any chance of breaking the hatch glass with 2 solo-baric l7 12" and a 3000 watt amp? the subs will be faced towards the glass. i just dont want to go with these subs if theres a chance of breaking the glass cause my ride means more than a system.

 

No, unless you already have a crack in it. I'm not sure how it goes but here's what I think is the deal with that. Every substance has its own frequency that can break it and glass' is really high and that's why tou always see stuff about opera singers breaking glasses, but if there's already a crack the vibrations can extend it until you get a break. I'm sure somebody can explain it right, now that I say that it doesn't sound right.

 

no theres nothing wrong with the glass as far as a crack or chip. i just thought that i had heard of alot of bass breaking windows.

 

The only way that you will break your glass is if you manage to build up enough air pressure behind the glass to break it.

That hatch is a very heavy very thick piece of glass, plus its curved, which helps distribute the force amongst the glass.

The likleyhood that you would be able to acheive this is low. Seeing as the air pressure will escape through the easiest way first. So the rubber seal between the glass and the back of the car, any other rubber seals, like with T roofs and such will let the pressure out before you can break the glass.

In addition to this, the windows on the pass and driver side will moe out away from the car easy enough.

There is plenty places for the pressure to go.

I don't think you will have to worry.

However, you DO stand a chance of harming the motor that holds the hatch shut.

I hope this helps.

 

demicon pretty much summed it up. one of the reasons why you dont see too many f-bodies in SPL competitions.

 

Someone told me they heard about a comp firebird who blew the glass out of the reach hatch, didnt break just poped it out. Didnt want to tell the dude that I didnt belive him because he sure belived it lol but... no.. I cant see it happening. That glass is very thick yes, have you ever tried to pick up your hatch without the shocks attached? Its heavy as all he||. Just imagine your car as a over sized bandpass box and that hatch being the plexi glass cover. Just like the rest said, expanding yes, breaking, un likly.. but if for some reason it does, asure yourself there will always be junkyards with more glass hatches for cheap.

 

Ya my friend has that setup in his firechicken and u can't blow it out

 

many people talk about blowing out windows and windshield but in reality it rarely happens unless you're above 160 db which will cost you a lot. It also depends the type of bass you have. In SPL comps many of the boxes are called "one note wonders" they are only designed to play one tone that is the loudest possible tone for that car. It is often fairly high bass (50+hz) while street beating is mainly for the mid-low bass 30-50+hz.

It is easier to hit a higher db if you tune your box higher. So if you had for example 4 15s and 2000 watts each tuned to 61hz and hit 156. If you had the same wattage and tuned the box to 28 hz you would be way lower, probably atleast 10 dbs lower.

But if you can get your system to play low bass loudly it is much more violent in the car. I pulled a 142.2 @ 27hz with 1 15 and 400 watts. This was quite violent in the car, it broke my glove box lock and extended what was once a rock chip in the windshield into 3 or 4 large cracks all the way across.

To answer your question, the rear hatch probably wont break with that setup if the window is in good shape.

 

how do you tune it to the hz's that i want? how do you ttune a mdf box? i feel stupid but this is one thing thats never been explained to me.

 

your tuning depends on how much port volume you have compared to the box volume.

this site helps you calculate the port (vent) that you want in the boxes near the bottom.

its difficult to understand at first but you get the hang out it really quickly.
http://www.carstereo.com/help/Articles.cfm?id=31

 

do i still need to know how to tune it with a sealed box?

 

no a sealed box doesnt have a tuning frequency. Except for if you make the box larger it will have a greater bottom end.