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Dayton Reference RSS390HF-4 15″ subwoofer DIY Home Theatre Cabinet Plans

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Design Goals

My goal in designing a cabinet for the Dayton Reference RSS390HF-4 15″ subwoofer was to achieve sub 20hz bass for my home theater system. I was previously using the Dayto Quatro 12, and while it was a nice performer, it just could not achieve the deep bass I was seeking. Anything above 30-40 hz was great but it had some severe bottoming out in a 2 cubic foot ported enclosure. After reviewing all the available 15s it became clear that the Dayton Reference RSS390HF-4 15″ would be a suitable choice. Not only did it have some nice specs that were easy to work with, it also had a nice affordable price tag. I decided to couple the sub with the Dayton HPSA500 500W Subwoofer Amplifier. While a better choice would have probably been the Dayton HPSA1000 1000W Amp, I decided to got with the Dayton HPSA500 for price reasons as I wanted to keep the costs to a minimum. If you want to keep costs even lower, then the Bash 500W Digital Subwoofer Amplifier would provide the same power as the HPSA500 for about $100 dollars less. While I don’t have direct experience with the Bash amps, they do have some nice user reviews on Parts Express.


The design on this enclosure was pretty straight forward. Since it was going to be a pretty good sized cabinet yet still needed to maintain spousal approval, i went with a rectangular low profile design that when veneered, it could sit next to our couch and look something like a coffee table. After modeling the box in software, I came up with a 7 cubic foot enclosure (after deducting the amplifer and sub displacement), with dual 4″ diameter and 22″ length ports. This gave me an approximate tuning of 18.5 hz which was well within my intended frequency response for the project. The cabinet has the following external dimensions, 17.5″ H X 36″ W X 25″ D. I will admit that the cabinet is rather large but if you want this kind of bass without spending a ton of money on a sub then you have no other choice


The build was straight forward and easy. I wanted to keep it as simple as possible in order to expedite the build process. This enclosure is quite easy to pull off even for the most novice DIY speaker builder. Since it is a simple rectangle, as most sub enclosures are, it makes for an easy build. I used MDF purchased at the local Home Depot. I like to use the precut 2’x4′ MDF panels. This makes for easy maneuvering when cutting boards to size as well as transporting them from the store to your home. While a table saw is the easiest way, you can also either have your local Home Depot or Lowes simply cut the panels to size or you can use a circular saw. Using a circular saw is a bit more challenging as far as getting your pieces all a consistent length as well as achieving a straight cut but it can be accomplished by using guides and/or a router. I will post some circular saw speaker building tips at a later date.


Construction was pretty straight forward, nothing special since it’s just a rectangle. Once the pieces were all cut to size, it was assembled using 1.5″ sheet rock screws and wood glue. For a better finish, I like making the panels that make up the outside part of the butt joint about 1/4″ oversize. On this box it would be the top, bottom and the sides. This allows me to use a flush trim bit on a router for a perfectly flush joints once the entire enclosure is assembled. It is important that all screw holes be pre drilled so that the MDF does not split. Wood glue is also an absolute must for ultimate strength. Another absolute must on an enclosure of this size and type is internal bracing. I accomplished this by cutting a third panel of MDF then cutting a hole in the center (see plans). This piece was then installed at around the middle of the enclosure, screwed and wood glued to the 4 sides. You could do 2 such panels glued together for added strength but the one does the job. Since the joints need to be caulked, I assemble all pieces but one (either the top or bottom) so that you can easily access all inside joints with a caulking gun. I like to use “painters caulk” for this.

After caulking, attach the last piece. The remaining joints can be caulked through the woofer, amp and port cut outs. Once the enclosure was fully assembled, I proceeded to make all of the cutouts, I prefer to do this as the final step because I find it easier. You could opt to make the cutouts after cutting the panels . The woofer and port locations are on the plans. I left out the amp cut out from the plans because this will be personal preference. I placed mine on the side panel closest to the sub. In hind site, the side panel opposite the sub would have been better for concealment purposes. You could also do it on the rear panel right behind the sub as well. For ports, I used the Parts Express Create-Your-Own Flared Port Tube System which consist of an inside flair, outside flair and port tube. You simply cut the port tube to length , apply some epoxy/gorilla glue/PVC cement to the port tube ends and attach the flairs. I went with this port system instead of 4″ PVC to reduce port noise. If you decide to go with the Parts Express port system, you will need 2 4″ inside flairs, 2 4″ outside flairs, 3 port tubes and 2 couplers. I should note that the ports are a bit pricey but they look a whole lot better than white PVC and the flairs help minimize port noise. You can simply use 4″ PVC to reduce costs, note that the flairs do not work on standard PVC pipes because the outside diameters are different. This enclosure uses 2 4″ ports 22″ in length. Below are the plans for this build. Click the image to enlarge.


Once the wood glue was dried, I gave the entire thing a quick sanding. This is where routing your joints flush pays off. If you don’t have a router and plan on veneering, then you should sand all the joints flush. Once you have all your joints flush, you can finish the box to your preference. I plan on veneering mine but haven’t done so yet. Once you have it all done, install your sub, ports and amp. Be sure to use gasketing for your sub and amp, I recommend the Parts Express gasketing tape. I completed the cabinet by installing rubber cabinet feet, I used the Parts Express rubber cabinet feet.

Listening Impressions

Once I got everything hooked up, I went through my collection of movies with heavy bass tracks. One of my favorites is the remake of Flight of the Phoenix, the start of the movie has a VERY heavy bass track that starts with a plane flying through the sky and coming in for a landing. . All I can say is WOW! The bass coming out of this is amazing! I was hearing (rather feeling) frequencies I had never heard. I went through some other heavy bass track movies and was hearing and feeling frequencies that simply were not present on my previous sub. While I do not have any measuring equipment, the bass was the lowest I have ever heard. Not only is the bass very deep, but it is quite loud and more than enough to rattle your walls. You simply are not going to hear or feel anything like it at Best Buy. I would say that the frequency response rivals that of some $1000+ subwoofer systems I have heard during my time working at a high end AV store. Best of all you can experience this for less than half the price! I’m not going to tell you that this is the best sub system ever or that it is the best design ever but the bass will more than impress and amaze you if you have never experienced sub 20hz bass before.

.Click Here to Download Plans

Parts, supplies and Costs

All in all, considering you will end up with an awesome sub 20hz sub system, the cost is pretty cheap when you compare to some of the high end subs on the market. You might find cheaper systems at Best Buy and the like but they will not even compare to this. Total cost can range from $500-$700 depending on the amplifier you choose. Parts Express also runs deals on the amps and subs from time to time so check the Parts Express site often. Below is the parts/supplies list and estimated costs.

Building Materials

5 MDF 2’x4′ sheets or 1 4’x8′ sheet mdf- $40 (home depot, lowes, etc)

Screws and wood glue- $10 (home depot, lowes, etc)

4ft 4″ PVC- $10 (home depot, lowes, etc)

Gasketing tape- $5.50 Parts Express part 260-540

4 Cabinet feet- $4.00 Parts Express part 260-774

Total cost about $70-$80


Dayton RSS390HF-4 15″ Reference HF Subwoofer 4 Ohm- $160
Parts Express

Amplifier (3 options)

Dayton HPSA1000 1000W Subwoofer Amplifier- $425 Parts Express

Dayton HPSA500 500W Subwoofer Amplifier- $325 Parts Express

Bash 500W Digital Subwoofer Amplifier- $229 Parts Express

Total cost about $400-$600 depending on which amplifier. Parts Express offers Free Shipping frequently so you can save some money there.

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