Low frequency 'boom' in cabin

[buikpijn]

can someone please post up a sound clip of this noise, if it's that bad it will record fine through a mobile phone.

 

Recording is one thing, but what about playback. You'd need quite a setup to reproduce the LF that is causing this rumble.  So both recording and playback should be spot-on. If the mic picks up -3db on  let's say 20hz (rule out the playback limitations) it's an irrelevant measurement.

 

Has anyone tried to throw in some bags of sand in the back? i've heard this noise in my neighbours hatchback (noticed it from the second i stepped in, on a relative rough road). The horizontal metal between the rear seats and the spare tire is very flexible. maybe a few bags of sand (or some random retrievers you can throw in the trunk). From my experience with acoustics I'd say its a LF rumble with perhaps a higher harmonic causing the noise. 

 

If you want to troubleshoot this, you'd need a spectrum analyser with calibrated mic to measure at what frequency this problem occurs. It's in the 10-40hz range. If a db meter is used, make sure it's not limited from ~30hz-8khz.

The facts so far for the affected vehicles;

 

-covers all engines and transmission

-multilink and torsion beam suspension is affected

-combi and hatchback is affected

-sportsuspension and normal suspension is affected

-new/different dampers don't solve the problem (at least the other dampers as provided by Skoda)

-fooling around with adjusting the boot isn't solving the problem (noticed lock swaps/adjustments, bump rubbers adjustments)

[DorsetKnob]

A few folk with spare wheel option fitted have said they don't get the boom.

Has this been bottomed out - can we say the spare wheel fixes it somehow? (And if so, how/why?)

This annoying issue is stopping me placing my order :(

[DorsetKnob]

...maybe the spare wheel is a more useful alternative to a couple of bags of sand?!

[phoenix123]

I have the spare wheel option and still have this issue in my hatch vrs. It is rather annoying but becoming less obvious as I get used to the car. I'm convinced it's the acoustic property of the boot space, which amplifies the noise from rear seat back area

[buikpijn]

-covers all engines and transmission

-multilink and torsion beam suspension is affected

-combi and hatchback is affected

-sportsuspension and normal suspension is affected

-new/different dampers don't solve the problem (at least the other dampers as provided by Skoda)

-fooling around with adjusting the boot isn't solving the problem (noticed lock swaps/adjustments, bump rubbers adjustments)

-problem occurs with or without spare wheel

[buikpijn]

...maybe the spare wheel is a more useful alternative to a couple of bags of sand?!

 

 

There are occasions where sand is more convenient.

 

 

You don't understand what i'm saying though. It's the metal between the backseats and the hole for the spare wheel. (the metal part being flush with the rest of the trunk). Not the place where you want to put your sparewheel either. I'm not talking about a long-term solution, just a test. Making a suspected metal panel 50kg heavier would greatly lower the fs. Sand in a bag is damping to begin with.

[DorsetKnob]

I see what you mean.

 

I was thinking that perhaps the spare wheel mounting puts that piece of metal under either tension or compression, thereby altering its acoustic properties enough to stop boom — supporting your bag of sand theory to damp that piece of metal.

 

I only say this because several folk with spare wheels have said they don't have the boom (although it could be just coincidence because one or two with the wheel do have booming). 

[djkarlos]

I have a spare wheel too

[DorsetKnob]

…and the boom, presumably?

[Leonblue]

I have the spare wheel AND the heavy rubber mat fitted, maybe the two together damp it out. It could be that the wheel clamp needs to be very tight to put tension on the panel. I've certainly not noticed the boom on mine.

[djkarlos]

…and the boom, presumably?

Yes indeedy

[DorsetKnob]

djkarlos - maybe you could try what Leonblue suggests above - put more tension in your spare wheel mounting and see if it makes any difference?

 

… I'm desperately hoping it does, I really want to want one of these cars!

 

Let us know?

[Dodgy]

Think it would be handy to draw a table and have everyone fill their details in affected or not, I just tried to do it but as soon as I hit preview, all the formatting was lost.

 

A table would perhaps show some common trends.

[DorsetKnob]

If you have the spare wheel fitted, the following test would be very useful:

-Tighten the spare wheel clamp. Does the boom decrease or even disappear?

Please report back to the thread if anyone does this with positive or negative results!

[Trekster]

If you have the spare wheel fitted, the following test would be very useful:

-Tighten the spare wheel clamp. Does the boom decrease or even disappear?

Please report back to the thread if anyone does this with positive or negative results!

I'll have a go at it tomorrow and see if it helps. I'm willing to try out anything to get it sorted

[Leonblue]

I'll have a go at it tomorrow and see if it helps. I'm willing to try out anything to get it sorted

Good Luck!

[phoenix123]

When I gave my car a good clean out last weekend I removed the spare wheel, added an old padded tablecloth between the wheel and floor pan and tightened up the spare wheel mount - I can't tell any noticeable difference I'm afraid

[myself24483]

Have you try to see what happens with the windows opened ? not much, to avoid the noises of the wind.

[GerrieS]

Apparently my car (one week old) also has this problem, but the odd thing is that I can't hear it, but my girlfriend does

 

I will check out the solution provided by peterbaarlo, thanks!

[Stodgy]

It's in my MkIII VRS Estate (3 weeks old, no spare), and was on the 13 Plate Rapid Skoda lent me while I was waiting for the VRS...Oh and on my mates Octavia II Tdi...in fact, every modern day Skoda I have been in has a 'booming' of varying intensity. 

 

Must admit though, doesn't bother me. Life is too short. 

[themanwithnoaim]

Drive it like you just stole it, then you'll only hear the high-frequency boom through the front bulk-head.

[DorsetKnob]

So as a potential customer, can I ask those of you who experience the boom how much it affects your enjoyment of the car?

Say on a scale of 1-10?

Does it give you a headache or do you find you can drive around it? Would you buy the car again even with the boom or think twice?

[davehiggins07]

In answer to DorsetKnob........

The booming doesn't give you a headache, but it's ever present & annoying

Personally, I would not buy again (or indeed in the first place) if I was aware of this issue.

My other car's a new Seat Leon FR - with the same MQB platform and is perfect & brilliant! 

[Neily03]

So as a potential customer, can I ask those of you who experience the boom how much it affects your enjoyment of the car?

Say on a scale of 1-10?

Does it give you a headache or do you find you can drive around it? Would you buy the car again even with the boom or think twice?

 

I have no booming in mine.

[DorsetKnob]

Neily ... maybe the silver ones are OK then?

That would be good - I want(ed) a silver one, with 'silver pack' for ultimate stealth.