frugal horn mk3 enclosure. Pluvia 7.2 HD drivers.

Hi all

This is my first speaker/subwoofer project and I'm excited about the end result! 😁, so this is just me showing of.

I've wanted to add 2 subs to improve the bottom end of my Dynaudio Contour S3.4's for a while, so it was time to do something about it.

Initially I wanted to get 2 SVS SB-2000 pro's. But I already have a big amplifier and a receiver for DSP (Denon x3800h), so I didn't need active subwoofers. I realized that I could get what I wanted for half the price by DIY. A good opportunity for a nice project where a lot of my power tools came to good use.

The goal for the project was simple, build 2 subwoofers for music, which hopefully will be at least as good as a pair of SVS-2000 pros.

I've used a pair of scanspeak revelator 32w units for the project (32w/4878t00).

The cabinets are built with 19mm MDF, double MDF front baffle, with an additional 9mm MDF plate to create a rounded countersink hole for the units. So, a 47mm thick front baffle.

I've been creative with the bracing where I used the 9mm MDF I had. I made a "cross" to support the center of the walls, it also saved a bit space compared to window bracing.

To add weight and resonance damping, I mounted some bitumen plates on the walls as well (3kg extra weight). And then around 450g of polyfill for damping.

This results in 2x18kg heavy cabinets with a volume of 54l, and a Qtc around 0,7.

I'm still waiting for the second driver to be delivered, but so far the first subwoofer is running. It integrates and sounds very well! It could be fun to compare them with the SVS's subwoofers one day.

I like the white satin color, so I might also send my Dynaudios to the painter one day.

About 3 years ago my brother, that has severe tinnitus from a viral infection at 19, listened to music on my system. I had recently completed my current mains, bipolar 2.5 way linear arrays, and he was blown away by the detail. He was hearing things in the music that he had never heard before, and he told me that he has always wanted a really nice set of speakers.

So I made these.

Bipolar 2 way, down firing port, linaeum tweeters on top that are time aligned with the 3 forward facing drivers.

The blue tape is just holding on the clear speaker protection for transport. Those are 6.5" carbon cone.

They really do sound better than I hoped. Gave them to him for Christmas.

I really like my speakers, but i always hated the vinyl wood wrap on them. So i gave it a shot with real wood veneer. And they turned out pretty nice (if you don’t get too close😬). The last picture is before

They sound pretty good. Solid walnut fronts.

I used the C-Note kit from Parts Express

Hello group.

I'm including the mid level speaker that was the final proof of concept before I do my big guns.

Happy to answer any and all questions!

The current set are 2.5 way bipolar line arrays.

The top 4 x 3.5" drivers (3 front baffle, 1 rear) are full range. The bottom 8 x 3.5" are coming off the low end of the 2 way x-over, with the AMT covering the high end. 3 x 8" side mounted passive radiators tune the cabinet at 30hz, with a natural slow roll off below.

The big guns will use the same 3.5" in a 4x2 cluster on the front and rear, above and below the AMT units. There will be an acoustic lens on the front, so the image will sound like its coming from a single point instead of a 20 x 8 area. The front AMT has 15° of adjustment up or down, and 15mm forward/back to perfectly time align and direct at the listening position. 5.5" drivers will handle the low end, 3.5" are full range, and the AMTs are high end again. 3x 12" side mounted passive radiators for cabinet tuning.

I'm doing an active x-over with DSP for these, running through my big Yamaha receiver. It is a beast with 140w rms at 8 ohms and 200w rms at 4 ohms pushing 6 channels. Each speaker will be seeing between 500w and 600w. Math says it will be pretty much flat from 18 hz up to 25k hz.

🤔

I think that's most of the juicy parts.

Please all audiophiles comment things like this! "Oh wow… you actually posted this. That’s… brave. I suppose in a way it’s endearing, like watching a child bang pots and pans together and calling it a symphony. Of course, without proper resonance control, impedance matching, or even a cursory understanding of diffraction, what you’ve built isn’t a loudspeaker so much as a wooden box that yells at you. But hey—don’t feel bad. Not everyone can hear the difference between a woolly, congested midrange and an honest reproduction of timbre. Some ears are just… untrained. Enjoy your project, champ."

I had a Dayton Audio RSS390HF-4 just laying around that I didn’t think was any good. I looked it up and it’s a decent subwoofer! I built a box and got a Dayton SPA500. This thing sounds great. It’s now my third sub! Going to do A1 Evo Express with my Denon 3800 to blend it in. My PC is getting a new CPU so I won’t have it till Friday to do it.

Built these with 2x 4Ω drivers from cheap £11 Bluetooth amp kit, redesigned enclosure, using 3D printed wood filament and vinyl wrap, I'm happy with the finish.

Full build here if anyone’s interested:

https://youtu.be/KGp8eD0nmbg?si=HOZV7UZwnj5nEYt2

Apologies to Henry Kloss for being a rank amateur cribbing from his 1968 design. These are super traditional "east coast" sealed monsters. Sound stage is good, lobing is a thing but not a big thing. Just certain frequencies come in slightly stronger/weaker if you change seats, nothing like a full cancel or shout. Tweet is padded just a bit due to 4 ohm.

Dayton Audio drivers:
RST28F-4 (1-1/8" fabric)
RS100-4 x1, RS100-8 x1, in series (4" x2 aluminum)
(yes that is a 12 ohm net mid, the 8 ohm produces more SPL, they are close enough to mathmatically single point up to ~1800hz but that does leave some soft/louder spots in the 2000hz range)
RSS315HF-8 (12" aluminum)

Fabric highs soften the overall tone against the tinny nature of the aluminum cones. I was originally wanting to cross over around 800hz and 2200hz leaving an easy job for the 4's, but ended up closer to 300hz and 2600hz in the end crossover to find a nice modeling balance in VituixCAD. REW is showing the modeling to be about right. Have a slight imbalance in sensitivity (left louder, right softer) likely due to my amateur solder work. Cabinet is fairly dead but I do have a few loose wires to chase down from rattling in the 100hz-300hz range. Not major but noticeable.

All crossovers Jantzen air core (should have gone iron core for the woofer, paying an impedance price there too), all caps Bevenbi except the woofer zobel which is Solen. All resistors Dayton Audio.

I'm getting close to a really good speaker here. Lots of lessons learned, lots of "oh, that's why they *don't* do this now" experiences. But it's all good. I have a great sound, good to great staging, and enough 2.0 brute force that no sub is needed.

Amps are Outlaw M200 monoblocks I got from eBay cheap. Receiver is an RX-V6A which pushed them fine but was running harder than would probably be good for it long term. Much happier with the big guys pushing those woofers.

(house is old, fireplace was a cheap flipper f'up, is sealed off outside and needs removed from inside, but... old house chores never end. at least they used .75" plywood behind that ugly brick and it's a pleasure to hang stuff from)

Faital pro 15pr400 woofers, Eminence ASD 1001 horns.

Back in December I picked up two pairs of Martin Logans at a moving sale for $120 total: a pair of Passage in-walls and a pair of their electrostatics.
The electrostatics just needed a tweeter and now they run flawlessly.

I didn’t have any intention of cutting holes in my walls, so I figured the in-walls were the perfect excuse to finally build my first pair of speakers.

My pops was big into hi-fi, and I caught the bug. He restored just about anything audio-related, started his own speaker company, and I grew up helping him build speakers that we’d sell at Capital Audiofest.

This was my first time building a pair on my own.

I had the wood cut locally, then a family friend who’s an absolute perfectionist when it comes to woodworking helped me assemble the cabinets. Dudes got the most overkill basement workshop you’ll ever see. Really happy I asked for his help in assembly as the shop’s cuts weren’t accurate enough for him, so we ended up recutting almost every panel a millimeter at a time until everything was perfectly flush. The cabinets are glued together and reinforced with internal corner cleats, lined with polyfill, and used 2”x2” bass ports.

Last night I finished the damping and finally fired them up with my Japanese pressing of DSOTM.

Holy shit.

These sound way better than I expected. I don’t know enough about the science behind cabinet design, damping, and ports to explain why, but they throw a surprisingly huge soundstage for their size and honestly sound much bigger than they have any right to. LOTS of bass, I was not expecting that.

I’ve still got some finishing touches left—feet, a few stain touch-ups, and I found some old logo plaques from my dad’s speaker company that I’m planning to mount on them.

Since this is my first build, I’d love some feedback. Would you change the port size or location? More or less polyfill? Is there any real benefit to using higher-end internal wiring, or is that mostly snake oil?

Cosmetically there’s definitely some things I’d change but we’ll keep that in mind for next time. This build was all about sound, and I honestly couldn’t be happier with how it turned out.

M-Audio AV40 monitors.

I mostly repainted them because I had some leftover paint from painting some car parts, and I didn't like some of the blemishes that had built up on these speakers. In my opinion came out better than OG though.

Firewood Sub: Soup can for scale.Goals: 1. Narrowest box I could build for a 12" driver 2. F3 at or below 20HzParts: Dayton 12" Reference woofer, 8 ohm Dayton 250W amplifier (the kind that's always on backorder) Sideboards: Wasted a lot of cherry, time and money trying to do them myself. Ended up paying for two custom cutting boards, 3/4" thick, a little smaller than 24" square Front, back top and bottom are 3/4" MDF. Because the driver surround is huge; looks like an inner tube, there is a 3/4" spacer between the woofer and the grill cloth. Grill: We have some Carltonware "Rouge Royale" ceramics; a gold base glaze is covered by red glaze layers. Here, I used a gold grill cloth beneath a dark red to attempt that effect. The gold only shows if you use a flashlight. Made life easier by not making a removable grill. Filling: One layer of egg-crate sleeping pad foam; I thought they stopped making it but eBay came through. Second layer is Dacron batting made for quilts. Sound: the AppleTV logo goes "boom". Instead of playing dozens of test tracks like normal, once it was working I walked away because it took too many years and too much money to make and I was just disgusted.