Very pleased with my recently completed microTowers.
I used Mark Audio Pluvia 7 HD2 drivers inside of 15mm Baltic Birch plywood cabinets. The 15 degree top and front baffles have a walnut veneer and exposed ply edges finished in two coats of Rubio Monocoat Pure (no part B accelerant used). The remaining exposed surfaces are painted with General Finishes Lamp Black milk paint.
Knowing I would elevate the speakers for my office listening level, I allowed space for a 3cm slab of black soapstone at the base/beneath the 2” diameter port. The stone adds weight and may reflect sound better than wood (perhaps?). I’ve also installed small cleats along the interior backside to allow easy removal of the back panel for adjustments - it’s a tight fit with strips of continuous gasketing. The panel will (?) eventually be glued on or several more screws will be added.
Inside the cabinet I have temporarily wired the drivers in parallel with single strands of cat6 feeders. (I picked up on this idea from one of @planet10 comments somewhere). Cat6 feeders are soldered to the drivers and I’ve made all other internal connections with Wago lever nuts to simplify possible adjustments.
For damping, I’ve used cotton batting to line the upper walls of the cabinets with 2 oz of teased Acousta-Stuf. I’ll be experimenting with the damping, but at the moment I am thrilled to have completed and to be listening to my first speaker project.
Thank you for being excellent resources!
-John
I used Mark Audio Pluvia 7 HD2 drivers inside of 15mm Baltic Birch plywood cabinets. The 15 degree top and front baffles have a walnut veneer and exposed ply edges finished in two coats of Rubio Monocoat Pure (no part B accelerant used). The remaining exposed surfaces are painted with General Finishes Lamp Black milk paint.
Knowing I would elevate the speakers for my office listening level, I allowed space for a 3cm slab of black soapstone at the base/beneath the 2” diameter port. The stone adds weight and may reflect sound better than wood (perhaps?). I’ve also installed small cleats along the interior backside to allow easy removal of the back panel for adjustments - it’s a tight fit with strips of continuous gasketing. The panel will (?) eventually be glued on or several more screws will be added.
Inside the cabinet I have temporarily wired the drivers in parallel with single strands of cat6 feeders. (I picked up on this idea from one of @planet10 comments somewhere). Cat6 feeders are soldered to the drivers and I’ve made all other internal connections with Wago lever nuts to simplify possible adjustments.
For damping, I’ve used cotton batting to line the upper walls of the cabinets with 2 oz of teased Acousta-Stuf. I’ll be experimenting with the damping, but at the moment I am thrilled to have completed and to be listening to my first speaker project.
Thank you for being excellent resources!
-John
Yep! A Debut III. I recently replaced its motor that decided to start becoming a noisy nuisance at about the same time my speed box gave up. It runs clean and smooth now, but requires a belt relocation anytime a 45 needs to be spun.
Naturelle LX, midbass tower using the same test cab as micor55 LX, but internally insert-divided to form a folded tapered TL instead of ML-TQWT. The story is, many years ago I brought to Beijing the unobtainium Mantra Sound Naturelle dipole with Audio Consulting passive crossovers (still-sealed wooden boxes each the size of basketball-pair-shoebox) -- ditching the 5" Supravox TL floorstander. Ten years passed. After my first two diy I tried the dipole simply cap-filtered/biamped with the 5" Eve Audio fiberglass honeycomb of diy #1 but in the oak TLonken cab of diy #2 -- superb clarity but MTM called for. Eventually the 6.5" version of the honeycomb driver became available so here I've made a minimalist first-order-XO taking advantage of LX configuration, acoustic centers aligned, using $1/pr steamer pot rack. Been listening nonstop. (Obviously not "fullrange forum" speaker, just an addition to my LX series.)
micor55 LX crossover-less stacked fullrange:
https://www.diyaudio.com/community/threads/full-range-speaker-photo-gallery.65061/post-7675238
micor55 LX crossover-less stacked fullrange:
https://www.diyaudio.com/community/threads/full-range-speaker-photo-gallery.65061/post-7675238
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That looks like the kind of crossover that I would use, accept I use wires twisted together, actually seems a much better connection than crocodile clips. Sometimes I stick the twisted wires into terminal blocks, as this stops them shorting out on others, and helps them stay twisted together.
Couldn't leave well enough alone... I inserted the Eve 5.25" nude driver above the 6.5" forming a 3-way LX -- Naturelle perched precariously above; their acoustic centers all lined up. Simplified the first-order XO (0.15mH->6ohm 6.5" up-firing; 0.47mH->5.25" frontal; 23.4ohm->2.7uF->8ohm Naturelle) but only had a few spare minutes to tweak. Anyway tone-sweep sounded pretty flat. If I had any sense this ought to be the end of diy.... Quite shocking how much more of musicians' intent and performance nuance came through.
And another in the same league as micor55 and Naturelle (LX versions) -- The Eazies: Fostex FE108eΣ and alnico copy of 168eΣ (obviously original Fostex cone/surround) placed over 27L steel can. The 108 has a very steep rise 1.5-2khz that I used to shelf-filter boldly. But with the 168 up-firing and naturally attenuated approaching 2khz, this LX configuration only needed a resistor-chain (23.4ohm on-hand) to make a pretty flat response 55hz-11khz more or less. Crossover-less, seamlessly integrated, acoustic centers aligned, and very wide vertical and horizontal directivity/dispersion -- if not quite omni-directional. Unlike the Naturelle/honeycomb however, The Eazies don't play very loud.
Yes, there are lots of trash bins/cans to choose from. Wall thickness varies (reflected in price, typically $10-30ea over here at the source). Also tall umbrella stands (cans) and commercial kitchen tubs. Generally well-made and attractive in a utilitarian/minimalist way, some are "designer" to go with interior furnishing. I have collected and used quite a number. Even the plastic ones (or inner-layer tube/tub) can be useful once stuffed/reinforced. I generally throw in some soft material and try to eliminate direct bottom reflection and pipe resonance. They look compact and take up much less room/floor-space than same-volume toed-in boxy speakers.
An early effort LXmidi 4/8 XO-less honeycomb folded concentric TL with plast-tape de-cone-resonance whizzer:
https://www.diyaudio.com/community/threads/1-order-crossover-help.391332/post-7151405
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@cracked case
the round form has lots of stability already. You can also buy any kind of round form and wrap it 3x outside with rubberized carpet like used for covering floors.
It works like a kind of black hole damping.
the round form has lots of stability already. You can also buy any kind of round form and wrap it 3x outside with rubberized carpet like used for covering floors.
It works like a kind of black hole damping.
While appealing, that will push the resonance down and perhaps make it more more of an issue, but as Freedom says, it is a cyclinder, very very difficult to set thamn off except forthe caps.
dave
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I machine a lot of thin metal tube at work, and I find blu tack very helpful in reducing vibration. Whilst a tube won't be "excited" by alternating pressure of the bass, it could have ripples sent from the top to the bottom caused by the force reaction from the speaker magnet, but then the effect would probably be so small that it's not a issue. I did try that car panel damping stuff on a thin wooden box, and it was pretty much useless, as planet10 said; I got much better results from a very thin, very well braced box, pushing up the natural frequency as far from the driver operating range as possible.
I do think that damping can work very well, in the right situation, but it has to be the right amount of damping; most of the time we're just guessing, and it can end up much too stiff, or much too soft.
Another advantage of the metal can enclosure (apart from looking cool) is it's non-flammable. .
I do think that damping can work very well, in the right situation, but it has to be the right amount of damping; most of the time we're just guessing, and it can end up much too stiff, or much too soft.
Another advantage of the metal can enclosure (apart from looking cool) is it's non-flammable. .