Hifi Speakers Based on the Linkwitz Labs LX Mini

thingiverse

I wanted to make a pair of speakers based on the highly-acclaimed LX Mini Speaker by Linkwitz Labs. These speakers have been called some of the best ever made and I really liked the DIY concept. These speakers possess some of the most natural transparent sound I've ever heard. Since they have no "box" they have no "boxy sound" - just a clean (nearly) omnidirectional sound that makes me think of using a bare flash on a camera vs an aimed flash unit. Simply amazing. They are a rather unusual monopole design that uses 4" plastic pipe for the bass enclosure with a upward facing 6.5" woofer, and a forward-facing full range speaker. The tube essentially becomes an omnidirectional 'bass radiator' rather than the typical woofer-in-box. The system uses a bi-amplified design with a 2x4 digital crossover to split the channels up and two T-class amps to power the drivers. The original design uses rather ugly rubber pipe junctions and metal clamps along with some other wooden parts to hold everything together. I thought this was screaming to be 3D printed..... Here I present my design that uses 3D printed parts to house the drivers and make a more aesthetically-pleasing speaker. Also I wanted to use less-expensive drivers so that I could make the overall project cheaper. For comparison, the original design calls for drivers that cost over $400 alone (and upwards of $700+ once you add in the amps and crossover) - I wanted to create a kit that would cost only $400 total. For this money you will be listening to some of the finest quality loudspeakers available - that look super cool - and that you MADE YOURSELF. What you will find about these speakers is that they present a very clean, uncolored audio field. Room placement is not as critical with these as with many other loudspeakers. They are especially good for listening to jazz and classical music, but all types of music sounds great on them. Google them to learn more and read reviews. I hope you enjoy building them and listening to them for years to come. (A disclaimer - I have no affiliation with Linkwitz Labs. This design is based on the LX Mini, however it is not taken directly from their plans. I have never seen the original plans nor even another LX Mini speaker in person. I have simply used the photos I've seen and designed something similar using my own drivers and components. What I have posted here works well with the drivers I have used. To use your own drivers or those specified by the original LX Mini plans, you will need to alter the dimensions of the 3D printed parts.) Instructions IMPORTANT NOTE: YOU MUST HAVE A FAIRLY LARGE PRINT PLATFORM TO MAKE THE LARGE TOP PIECE. YOUR PRINTER SHOULD BE ABLE TO DO 200MM X 250MM X 200MM MINIMUM. Here's the parts list that I used: DRIVERS 2x MCM 55-1862 - 6 1/2'' High Excursion Aluminum Cone Woofer $24 each from MCM 2x Markaudio CHR-70A Champagne Cone 4" Full Range - $36 each from Madisonsound CROSSOVER 1x miniDSP 2x4 Digital Signal Processor - $115 from Madisonsound AMPS for the Bi-Amp 2x Tripath T2021 based 25w stereo T-amps from eBay etc. These are from brands like MUSE and others, that use a very nice T-class amp to deliver nice, low distortion sound. These run $40-$70 each depending on what you want. (update: the only caveat about using these 25W amps is they can't drive the speakers super loud. At full gain they are only the equal to maybe a 60% on a normal amp. If you like your music loud, I'd get 50W @ 8 ohm per channel amps). PIPE AND OTHER HARDWARE 2x 4" black ABS pipe in lengths from 24" to 36" (depending on the exact size you want and also based to some degree on the formula to calculate the bass enclosure volume for your speaker). I used 24" because it fit well with the guideline for bass enclosure size. 2x 4" pipe end caps 2x 10" x 10" mounting base boards (optional) 2 lb Polyfill to fill the bass tubes and reduce harmonics. speaker wire (get something 14 gauge at least). silicone caulk to glue everything up 4x 2 1/2" 10-24 bolts, washers and locknuts. Optional: Nice speaker terminals Paint for the tubes INSTRUCTIONS: You must print the BOTTOMSTAND piece at 121% to get it to fit the 4" NIBCO ABS endcap!