Bassic-12
Straightforward, easy to build subwoofer designs.
Straightforward, easy to build subwoofer designs.
The Bassic-12 Overview:
If it's not already obvious from the name the Bassic-12 is designed for 12" woofers and measures 18" wide x 20" deep x 22" high which results in an internal net volume around 3.25cuft. It is tuned to approximately 20Hz using the 4" Flared Precision Port kit at it's full assembled length or optionally a slot port.
Performance from this design should be adequate for most small to medium sized rooms though multiples can be used for larger rooms or when higher output levels are desired.
Cabinet Design and Cutlist:
The cutlist for this cabinet is as follows:
Sides (x2) - 20" x 22"
Baffle / Rear (x2) - 16.5" x 22"
Top / Bottom (x2) - 1.5" x 18.5"
Horizontal Window Brace (x1) - 16.5" x 18.5"
Vertical Window Brace Top (x1) - 16.5" x 12"
Vertical Window Brace Bottom (x1) - 16.5" x 7.75"
The cabinet is designed using a single 3/4" baffle for simplicity but a second baffle layer could be added for extra strength if desired. The second baffle should be 18" x 22" and would add 3/4" to the overall cabinet depth.
The cabinet bracing is more or less just an example of how it can be laid out. Bracing can certainly be adjusted if desired such as using stick style bracing to minimize material usage. Don't feel the need to stick to the plans 100% there.
Cutouts:
The center of the woofer cutout is 7" down from the top of the cabinet and the center of the port cutout is 4.5" up from the bottom.
Be sure to leave space in the center of the lower vertical brace for the internal flare of the port tube. A 6-1/4" diameter cutout is needed to fit the flare through the hole if using the recommended 4" precision port kit unless you wanted to assemble the port inside the cabinet in which case that cutout could be just larger then the port tube diameter. I made the cutout in that brace an octagon in the model but it would be perfectly fine as a square or circular cutout as well.
The rear panel has an open area above the horizontal bracing large enough to accept most plate amplifiers if you choose to install one.
Damping:
Enclosure damping is not a strict requirement for ported subwoofers but I still recommend a light amount of lining on the internal walls to help kill off reflected noises occuring above the subwoofer passband. Damping could be placed on the side walls, top/bottom and rear wall above the horizontal brace. The area behind the port should be kept open to allow unrestricted air flow. I would recommend 1 - 1.5" acoustic foam or poly batting / dacron of a similar thickness.
Major Cabinet Dimensions:
Cutlist Example using a 4x8' sheet:
Optional Slot Port:
The design could be changed to a slot port for reduced cost. A full width slot port, 0.75" high could be used.
Panel changes:
The panel size of the slot port would be 16.5" wide x 17" long.
The bottom 1.5" of the baffle should be removed also making it 16.5" x 19.75".
Similarly 1.5" should be removed from the lower brace which makes it's dimensions 16" x 6.25".
Finally the bottom panel of the cabinet needs to be extended forward 0.75" to make it flush with the front of the cabinet, filling in the removed section of the now shortened baffle. The dimensions of that bottom panel should now be 16.5" x 19.25".
Subwoofer Driver and Amplifier Selection:
There are a variety of 12" subwoofer drivers that can be used in this cabinet, the following is a selection that I have modeled and should work well with this cabinet with minimal to no DSP work to equalize the response.
As this is a ported cabinet it is still recommended that for whichever driver you choose you should implement some form of highpass filter to prevent the driver from over-excursion and bottoming below the tuning frequency as the cabinet becomes unloaded. Most plate amplifiers will have one built in but if using an external amplifier you should also use a DSP and insert a highpass in the 17-20Hz range.
The Dayton DCS305 is lacking a bit in xmax compared to some of the other longer throw drivers but it does have slightly higher sensitivity then most.
Overall I'd say the GRS is a better pick for lower cost.
Recommended amplifier power in the Bassic-10 cabinet is 100-200 watts.
Dayton RSS315HF (4 Ohm) / (8 Ohm)
The 12" Dayton Reference HF drivers are probably the best modeling in the Bassic-12 enclosure. They should provide a very flat response with the lowest F3 of any of the drivers. The excellent mix of displacement and power handling and low distortion motor design make these one of the best driver options in this cabinet for overall deep bass output, sound quality and extension.
Recommended amplifier power is 200-500 Watts. Port velocity (chuffing/compression) does become a bit excessive near max power, limiting things to 200-300w will keep it cleaner at the expense of some dynamic headroom.
The SD315-88A is the weakest option for this subwoofer cabinet that I have included. While it has the highest midbass sensitivity which allows it to keep up with the other sub drivers in the upper bass it falls behind at lower frequencies due to more limited xmax and a weaker motor.
The only real reason I've decided to include it here is if someone wanted a matching subwoofer to my Nexus designs since the frame/cone is a match that used on those drivers.
Recommended amplifier power is 75-150 watts.
The Lab 12C offers a good mix of displacement sensitivity and power handling. Probably the highest output option in this enclosure if you consider the whole range.
Recommended amp power in this cabinet is 200-400 watts. The woofer could handle more power with a higher frequency highpass especially in combination with a higher tune (shorter port length) near 25Hz.
The 12SW-4HE is one of the best bang for buck 12" subwoofer drivers available right now even though the price has increased a bit since launch. Excellent specs and displacement for the cost and it works great in the Bassic-12 enclosure. This driver would be my general recommendation in this cabinet for it's good mix of performance and value.
Recommended amp power in this cabinet is 200-300 watts.
The XXLS-P830845 is an excellent option if you are looking for a higher quality drive unit. Should be a very low distortion option comparable to the RSS265 with a good balance between sensitivity and extension. The only downside is a lower continuous power rating then the other drivers with comparable displacement.
Recommended amp power would be 150-250w.