Sub vibrates rear shelf

andy · Post by **andy** » Wed Aug 20, 2003 10:01 pm

With certain bass notes my rear shelf vibrates and makes a horrible noise. I haven't looked that closely at how to fix it and I was wondering of anyone else had suffered and fixed the same problem.

It's definitely not the sound system because I can cure it by wedging my fingers against the shelf.

EyezOnMei · Post by **EyezOnMei** » Thu Aug 21, 2003 12:02 am

The great thing about the FTO when it comes to car audio is that it is one of THE easiest, if not the easiest car(s) to install car audio into. This is because its a nice length, is ready for 6x9's and 6.5" speakers and almost everything clicks on or off. However, the click on click off means that not everything's super tight.
Probably the most horrendous noise producer are those rear quarter panels next to the rear seats (or cargo space, whatever u wanna call it). If u've got a sub, I assume u've LPF the 6x9's so the rear shelf shouldn't be too much of a problem, its those quarter panels.
My suggestion is remove them and sound deaden them, as well as the rear shelf... Not an easy task but it keeps u sane if the rattles annoy you, and can also improve midbass (although, doesn't really apply for subs).
Oh, sound deaden everything else too because u sound deaden one part without sound deadening another, it just transfers the rattles.
I did the rear shelf before the sub cos the 6x9's already caused it to vibrate and just 1 layer of the stuff not only increased midbass performance noticeably but also stopped the parcel shelf rattling... Of course it started rattling the rear quarter panels instead!
So now I'm sound deadening the entire car, bit by bit. Its worth it though, reduces road noise, doors close nice and solid and music sounds awesome! P.S. If u need help/tips on this feel free to ask (also see pic at bottom in the broken locks topic).

J1 · Post by J1 » Thu Aug 21, 2003 1:38 am

yea i just had a roll of brown bread put onto my rear parcel shelf and 1/2 a roll on each side of the rear quarter panels (cos they were a huge pain in the ass!) ... but my parcel shelf still rattles sometimes when my sub goes off... and i've only got one 10" sub too... my friend had a new parcel shelf made from MDF & carpeted... anyone else out there done that with good results?

thecook · Post by **thecook** » Thu Aug 21, 2003 3:22 am

when i play the subs loud, the back.. near the rear window somewhere, rattles! my friend reckons theres something loose, but i dunno! its hard to look at the back speakers coz theres hardly any gaps......

i got stock speakers

YYgirl · Post by **YYgirl** » Thu Aug 21, 2003 7:44 pm

hi, i think the spoiler moves and makes sound? hehe

EyezOnMei · Post by **EyezOnMei** » Fri Aug 22, 2003 8:18 pm

Don't forget the boot people! Subs cause almost every boot of every car to rattle. Stand outside and turn it up (use a remote or if u don't have one the manual way) and witness it rattle.
Some spray on sound deadening will do the trick, but I don't know which ones are CLEAR so they don't make your boot look ugly. Can always do the sound deadening matt thingie.
Oh yeah, relevance is that boot can transfer top parcel shelf or if u hear a sound from the rear it could also be your boot rattling...

thecook · Post by **thecook** » Sun Aug 24, 2003 1:36 am

whenever theres a loud thump from the subbies, i here something rattle..... i cbf lookn a what it is.....

now i got another problem rising up! everytime i accelerate to 2500 rpm, i hear something rattle in the back!!! f**k

GPXXX · Post by **GPXXX** » Sun Aug 24, 2003 3:49 am

this is one reason that's holding me back from puttng on an ICE system on my FTO... nothing worse than to spend X amount of money on things that are supposed to sound good, but gets spoilt by unforeseen vibrations and annoying rattles!

for what it's worth, i think a thicker MDF rear parcel shelf might minimise the rattle when the sub is thumping away...

EyezOnMei · Post by **EyezOnMei** » Sun Aug 24, 2003 8:09 am

Lol, yeah that's why u have to factor in sound deadening. I mean, the FTO's performance is almost built on power to weight ratio, just like the DC2 Type R which removed sound deadening etc to reduce weight. However, just spend a bit more and take into account sound deadening and not only will u have an awesome car with a nice ICE that doesn't cause the car to vibrate etc, you will also have an FTO with reduced road noise and doors that close like euro cars.
However, if your looking to hold your weight down of the FTO, an ICE and sound deadening really isn't for you.
Question, are your 6x9's got a low pass (or is it high pass I can never remember) filter on it at the moment? Because usually its not the sub that vibrates the parcel shelf if its sound deadened a little bit, its the 6x9's. I found that using closed cell foam tape from Clarks/Super Chea Auto as a surround on the 6x9's before mounting them fixes this problem superbly. Really its the rear quarter panels I tells ya that are the biggest pain. Cos that's where the rattles will transfer to when u secur the parcel shelf. But I think sound deadening these panels is easier than making an MDF parcel shelf! (Well, for unco ppl like me it is).
But yeah, it is a pain in that extra effort/time is required, but hey its part of owning the FTO I suppose, and the end results are great!

andy · Post by **andy** » Mon Aug 25, 2003 9:55 pm

Thanks.

Where did you get your soundproofing from?

I think you're suggesting a high pass filter (ie high frequencies pass, but the lows are blocked) - the reason being that the sub is there to provide the lows, so you don't need your 6x9s working overtime on the low stuff (and making the shelf rattle). But, no, I haven't tried that yet. The system is as it was when I bought the car. Apart from adding an earth to the amp and resoldering one of the 6x9 connectors back on! That made a bit of a difference.

REDFTO · Post by **REDFTO** » Tue Aug 26, 2003 9:00 pm

The rattle near the roof/rear window is from the high stop light, the plastic bit around it vibrates and hits the window and causes a horrible noise, especially for something so small, at least on mine that is.

Just put some rubber between it and the window are your sweet.

EyezOnMei · Post by **EyezOnMei** » Wed Aug 27, 2003 9:01 pm

I used Flashtac which isn't really designed to be a sound deadener but works a treat! you can get that from Bunnings and something called 'Gripset' for non-smelly liquid form sound deadener.
Otherwise head on over to Webaudiodirec.com and buy some Serenity Max packs which are really good value for money and made for sound deadening. Also the G-SPOT stuff for liquid equivalents.
And yeah, I meant the HPF =P
What I can tell u is that when I just had 6X9's, the bass was already quite strong so it was already vibrating. One layer of flashtac stopped the rear shelf vibrating but transferred it to rear quarter panels. But the bass was definitely louder and I could turn the bass setting up higher before the rattles would come up.
However, after the sub etc, well u can imagine it got crazy, though the deep bass notes took care of most of the noises.
Oddly enough after I sound deadened the doors (purely for road noise reduction/more solid sound doors when closing rather than rattles) I don't really hear any rattles no more.
Oh, a HUGE source of rattles is also the rear seatbelts, but I have those seatbelt holders to take care of that... Also the passenger seatbelt...
But yeah, never thought of the top brake light, but seriously, the rear quarter panels cause the MOST problems!!!

andy · Post by **andy** » Sat Aug 30, 2003 10:02 pm

I went for the flashtec today. Using the 65mm x 10m roll I worked on the rear shelf, rear seat side panels and the upper rear panels. I also used some self adhesive foam strips (draft excluder) to make sure everything fitted snuggly and there was no movement in the panels.

I wasn't expecting too much of a difference, but what a fantastic result for $35 and a few hours effort.

I can't believe the difference it has made. Top tip mate - thanks a lot.

EyezOnMei · Post by **EyezOnMei** » Sun Aug 31, 2003 8:22 am

Glad it worked out for you mate! It encourages me as that's the last part of the car for me to do (If I feel like doing the floorpan/engine thingie, its not really something I can do myself)...
I was surprised how much of a difference it made too! So all, flashtac is a value for money sound deadening!!! =P
It just gets messy when doing the doors that's all, primarily cos of the need to remove all that gunk they use to stick that plastic sheet and also maybe b/c my forearms were a little chubby which really didn't go well when trying to do the lower part of the outer door skin!