Additional DS1501 front firing plan can be found here Its supplemental drawing for metric version of it can be found here (courtesy of Alex). This means that if an owner uses 1 inch medium-density fiberboard (MDF), and he or she needs a box 12 inches high, 13 inches wide, and 11 inches deep, the person actually needs to build a box 13 inches high, 14 inches wide, and 12 inches deep. Wood/drywall screws – about 100 should do. You’ll want 4 – 6 to mount each sub, and enough to space about 6″ apart when assembling the box. Having made one similar to this, build 2 circuits, and route your left & right inputs to the separate chips.
In fact, at box tuning, almost all the bass is produced by the vent – not the woofer. Many plans can be considered a place to start, and you can certainly make alterations or substitutions that suit your needs or your budget. Take the front piece and use a compass to mark a circle for the front of the subwoofer driver. Aligning the subwoofer along a line drawn between the left/right main speakers will help to keep the speakers in the same time domain (yes, a foot or two can matter here!) and will improve coherence.
A crossover network for a subwoofer has the primary job of filtering out high frequency program that is above the intended operating range of the sub. If you are reading this you are probably well aware that a good subwoofer box needs to secure the subwoofers, allow air to flow through them, and be the proper size. The most popular current thinking regarding efficiency relative to subwoofer output is to select a driver with a fairly high mass stiff cone, good linear excursion capability, and power handling that is high enough to withstand the power required to move that massive cone and long voice coil.
If there was a vent in the rear of the box the compressed air would be vented through the vent. Fori 00% certainty that everything is correct, you may want to measure the box tuning frequency for vented enclosures. Measure the frame diameter of your woofer, or check the mounting template that may be included with the owner’s manual, to determine the minimum height and width for the front of your box. You really want an enclosure box that is lightweight so that it won’t add unnecessary weight to your vehicle and also so that it will be much easy and convenient to move out and back in place when the need arises.
The implementation and set-up of your new subwoofer will also be discussed to ensure that you are able to maximize the potential of the new addition to your audio family. Boxes with vents for Sub woofer are also highly vulnerable to variations in driver fatigue, humidity and temperature. You can compensate somewhat for a small box volume by adding stuffing to the box.
If you’re going to build your own DIY subwoofer, you need to make sure you model it before you get started so you know what to expect from it. If your speaker’s spec sheets show a listing for enclosure displacement, you can use the speaker box volume calculator at the DIY Audio and Video website to find the best measurements for your box. Once the box is assembled and braced, silicon all the edges in the box including the batten edges, as seen on the left. Braces may be considered as they can keep the box held tightly together and also for securing the box to the vehicle.
I was able to find one of these for about $5 (though allelectronics is listing something similar at $9 -a-store/item/GW-2048/4-40W-SHIELDED-WOOFER-8-OHM/ ). This is a much better speaker than you need in order to build out the project, but I liked my speaker so much that I ended up putting the same speaker into all of my designs. If a vented box is used, careful attention should be paid to the design of the vent.
With the subwoofer in place, we used a pencil to mark the screw hole locations, then removed the subwoofer and pre-drilled holes for the mounting screws. Parts Express offers a great selection of pre-engineered subwoofer kits in a wide range of performance and pricing. Now that you’ve taken your measurements of the subwoofer and the area you plan to putting it in, you should sketch out the box itself. Compound loading can be applied to any of the enclosure designs described earlier in this section with the benefit of greatly reduced box size. If you look on the diy subwoofer forums like HTS and AVS, you will see that good multiply plywood is the material of choice.
Boxes that are more than 1 foot in width, length, or height, should be braced to eliminate flex (use a piece of wood 3 or 4 inches wide for cross bracing, so that box does not flex). A vented box will allow the ‘woofer to move more freely, which will generate the reverberating low frequencies Hip Hop listeners love, but will still provide suspension. Fiberboard also does not warp or expand like real wood; making it possible for your sub box to withstand a wider range of temperature and weather conditions.
Although you can go into more depth than this, essentially what you do is input the driver parameters into a modelling program like winisd, then adjust the box volume in the program til you have a desirable Qtc. If you use MDF be sure to thoroughly epoxy resin the box inside and out and wear a respirator mask when cutting.75” should be the minimal thickness.