The right subwoofer enclosure is highly essential in pickups when subwoofers are to be placed under the rear seat.
The enclosure must not only be built perfect for the subs to perform well, but it must also protect the speakers from damage. Damages can arise from water seeping in, or dust that may penetrate inside the speakers. Damage can also result from passengers in the seat that may adjust the seat or even kick the speakers by accident.
It is, therefore, recommended in the case of most underseat boxes to have enclosures face the speakers upwards or downwards for this very reason. So in addition to being built right for the speakers, it must not face outwards unless the installer will be using speaker grilles to protect the speakers. The box plays such a critical role in the overall performance that it’s very important to select the right type of enclosure to match your truck as well as the subs you intend on using. Outlined below are the different types of underseat enclosures.
Sealed and shallow mount box
Sealed and shallow mount should be described together since they are practically synonymous with each other. A large majority of late model trucks leave very little space underneath for large subwoofers or big boxes. Instead it is necessary to scale down the effort and go with what will fit. When you only have 6 or 7 inches under a seat, you may be required to use a shallow sub, ie subwoofer with a very low profile. Most shallow subs work in very small volume enclosures, which are typically sealed. So if you have very little space to spare, a sealed box with a shallow sub makes a very good solution.
They are commonly referred to as the vented enclosures and have a small vent as the name suggests. The small vent allows air and minimal frequency to pass through the system. A minor sound distortion is added because of the vent presence. The box has high efficiency and gives out loud bass, and this is the main reason why the vented boxes are highly preferred than sealed boxes. There are various sizes in which one can choose from such as 8, 10, 12, & 15 inches. However these are not typically compatible with most trucks. Sometimes it may be possible to have two 10s ported, but typically nothing beyond that.
These are the largest size of enclosures. The central working principle is that the sound is re-imposed and quality sound is produced. Bandpass enclosures have two chambers and a minor ventilation like a ported box inside. The subwoofer emits bass frequency and superimposes with the sound waves from the minor chambers. This gives higher quality than the above two subwoofers. The downside is that a bandpass enclosure needs to be so large that it really doesn’t work for most trucks.
While deciding to use an underseat subwoofer box, it is important to consider the working principle of the voice coil as well as the best option available regarding size and shape.