DIY Center speaker

Just completed Home surround system. I have been using ELAC FS207A as main speakers, and wanted to have matched center speaker, so bought ELAC CC203 used in last year September. However, its 330 mm of depth doesn’t fit to my livingroom layout, since there is a TV set in front of the sofa. So eventually I ended up developping my own designed speaker housing. The box was designed to have roughly same cavity volume, and shortend the depth and expanded the width. I added a step behind the housing to fit to the frame of the screen and minimize the dead space. I bought cheap plywood board with 15 mm thickness and used cutting service at hear by DIY shop. Made unit holes by myself with circular cutter on the drill. Had build the housing with adding many reinforcement inside using small piece of plywood, and fixed them by pouring epoxy bond inside of the housing. Finish of bottom and rear side are quite rough. There are mismatches of the board end for ca. 1 mm, but it’s OK as far as there is no air leakage. Front, Top and sides are finished with sealer and polished with an electric sander. Spray can was used to cover overall surface with gloss white. Finally polished with fine water-proof sand paper. Speaker units were assembled, and the original glass wool was filled, then it’s completed! As seen in photos, it just fits into the tight clearance below the screen. When TV monitor is set in front of the speaker, the sound is expected to come through the gap by the TV stand. The JET3 Tweeter commonly used in the main speakers must achieve perfect sound balance, I believe. It took half year as I was so slow and lazy, but now I’m really satisfied.

Status of fitting. There are only a few mm of clearance around it. The bottom board sticking to lower side was designed to fix the position between two angled supporters. The side panel of the housing sticks from the bottom panel for ca 1mm, due to low accuracy of cutting by the DIY store, but I don’t care as far as it’s not facing to the front or to the top.
This is original ELAC CC203. I wonder how people put such deep speaker housing in front of the screen or TV monitor in the room. It must be obstacle when walking around. Or does everybody have so large room where they can ignore this size of speaker box???
Original housing photo, as a record of the wiring. The front panel is machined to accomodate speaker units to be flat, that’s smart. Therefore the thickened front panel is rigid. However, the side, top and bottom panels have only 15 mm thickness and nothing significant. Top and bottom panels are just wide & flat, so it should make some resonance peak. Probably that’s the reason why it’s filled with so much glass wool.
Assembly process. Now it fixes the most visible corner between the front and top panel, therefore I was a bit serious to avoid any gap and to make them perpendicular accurately. I learned speaker DIY in the audio club of university. I myself finished in total only ca. 10 units in 30 years, but I have necessary tools. I own 5 books of Mr. Nagaoka about speaker DIY, too.
Cabinet inside showing the air ducts. I used plastic pipe, with duct tape winding several times on it for dumping. There are reinforcement plates, and all of them were rigidly tightened with epoxy bond.
Building the housing at my basement room. The length of the panels had a few mm level of mismatches, but they were fixed by the electreic sander. The speaker unit holes were originally square shape, but I made it round shape since it’s not possible to make square holes without proper machine. Then I needed to create many small odd shapes around the fixing holes by hand to avoid conflict with the speaker units, and it was really hard work.
Drying the painted housing with can spray. The shape, long in side direction is not seen often in the hifi market, but I don’t know why. If this shape is not suitable for the loudspeakers, tall boy style shouldn’t exist. I believe that this is the best design and easy to use as the center speaker, or?
I cut corners in finish of the bottom and rear panel. It’s such rough! The bottom and back have no sealer applied, so you can see the wood grain.
May I name it “Made in Germany”? As I’m in Europe, I selected ELAC, German brand.
Movable TV board can go below the center speaker. It was possible to lower the speaker height for another 5 mm. Of course it’s totally wrong to put such things in front of the speaker, but it’s OK as I’m not serious in sound quality when watching TV. When watching Movies, TV board is removed.

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