My new year’s resolution: Dual Dayton DVC385 ported build / DIY HT speaker / room acoustics...

This is long overdue but I am finally getting around to it. The HT was done about 5 years ago and as far as the speakers go uses cheap Menards in-wall speakers all the way around, two for the center plus 5 JBL HTIB speakers that brings the total number of center channel speakers up to 3, more is better right. For the bottom end there is one JBL sub 10 placed in the front.

Looking forward


And at the mess behind


Now laugh all you want but this was all done before I knew about AVS forum and the only place I knew you could get raw drivers from was RadioShack before they stopped selling them. About a year after theater was built did I discover this forum then Parts Express Maidisound, Meniscus. Then my interest in DIY speakers exploded and have been learning and building ever since. Enough talk about me and on with the project.

Now the plan is to replace the JBL with two Dayton DVC385’s each in a 9.5cuft ported enclosure tuned to the mid teens. I had been looking for a decent driver deal for a while and when the DVC’s went on sale for $99 I could not pass them up. One sub did come with the spider mount cracked but PE took car of it and got a new one out to me less then 48 hours after I sent the bad one back. I really like how they model in the ported enclosure. Around the tuning frequency the two of them should give me equal SPL as four 18” Dayton’s with 5 times the power in a sealed enclosure of the same size 19 cuft total. Ported FTW!

If you have not seen it here is a excursion video I made with the DVC385:


As far as the speakers go I plan on replacing the side surrounds with my small on wall surround design here:http://www.diysoundgroup.com/forum/index.php?topic=71.0 Currently the rear surrounds are way on the back wall and I might make a modified version of the on wall surrounds to place on the ceiling just behind the listening area.

I am not set on what I am going to do up front yet I may try running the MTG-08’s with a phantom center or possibly three of my dual 6.5” woofer / waveguide designs up there once I get around to switching out the CD and reworking the crossover on those. There is not a lot of room up front so any of the larger designs are out.


Right now I am going to focus on building the subs then move to speakers then treating the room. I have got my work cutout for me.

Happy new years everyone!

Hehe I remember back when I built my first set of speakers using buyout drivers and a first order crossover derived from an online calculator. I thought they were the best sounding speakers I had ever heard.


Yeah I do believe they are almost the same. Though I thought I remember some say one had a different VC diameter way back when all the MFW drivers were on closeout.

I have thought about that but those are just a little too big and with the ported enclosures am I shooting for extension into the low teen’s, something a little below what the F-20's will do. I also don't need extreme SPL levels, at least not indoors. I may build something like those for the bottom end of my synergy horn based backyard theater when it warms up.

Unfortunately I got pulled into another project for my brother that needs to get done before Saturday. So far I have only managed to get a simple inexpensive circular saw guide built and make one cut with it.

They will get 100 watts each which should hold me over for now with a future upgrade possibly being an EP2000/NU3000.

I did not make as much progress as I wanted on these the past few days, but I did accomplish a few other things. First I built a new dust separator so I could try it out on this project. I moved a spare PC into the shop and I made a very simple strait edge jig for my cordless circular saw too. It works great cuts that would be troublesome on the table saw are now a breeze. It took less then 5 min to build and cost me nothing.



All that is needed is some material with a straight edge for the guide. I used some scrap 7/16" OSB I had and cut a nice straight edge on the table saw. This should be a little wider then the distance from the side or your saw's base plate to the motor so there is room for clamping. Then you take some thinner material 1/8" or 1/4" should work well, I used some 1/8" hardboard I had. This is used to line up the cut and should be made a little wider then the total distance of the strait edge board plus the distance from the edge of the saw's base plate to the blade. Once those two are glued together you run the saw along it to cut it to the exact size and removing any excess material. Here I after I made my first cut with it:




With the PC in the shop I can now stream music from my library down there and started to notice a problem I had, the Optimus Pro X7’s that I have in there just don’t get loud enough on the old realistic stereo receiver when i feel like cranking it. So I switched them out with something a little more sensitive and now I have no trouble hearing the music when I am sawing with ear protection on.






I got all my panels cut, next up I am going to start gluing the boxes together and start cutting the recesses for the drivers/ports on the baffles. I also need to figure out what I am going to do for bracing before I get too far with assembly.

How does that help?

The clamps work very well, it takes no longer then 15 seconds to setup for a cut and I can get within a 1/64" every time the limiting factor being how well I measure and mark the sheet before cutting.

I forgot to mention the dimensions of these are 20.5”w x 26”h x 40”d with a double thick front baffle. They can be cut from 3 4x8' sheets or 6 4x4' sheets. I went with the 4x4' sheets because when they go on sale at menards (20% off handy-panels) it is cheaper to buy a pair then a full 4x8" sheet. The 4x4' sheets also fit right into the back of my XJ with the rear seats folded down.

I started the enclosure assembly which is just clamps and titebond I as I can work on the baffles as the glue is drying. I marked out my port and driver locations and started making my cutouts on the outer baffles. You can see my trusty old circle jig and cheap harbor freight trim router hard at work.





I test the fit of one of the port flares, I am using these her:Port Tube 4" ID x 4" L Flared
They happen to have the same ID as 4” PVC so I am going to run those for the rest of the length. The total length of the ports is going to be approximately 28”, that puts tuning right about 15hz. I have a feeling it may come in a little lower then that when I test it.



I just made the inner baffle cutout with a jigsaw as there is no need for a perfect cut there and the jigsaw creates far less dust.
While those are gluing together I figured out what I am going to do for bracing and marked locations for it. My leftovers from the main panels are going to become the bracing. Much less waste then making the window bracing out of sheets.







Once that was done I glued the baffles on.



These cutouts from the outer ports flares are going to be my inner port flares.



If you have not tried one of these before I recommend it, it an adjustable hole-saw and cuts through MDF much quicker then your regular hole-saw does as it ejects all the dust as it spins instead of trapping in the cut. These cuts only take a few seconds each on the drill press.







Here is where I stopped for tonight, I am going to see if I can get the bracing and ports cut and in place tomorrow then get the last side panel in place.

Thanks guys,

Here is 4 DVC385's in a 19cuft enclosure (would be two per 9.5 cuft) tuned to 15hz vs 2 HO18's in the same enclosures (9.5cuft each). Both powered by a single EP4000, the dvc's would get 2400watts (bridged mono 4ohms or two 2ohm) and the 18's would get 1500 watts (two 4 ohm loads). I think I have those numbers right but am not sure. Note both have a highpass at 15hz, the DVC's are at their limits where as the 18's could take a little more power.




I am sure they will blow it away both in output and extension.

I am sure the coils could take 600w for the short blips they might see during a movie. It is not like that is continuous and while they are a little over rated xmax I do think they are still within reasonable excursion limits.

Though I will agree that it is a little on the high side.

Time for an update, boxes are assembled just need to do some sanding and round-over’s then paint.


Here is what those flares look like on the ports.




Ports and bracing installed, the outer port flares need to be glued in so I painted around them before I did that. They are glued to the PVC but the duck tape is used as extra sealing measures. Even though I used the MDF cut in strips for the bracing I ended up with window style bracing anyway as it made things easier to assemble.

Thanks Andrew!


I have been working on better dust collection for my tools and as I am sure you all know MDF dust it terrible. I now my miter saw, orbital sander and router with DIY setups. It makes it a whole lot nicer to work with when there isn’t dust flying everywhere and you don’t need to worry about the cleanup.

The sander and miter saw just needed adaptors which I made using some PVC fittings.
For the router I made a little shield that gets mounted to the bottom. As I usually do I just scrounge around for parts to build it, found a clear cylindrical container that I had saved a while ago because it was a nice size and pretty sturdy which had originally held some food product. I cut the bottom off that then cut it in half; it forms the collection shield part. I found one of my many circle driver/port cutouts that was the same diameter cut it in half and mounted to the shield forming the bottom. I made a round disc out of ¼” hardboard the same size as my router base that will form the new base for the router where I will mount the shield to. I also cut and mounted a piece of 1/8” hardboard to the shield where the hose is connected as reinforcement. The shield was mounted to the new base using a combination of short screws and my favorite adhesive hot melt glue (I’ve even assembled a whole enclosure using only that).








Works better with the flush trim bit then the round over though I might be able to modify it to fix that. Here is one that was flush trimmed with some light sanding, then both with roundovers ready for filler/priming.

Just two more

Hop over to the SI thread

The magnet on the SI is a bit bigger, the dayton is closer to the camera plus the smaller frame makes for a bit of an optical illusion.

I did rotate the tinsel leads on the Dayton after I found they slapped the bottom of the cone in their normal position when I was running the driver with some sine waves free air. They were pretty loud and I had thought the driver was bottoming. Once I realized it was the tinsel leads I played around with them until I found a good spot which is about a 45 degree angle from the terminals then pulled slightly tighter. I would say that gave them a good extra 5-8mm of throw before they start to make suspension noise.