4 Inch Subwoofer

thingiverse

Simple 4 Inch subwoofer using a Dayton Audio 4" long-excursion driver in a ported box. The box is braced and printed at 50% fill, although the brace is printed with 80% fill. I used cotton stuffing on the back and top wall near the driver. The box is tuned to 50Hz and with room reinforcement, it provides nice bass down to 40Hz or perhaps a bit lower. I created passive and active versions. The active has a 30/30/60w or 50/50/100w plate amplifier and the passive has holes on the rear side for a pair of spring loaded binding posts. 4 Inch Dayton Audio Speaker Driver https://www.parts-express.com/Dayton-Audio-TCP115-8-4-Treated-Paper-Cone-Midbass-Woofer-8-Ohm-295-416 Bluetooth 5.1 Plate Amplifier https://www.aliexpress.us/item/2255799823670271.html Speaker Terminals (Passive Version) https://www.aliexpress.us/item/2255801103439930.html Subwoofer Crossover (Passive Version) https://www.aliexpress.us/item/2255800533711868.html Cotton Fiber Insulation https://www.amazon.com/gp/product/B004Y6SX1Y Listening Tests I got the system set up with a pair of 2" mini monitor speakers that I also created for this. I set the subwoofer on the floor and ran it using an external 2.1 (50w/50w/100w) amp from AliExpress. I let it break in on test tones and also confirmed the 50Hz tuning frequency of the box was spot on. After the break-in, I put on some familiar music and adjusted the bass/treble/xover freq/sub level until they sounded good to my ear. Then I put in some more music and let it rip. I was very surprised that the output was so clear, loud, and deep. While it won't rattle the windows, it'll play much louder than I'll likely use if I want to preserve my hearing. Because the distortion was low, it was almost difficult to tell how loud it was until I walked out of the room and could hear it on the other side of the house. I had a friend over and after listening he said, "There's no way all that bass is coming from that little speaker." I showed him the subwoofer which is about the size of a lunchbox. He still couldn't believe such a small sub with a single 4 inch driver could play so loud and deep. While it's foolish to think it could ever approach the deep bass and resolution of my reference B&W 801 S3's and 801 D4's, it's a cute little speaker that sounds better than it should for its size and price. I think of the two versions of the mini monitor, the Peerless version sounds better to me than the Aiyma but the drivers cost 3 times as much. Even that being the case, they are still quite inexpensive. I might do a combined unit for travel with a built-in lithium battery pack. That'll be my next project.