Sound Actuator Question

26896 Views 79 Replies 35 Participants Last post by stephenc, Mar 14, 2019

Fliz

Discussion Starter · Feb 12, 2018

Does anybody know if the sound actuator in our cars is simply amplifying emitted sounds from the engine/drivetrain or adding new sounds not actually emitted by any part of the engine/drivetrain? Perhaps sometimes canceling or augmenting sound somehow?

If it is not simply amplifying existing sounds, any ideas on what the algorithm is?

Thanks!

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johan

· #2 · Feb 12, 2018

Its just a "speaker" or more like a buttkicker that makes the firewall vibrate in different ways.
It changes in sound depending on drive mode but I cant say if its changes algroritm but I suppose it does.
I only have been driving a couple of days with it before I disconnected it and I will never use the sound actor again!

Fliz

Discussion Starter · #3 · Feb 12, 2018

johan said:
Its just a "speaker" or more like a buttkicker that makes the firewall vibrate in different ways.
It changes in sound depending on drive mode but I cant say if its changes algroritm but I suppose it does.
I only have been driving a couple of days with it before I disconnected it and I will never use the sound actor again!

Thanks for that Johan. I do want to try to disconnect as well, but don't want to mess with it until I have the dealer check a recurring buzz/rattle in my BS again.

johan

· #4 · Feb 12, 2018

I hope they will find it, that's one of the worst things to have in a car!
Its pretty straight forward to disconnect it, a bit more easy in a Cayman.

Good Luck!

Reactions: 1

trusted

· #5 · Feb 12, 2018

Fliz said:
Does anybody know if the sound actuator in our cars is simply amplifying emitted sounds from the engine/drivetrain or adding new sounds not actually emitted by any part of the engine/drivetrain? Perhaps sometimes canceling or augmenting sound somehow?

If it is not simply amplifying existing sounds, any ideas on what the algorithm is?

Thanks!

@johan is correct. It's an inverse speaker that creates additional vibrations at the firewall. They are only audible inside the cabin. The speaker signal comes from the control module in the trunk. The algorithm of the control module gets its parameters from the engine control unit. They are: RPMs, torque and speed. The intensity (volume) is dependent on the drive mode.

Fliz

Discussion Starter · #6 · Feb 13, 2018

trusted said:
@johan is correct. It's an inverse speaker that creates additional vibrations at the firewall. They are only audible inside the cabin. The speaker signal comes from the control module in the trunk. The algorithm of the control module gets its parameters from the engine control unit. They are: RPMs, torque and speed. The intensity (volume) is dependent on the drive mode.

I'm not quite sure yet but it seems that intensity may be also dependent on audio being on or off. At least, I hear less buzz/rattle when I have audio turned on. But this could also be a masking effect. I will need to try it with silent audio.

GregW

· #7 · Feb 13, 2018

I honestly can't hear anything on my Boxster. With the windows up it is very quiet, even in Sport. Opening the windows brings in some exhaust, and the top down brings in more. There is no difference in sound with the audio on or off.

I thought of trying to disconnect it for a listen, but the boot lining was pretty secure and I couldn't determine (from the other threads) exactly where the controller was located. Some stuff on the right-hand drive cars is reversed and some seems the same as LHD.

johan

· #8 · Feb 13, 2018 (Edited)

GregW said:
I honestly can't hear anything on my Boxster. With the windows up it is very quiet, even in Sport. Opening the windows brings in some exhaust, and the top down brings in more. There is no difference in sound with the audio on or off.

I thought of trying to disconnect it for a listen, but the boot lining was pretty secure and I couldn't determine (from the other threads) exactly where the controller was located. Some stuff on the right-hand drive cars is reversed and some seems the same as LHD.

Both in my Boxster and especially in the Cayman there was a big difference in sound, to the better.
No more strange rumble that did not fit in, like a badly tuned subwoofer, the system used on 981 is way better and its more of a analog system based on the intake.

The exhaust should be louder in sport even without Pse, the easy way is to shift modes when your standing still, there is a deeper growl in sport a idle.
I havent realy understand and its hard to find info on it but i think its a change of muffler in Sport.

Here you can hear the differens between Normal and Sport on a Cayman 2,0 without Pse

Code:

[URL]https://www.youtube.com/watch?v=DDB54Qu-KY0[/URL]

I will not guess if the aktor is on right or left side on you car, but you sould be able to spot it.
The trim that has to come of or bent down is big, all the way in front of the Wheel arch, over the arch and to the locking mechanism and also the bottom of the trunk.
If you start above the Wheel arch you can work your way to the looking mechanism and slowly bent it down so you can get your hand inside and bend the lining up as a bubble.
The aktor is bolted on the chassi and its sits pretty low just behind the Wheel arch so even if you bend down the lining your just gonna see the top.
There is a smal piece of styroam on the bottom you have to remove to be able to loosen the wire.

The red thats the styrofoam on the bottom and yellow thats the Aktor.

I dont have the Boxster anymore so i cant show you exactly how its done.
Its done in 10 min tops

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Viffermike

· #9 · Feb 13, 2018

When you have an opportunity, start your cars (preferably when warmed up), exit the vehicle, and walk around to the back -- first in regular mode, then in Sport mode. The difference is substantial.

Then, have a friend switch the driving mode while you're standing directly behind the car. The difference is even more marked.

Then, have a friend blip the throttle to rev the motor to 4k RPM or so in one mode, then the other mode. The difference is palpable (especially with the pops and gurgles).

Sport makes a huge, huge difference. You just don't hear it from the seat of your car nearly as much as you would from the seat of the car behind you. Why is that? Because the change in tone is created toward the end of the exhaust, after the catalyst and resonator(s). That effect is even more pronounced in our mid-engine cars because no part of the engine is in front of us -- so adding, say, a downpipe for sound and flow may not make as much of a difference aurally as it would in, say, a BMW M car. That's made up for by the induction noise from the side scoops, which can be heard easily even with the windows up in a Cayman.

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johan

· #10 · Feb 13, 2018

Anyone tried the trick people made one the 981?
And did the 981 behave the same way in sport as 718, without Pse.

ZuffenHouseRules

· #11 · Feb 13, 2018 (Edited)

This is not my thread, but allow me please to inject just a little balance and not freak-out those reading who don't yet have their 718 in order to judge for themselves....

The Sound Aktuator is another example of something I'd have taken zero notice of (audibly: you can't miss seeing the speaker) if I hadn't read about it here. Honestly, I can't begin to discern what if anything I hear coming from the speaker versus all the surrounding natural sound. Since I'm usually driving top-down, that includes wind noise -- esp. at speed -- and engine/exhaust sound reflecting back into the cabin from all sides, not just behind the firewall.

Bother to disconnect? First I'd have to actually hear it and have some sense of what it is I'd be disconnecting.

Reactions: 3

johan

· #12 · Feb 13, 2018

ZuffenHouseRules said:
This is not my thread, but allow me please to inject just a little balance and not freak-out those reading who don't yet have their 718 in order to judge for themselves....

The Sound Aktuator is another example of something I'd have taken zero notice of (audibly: you can't miss seeing the speaker) if I hadn't read about it here. Honestly, I can't begin to discern what if anything I hear coming from the speaker versus all the surrounding natural sound. Since I'm usually driving top-down, that includes wind noise -- esp. at speed -- and engine/exhaust sound reflecting back into the cabin from all sides, not just behind the firewall.

Bother to disconnect? First I'd have to actually hear it and have some sense of what it is I'd be disconnecting.

For me, coming from 986 and straight in to 718 Boxster did off course noticed the difference in exhaust note.
And after awhile i was starting to wonder about the rumble i heard and why it was muffling the engine sound and exhaust sound..
When i then heard about the aktor I just did a quick test and was sold!

For me it sounds more pure in a sense.

Viffermike

· #13 · Feb 13, 2018

ZuffenHouseRules said:
This is not my thread, but allow me please to inject just a little balance (even if a minority view) for those reading who don't yet have their 718 in order to judge for themselves....

The Sound Aktuator is another example of something I'd have taken zero notice of (audibly: you can't miss seeing the speaker) if I hadn't read about it here. Honestly, I can't begin to discern what if anything I hear coming from the speaker versus all the surrounding natural sound. Since I'm usually driving top-down, that includes wind noise -- esp. at speed -- and engine/exhaust sound reflecting back into the cabin from all sides, not just behind the firewall.

Bother to disconnect? First I'd have to actually hear it and have some sense of what it is I'd be disconnecting.

That's all part of the controversy surrounding so-called 'fake engine sound' generators in cars -- and it's only going to get more controversial as relatively quiet and unspirited-sounding hybrids and EVs begin to take over the sporty car marketplace. For example: At what point does artificial engine sound become an aural operational cue meant primarily to tell you how fast the engine is running? In everyday driving, it could be viewed as a nuisance by some. On a track, however, it could be viewed more as a necessity.

Owners of VW AG products like us are actually among the lucky ones: the sound generators operate largely as independent accessories that can be unplugged/removed without affecting the operation of the rest of the car. On the other hand, most BMWs have theirs installed as a physical part of the audio system so that:
- it can't be defeated without completely disabling the audio system in the car
- it is built into the amplifier unit itself in many cases, so that physical removal is impossible
- it adversely affects the audio system's sound quality

So really the "If a tree falls in the forest and no one's around, does it make a sound?" question is the central one in my mind. If you don't notice it, why worry about it? Well, that begs this question to me: "If you remove it, will you notice its absence?" And would that absence be a positive or a negative?

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Reactions: 3

GregW

· #14 · Feb 14, 2018

johan said:
Both in my Boxster and especially in the Cayman there was a big difference in sound, to the better.
No more strange rumble that did not fit in, like a badly tuned subwoofer, the system used on 981 is way better and its more of a analog system based on the intake.

The exhaust should be louder in sport even without Pse, the easy way is to shift modes when your standing still, there is a deeper growl in sport a idle.
I havent realy understand and its hard to find info on it but i think its a change of muffler in Sport.

https://www.youtube.com/watch?v=DDB54Qu-KY0
Here you can hear the differens between Normal and Sport on a Cayman 2,0 without Pse

Code:

[URL]https://www.youtube.com/watch?v=DDB54Qu-KY0[/URL]

I will not guess if the aktor is on right or left side on you car, but you sould be able to spot it.
The trim that has to come of or bent down is big, all the way in front of the Wheel arch, over the arch and to the locking mechanism and also the bottom of the trunk.
If you start above the Wheel arch you can work your way to the looking mechanism and slowly bent it down so you can get your hand inside and bend the lining up as a bubble.
The aktor is bolted on the chassis and it sits pretty low just behind the Wheel arch so even if you bend down the lining your just gonna see the top.
There is a small piece of styroam on the bottom you have to remove to be able to loosen the wire.

The red thats the styrofoam on the bottom and yellow thats the Aktor.

I dont have the Boxster anymore so i cant show you exactly how its done.
Its done in 10 min tops

Thanks mate, those instructions fit my right-hand-drive car perfectly.

I'd only like to add: "in front of the wheel arch" is actually "behind" unless you are driving in reverse:laugh:, and "be brave" when pulling out the carpet--it goes back in place easily; and there is a small grey locking slide on the connector that is best moved with a screwdriver.

I'll let you all know how I like the sound after a good drive this evening.

Lastly: according to Porsche the change in sound with Sport on, even without PSE is due to more petrol being fed to the engine. I have noticed that Sport mode and 'choke' when engine is cold sound much the same.

Reactions: 2

johan

· #15 · Feb 14, 2018 (Edited)

GregW said:
Thanks mate, those instructions fit my right-hand-drive car perfectly.

I'd only like to add: "in front of the wheel arch" is actually "behind" unless you are driving in reverse:laugh:, and "be brave" when pulling out the carpet--it goes back in place easily; and there is a small grey locking slide on the connector that is best moved with a screwdriver.

I'll let you all know how I like the sound after a good drive this evening.

Lastly: according to Porsche the change in sound with Sport on, even without PSE is due to more petrol being fed to the engine. I have noticed that Sport mode and 'choke' when engine is cold sound much the same.

Thanks for that!
I thought it had to do with the two mufflers and that the exhaust was routed differently.
That also held me back to test the 981 hack, but I will give it a try

GregW

· #16 · Feb 14, 2018

Porsche Sport Exhaust IS a valved exhaust with two different tracks. The standard exhaust doesn't change routing with the Sport button.

My ride with the Soundaktor disconnected was as you said--the sound is more "natural" and I do prefer it. Despite the Soundaktor not making much increase in volume (I found it hardly perceptible), it seems to blur the definition of the pulses from the exhaust. I have yet to try with the windows closed and top up to see how much it is quieter on the highway.

After cruising in town and around the beaches I doubt I'll be re-connecting it.

Let is know how the 981 hack goes--is that the one where the tail-pipe section is partially disconnected?

johan

· #17 · Feb 14, 2018

GregW said:
Porsche Sport Exhaust IS a valved exhaust with two different tracks. The standard exhaust doesn't change routing with the Sport button.

My ride with the Soundaktor disconnected was as you said--the sound is more "natural" and I do prefer it. Despite the Soundaktor not making much increase in volume (I found it hardly perceptible), it seems to blur the definition of the pulses from the exhaust. I have yet to try with the windows closed and top up to see how much it is quieter on the highway.

After cruising in town and around the beaches I doubt I'll be re-connecting it.

Let is know how the 981 hack goes--is that the one where the tail-pipe section is partially disconnected?

We where talking about the difference in tone between Normal and Sport without the Pse

The mufflers on Pse are a bit smaller and with a valve on the passanger side.

That's correct, to open it a bit.
But I don't think its gonna be Great!!

Acky

· #18 · Feb 14, 2018

Is it correct that disconnecting the sound actuator does only have any effect in sport mode, because it is not active in normal mode?

trusted

· #19 · Feb 14, 2018 (Edited)

Acky said:
Is it correct that disconnecting the sound actuator does only have any effect in sport mode, because it is not active in normal mode?

I don't know the definitive answer. I have not disconnected the module in my car because it sounds fine to me.
But have a look at manual page 232.
Page 232 | 2017 718 Boxster Manual | Porsche iManuals

Row 5 shows "optimized engine sound in the passenger compartment" as not active in normal mode. imo that can only refer to the sound actuator.
Hopefully someone who has disconnected it can chime in on that.
If the car sounds different in normal mode with the module disconnected I may try it out. Just out of curiosity.

johan

· #20 · Feb 15, 2018

trusted said:
I don't know the definitive answer. I have not disconnected the module in my car because it sounds fine to me.
But have a look at manual page 232.
Page 232 | 2017 718 Boxster Manual | Porsche iManuals

Row 5 shows "optimized engine sound in the passenger compartment" as not active in normal mode. imo that can only refer to the sound actuator.
Hopefully someone who has disconnected it can chime in on that.
If the car sounds different in normal mode with the module disconnected I may try it out. Just out of curiosity.

My impression was that its on even on Normal mode.
I can give it a quick try in a day or two

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