[C5 X7] Parcel shelf speakers and extra sound deadening.

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the-termin8r
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[C5 X7] Parcel shelf speakers and extra sound deadening.

Post by the-termin8r »

Hi everyone, I want to knock out two questions with this post.

1. Did any version of the saloon ever have speakers in the parcel shelf? I noticed there are grilles, but riding around in the back of mine as a kid (it used to be the family car) I never heard music coming from behind my head. I always assumed my dad had shifted the balance forward. But now being the owner of the car myself, I've set neutral balance in all directions and still couldn't hear music. I ended up climbing into the boot to have a gander and to my surprise saw daylight coming through the grilles. I initially thought I might have had dead speakers, but it seems I don't have speakers at all. Did the higher spec speaker option come with shelf speakers?

2. We got a delivery at work and I noticed that the packing material appears to be the same stuff used on the rear wheel arches, inside the side panels on the dash and inside the parcel shelf (among other places, I'm sure). The bag says that apparently they're recycled textile fibre scraps from a factory sweatshop floor. To my hand it feels like the same stuff. I'm planning on shoving it somewhere inside the car to potentially improve the sound isolation and wanted to ask if there's any specific place anyone would recommend (or not recommend). I should point out, I don't have very much to work with, I have pair of pieces, one is 880x200mm and the other is 800x380mm. Both are about 20mm thick I was thinking of potentially shoving the 880x200 one in the parcel shelf since there are no speakers there.

Or alternatively, is there better sound deadning material to use that would actually make a difference when placed correctly?

Thanks.
- Rob

My account accidentally got deleted late Dec '23, so if you're reading my posts from then or earlier and they look weird / are missing media, that's why. Not much can be done, sorry.
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Re: [C5 X7] Parcel shelf speakers and extra sound deadening.

Post by Jay-Bruce »

I can't help you ith the model trim level information, however, I can give you a good few pointers on sound deadening...

Sound deadening works best by attenuating the sound at the source, in the case of a car body this typically means preventing the vibration of any panels. The biggest sources of vibration within a car are the engine noise resonating off the front firewall/footwells, and the road noise coming up through the rear suspension and into the wheel arch/strut towers. The simplest way to stop panels vibrating is to add mass to them, which is why premium motors like mercs and rollers typically used steel that was way thicker than economy/entry-level models such as the ford fiesta.

To add mass to car panels, there are specialist sound-deadening products like dodo mat, lead sandwich, etc, but the cheapest is flash band, the roofing repair product, and I'm not pulling your chain there. I had actually bought quite a lot of flashband-sold-as-sound-deadening on eBay from a rather enterprising seller who was basically reselling an inexpensive building material as a more expensive automotive sound-deadening product. I'd lined the back of a couple of our lad rovers with this stuff to help attenuate the road-noise associated with the vehicle's aggressive offroad tyres, and it worked.

After mass-loading the panels that make noise to prevent them from vibrating as much and thus reducing their noise level, the next step in the process is applying the absorbent materials over the top of the mass loading, at which point you'd be spray glueing the fabric stuff onto the back of the flash band. As for where to locate the sound deadening for maximum effect, this will depend greatly on your car's specific options, and what noise you hear most. The inline-four engines make more noise than the v6's so an inline 4 engined vehicle would benefit from sound deadening the front footwells. However, cars with steel springs and or large alloys and low profile tyres will have more tyre roar to contend with than a vehicle with smaller rims and taller sidewalled tyres and as such would benefit more from sound deadening the areas around the back wheel arches than they would from treating the front footwells. All X7's have tinny lightweight doors, which would benefit immensely from lining with the flash band type of materials. I wouldn't put anything potentially absorbent, such as the adhesive foams or the upcycled fabric you mention into those areas as the material would most likely hold moisture and become a corrosion hotspot, rotting the doors from the inside out. However, if you do buy a couple of rolls of flash band to do the arches / footwells, stick some into the door skins, as this will offer a lot of bang (reduction) per buck.

Applying the flash band stuff is pretty simple, peel off the backing paper, stick it on to the panel, black side first, greenish side outwards, heat it with a heat gun/hair dryer, run over it with a hard roller or tamp it down with the back of a hammer handle or such like, let it cool, job done. Doing this to the door skins will make a lot of difference to the car, but will require removing the door cards, the polythene vapour barrier, a bit of awkward keyhole surgery through the apertures in the door shell, but it's inexpensive, requiring little more than gaffer tape to succeed. If you don't have proper plastic trim tools, you can usually get away with using gaffer tape on flat screwdrivers to stop them from scratching the paint as you spring off the door cards, if you already have plastic trim tools, you'll still need gaffer tape, to reattach the vapour barrier membrane behind the door skin. If you muller the door's vapour barrier, you can either get a suitably big piece of heavy polythene and tape it into place with gaffer tape, or if you fancy partaking in some in real read-neckery, cover the entire door skin in overlapping strips of gaffer tape.

TLDR - for best effects, stick flash band on the metal then top off the flash band with your fabric stuff. Do not put the fabric anywhere it could get wet, ie: inside the door skins. Best placement of sound deadening is either the back wheel arch area, and or front footwells, and will depend on which you hear more and find most annoying, road noise / engine noise, and the vehicles configuration, steel/hydro springs + engine type + wheel & tyre combo all have an effect on where the noisiest part of the car is. Sound deadening the door skins with flash band stuff will make a huge difference, but do not put your fabric stuff in there.
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Re: [C5 X7] Parcel shelf speakers and extra sound deadening.

Post by GiveMeABreak »

the-termin8r wrote: 21 May 2023, 16:25 Hi everyone, I want to knock out two questions with this post.

1. Did any version of the saloon ever have speakers in the parcel shelf? I noticed there are grilles, but riding around in the back of mine as a kid (it used to be the family car) I never heard music coming from behind my head. I always assumed my dad had shifted the balance forward. But now being the owner of the car myself, I've set neutral balance in all directions and still couldn't hear music. I ended up climbing into the boot to have a gander and to my surprise saw daylight coming through the grilles. I initially thought I might have had dead speakers, but it seems I don't have speakers at all. Did the higher spec speaker option come with shelf speakers?
No they didn't. Depending on your trim level the rear parcel shelf could come with an integral roller blind for the rear window on the saloon. I had this on mine.
X7 Saloon Blind.PNG
Secondly there were options available that included the HiFi Equaliser Amp options or 6 Cd Changer. The equaliser amp was fitted in the dash, but the sub woofer was fitted in the right hand side boot storage area behind the panel. So it makes sense that there would be some way for the sound to enter the cabin, which may account for the 'gaps'. Then there are some tethering points I believe (should be marked on the parcel shelf) that could be for a guard or for tethering through the parcel shelf to the boot tethers - I can't remember now.
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Re: [C5 X7] Parcel shelf speakers and extra sound deadening.

Post by the-termin8r »

Jay-Bruce wrote: 21 May 2023, 17:22 As for where to locate the sound deadening for maximum effect, this will depend greatly on your car's specific options, and what noise you hear most. The inline-four engines make more noise than the v6's so an inline 4 engined vehicle would benefit from sound deadening the front footwells. However, cars with steel springs and or large alloys and low profile tyres will have more tyre roar to contend with than a vehicle with smaller rims and taller sidewalled tyres and as such would benefit more from sound deadening the areas around the back wheel arches than they would from treating the front footwells. All X7's have tinny lightweight doors, which would benefit immensely from lining with the flash band type of materials.
Thanks for the detailed reply. This sounds like a project for when I've got more time and have done my research as it sounds like a bit of a faff.

Mine's a 2L HDI (138 BHP) with H3+ and, thankfully, 17" Baltic rims. I run Michelin Primacy 4+ on the rear and regular 4s on the front (will be upgrading them to 4+ as well when they wear out).

Funny you should say the X7 has tinny doors. Of all the cars I've been in over the years, the X7 by far has had the beefiest doors. I die inside every time I'm giving someone a lift, without fail, every single person has slammed the door like they're trying to smash the window. People are clearly used to coke can doors that can't close under their own weight with a slight tug / push. I honestly feel like I should start warning everyone I give a lift to.

With regards to the front footwells, where would the deadening go, is it under the carpet or somewhere up in the panelling above?
Jay-Bruce wrote: 21 May 2023, 17:22 stick some into the door skins
By 'door skin' do you mean the trim panel with the handle and door pocket or the other side of the surface that's exposed to the outside world?
Jay-Bruce wrote: 21 May 2023, 17:22 which you hear more and find most annoying, road noise / engine noise,
At motorway speeds, the engine noise is honestly not that bad. It's more road and wind I want to reduce. I was looking at those ClimAir wind deflectors Marc was running on his X7 a while back, but they're £110 for a full set, so will probably have to wait until Xmas or my birthday lol.
but the sub woofer was fitted in the right hand side boot storage area behind the panel. So it makes sense that there would be some way for the sound to enter the cabin
That would explain it. Regarding the anchor points, there's three for ISOFIX behind the head restraints.
- Rob

My account accidentally got deleted late Dec '23, so if you're reading my posts from then or earlier and they look weird / are missing media, that's why. Not much can be done, sorry.
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Re: [C5 X7] Parcel shelf speakers and extra sound deadening.

Post by Jay-Bruce »

the-termin8r wrote: 21 May 2023, 19:04 Thanks for the detailed reply. This sounds like a project for when I've got more time and have done my research as it sounds like a bit of a faff.
It's not that bad, just a bit of prior work required to access the areas you want to apply the sound deadening to, as it's going behind trim pieces etc, rather than just slapped in like a set of floor mats.
the-termin8r wrote: 21 May 2023, 19:04 Mine's a 2L HDI (138 BHP) with H3+ and, thankfully, 17" Baltic rims. I run Michelin Primacy 4+ on the rear and regular 4s on the front (will be upgrading them to 4+ as well when they wear out).
One of the quietest set ups then, with decent sidewalls on good quiet tyres, primacy's are awesome for their low road noise, and hydraulically sprung so should soak up a lot of the road noise/buzzing.
the-termin8r wrote: 21 May 2023, 19:04 Funny you should say the X7 has tinny doors. Of all the cars I've been in over the years, the X7 by far has had the beefiest doors. I die inside every time I'm giving someone a lift, without fail, every single person has slammed the door like they're trying to smash the window. People are clearly used to coke can doors that can't close under their own weight with a slight tug / push. I honestly feel like I should start warning everyone I give a lift to.
You should try some more cars, the 407 coupe's doors feel about 4x heavier than the doors on our C5, the C5 doors are genuinely light, maybe half the weight of the doors on my nineties MR2, a third the weight of the doors on my BMW etc. But while it's good for access and egress, and fuel economy, they are prone to making noise, hence suggesting getting some material on the inside of the door skins.

To answer the question about the terminology I've used for the parts of the door, on the inside you've got the plastic trim panel, known as a door card, then there is the door shell / frame which is the large stamped metal frame that makes up the bulk of the door, and has the mounting points for handles, locks, latches, window mechanism (regulator) etc. The outer panel of the door, it the panel you see when the door is closed, is known as the skin, it is actually a separate piece of metal that is placed on the outside of the door shell, then the edges are rolled back around the edge of the door shell. Here's a video of a dude replacing a door skin to let you see what I'm trying to describe:


the-termin8r wrote: 21 May 2023, 19:04 With regards to the front footwells, where would the deadening go, is it under the carpet or somewhere up in the panelling above?
Under the carpets, onto the metal of the footwell, particularly the front of the footwell where it turns up towards the firewall, ie: where the pedals are. The source of the noise is on the outside, coming into the cabin through the metal, so you want to put the deadening on the metalwork, not on the interior panels to capture it at source.
Jay-Bruce wrote: 21 May 2023, 17:22 stick some into the door skins
the-termin8r wrote: 21 May 2023, 19:04 By 'door skin' do you mean the trim panel with the handle and door pocket or the other side of the surface that's exposed to the outside world?
Cabin interior --> Door card --> polyethelyne membrane "vapour barrier" --> door shell / frame --> door skin --> outside world :-)
Jay-Bruce wrote: 21 May 2023, 17:22 which you hear more and find most annoying, road noise / engine noise,
the-termin8r wrote: 21 May 2023, 19:04 At motorway speeds, the engine noise is honestly not that bad. It's more road and wind I want to reduce. I was looking at those ClimAir wind deflectors Marc was running on his X7 a while back, but they're £110 for a full set, so will probably have to wait until Xmas or my birthday lol.
Diesels are inherently quiet at speed, so it will be road noise that is left, ergo you're looking at back wheel arches and or area under the back seats for your freshly acquired fibre material. big gains will come from mass-loading the doorskins, an example can be seen in this short clip:

clock how little resonance there is from the "loaded" panel, this stops the door shell cavity acting like a resonance chamber and rinigng like a bell.
but the sub woofer was fitted in the right hand side boot storage area behind the panel. So it makes sense that there would be some way for the sound to enter the cabin
the-termin8r wrote: 21 May 2023, 19:04 That would explain it. Regarding the anchor points, there's three for ISOFIX behind the head restraints.
Nothing stopping you putting a couple of 6x9"'s in that penel then, and on a hatchback the sound would reflect off the back windscreen and project forward giving you some nice sound-fill, a bit like a lot of premium cars have tweaters mounted on the dash pointing at the front screen.

Going back to the wind noise, exclusives have secondary seals on the doors, which helps with wind noise, wonder if your car has them or if not can they be sourced as replacement parts?
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Re: [C5 X7] Parcel shelf speakers and extra sound deadening.

Post by the-termin8r »

Jay-Bruce wrote: 21 May 2023, 20:36 primacy's are awesome for their low road noise,


That's my main reason for running them. They're pretty good in the wet as well.
Jay-Bruce wrote: 21 May 2023, 20:36 You should try some more cars, the 407 coupe's doors feel about 4x heavier than the doors on our C5, the C5 doors are genuinely light, maybe half the weight of the doors on my nineties MR2, a third the weight of the doors on my BMW etc. But while it's good for access and egress, and fuel economy, they are prone to making noise, hence suggesting getting some material on the inside of the door skins.
Wasn't the 407 just a less comfortable Mk2 C5? My family had a Mk1 and Mk2 and their doors felt lighter. My dad's current Passat B6 has comically light doors, so too does my mate's 1Z Octavia. A co-worker's 2017 Tiguan also has weirdly light doors. I tend to judge a door's weight more by how hard I have to pull it to get it to shut properly. Typically takes me two attemps on other cars.
Jay-Bruce wrote: 21 May 2023, 20:36 Going back to the wind noise, exclusives have secondary seals on the doors, which helps with wind noise, wonder if your car has them


Mine's an exlusive so probably has them, it's also got the double galzing / laminate on the side windows.

I was looking at Dodo mat options and the combo of the weighting material + deadening foam will end up being close to 7mm thick. How would that play with clearances? My concern is for jamming the windows or for making bulges in the floor that won't let the carpet fit back on properly.
- Rob

My account accidentally got deleted late Dec '23, so if you're reading my posts from then or earlier and they look weird / are missing media, that's why. Not much can be done, sorry.
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Re: [C5 X7] Parcel shelf speakers and extra sound deadening.

Post by Jay-Bruce »

Here are a couple of pics showing these extra seals:
IMG_20230521_204235_431.jpg
IMG_20230521_204217_665.jpg
IMG_20230521_204230_598.jpg
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Re: [C5 X7] Parcel shelf speakers and extra sound deadening.

Post by Jay-Bruce »

the-termin8r wrote: 21 May 2023, 21:00
Jay-Bruce wrote: 21 May 2023, 20:36 primacy's are awesome for their low road noise,


That's my main reason for running them. They're pretty good in the wet as well.
Jay-Bruce wrote: 21 May 2023, 20:36 You should try some more cars, the 407 coupe's doors feel about 4x heavier than the doors on our C5, the C5 doors are genuinely light, maybe half the weight of the doors on my nineties MR2, a third the weight of the doors on my BMW etc. But while it's good for access and egress, and fuel economy, they are prone to making noise, hence suggesting getting some material on the inside of the door skins.
Wasn't the 407 just a less comfortable Mk2 C5? My family had a Mk1 and Mk2 and their doors felt lighter. My dad's current Passat B6 has comically light doors, so too does my mate's 1Z Octavia. A co-worker's 2017 Tiguan also has weirdly light doors. I tend to judge a door's weight more by how hard I have to pull it to get it to shut properly. Typically takes me two attemps on other cars.
Jay-Bruce wrote: 21 May 2023, 20:36 Going back to the wind noise, exclusives have secondary seals on the doors, which helps with wind noise, wonder if your car has them


Mine's an exlusive so probably has them, it's also got the double galzing / laminate on the side windows.

I was looking at Dodo mat options and the combo of the weighting material + deadening foam will end up being close to 7mm thick. How would that play with clearances? My concern is for jamming the windows or for making bulges in the floor that won't let the carpet fit back on properly.
The 407 and C5 x7 are mechanically the same car, the difference was body/interior, and the C5 could come with hydraulic suspension which was never available on Peugeots, however the 407 coupe is a different animal, mostly 407 running gear, but an entirely different, and much more ridgig body, and it has much heavier doors than the C5, it actually achieves EuroNCAP 5* rating, in part because the lumping heavy doors are locked into the doorsills adding to the cabin integrity. Trust me, these cars doors are light.
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Re: [C5 X7] Parcel shelf speakers and extra sound deadening.

Post by MattBLancs »

I think it may be to do with how Citroen set the door hinges - they seem to naturally want to swing closed, so rely more heavily on the check strap detents to lock in position. The net result being the doors (little) weight assists in closing the door.

The net results of that are doors that close pretty sweetly given their low weight, and the uninitiated / perpetually oblivious repeatedly slam the living crap out of them (often despite subtle hinting or even direct instruction to close them gently!)