Yet another Overnight Sensations build

[Bugsi]

Over the last couple years I've really come to admire the Overnight Sensations and have enjoyed reading about everyone's builds. Perhaps a year ago I bought the kit from Parts Express on a C-note sale, but never got around to assembling them. Recently I got an Amazon Echo Dot, which I plugged into a Panasonic portable stereo system for better sound. It has replaced my alarm clock, and I can order Alexa to play various music on a whim with a request. It was so handy that I bought another Echo Dot for my two boys for their bedroom, to be a more reliable alarm clock for them, as well as an on-demand entertainment system for music. For now I will be pairing the speakers with a Dayton Audio DTA3116HP amplifier. I've been using one as a headphone amp at work for around a year, and I find it to be very clean and completely silent with no signal. I don't expect my kids to be playing their system too loudly.

I intend to put the speakers on a bookshelf in their room, so I am locating the ports on the front, using the 260-474 flared port tube. I'm using the 260-283 terminal cup in the back, where the hole is pre-cut on the back in the kit. I had to enlarge that hole with a hole-saw on a drill press to fit the terminal cup.

I assembled the knock-down kit using ordinary Titebond II Premium wood glue, then sanded the hell out of them. Even with a very good fit, some of the edges required a lot of sanding, glazing putty, more sanding, and repeated iterations of priming, wet-sanding glazing putty, and more sanding before I got a final wet-sanded primer finish I was happy with. I'm painting the cabinets with Rustoleum Professional High Performance Enamel in flat black. At the moment I just finished my first coat on one speaker. I originally intended to finish these with water-based brush-on clear gloss polyurethane, but a test on a pinewood derby car using the same primer and paint did not go well. I will either use clear gloss spray enamel, or I'll keep the flat black finish, or I might go with roll on Duratex finish. I haven't decided yet.

For the crossovers I just don't like joining all the components by their leads on the underside of a board. I know it's perfectly functional, but it just strikes me as ugly. I decided to create an old-school eyelet-board layout by mocking up the parts by their dimensions in Illustrator and finding a layout where the parts all fit neatly, with the inductors mounted orthogonally to each other. The goal was to require no additional wiring, just pop in the parts into the eyelets, solder it up, clip off the leads, and be done. However, I also like the nylon screw terminals for connecting the speakers and the terminal cup, and that required adding five wires, which I positioned on top of the board. One could solder the speaker and terminal cup wires directly to the eyelet terminals, however. I bought 3" wide fiberboards, 1/8" eyelets, and an eyelet stamping tool from antique electronics, and whipped up the crossovers with my layout. I used hot-glue to tack down the inductors. The crossovers can fit through the mid speaker opening in the kit's front panel.

Photos:

Knock-down kit glued up and clamped


One cabinet finish-primed and wet-sanded, the other after rough sanding after assembly


One cabinet with first coat of flat black paint


The assembled crossovers on eyelet-boards


Full-size eyelet layout

[ceiol]

Looks great!

[Kornbread]

The coils aren't very big, but I still like a few small zip ties helping hold them to the board, jic.

Keep in mind, I am not very good at finishing, but Zinsser bin (dewaxed? shellac + white pigment) is pretty good at sealing the wood and filling small imperfections. It builds up far quicker than normal primer. So far, it also seems to work ok if you're going to spray lacquer primer/paint over it. Like you, I've found the seams to be a bear to hide, it sounds like you've got that covered and they'll not resurface later.

There was a post on here somewhere where a person covered the speakers with a globe map, and then cleared over that. Looked really kool. Don't know how old the kids are, or their interests, but a celestial view, plane, train, etc. could be substituted according to their interests.

Lucky kids!

[Bugsi]

Zinsser bin (dewaxed? shellac + white pigment) is pretty good at sealing the wood and filling small imperfections.

Zinsler 1-2-3 is the spray primer I used. I've tried others, but I really like the finish I get with Zinsler. It takes to wet-sanding really well, leaving a super smooth finish ready for paint.

Agree about the seams. I spent extra time getting them really well aligned when I glued and clamped them to minimize the sanding needed to get the sides smooth, but it still took a lot of time with 50-grit and an electric sander to get them smooth, and even after they looked and felt perfectly smooth it *STILL* required glazing putty to completely hide the seams and fill in the grain in the wood. I briefly considered just staining the wood from the knock-down kit, but I'm of the opinion now that the knock-down kit is really best used for a painted or veneered finish. If one wants a natural wood finish without veneering, I think one should build their own cabinets out of the desired wood. The knock down kit is *really easy* to assemble, and I really like it, but I recommend it only for painted or veneered finishes.

Second coats of paint going on today. *Still* had some marks that required glazing putty to fill in. I have a lot of hours into these, but I think it will pay off in a professional looking result.

[Kornbread]

Never used it as a spray on, only brush. Getting, and keeping the seams invisible is a pita. The kids will have a nice sounding pair of speakers that can follow them to college.

[Bugsi]

My entire build came to a screeching halt when I realized I don't have any black screws to install the speaker or the terminal cup. I ordered the Parts Express #6, 3/4" deep thread pan head screws. I think some black allen-head wood screws would look better, but I don't think they exist.

[EDIT] Or would I be better off with M4 Socket Cap Recessed Head (machine) screws and M4 T-nuts? These are available at Home Depot.

What do other people use on their Overnight Sensations?

[Dropcarve]

My entire build came to a screeching halt when I realized I don't have any black screws to install the speaker or the terminal cup. I ordered the Parts Express #6, 3/4" deep thread pan head screws. I think some black allen-head wood screws would look better, but I don't think they exist.

[EDIT] Or would I be better off with M4 Socket Cap Recessed Head (machine) screws and M4 T-nuts? These are available at Home Depot.

What do other people use on their Overnight Sensations?

Part # 081-308 should do. 3.5mm should work too.

[Jeff F.]

I think some black allen-head wood screws would look better, but I don't think they exist.

They do exist...https://www.parts-express.com/m35-x-...0-pcs--081-304

[Bugsi]

Oh wow! Thanks to both Dropcarve and Jeff F! That's a game changer! The speaker and terminal cup mounting holes are close to the openings to make using a T-nut difficult or impossible. Those cap head wood screws are perfect! THANK YOU!

[Bugsi]

One speaker completed
(I used the #6 Phillips screws because my wife liked the look of them better, because they were more flush to the cabinet, -vs- the cap-head screws):

[joeybutts]

Nice work. PAint looks great.

[Bugsi]

Nice work. PAint looks great.

Thanks! Rustoleum Professional High Performance Enamel is a quality product. I've been using it for years on my kids' pinewood derby cars for Cub Scouts, and with careful application, wet-sanding, enamel clearcoat, and polishing, I get finishes that rival professional automotive car paint. I was planning to clearcoat these, but I think the flat black has a beauty of its own that I really like, so for now I'm planning to leave them like this. The nice thing is that I can always change my mind, pull out the speakers, port tube, and terminal cup, and change the finish if I choose to.

But most of the work went into the sanding, glazing putty, and priming stages. It took many cycles of glazing, sanding, wetsanding, priming, and repeating before the knock-down cabinet seams weren't visible. Attention to detail in that stage pays off. If the primed cabinet doesn't look good, the painted cabinet won't look good. The wetsanded primed cabinets looked beautiful in white. I was tempted to leave them white!

[Bugsi]

Completed pair.


They have a very impressive sound. They were very convincing in my home theater setup in place of my Klipsch SF-1 speakers. They were very transparent, with a touch of brightness, but lacked the lowest bass extension of my Klipsch SF-1's. For use in my kids' room, they will be perfect just the way they are. I'm extremely happy with these speakers.

[tomzarbo]

Bugsi,

they came out real nice. Love the look of the finish, the sheen is classy looking.
Man, those ports look huge for some reason; guess I'm not used to seeing them on the front.

Nice job on the crossover too. Have you assembled many crossovers? I've done dozens and I never seem to get mine looking that nice.
Great job!

TomZ

Oh, how do the boys like them? I can only imagine!

[Bugsi]

Man, those ports look huge for some reason; guess I'm not used to seeing them on the front.

You bring up a good point. You're not imagining things; the port diameters on my Overnight Sensations *are* larger than usual.

The Overnight Sensations kit comes with a pair of part number 260-388: adjustable-length ports with a 1.375" diameter, which is to be adjusted to 6" long to tune the box to 53Hz. The volume of the air in the port is thus 𝜋*0.6875^2*6 = 8.9 cubic inches. I don't like that the included ports have a thick, flat flange extending around the port tube, as I think when front-mounting it would detract terribly from the appearance of the recessed-mounts of the Dayton tweeter and Hi-Vi midwoofer. Since I knew I'd be placing the ports on the front, and since I didn't have an appropriate sized forstner drill bit to recess the port opening, I opted for part number 260-474, which is a 1.625" diameter port with a flared opening. It is 4.875" long. To match the 8.9 cubic inch port volume of the Overnight Sensations design with the smaller diameter port tube, this larger diameter port tube should be shortened to 4.29" (cut off 0.585").

[EDIT: See page 2 discussion. This is apparently not how port tuning works. Increasing the port diameter raises the tuning frequency, requiring lengthening the port tube to compensate and lower the tuning frequency back to the desired value.]

As it happens, I didn't trim mine down, but now that I've worked out the math, I think that was my intention when I bought the things some time in 2016. I just forgot about that detail in the time I've had the kit sitting around waiting for me to get to it. I will likely pull the midwoofers and pop the tubes out (which I simply friction-fit into a hole in the speaker front panel) and trim them and reinstall.

I also lightly stuffed this pair of Overnight Sensations with some loose polyfill fiber. I can tell you that the port definitely pumps air, and larger diameter ports tend to avoid chuffing noises that can plague smaller diameter ports, although I don't know how much Overnight Sensations suffer from that, if at all. Since there is a fair amount of sound that comes from the port, I feel quite happy with my decision to front-mount the ports, considering their intended location on a book shelf.

I haven't installed the set in the kids' room yet, but we tested them out both with my home entertainment system, and with the Amazon Echo Dot and the Dayton DTA3116HP amplifier. The Echo Dot at max gain will overload the input of the DTA3116HP amp, but when dialed back a few notches on the Echo Dot, the DTA3116HP can be left at max volume with no apparent clipping. My home entertainment system with a large Pioneer surround receiver can obviously drive the speakers harder, and they definitely can go louder than the little DTA3116HP can drive them. I also drove them with the audio output of my 2014 Retina Macbook Pro 15" into the DTA3116HP amp, and the bass extension was deeper than with the Echo Dot, so the Echo Dot apparently has a slight bass frequency roll-off as a source. For home theater use I would pair these with a subwoofer. For desktop or bookshelf use I think they are fine on their own.

That paint really did come out good. It took lots of attention to sanding the kit, spot-putty glaze to fill low areas and wood grain, more sanding, and several coats of primer with wet-sanding and glazing, before applying several coats of the Rustoleum Professional High Performance Enamel. I've been *very* happy with that paint in different colors, both flat and glossy, on different projects. For glossy finish I always follow it with Rustoleum gloss enamel and polishing. I intended to do that with these speakers, but the flat finished looked so good I decided to keep it.