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Discussion Starter #21
They are far from perfect, but I am quite happy with the results. They sound pretty fine, too.

A search revealed that the tacky paint problem will be ended by a coat of spray polyurethane. I will try that when i take the top off for the trip to Alabama tomorrow.
 

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Really enjoyed this build thread, Wayne. I thought the LXmini sounded super sweet at Axpona...would absolutely love to fit a pair of these into my office.

What's the total cost buy and build?

Thanks for taking the time to create this great follow along!
 

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Discussion Starter #24
LXmini Final Bill Of Materials - The Way I Built Them

Major Purchase Items
  • 1 x $897 - LXmini Linkwitz Lab Speaker KIt, Pair, from Madisound, INCLUDING wood pieces and related items, INCLUDING miniDSP 4x10 (instead of miniDSP 2x4 - the 4x10 allows 3-way crossover for use with stereo subwoofers for deeper bass and louder overall volume). For this build, both a 2x4 and a 4x10 unit were supplied by miniDSP.
  • 1 x $105 - LXmini Construction Plans from Linkwitz Lab in PDF form.
  • 2 x $10 - 4-inch Schedule 40 PVC Pipe, white, 4” ID, 4.5” OD, solid-wall construction for high-pressure application, cut to 31-inch length.
  • 2 x $3 - 3-inch Schedule 40 PVC Pipe, white, 3” ID, 3.5” OD, solid-wall construction for high-pressure application, cut to 5-inch length.
  • 2 x $8 - 4-inch Plastic to 4-inch Clay Coupler, with clamps, Amazon.
  • 1 x $6 - Silicon Sealant, clear (I used white for a highlight accent, ended up wishing I had also purchased clear for invisibility and easier cleanup at several of its application locations)
  • 9 x $4 - Primer and Paint - I used spray paint in cans, 1 x white primer/sealer, 2 x black, 3 x navy blue, 2 x red, 1 x royal blue.
  • 8 x $0.40 - M5 x ½-inch Phillips-head machine screw with nut (no washer or lockwasher) for clamping HF driver in place in 3-inch pipe. The size and type might be ms-reported in the video or elsewhere, this is the official and correct size/type that I used.
  • 4 x $0.90 - M6 x 3-inch Phillips-head machine screw with nut and washer and for attaching HF driver assembly to LF driver assembly. The size and type might be mis-reported in the video or elsewhere, this is the official and correct size/type that I used.
  • 1 x $4 - Speaker Wire, or Hookup Wire, I used 14-gauge speaker wire, overkill but it was on hand.
  • 2 x $3 - 2 packages, male & female pairs of Inline Connectors for 8 individual connections (4 drivers x 2 connections each) to allow easy connection and disconnection of drivers from base of unit during build or maintenance.
  • 1 x $2 - solder.
  • 1 x $2 - sandpaper, medium grit.
  • 1 x $5 - Polyfill, 1 package, from Michael’s Craft Store (any craft or sewing supply store should carry it) - I added a little extra to the 4-inch pipes.
  • 2 x $4 - Mesh laundry bag for Acousta-Stuf damping material in 4-inch tubes, so it can be easily removed if desired.
  • 1 x $3 - Package of blue poster putty, for anchoring bricks to base of speaker.
  • 8 x $2 - four 6-pound standard construction bricks per speaker for adding extra weight to base, stuck in place with 4 squares of poster putty each, which also protected the finish. It might not look like much, but the Soundstage and Imaging were much improved.
  • 1 x $0.50 - Hot Glue (and hot glue gun) for temporarily holding nuts inside the 3-inch tube in place until mated with machine screws. No strength was needed by the hot glue once tightened, it simply made getting hardware all in place and mated up easier to have it held in place during assembly.
  • 1 x $0.25 - Blue masking tape to protect hardware inside of 3-inch pipe so Acousta-Stuff does not snag on it.
  • 4 x $0.05 - Cable ties for strain relief of speaker cables to leveling hardware on base of each speaker.
  • 4 x $5 - Speaker cable, 14-gauge,12 feet long, with dual banana connector at amplifier end. Wires were stripped and tightened onto the Banana lugs under the base of the speakers at the LXmini end.
  • 1 x $????.?? - 4-Channel Power Amplifier, RCA interconnects, and TOSLINK interconnect for connecting to your system and from the miniDSP 4x10 to the Power Amps to drive them.


Included in Madisound Kit

  • All Wood Pieces, plus 3 spacers for positioning the HF driver while being clamped into place.
  • 2 x 4-inch ABS Schedule 40 Cap Hub, flat, black, pre-drilled with 4 mounting holes each for banana-type connectors, pre-drilled with 4 holes each for screwing to wooden base plate.
  • 8 x long black self-tapping screw, to attach ABS Cap Hub to wooden base plate.
  • 6 x short black self-tapping screw, use as spacer screws for spacing the HF driver assembly above the LF driver assembly.
  • 8 x Banana-type connector with nut, washer, and solder lug, for speaker signal conductors through the base of the LXmini. I soldered onto terminals on the inside of the base of each speaker for maximum reliability.
  • Acousta-Stuf for driver damping the driver mounting pipes.
  • 8 x Plastic plugs for speaker mounting holes, used for LF drivers (16 were supplied, I did not use them for the HF drivers).


Base Leveling Hardware

  • 8 x $0.80 - M6 hex-head machine screw, full thread (threaded the full length of the screw from the tip to the head0). The length will depend upon your leveling requirements. Minimum length is 1-inch; I have used lengths up to 3 inches. If full thread is not available with hex head, try with Philips head.
  • 8 x $0.20 - M6 nut, for locking the leveling hardware in place once leveling is done.
  • 8 x $0.20 - M6 washer, large O.D. so a nut driver or socket, if used, will not scratch the finish on the base.
  • 8 x $0.80 - M6 T-nut.
  • Wood Glue for gluing the T-nuts in place once tightened down.
  • 8 x $1.00 - M6 Coupling Nut, for attaching spike to M6 machine screw, Amazon.
  • 2 x $19.99 - Set of four Dayton Audio Speaker Mounting Spikes, part #DSS2-BK, flat black (other finishes available).
 

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Discussion Starter #25
My work on the LXmini Project is done. Documentation includes:

LXmini Build Thread (this thread).
LXmini Performance Review.
JBL Subwoofer Review, a pair was mated with the LXmini for deep bass support and higher volume capability.
Video of the build process.
Bill of Material.

Links to all of these exist in the first post of this thread.

And a big THANK YOU once again to the sponsors of this project: Linkwitz Lab, Madisound, and miniDSP.
 

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Thanks for posting this with the included build video. That was quite cool and I enjoyed it a great deal.

I am not sure if I will give it a try but if I do, I can re-watch and look out for the pitfalls. :T
 

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Discussion Starter #28
The LXmini vibrate quite a bit when they are playing. We know how that affects Soundstage and Imaging (SS&I), don't we?


The best quick and simple solution I could think of was to add mass.


Four bricks per side, each brick weighs 6 lb, so each LXmini is about to get 24 lb heavier. I only helps if that mass is tightly coupled to the mass of the LXmini assembly itself, so the extra mass is making it harder for the normally non-moving parts to vibrate. Four squares of poster putty per brick will hold each brick firmly to the base. Here they are prepared for placement.


Here they are attached (set into place). The already strong SS&I performance was dramatically improved.


Next I will experiment with adding more mass to the upper parts of the assembly.
 

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Hey Wayne, have you considered using a larger pipe over the existing one with internal bracing between. I think that would look better as well as provide a space for extra mass. Just a thought.
 

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Discussion Starter #30
Hey Wayne, have you considered using a larger pipe over the existing one with internal bracing between. I think that would look better as well as provide a space for extra mass. Just a thought.
Sounds like a good idea, maybe fill the space between with shot or gravel. I hate to cover up the paint job, but the audio comes first!:surprise:
 

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