How do ATC control the vertical dispersion Merlin? Let's get that question sorted before we continue.
Midrange Masters - ATC vs ESL vs NS1000
- Thread starter halvis
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How do ATC control the vertical dispersion Merlin? Let's get that question sorted before we continue.
Tony L
Administrator
Think of two or three drivers spaced apart and in a line, now tilt the speaker so you are closer to one and further from another and think about what happens in the time domain. You now understand the basic concept of time / phase alignment. This is why ATC only claim a 10% vertical dispersion, i.e. it is time interaction with the other drivers, not simple driver dispersion that dictates this figure.
Golly, thanks, I never realised that. But we were talking about dispersion.
Tony L
Administrator
You may have been, ATC and the rest of us weren't. This is the reason why they claim a narrower vertical dispersion than horizontal - it's the same for all multi-driver speakers. Move too far of vertical axis and you get time/phase error, comb-effects etc. It's a core reason why a point source is the ideal.
I know what the rest of you chose to talk about, but the subject was actually dispersion.
Someone (Markus) decided to talk about phase coherence instead. Merlin seemed to be under the impression that ATC limit vertical dispersion!
Tony L
Administrator
Phone up ATC and ask them why they give different figures for vertical / horizontal dispersion. They'll tell you exactly what Markus, I etc have attempted to many times. This is incredibly basic stuff - you should know it. Hint: the figure given is for *the loudspeaker system as a whole* not the midband driver!
joel
Painter of Dragons, Maker of Mirrors
Acoustic waves become narrower as frequency rises. In addition, a wide baffle can operate as a wave guide at higher frequencies. I don't know to what extent this is the case with ATC, but the baffle will have some effect.
merlin
Avatar changed - Town names deemed offensive.
No James. I was explaining that vertical dispersion is controlled - by the alignment of the drive units - hence Simon's suggestion being valid. Apologies if you misinterpreted that. For clarity, ATC state,
Of course you will get sound above and below that window - it's just that it will be coloured, and not what ATC intended when they designed the loudspeakers.
As Tony says though, just give ATC a call to clarify and put your mind at rest.
cooky1257
pfm Member
I'd add 'dictated' to 'controlled', by the driver placement/xover slope and polar pattern at xover.
Bub, this thread illustrates prescisely why I now get grown ups involved -- and learned to stay quiet about the outcome and ignore online kiddies with graphs, RTA mics and attitude instead of experience and knowledge and go to professionals with RTA mics and experience (and yes some of them have attitude too). The former may work on hifi and hobbyists but what you have (and what I am trying to achieve in my life) goes way way way beyond a hobby. A pro saves me having to deal with misinfo... and I can get on with drawing squiggles on lined paper and eating crayons... As the good lord himself gave me the skills to do.
Now be sure I am not accusing anyone here of misinfo, but sifting it and reliability checking is harder work than asking an expert. Great if you have the time, or the perversity, but if you have other things to be doing, it's counterproductive.
I make fewer dead ends this way as well.
I got ATC, my professor and my installer in on the 4-channel +sub +room install and they all disagree with much of the anecdotal data from PFM -- or rather while the points raised (some are "just so wrong they're not even right") the professionals explained a succession of points that erode PFMs "things we hold to be self evident" so much so that I see a repeating pattern there and here that PFM usually concerns itself with peripheral considerations that are tiny in the context of "what really matters".
Not seeing the Wood for the trees, as it were
What I learned with subs and here is: one has reached the limit of an internet forum's ability to reliably inform. If in doubt, (and rest assured the internet forums all create doubt) then wheel a pro in. There are always Internet Experts and much of the advice is going to be well-intentioned, kind, sagely and wise -- and free! But it's hard to verify and unreliable, and that's not really useful to anyone in the long run.
Now be sure I am not accusing anyone here of misinfo, but sifting it and reliability checking is harder work than asking an expert. Great if you have the time, or the perversity, but if you have other things to be doing, it's counterproductive.
I make fewer dead ends this way as well.
I got ATC, my professor and my installer in on the 4-channel +sub +room install and they all disagree with much of the anecdotal data from PFM -- or rather while the points raised (some are "just so wrong they're not even right") the professionals explained a succession of points that erode PFMs "things we hold to be self evident" so much so that I see a repeating pattern there and here that PFM usually concerns itself with peripheral considerations that are tiny in the context of "what really matters".
Not seeing the Wood for the trees, as it were
What I learned with subs and here is: one has reached the limit of an internet forum's ability to reliably inform. If in doubt, (and rest assured the internet forums all create doubt) then wheel a pro in. There are always Internet Experts and much of the advice is going to be well-intentioned, kind, sagely and wise -- and free! But it's hard to verify and unreliable, and that's not really useful to anyone in the long run.
I would have to pay them and I am already paying them to do my room and setup and to not score points in a war of ego driven battles and fear of losing face. The problem as always is an expert will tell me something and I may mis-use that information because other considerations that apply to me and not to you come into effect that may change the advice in the wider sphere.
Learning is serious business and to do it well you have to come from an open minded point of view and an honesty that you will never ever know enough of anything other than our own specialism.
It's very liberating.
Learning is serious business and to do it well you have to come from an open minded point of view and an honesty that you will never ever know enough of anything other than our own specialism.
It's very liberating.
johnhunt
pfm Member
Given I can't afford an acoustician ( I worked with them professionally in the past) can anybody point me in the right direction for room treatment. Mine is a bit live. I was thinking of plonking a foam bass trap in each corner. The room is 3.5 by just under 7. The 100 fire the longest plane and I listen 3/4 back. Construction is breeze block walls , on concrete with wooden floor on top. I have two sets of double glazed doors to the garden along one lo g length. Also the other long length opens perdicular to the kitchen about 2/3 along.
Still really enjoying the 100s, almost as much as I'm enjoying my separation
Still really enjoying the 100s, almost as much as I'm enjoying my separation