[terry j]

Xenon, that reminded me, forgot to give my gag about the noble gasses that you obviously have an interest in.

Well I too, strangely enough, am fascinated by these noble gasses, these distinguished beasts that enrich our lives at so many times and at interesting moments.

Meh, but the wife, she doesn't share the same delight and pleasure in the noble gasses as I do, she just says 'stop farting'

...oh dear, now I typed it that's actually pretty lame!

Originally Posted by Xenon

Au contraire, monsieur.

Bloody hell!

Well, in that case, yeah as you say may as well assemble it!!

I will say though that there is a big issue in ripping 2.5mm plywood. Even with our 100-tooth 10" saw, you always get that natty-ragged-flaky edge, which we sometimes have to lightly sand (with 80 or 120 grit). So this would involve a lot of re-staining, actually for every piece, on both sides, and by hand (versus a sprayer). For such thin wood, pre-staining panels may not be so time-effective as a result. Sure, could be done, but you are talking about 2-sided edges of hundreds of pieces, which also need to (re)dry.

This is just 'FYI' for anyone who reads it, not debating or trying to say you're wrong etc. I do get what you're saying about the edge needing a sand, it does. (forgot to mention that bit)

Anyway, that is how I do, and have, done it. Taking a bit of care in setting the fence parallel really helps for a smooth cut. Yes a light rub (one or two sides) with a sanding block, very quickly chamfering the corner as you go, then a quick wipe with the side of the brush.

Making the space couplers that I have been doing involved a lot of that.

As I say, I am not right or wrong, neither are you, just that it does work and each can make their own mind up.

Admittedly I only used a brush, but when I made my bank of diffusors the painting finish took as long as the entire build! That boring (and horribly frustrating) experience was enough for me to say never again!

Ah, you haven't done low-viscosity spraying then. When you get the pressure and droplet-size set (with test pieces) it's really a dream.

This is interesting, but not being a spray painter I am not fully following. Is this similar to these electric stuff you get at hardware stores?? Or does it still require the full kit, compressor lines etc and a special gun.

As I am renovating a house I have the compressor and lines etc, but (depending on price I suppose) am not too keen I going out and buying a set of dedicated spray gear.

Also, as YOU may guess, I would like to keep my build simple and not requiring special stuff!!

Really? It seems questionable when near-symmetry between the +1/-1 periods differs by only one well-position. What I wonder about is say, with N23 as an example, if you were to position +1 as a split (left-right) zero well, and the -1, with a zero well in the middle. In other words move the wells over so that there is a 'greatest visual difference' between the two panels (real scientific, huh).

Well, that IS the $64 question innit.

See, here's the trouble. We ask, and get clarified, what Jason meant by his implementation of the barker code.

We still look at it (with the same 'doubt' as before), and can go no further! Sure, we can 'push' him again, but I don't think the answer will change (and am pretty sure he does not keep a close eye on this or my thread, nor does glenn)...so where do we go???

It seems such a huge hole or gap in the data base that there is no clear definitive answer...unless we HAVE been given it and we just don't accept it!

Aaarrgghh

It's engineering, you get to pick your own compromises.

I'm afraid I would look at a diffusor with a proper inverse panel and think 'what a waste of depth, 80% of the depth is wasted all because ONE panel had to go *twice* (or whatever) as deep as the rest'.

I'd rather choose slightly worse lobing and either save space, or go lower in diffusion across the entire panel.

Others could very well think the opposite.

In measurements in a room... And it doesn't seem easy to get proper readings in rooms with other issues.

I don't think in room will help. Have tried it (but of course I don't know what I am doing) but there was absolutely nothing to see.

On a side note, (maybe it was only me) but I really don't think we have any idea of just how fast these events happen in a room. You read what glen and ethan and the other experts say, and kinda think 'putting a panel on the wall ten feet behind me stops interference with the main wave?' etc etc.

Phrasing it poorly, but you know, it's true that in 'one second the wave has been reflected 500 times' or whatever it is, it IS a complete mishmash of reflections and interference...we just tend to think in our own time scale.

So, all that means is even using a sweep in a room, all the reflections etc completely obscure and mask any measurable result from a qrd.

(I will only find out if I am close to being right when I repeat the measurements outdoors, if I get the same results then I have built it completely wrong! or it was my measurement method that was stupid...time will tell)

It does bring up the question of which software and what particular tests would be most helpful. Do you or does anyone have an answer for this? I'm in no position to judge.

All I tried to do was put a source normal to the qrd, and move the mic in different positions in an arc around it. And similar with a flat panel.

I wanted to see obvious indications of reflections at angles different in one case than the other, start to build up the diffusion map we see often.

Need to try it outdoors at night, prob won't be for a few months tbh.

It would be cool to make diffusors without wells, and you are working on the fractal insert which is very cool -- so there you go. Probably our end has to do with inexpensive, easy-to-build solutions. One QRD per child, I say.

Well, the auralex qfusor does not have wells. It claimed to diffuse down to 800 hz with a depth of three inches.

That claim was met with a great deal of skepticism around here, which I took on board.
'
However, (as I was mucking about with 5 primes at the time, for the trifractal build) when I looked at a five prime, and saw how low the reported diffusion point was, AND imagined it without wells, suddenly the auralex claim did not seem so outlandish to me. (if you have a look at the qfusor, you can kinda see a mixture of seven and five prime in there, if you mentally remove the walls)

And in my thread, you will see lupos demonstration of a seven prime with and without fins...which went a long way (bearing in mind the limitations of the demonstration tool) in allaying fears about removing wells.

(made many 'examples of qfusors' in the ripple tank...all seemed to give very good diffusion too)

Maybe that brings into play the 'greatest good'? Normally it is the COST of these devices that prevent wider use, so if we had a much cheaper alternative like the slutzffusor (tm) without fins, that diffused well anyway, (and being cheaper means you can put more SA in)...well you are at least getting a good (if not perfect) diffusor in place rather than none at all.

All due to much cheaper cost of entry.

You know, demand 'perfectly mathematically rigorous diffusors or NONE at all' and a vanishingly small percentage use them, or allow 'less perfect diffusion yet lot's of them' and due to being cheaper, a much larger percentage get to own and use them.

gee, wandered around a bit myself!!!