z00m

Ok, I just got home and I was thinking to myself I wish I could just figure out what was causing the last main rattles w/ my system. Then I thought I'm sure many people on the forums have systems and could help me out, so what rattles have you had and how did you fix them?

Lets see, my whole trunk lid rattled and I fixed that by spraying the whole underside of it with rubberized undercoating (including the middle section.. hey.. it keeps the sound in, its the poor man's dynamat ). That really helped out my situation because I figured out that that was the main rattle that i was hearing from the inside of my car.

There are no sharp rattling noises anymore, I've got my car very de-rattled And its not bad at all when standing outside of the car (not embarassing like some people's systems)

Anyways, my final rattle is more of a vibration, sounds like the rear deck's carpet is making the sound.. but even if I hold it down I still hear the noise. My friend said it could be the vents, but I can hold them down and I still hear it too. What else could it be? It's something big, like the whole rear deck itself that is causing it. But I wanted to see if anyone had found out the exact rattle and fixed it.

What is it?

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old school

 

Steveman09

It's prolly the high volume air movment thats escaping in the little holes in the rear seats and rear deck. Only real solution is to completly seal the trunk from the cabin, but you will most likly loose lots of sound ouput.

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94 Legend LS Coupe Type-II

z00m

well shoot that stinks. Its not so bad on some songs, but on the songs that have long drawn out bass that goes in and out its pretty bad. If I listen to eminem's rap game it is very noticeable at any volume

grrr, well I ordered my 15" eD sub, hopefully the better sound quality will make up for that vibration or whatever it is

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old school

Legend_master

there is a little black bar that runs across the underside of the rear deck, you could check that out and just put a little piece of cotten or matting between the bar and the rear deck.

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My 1986 Accord Hatchback With an LS/Vtec

z00m

bump

no one else has any advice? i know you people have systems. don't tell me u just left the rattles or have a weak system that doesn't make the car rattle :p


btw legend master, i'm gonna check that tomorrow, i've looked at all of those bars before, but they seemed pretty stable and sturdy.

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old school

ND1980LS

check your power antenna, abs unit and even your spare tire to make sure it's bolted down tight.......

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'90 Granada Black Pearl LS Coupe, 302K miles
'89 Geneva Green Pearl LS Coupe, 142K miles

My 1989 & 1990 Legend LS Coupes

Steveman09

abs unit??????


what the hell?

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94 Legend LS Coupe Type-II

GREYLEGEND

OK Zoomer, you want to look a resonance. At a particular frequency something vibrates like hell. How the heck do you do it?

What you need to do is to play different frequencies and find when the vibration starts and when it is loudest. When you find it, keep the frequency there and then look for it by ear and touch what you think is causing it. The minute you touch it, the vibe will go away.

What we need now is a frequency generator. If you have one, well you wouldn't probably need to ask this question so you need to know how to get one. Easy. You got a PC. Download a frequency generator. It's a program that generates frequencies through your sound card. I suspect you have a sub amp. get a mini to rca adapter to do this. If you or your buddy has a laptop, this is even easier.

Now starting at a high frequency e.g. 200Hz and at a "LOW" volume, start going down in frequency like every 5 or 10 Hz or so until you get the vibe where it is loudest now you can easily go find it.

Some warnings.
Do this at the volume where you just get the vibe and not much louder. Constant tones can be hard on your system compared to music.
IF you start at a low frequency and have a ported system, you will "unload" the sub. The sub can easily run out of travel and be damaged if it is of poor design.

Try these sites.

http://www.dazyweblabs.com/val/

Using the sweep generator and mic you'll see your in car frequency response.
A cheap mic is not to be totally trusted at the bottom and top end, but it could be interesting. Cheap sound cards are also not reliable for flat frequency response.


Recommended one for newbies
http://www.marchandelec.com/programs.html
download fg_lite.exe

This is simple to use and use a sine wave.

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When you need good affordable printing solutions

z00m

great idea grey! i didn't think of that. i can d/l a competition hz cd and it'll have tracks that have solid bass at diff frequencies. i got my old system mic'ed at a car audio pro's house (that i met on caraudio.com) and he had one of those cds.

Only problem is that if the vibration is in the trunk, it might not keep doing it if the trunk is open when i'm looking for it. hmmmm i'll figure it out somehow

thanks once again grey! btw, i'm changin my o2 sensors in a little while, i'm bout to go get them now

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old school

ND1980LS

...yeah....the ABS control unit in the trunk.......

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'90 Granada Black Pearl LS Coupe, 302K miles
'89 Geneva Green Pearl LS Coupe, 142K miles

My 1989 & 1990 Legend LS Coupes

z00m

no need in worrying over the abs unit.. seein as i don't even have it :p

<-- base model w00t

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old school

LLegend

I got dynomat in spts near the license plate, around each speaker, and everywhere i coud not see some rust proff, but I got a 90 and my system is 2 10's so bass is clear not too booomy, maybe I'm bias but no boom not ratttle, clear bass is clear bass. I got dyno under the deck and that seams to be the isssue, and each pillor behind the pass. seat.

remickz

i need to hurry up and do sumthin about my rattles. its gotten to the point where there is rattles comin from parts of the parcel shelf, the roof 9less rattles when the sunrof cover thingo is closed) and there is a clicking sound i now get in the dash, like behind the tacho and spedo, just a clicking noise like something is ticking over when i move.

mike.

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ND1980LS

well....the ticking in the dash is your speedo cablethat needs to be cleaned/adjusted.....

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'90 Granada Black Pearl LS Coupe, 302K miles
'89 Geneva Green Pearl LS Coupe, 142K miles

My 1989 & 1990 Legend LS Coupes

remickz

thanks, i will have a look into that later on, i know i have seen lots of posts about this issue, so later tonite i will have a look back in the forums.

Mike.

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