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About BioBrian

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  • Birthday 06/11/1954

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    Mountain River
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  1. No surprises there. Phew, I can go back on the streets... This is my target - I think I can make it happen. If not, then there's plenty of room for the lucky person who finds these in the "roadside collection" to screw a nice Hypex on 🙂. The boxes are designed to be in the wall-ceiling corners, so their width is I guess what you are asking. Internal (longest) dimension is 1500 minus 2 x 30 mm ends, so 1440 mm. The other dimensions are harder to name, as it's basically triangular, with 2 corners a bit filled in. The question about stuffing in subs - this is still being asked around the forum, and is still unclear to me. With the previous build, 15" woofers in 240 litres vented, we ended up with basically none, as you considered it unnecessary, and possibly a hinderance. Yet every sub build I read about has carpet or eggshell foam or something on the walls, and various other pillows etc inside. But... Some of this would have a dual purpose, one being damping the panels. I'm working on having a very stiff box which won't need this. Fluffy stuffing alters the apparent air viscosity, makes the air behave like it's in a bigger box? My box is big enough not to need this. I can't test the impedance until all is finished, and adding stuffing will be difficult. To reduce resonance, I've gleaned that it would be most effective in the centre compartment of the box, which might be reachable through the driver hole. I remember it helped @acg with his cannons (after exhaustive testing; at least I was exhausted after reading it ). Sorry to bring intuition into it deliberately, but I can't imagine stuffing being much more effective than holy baffles, to affect air behaviour when belting out a bit of Madonna (might happen for demo purposes at some stage). I'd quite like to sort this. Thanks for your compliment on my pic; the river is full of wonderful gifts.
  2. Spent a while lining up the 8 cross-pieces in each box, trimming here and there. Fortunately, not too many edges have needed bits glued on and re-trimming. There aren't many holy days around here, and I'll need at least one more. 60 holes in the cross-braces so far; probably another 12 to follow. Each have 5 holes, all different diameters. Then it'll be the "spinal lesions" - I should be good at that 😧. I'm trying to confuse those pesky end-to-end reverbs. Probably futile, but it keeps me off the street.
  3. Hi @Sierra, great to hear these are going well - 2012 seems like a lifetime ago. I love the way your Jarrah has kept its redness, and the contrast with the pale "Tas Oak" (gum trees). The stuff we are sold under that name down here is more orange-brown, I think more like your side veneer. The eucalypts that grow above my house have this nice pale yellow colour; you did well I think. (Don't use it for fence posts though - they rot out in 5 years). This pic is from your first page, nearly 8 years ago, and they look even redder now. (In contrast, my myrtle has faded from red to a non-descript brown). There was some lovely work going on here. Pity it's on the inside 🙂, but good to know it's all still there.
  4. Well I've stolen the best hours out of most days since the last post, to peck away at these delicate giants. Everything's just BIG, and so the errors can multiply, eg when joining two 48mm thick panels at 135 degrees, the mating surfaces are something like 52mm wide and 1500mm long, so any cracks would show more than if just using 18mm in a normal box. This one shows a dry-fit of an end, and a spine. The fun part of cutting all the holes has to wait, as each of the 6 pairs of cross-braces will have to breathe in relation to the holes in the spines. For the moment it looks like this - a dry fit of and end and a spine: There will be 3 pairs of cross-braces, which I'm making whole, then I'll cut 12mm out of their middles, so they can go either side of the spines. (8 cuts, instead of 10 for each - none are easy with the track saw). So, 12 pieces that have to line up with the ends - that's 96 cuts even if I get them right 1st time [edit: not good maths there, but turned out to be more], and that's after trying to cut 4 identical ends out of 30mm BB ply with no split edges, etc etc. Each pair will have different cutouts, eg these are behind the woofers: I've found the biggest challenge is not being able to actually start gluing - nearly all the panels have to be designed and cut first, then the order of joining will be quite tricky too (clamping large, odd angled pieces without being able to move the whole structure, etc). If I have to trim something smaller due to inaccuracy, there's a chain reaction that affects the sizes of everything to follow, so it's been quite a test of concentration. Hoping it can all fall together from here without too much drama. The rest of the build should be a bit more rewarding.
  5. Well they should put an earth pin in there anyway, so the plug's got something to grip onto. Listenus Interruptus is not my favourite experience, especially when you find it's caused by the IEC plug falling out (cordus interruptus sounds more like it).
  6. Some manufacturers have obviously found this confusing also, and gone for the simple option - "If in doubt, leave it out". Taking it to another level, getting rid of IEC sockets and hardwiring the mains cord would be the best option. (There's another can of worms). Practically speaking, it would be nice to have a standard, as the only thing that matters to most of us is how to orient the plug when provoking apoplexy, fishing around the back of your gear in a dark cramped space full of other audio jewellery.
  7. https://www.bunnings.com.au/sutton-tools-9-piece-multi-purpose-carpenter-holesaw-tct-set_p6370612
  8. Just my 2-bobs-worth: - The yellow ones with 3 tungsten teeth cut plywood very fast and reasonably cleanly (especially if rounding over edges later with router bit). One quick cut - very satisfying. - The blue ones with many small teeth are not good for this job. They cut a very clean, accurate circle, but you can only penetrate about 2 mm before having to back off, stop, and clean out the teeth before going again - I find this very frustrating. Both require you to buy the cutter (many options on diameter), but also a matching centre drill part. I have a "vertical drill" to do this - not sure I'd recommend using 100 mm or larger cutter with a hand-held drill.
  9. But I thought this was supposed to be the good-news channel 🙂. I went back to the drawing-board, and lived in denial for a few weeks, but just couldn't live with the back of the vent being so close to the back of the cabinet. Originally the thought was to have the vents protruding out of the baffle, and having the option to screw on those very attractive sewer pipe caps. Taste won over practicality in that case, but moving the vents back to be flush with the baffles sort of blinded me to the problem of breathing space at the rear of the vents. Hmm... I tried a couple of other box design options, but they either looked hideous or became impractical. If I did it again, I'd stick the vent out of one end, but the baffles already had the holes cut, so I made the box a little deeper, and have made some 60 mm "prolapses" to extend the vents out the front again. That involved more complex routing than the plain baffle flares seen a couple of posts above - it involved more laminating, and trouble from being deeper than my longest router bit (50 mm). I suppose it was good to confirm the strength of the Liquid Nails Polyurethane glue though - I thought that with a bit of padding and a sledge hammer, I'd be able to break the vent-baffle glue, but this was not going to happen without breaking the pipe. So I cut a large circle in some ply, clamped it onto the front of the baffle, and routed away the end of the pipe, until the glue line was small enough to be broken by reasonable force. I think there was only about 12 mm left before a very determined karate-kick could break the bond. So the new vent flares are prepared, but I won't glue them in now, as the build has to proceed face-down. Fires? I'm better prepared this year than ever before. Hoping this can give me some freedom for chosen activities. Took a few reflective minutes, early on New Year's Day, to make an unintentioned model of my life story (or whatever the observer may see): What I didn't notice until getting down in the river to take the pic, was that the huge base rock (1-2 tonnes?) is getting some support from a tiny compression strut. All support appreciated - thanks Linc, I'll get on with it. Promise!
  10. This has brought up an old question for me - can I use a single cable between the host/server computers (both Asrock mITX boards, J3700 and J3710) - I was told it's not possible. - No noise introduced by a router or switch - No need to power up another box - Less connectors, which are more problematic than the actual cable, in my experience - Would prevent software interrupting proceedings by doing automatic updates, and communicating with the internet at all I'd thought a crossover cable might be the simple solution, but I don't want to blow anything up.
  11. It's alive! Or one of them might be the new AI model, beta version. Try moderating what you watch on TV while dining (never the news), or offering it some of your delicacies, so it doesn't feel left out and get into a flap. Maybe it would appreciate some counselling? (Feeble gratuitous wink emoji due here). It's not clear what you are feeding them - is it high level speaker wires from the power amp that runs the other drivers? It's not from a preamp, where you could have one channel from the Pre Out and one from Tape Out or something? Plate amps have a rather miserable reputation; it sounds like you have good ammunition for a warranty claim. Have you checked that both plate amps set for 240 V? (I'm scratching too).
  12. I'm an old fan of Sikaflex. But I used Sikaflex Pro to seal my flue, and the creosote melted it, also corroding zincalume and colorbond, dripping poison into my house, so I lost the faith, unreasonably of course. Silicon better there. Should have looked closer, as the Liq. Nails has a lot of bubbles and no substance where it expands out into nothingness. Still spongy after days, not as deadening as the Sika would probably have been, maybe. Whatever; the vents are strongly bonded to the ply, and are acoustically dead. I may add more weight or bracing to the pipes, but doubt it would make a huge difference.
  13. Spurred on by hearing @deblur's lovely sealed 15" AE subs yesterday, it's good to get another step closer to finishing these (here comes another one) big birthers. The baffle flares worked as well as they could have: The rest of the build will be face-down, so it'll be a while before we see these again: And the SNA-inspired inner flare (it's all been quite a journey): Oh, and admission that a little flutter of joy was had, and thanks given for being alive when these amazing tools are available to us.
  14. I had professional advice to change the Vifa D19 tweeter with Scan Speak's "Classic" series D2008/851200. It made a great improvement, with no change necessary to the crossovers. This was on 2 versions of the SA-130, but I'm sure the same would apply to yours. The D19 membrane reminds me of bats' wings.
  15. Vents. Warning: the following footage may offend some viewers. For the inner flares, I found the cutouts from my 2012 DTQWT-12 woofers to be just the right diameter and (30 mm) thickness, so am very happy to be able to recycle them in triumph for this honourable exercise. Already having a centre pivot hole and being circles, only left another 6 router circle cuts to go. The sequencing has taken a bit of brain-stretching, but is going to plan OK. The same cuts are being done into the baffles, to let in the 150 mm PVC pipe. The final inner trimming and rounding will happen after the glue cures properly. 9.5 mm rounding to the pipe part, 22.4 mm rounding to the outer and inner flare parts. Pics might explain better - this is one on a pipe, the other upside down, showing the rebate to glue the pipe in: The baffle got the same diameter rebate, but both are let in (baffle is 48 mm, inner flare is 30 mm thick) so the 22.4 mm rounding bit can take just 2 mm of pipe to make a clean curve (yet to happen): Not sure about this Liquid Nails goop - 1st time using - it's certainly strong and convincingly sticking the PVC, but the sample I did a couple of days ago is still a bit soft where it's thick. I used a fine water spray as directed, but not sure how effective that was. Will have to revisit this after a certain "sub - culture" meeting tomorrow, depending on the entertainment/frivolity level...
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