986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post

boxster7614 · 04-15-2008, 12:15 PM

Sorry to break the bad news to you guys but your trunk LEAKS!

Take a closer look at your boxsters. Does your engine cover sits flush with the top of your car? Mine has a rear storage compartment on top of it and enough room for the convertible top to retract into. Almost half of the wall in the rear trunk goes right OVER the engine into the area ABOVE the engine....this is where the sound is passed not into the engine. This set up is not going through the fire wall but over it. The fire wall seals the engine off completly but not the trunk. If that trunk was completly sealed, it would never close because of the traped air.

Trust me there are plenty enough factory air leaks to allow sound to pass into the cabin to hear the bass.

However I did drill a few holes that pass through into the top, right Above the engine. To maximize sound.

The bass is louder when the top is up then when down, but that is completly normal with a convertible.

I did consider using a bandpass box and venting it into the cabin the same place I drilled the smaller holes. However bandpass boxes are very complicated and have a narrow frequency range. They are difficult to tune and end up sounding boomy. That is why I used the sealed box because it provides a tighter bass sound, isn't a narrow range, and requires less air space. That said with the sealed box inside the trunk it almost acts like a box within a box... the trunk acts as a box itself and the small air leaks would be the ports. All the leaks/ports allow for sound to pass through into the cabin....not through the fire wall!

Quote
"I have often suprised myself when I have played the "it-just-cannt-be-so" game based on my understaning on the theory involved. Only to find out that in fact, in practice it was so..... fun stuff,"

I wonder how hard it was to convince people the world was round?

04-15-2008, 12:15 PM	#14
boxster7614 Registered User Join Date: Mar 2005 Location: utah Posts: 96	Sorry to break the bad news to you guys but your trunk LEAKS! Take a closer look at your boxsters. Does your engine cover sits flush with the top of your car? Mine has a rear storage compartment on top of it and enough room for the convertible top to retract into. Almost half of the wall in the rear trunk goes right OVER the engine into the area ABOVE the engine....this is where the sound is passed not into the engine. This set up is not going through the fire wall but over it. The fire wall seals the engine off completly but not the trunk. If that trunk was completly sealed, it would never close because of the traped air. Trust me there are plenty enough factory air leaks to allow sound to pass into the cabin to hear the bass. However I did drill a few holes that pass through into the top, right Above the engine. To maximize sound. The bass is louder when the top is up then when down, but that is completly normal with a convertible. I did consider using a bandpass box and venting it into the cabin the same place I drilled the smaller holes. However bandpass boxes are very complicated and have a narrow frequency range. They are difficult to tune and end up sounding boomy. That is why I used the sealed box because it provides a tighter bass sound, isn't a narrow range, and requires less air space. That said with the sealed box inside the trunk it almost acts like a box within a box... the trunk acts as a box itself and the small air leaks would be the ports. All the leaks/ports allow for sound to pass through into the cabin....not through the fire wall! Quote "I have often suprised myself when I have played the "it-just-cannt-be-so" game based on my understaning on the theory involved. Only to find out that in fact, in practice it was so..... fun stuff," I wonder how hard it was to convince people the world was round? Last edited by boxster7614; 04-15-2008 at 12:21 PM.