Ethan, the video I had not seen was the small room (narrated by someone other than yourself) with diffusion all round. thanks for that (I assume the other is you in front of polys and qrd's?? TBH, have my doubts about the validity of that one, I know you wanted to demonstrate worst case scenario, but still quite an invalid test I feel as they were both being used in a way that is simply inapplicable).
Got it about testing a room twice, once with polys and once with qrd's. Yeah, quite impractical really!!!
I only really mentioned the 'dispute' (well, it IS a good point regarding the relative work levels!!) as it kinda made me laugh at my reaction (confusion to a degree).
What I mean is, (and traditionally I used to inhabit normal hi fi/audiophile forums..) a new guy to audio gets on and asks 'which cable should I buy?? *he
knows that cables are important, all the reviewers and mags say so yeah??* and a guy like me says 'if it conducts, then it will do' and it spins him as it rocks his stable datum.
So I get on a 'scientific/pro' type forum and ask 'which qrd should I use?' *I
know qrds are the rolls royce, all the studios and all the scientific literature say so yeah??* and some guys get on and reply 'not really better'....threw me into a spin as it rocked my stable datum!
So, in all of these fields, you gotta be able to sort the wheat from the chaff and get a sufficient understanding of it all that you can work it out reasonably well for yourself.
Else just pay a bloke and do what you're told! (and you will be happy, cause at least it WILL sound different!)
thanks Jason (and Glen). At times there is enough of the cox and d'antonio book available on google books that half of this stuff can be worked out. Re your 'flipping', (and what you mention is enough for me to have a better check tonight) is not, for example, a seven well qrd (heck, all qrd's, as I say I will check) symmetrical? Ie, flipping will end up presenting you with the same profile? In the cox book when they give the example of the -1 of the barker code, well I guess a good enough word would be 'the inverse'..and stangely enough it starts
behind the normal ones, ie goes deeper. Heck, may as well make
all of them deeper and diffuse lower! if you follow.
When I get sensible about it I realise it was a silly question for me to have asked. There is no need for me to have that problem in the first place (if diying). That problem really only arises if you are buying commercial stuff, AND you have decided to 'fill that wall in of length 'x'.
For commercial practical reasons, a company prob only has (at most) a few different models, and so to get length 'x' it rerquires a few of them (and hence we get the repeat problem.
Me? meh, just build a single diffusor of a longer length (greater base number, dunno 29 instead of four sevens or whatever) and no repetition problem. Maybe it will be slightly more work doing 'one 29' than 'four sevens', but better results.
But thanks for your help offer, it WILL be gratefully accepted as we proceed!
NOW, on to one of those 'technbical' questions hinted at, and this is really to start cleraing up some of my confusions...or was that diffusions
...in this area.
Was going to quote and link (and will if needed) but maybe all will follow if I do this from memory.
For most of us, and a few of the skyline calculators out there, we get the idea of the BBC model when we use that term. In the BBC paper, they quite clearly mention that it is simplified in many ways to help ease manufacturing costs and effort, and some of those measures include quantising the heights (four was it) and only having a 12*12 grid. And here is the question, they also make it clear that the well dividers are removed, accepting that for floor and ceiling slap echo amelioration that will not lead to too many compromises.
Ok then, often it comes up that 'having wells in skylines' is not a bad idea at all, and it seems to stem from that type of thing in the BBC paper (?), and indeed I used to think that this
was simply a 'skyline with wells', except of course it isn't! (it's qrd based rather than prd based)
But nonetheless you get the idea.
So my confusion?? It was only last night that I finally printed off the patent for the skylines and went thru it.
There is NO mention in it at all about well dividers! (will double check tonight), no mention that for ease of manufacture 'we leave them out' or anything.
So is the BBC paper talking about something different yet 'we' have comingled them?
Again, the reason I'd like to know is I think I have a way where I could make an RPG skyline (with wells that is) in an afternoon...no wells and then it's back to the very long and tedious method. So it would be good to clear that up!
that's enough for this post, thanks for your time and hope to start moving soon.
Glen and Jason, any thoughts about a profile 'similar' to yours that works? Dunno, maybe you have a profile that is
better than the one linked to earlier, but impractical to manufacture or that would be commercially too expensive or sumthin. Or one that you found 'good enough', but still not as good as the one you DID manufacture.
I could easily test my trick on 'any old shape', but no point is simply making a complex shape (ie proves it works) on a shape that is no good for diffusion. May as well get a product if I can out of the test.