PeachParts Mercedes-Benz Forum - View Single Post

Mike400E · #6 05-30-2002, 01:02 AM

Definitely read the JL Audio "Primer". It is a very good summary of the different types of enclosures and their pros and cons.

I'm guessing that what you describe as "boomy" is probably really inacurrate bass. By this I mean that at some frequencies or notes of music or percussion you get a nice solid sound. Others seem to disappear, and still others are very loud and/or muddy. As the bass plays up and down the scale, or the drummer does a roll around different drums and changes tone, you may find that the the quality of the sound and volume change. This is probably because your sub is playing into a very small space, IE the trunk, and creating all kinds of secondary resonances. As the sub hits certain notes, you will get a doubling or a tripling of the sound waves that are being transferred into the cabin via the hole you made in the First Aid Kit space. This will sound "boomy". While it might be loud, it won't sound accurate or crisp. Conversely, there are other notes or frequencies that cancel each other out so those notes will seem to disappear.

By porting directly into the cabin from your sub enclosure, you will take half the energy the sub is making and put it directly where the listener is. The other energy is still in the trunk obviously, but it should be shaking the rest of the vehicle, and overall should sound pretty good - IF the box, speaker and port are properly matched - tricky business isn't it?! It IS important however, that you seal the rear deck, so you won't also get the weird resonances and multiplied and/or canceled frequencies you are getting now. Simply poking a 3" port up through an 8" hole will NOT solve your problem. In fact, it may exacerbate it.

Since you have a sealed box, the thing to find out is if it can be ported. If so, how big does it need to be, both in cross section and in length? Many drivers simply won't work very well in a ported enclosure, because they are designed to use the sealed air in the box as a cushion. Without the cushion, they may over extend their cone excursion range and either distort or fail. Did you buy this sub, or make it? If purchased, what is the brand name? A reputable manufacturer should be able to give you advice regarding porting. Trying to figure it out by trial and error will definitely be a ton of brain damage

Thanks for the offer regarding wiring. I may take you up on that! The battery in my car is in the trunk, and the stock amps are also in the trunk, so I am hoping I don't have to run anything from the engine bay to the trunk.