Sound generators...

Leonard Hofstadter

Just wondering, what do people think of them?

In today's increasingly emissions obsessed world, where tax levels are getting increasingly high, and therefore makes it harder and harder to financially justify an engine with more than four cylinders, are they really such a bad thing?

Have a listen to the new BMW 428i. Now we all know there was a time when 428i would have meant a silky smooth naturally aspirated six cylinder engine, but we all know that times have changed, and we know that for quite some time BMW has replaced most of its lovely NA six pots for dull and boring four cylinder turbos, the same as what you'll find in a Skoda Fabia for example.

And of course, the 428i is no exception - it has only four cylinder rubbish rather than a proper six pot.

But, as anyone who listens to this youtube link will notice, this sounds like a six cylinder, not a dreary old four banger lump. Up to this point, BMW's four cylinder engines (apart from an E30 M3), like most other four cylinder engines, have sounded about as interesting as watching paint dry... but this, sounds so much nicer, it sounds like a six cylinder lump, and considering that it has more power than many a six cylinder unit, is no bad thing considering that you can have six cylinder noise and performance but four cylinder economy. It doesn't sound like a BMW six cylinder, more like a Japanese V6, but at least they have the right idea. Either way it's streets ahead of any other BMW four banger (including the E30 M3).

Of course, it doesn't sound as good as a real BMW six cylinder, as this video of the latest 335i shows, but I much prefer it to the 328i, which is linked below. I have no need for something as fast as a 335i or 435i, but I love, and have always loved, the sound of a six cylinder engine. Now I could have the best of both worlds, a car that's cheaper to buy, not to mention cheaper to run, and still have a car that sounds good (on the inside anyway). Okay, it still won't be as nice to drive as a six cylinder engine (obviously), but it will be much nicer than a diesel to drive.

Sounds good doesn't it? Until you realise that, like the F10 M5, it has a sound generator. Of course no four cylinder engine could sound almost the same as a six cylinder (especially a BMW straight six) - it's not possible because of how engines work.

But it sounds good enough to me, and a hell of a lot sweeter than the true sound of the N20 engine. In its sister car, the 328i, the same engine sounds like this, the same as a regular four pot, dull, boring and no character. It might not be a genuine sound, but at least it's an intersting, sporting sound. It's a sound that does far more justice to the 'Ultimate Driving Machine' than the standard N20 sound. And a good soundtrack is driving pleasure, well to me at least.

I wonder what people think? I have mixed feelings about it. One half of me knows it's not the engine's true sound, and I don't like the idea of hearing what is literally a recorded soundtrack. Driving a fake is never the same as driving the real thing. Of course engine notes are manipulated in many cars these days, so this move is hardly controversial. In many cars the noise in the cabin isn't the same as the noise you'll hear in the engine bay (or from the exhause), but in say an old Z4, they used induction loops to take the good bits of the true engine note, and filtered that into the cabin. So, the noise was coming from the engine, not from a recording.

And hearing a straight six under maximum acceleration on youtube is nowhere near as pleasant as hearing it in real life. It's a bit like comparing going to a concert of your favourite band and hearing the live recording of the concert you went to afterwards on the TV or on radio - it never sounds as good through this medium as it does when you're actually there and listening to it.

But, if it means that we can still have nice sounding cars, and keeping the greenies happy, then it's a compromise I'm willing to accept. You can't even say that BMW straight six petrols sound all that nice now anyway, after all they're turbocharged and if you listen to a turbo engine versus a NA engine it doesn't sound the same. Certainly they don't sound as nice as they used to. Let's face it, we're never going to hear a six cylinder engine sound as good as an E46 M3, those days are over. So, if an articifical recording can make a six cylinder turbo sound more like an NA engine, that's a good thing in my book as well. I would much prefer an artificial sound to say an electronic parking brake, or an automatic gearbox.

Sound generators can be so effective that they can even fool Chris Harris. If you skip onto 13:30, you will hear him say 'How good does this sound' in reference to the M135i. And you're probably thinking, yes it does sound very good, of course it does, it's got a BMW straight six under the bonnet.

But, it's a fake sound too, and none the worse for it. The best sounding six cylinder engines - the NAs with no direct injection or anything too complicated, aren't made anymore, so even the sixes without a sound generator don't sound as good as they used to anyway. The other advantage of having a sound generator is they can make the engine note you hear in the cabin sound nicer without affecting fuel consumption or emissions. That's a good thing.

It would be possible to make engines sound like they used to, before turbos came along and direct injection and all that kind of stuff. You could even change the sound to suit your mood, if you felt like you wanted to hear a five cylinder engine, you could have that one day, then the next day you could have six cylinder sound. Even diesel drivers would benefit, you could make them sound like petrols inside (they'll still be as horrible to drive anyway, so petrol will still be better:D).

You could also have a V8 sound in a four cylinder motor as well. And that's surely the biggest drawback of sound generators? A car that sounds like something it's not. A four cylinder car will never be a six cylinder car, six cylinder sound or not. It's like poverty spec 316ds with their miserable 114 bhp festooned with M Sport packs and M badges - an oxymoron if ever there was one. Or, to use another analogy, the fad for RS4 TDIs. Just because they're popular doesn't mean it's right. But I guess that's the way things are heading with cars.

It's a sad reflection of where things are at, but I'd rather a four cylinder that sounds like a six than no six cylinder like sound at all. Soon that will be the closest we'll get to six cylinder plus engines.

YbFocus

I thanked that for the sheer effort you put in

No to sound generators! Everyone would look ridiculous. If it goes the way of no car having a decent engine anymore I'll get myself an old vintage machine before I'll have a fake soundtrack

jimgoose

Anyone who thinks the sound of a four-pot is intrinsically inferior has never heard a crossplane R1 on full yowl! And, I will use a "sound generator" shortly after I sign up for a speed governor ta get de chape insurance, like.

YbFocus

jimgoose wrote: »

Anyone who thinks the sound of a four-pot is intrinsically inferior has never heard a crossplane R1 on full yowl! And, I will use a "sound generator" shortly after I sign up for a speed governor ta get de chape insurance, like.

Oh there are plenty of sweet 4 cyls it there alright

Kenny Logins

What's next? Automatics with fake gear changes as you accelerate? With up to 8 gears.

H3llR4iser

Kenny Logins wrote: »

What's next? Automatics with fake gear changes as you accelerate? With up to 8 gears.

Or the "Fast and Furious" option, with 15 or 16 gears

To the OP: Simply NO. The idea of sound generators is quite a silly one, even for electric cars (there is something intriguing to the whirr from a Tesla Roadster, to say). Technology evolves, and the sound of engines goes with it; It's all a matter of getting used to it - a handful of current supercars, with their "screaming" engine note, would have been considered dull say in the '50s-'60s, when most engines had a more throaty roaring sound.

And for the "dull 4" against "smooth 6", well the world doesn't begin and end with BMW. There's quite a difference between the sound of a Twin Spark 4L and a Skoda Fabia, to say...and I'm fairly sure BMW itself makes decent sounding 4Ls.

jimgoose

Kenny Logins wrote: »

What's next? Automatics with fake gear changes as you accelerate? With up to 8 gears.

I believe Audi's Multitronic transmissions have been doing precisely that for years!

jimgoose

H3llR4iser wrote: »

Or the "Fast and Furious" option, with 15 or 16 gears ...

Aye. Eaton Twin-Split, presumably. Like an oul' Seddon Atkinson.

JoeA3

The current Golf GTI also has a sound generator (or "actuator"), under the base of the windscreen. It gives a big "induction" roar into the cabin under acceleration! The GTD has one too, making it sound like a petrol from the inside (still sounds like a tractor on the outside).

muckwarrior

IMO it's just one step above those eejits that stick electronic dump valve noise makers in non turbo cars :rolleyes:

Part of enjoying the noise of a nice engine is appreciating just what makes it. If the sound is fake, then no matter how good it sounds it's just pointless IMO.

mickdw

jimgoose wrote: »

I believe Audi's Multitronic transmissions have been doing precisely that for years!

Try a Lexus Gs 450h, now fair enough, the cvt box does what its supposed to do very well, holding a specific rev and altering the ratio to accelerate. The stupid 'manual' option that they have included does little more than allow you to change the gear number displayed in the dash. Its makes little difference to what the car does.
Re sound generators and the like, I guess a system that magnifies actual engine sound inside the cabin is just about acceptable if it is done by perhaps allowing a sound tunnel into the cabin under certain circumstances and doesnt use the stereo to produce the sound.

MetzgerMeister

Sound generators are like having Metallica playing on a stereo and listening to a Metallica tribute band through earphones on a phone.

What is the point???

The 4 pot 2.3T engine I had in the MPS sounded good IMO, nice roar from it and there was no sound trickery or anything like that.

dantastic

It really is the same as knock off brand clothes, hand bags etc. Why not spend the time and effort making the engine sound good and just embrace it for what it is? The 4 cylinder can sound good too. This is all to do with character of the engine and I think if you need a sound engine for the engine you have misunderstood the whole thing.

Just like with fake hand bags, the only people you impress are those who don't know any different.
This is what you look like to everyone else....

Anan1

You can tell a lot about the health of an engine by listening to it. It's down to personal taste of course, but it's a bit Playstation for mine.

Dord

Anan1 wrote: »

You can tell a lot about the health of an engine by listening to it. It's down to personal taste of course, but it's a bit Playstation for mine.

This.

I'm intrigued by the concept of the sound generators, but more importantly how they're doing it. I don't really agree with their use for the reason mentioned above though.

de Ville

I,ve a sound generator on the front passenger seat, thankfully she uses her own car most of the time....