Ive got a 71 Dart 4 door with 2 15' subs on a 5000 watt amp. I have isolated the horrible vibration sound to the backing on the rear seat. is there a way to stop this from vibrating without removing it? and if it had to be removed would that cause any problems?

Do you mean the cardboard divider between the rear seat and the trunk?
If so then, yes, you can remove it as it is only for cosmetics and minimal noise suppression entering the cabin from the trunk area. I bet your getting some vibes from the package tray area as well.
Dynamat or similar might help.

Watch the trunk lid torsion bars too, they can vibrate against each other or the package tray. Take a short length of fuel or other rubber hose, slit it down the side, and push it on the torsion bar to act as an insulator where metal meets metal.

Make sure the rear seat back is set on the hooks too. You shouldn't be able to pull it straight back by hand.

You want the least amount of insulation between your rear seat and cabin. The more there is, the more the pressure waves have to fight to get through to your ears.

Random side question: whats the fuse size on your amp?

Alright I'll mess with it when I get back. Also does the rear seat fold down? And if not ho hard is it to unbolt it? I want to put a cover on the top at least it has tears where the sun hits it

The only a-bodies that had a fold down rear seat were the Dusters and Dart Sports with the optional fold down rear seat package.

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Casually looking for a Clifford hyperpak intake for cheap.

It's so tempting for this old man to blithely say...turn the bass and volume down...but I won't.

+1. I find it a bit difficult to believe you can't get the sound you want with a couple good 6x9s in the package tray.

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Casually looking for a Clifford hyperpak intake for cheap.

I gotta side with 64 Convert and Reed in the last two posts.

Mr. Moparlewellen is going to get to the ripe old age of 60, and wonder why he can't hear his grandkids over the ringing in his ears.

Us older guys suggest you invest in quality of sound, not quantity.

Roger

If your like me, NO you cant get the same sound out of a pair of 6x9s... They will produce crisp mids and high notes, theyre not intended to provide any type of real low frequencies...

Get some dyna-mat, lay it down on all of the inner panels, on the bottom side of the rear deck lid, make sure the foam around the trunk lid is good, trunk latch is adjusted tight, and that should get you to being pretty rattle free...

1200w Pioneer 12", Pioneer 6.5" (x2), 2000w Lanzar Legacy for the lows, and a 1200 MB audio for mids/highs, Pioneer head-unit, 8awg power/ground, 50 Maxi-Fuse, Optima red-top... Will leave your eyes blurry, short of breath, and tickle your nose lol!

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"if it aint broke, fix it till it is"
78 Plymouth Volare Super Six wagon
89 Volkswagen Golf GTI 16v
92 Chevrolet K1500 5.7
98 Ford Escort ZX2 zetech

But now you have lost 1/2 of your cargo carrying capacity….

I recently went through the process of rewiring the stereo in my brother's 83 Dodge van. Six speakers mounted in the ceiling (two 6x9s, four three inch mid/high speakers in their own boxes) and two in the walls (6x9) driven by two amps hooked into one deck. Holy overkill Batman. Frankly, I have heard double speaker systems that sounded better and were much easier and cheape rto hook up.

But I know car audio guys are their own break of cat, so to each their own. Perhaps you could build a bass reflex box behind the rear seat and use the 6x9 holes in the package trays as the outlets?

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Casually looking for a Clifford hyperpak intake for cheap.

Not true, the '64 - '66 Barracudas had fold down rear seats.

D'OH! How could I forget that! I used to have a 6 Cuda. However, I was thinking more along the lines of cars that had a fully sealed trunk compartment with a fold-down rear seat, rather than cars with free standing rear seats that folded down (a la 64-66 Barracudas and all station wagons).

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Casually looking for a Clifford hyperpak intake for cheap.

This is why I asked for fuse size earlier. Simple math. 50a * 14.4v (assuming your electrical system can maintain this during transients at the amp terminals) = 720w absolute maximum @ 100% efficiency, of which amps never are. 1200w, 2000w... all laughable. A true 2000w is something like 160a fuse @ more realistic 80% efficiency.
How do you define quality? An audiophile may say that equates to flat response (all frequencies represented equally, reproduced in exact proportions as it was recorded). If all your using is 6x9's that roll off at what, 100? Maybe a generous 80 hz... your missing a decent portion of content depending on the program that's being auditioned. Loud bass isn't necessarily excessively loud - its just musical content that one system can reproduce that another simply can't.

The "no replacement for displacement" rule of thumb holds true too for audio. You simply need more cone area to more easily reproduce the lower frequencies.

As for the bass bug - it's kinda like hopping up a slant. An outsider just doesn't understand if the bug hasn't bit them.

There's too many variables to say fuse size... Along with the power supplied from the power source, there class of amp, power requirements of the components attached, the way they're wired, and other factors. I know I'm not pulling anywhere near the 3200 combined watts, just as the O.P. isn't pulling a true 5000w.


I think we're straying off subject here though, he's just asking how to get rid of the vibrations. Like I said, make sure stuffs tight, and cash out on some quality sound deadner to help insulate things and clear up the quality of your lows, and you won't sound embarrassing rattling down the road.

I can't agree more with the bass bug comment! That is all too true, if you havnt experienced it you just don't know what your missing. Its just a feeling of absolute power when you can shake and rattle everything around with something so small as some subwoofers in your car. But you have to have quality mids and highs that can keep up. Otherwise there's no point in so much boom. Just like building a powerful engine, its all a careful balancing act.

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"if it aint broke, fix it till it is"
78 Plymouth Volare Super Six wagon
89 Volkswagen Golf GTI 16v
92 Chevrolet K1500 5.7
98 Ford Escort ZX2 zetech

Don't forget the package tray liner itself can buzz too.

It's not straying off the subject. I'm trying to get a general sense of the true power we are dealing with. A system with true 5000w is gonna need waaaaaay more soundproofing then a "fictitious" 5000w. An easy way to do this is by fuse size, hence my question.