This Twenty Thousand Hertz podcast discussed how sounds that a car makes are engineered, starting with how the door sounds when you close it.
They mention that some cars either synthesize or mic engine noise and pipe it into the passenger compartment (around the 5:00 mark). I won’t get into all the reasons this is done but they don’t mention any examples. This is not something the manufacturer would want to put in the owner’s manual. How would I know if my car does this?
I’m fairly sure that every popular make has at least some models with synthesized engine noise. Ford, BMW, Volkswagen, and Toyota are known for sure. But none of them are very talkative about it, so for any particular model you’ll probably have to prove ti on your own (by pulling fuses, etc.) or find someone else that has.
Is it a Ford Mustang Eco-boost? That model and others are discussed here.
Car & Driver usually mentions it when they review cars, so they must either get the info from the manufacturer or know how to figure it out. I don’t recall them mentioning how they know.
Figuring it out is pretty trivial.
Use a Decibel meter to gauge sound pressure in front of a speaker while revving the engine and then letting it return to idle.
Yank the fuse for the car’s stereo.
Repeat the test with the Db meter.
If the second test is obviously different from the first, then the car is supplementing engine noise with speaker noise.
Smartphone apps are pretty terrible for measuring absolute sound pressure levels, but they would probably work well enough for the relative difference this test is looking for.
Finally, I suspect that the car companies’ media liaisons usually just tell the editors at C&D (and other magazines) whether the engine sound is juiced. It’s easy to detect. They may provide this information off the record, but it’s silly to think that the editors might not notice.
Some makes at least have a completely independent system, including speakers. They’re liable to have a different fuse as well.
FTR mine is an Infiniti Q60S convertible.
Some cars measure the engine noise and pipe in sound frequencies opposite in amplitude of it to reduce the engine noise inside the cabin.
Cars that tend to be more performance oriented are the ones that generally have the engine sounds enhanced. Cars that are more for luxury and comfort tend to measure the engine noise and pipe sound of the opposite amplitude into the cabin to reduce the engine noise. So it can go either way, depending on the car.
Is it opposite amplitude, or opposite phase? Amplitude is basically loudness, or volume, right? I don’t understand how “opposite amplitude” works.
Yeah, opposite phase.
It would have been really helpful if OP had stated what kind of car OP has.
Edit: oops, didn’t see the follow up post. Yes, it would seem the Q50S has engine sound enhancement:
http://www.autoguide.com/manufacturer/infiniti/2016-infiniti-q50-red-sport-400-review
Thanks for the link. However, that’s not my car (mine is the Q60S). Mine is one model year older with a different power plant, and 2-door rather than a sedan. At least this confirms that Infiniti plays this game.
VW uses a thing called a “soundaktor” which vibrates the A-pillars and windshield to create a sort of V8-y rumble. There are a bunch of YouTube videos showing what it sounds like turned on and then turned off, but I can’t tell the difference.