of what the car is doing by, let’s say, synchronizing with its speed.
Here’s a sample of what your BMW i8 fake engine sound might be like.
Luckily, BMW didn’t leave you without a choice. If you have the car sound simulator in your vehicle, you can adjust the settings of your ASD in the iDrive menu to change the intensity of the sound. Depending on your preferences, you can choose to have it reduced, balanced, sporty or applied to the driving mode.
Here’s how to adjust the ASD in NBT Evo ID5 / ID6 head units:
And that’s about it! You can now change the modes to your liking.
As we can imagine, not all BMW drivers are subtle torque fans, nor want to hear squeaky barks under the hood. Since the ASD application operates within the BMW audio amplifier, it clashes with its volume and may cause significant sound distortion. If you’re experiencing that in your BMW, there are 2 ways to get rid of it:
Either way you choose to deactivate the BMW Active Sound Design, BimmerTech will permanently disable engine noises pumping through the speakers, helping you enjoy the natural sound of your music tracks.
Found our post helpful? Let us know down below in the comment section. If you feel like we didn’t touch on an important ASD topic or issue, give us a heads up. We’re glad to hear about your ideas!
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