Tech Info  |  FAQs  |  Answer
My Bazooka® plays great when the trunk is open but, when I close the trunk lid the bass goes away.

Where's the BASS?
First you should rule out any Phase Cancellation problems that may exist in your system.

When this variable is eliminated from the equation, there are primarily two factors left that could cause this effect in your vehicle.

  • Restriction of AIR FLOW

  • Development of STANDING WAVES
If the bass response in your system drops when you close the trunk, chances are it is due to poor AIR FLOW, excessive STANDING WAVES or a combination of the two.

The Bass Response will suffer if the trunk is sealed off from passenger compartment so that AIR FLOW is restricted between the two areas. Since sound waves are nothing more than moving air, any reduction in the AIR FLOW from the trunk will result in a reduction of the bass response in the passenger compartment.

Can I Get Some Relief Over Here?
To cure this problem you must reduce the restriction of AIR FLOW between the two areas.

This can be accomplished by removing some insulation or other acoustically opaque materials from behind the rear seats, under the rear deck or beneath the rear package tray.

If this is not possible, the only other way to overcome this problem is to create an opening in the acoustically opaque material between the trunk and the passenger compartment that is causing the AIR FLOW restriction. In most cases the back deck is the easiest area to create this type of opening. The opening can be in the form of a matrix of small holes, one or more ports, ducts or vents. Since the object is to increase AIR FLOW, the opening should be as large as possible without compromising the integrity of the vehicle.

With this opening(s) in the acoustically opaque material the Bass Response will pass through other acoustically transparent materials such as foam or cloth found in the rear seats, package tray or rear deck areas.

If the opening is visible, it can be covered with a cosmetic grill or a custom rear deck. This process requires custom install skills and we recommend that you consult with a qualified installation professional or have the work done by an Authorized SAS Dealer.

When sound waves of the same frequency come together at opposite directions, they interfere with one another resulting in a full or partial cancellation of the output at that frequency. This type of wave interaction is known as STANDING WAVES.

What Do I Get?
If your Bazooka® subwoofer is positioned too far forward in the trunk area, it may result in systems of COMPLEX STANDING WAVES, resulting in a loss of bass output.

In a trunk, the paths that sound waves take to the front of the passenger compartment are rarely 100% acoustically transparent. This creates acoustical resistance or reduced AIR FLOW between the trunk and passenger compartment.

When this sub-division of the vehicles air space is compounded by the reflective and semi-reflective surfaces common in a trunk compartment, the development of COMPLEX STANDING WAVE SYSTEMS are common phenomenon.

If your Bazooka® subwoofer is placed near a semi-transparent surface in the trunk, like the area under the rear deck or behind the rear seats, the sound waves tend to bounce around in the trunk until pressure forces these sound waves into the passenger compartment.

This typically reduces the Bazooka® subwoofers output due to extreme systems of COMPLEX STANDING WAVES and takes away from the overall sound quality of the bass response.

There is a Remedy!
If you think you are experiencing output problems due to STANDING WAVES, the good news is you can easily correct this problem by simply relocating your Bass Tubes® enclosure(s) toward the rear of the vehicle.

When a Bazooka® subwoofer is loaded into a corner at the rear of the trunk the sound waves reflect off of the acoustically opaque corner and travel forward in a direct path towards the passenger compartment, reaching the listener with fewer STANDING WAVES and greater Bass Output.

Once the placement of the Bass Tubes® enclosure is at the rear of the trunk you should notice a marked improvement in the quality and output level of the bass response created by your Bazooka® subwoofer product.

SAS, BAZOOKA, BASS TUBES, and LISTEN TO YOUR EARS are registered trademarks of Southern Audio Services, Inc.