“The mini-bass won’t be bunched together, but placed along the moulding, at about one and a half metres from each other. The moulding extends to the sides of the stage, nineteen metres in all. That’ll take twelve speakers and I think it’s enough. Fitted almost against the ceiling, you’ll hardly notice them once they’re painted. Now let’s discuss the alternative, the second option. The small mini bass sizes mean they can also be placed behind the upper part of the grand drape, between that and the fire-curtain. I’d prefer not to go for this solution as the stage opening only measures thirteen metres and we would have to place the speakers in two rows. Then, installation is much more complicated. It definitely needs ad hoc brackets made and the heavy drape material, just renewed, would have to be replaced by a more sound transparent one. A considerable complication and additional expense. And the space behind the grand drape could act as a resonator, dirtying sound. Last of all, compared with the first solution, the sound pressure produced would be lower, with the same number of speakers.” I chew over Saundman words trying to find ten thousand reasons why these unusual solutions which leave me dumbstruck can’t work. My concentration is decidedly disturbed by the grin on my mentor’s face as he watches me amused. In the end, my mind clears and my voice comes back. “Sorry, but some things don’t convince me. First of all, cost. Twelve or more speakers are not cheap. “True. However, as you undoubtedly know, large bass speakers are not cheap either. So the cost difference, though considering the greater amplifying power required, is anything but unacceptable. The Superintendent has asked for a system with a low aesthetic impact, not for a cheap one. That doesn’t mean, seeing the times we’re living in, we shouldn’t do all we can to reduce costs. But we’ll discuss that later.” “Alright, maybe costs are ok. However, on reviewing your proposal, one thing is clear to me. What you mean to create is nothing but a line array for low frequencies. And line arrays have high directivity features, especially if they’re nineteen metres long. While the bass must be heard in the entire theatre. What about that?” “My dear sceptical friend” Soundman replies “we’ve discussed the virtues of beamforming to incline a sound ray, duplicate it, focus it, redirect it. There’s nothing to stop us widening it. Transforming the line array formed by the bass into a steering system does not need any particular costs or complications and is easy to plan so it covers all the theatre seats.” “I didn’t know that. But twelve speakers aren’t enough. This theatre is pretty big.” “Right. But we won’t be having just twelve. At least twenty-four, minimum, and if we do things right, even more.” “You said twelve. Now we’re already up to twenty-four. Where will we put them? And costs? You said your planned to reduce them…” “No, no. The bass speakers are physically twelve, but by organising them in a line array, they produce the same sound pressure as at least twenty four speakers of the same type spread throughout the environment. The line array’s sound sources work in phase in the useful propagation direction and in counter phase, in the direction/s you mean to limit. However, two sources operating in phase produce sound pressure 3 dB higher than what they generate, but positioned so that emissions are not coherent. Basically, acoustic energy emitted doubles. It’s like magic, a multiplying of loaves and fishes at no cost. But it’s simple physics. If you’d read the article on acoustics I gave you some time ago you would know this depends on impedance, on the way the source transmits energy from the loud speaker cone to the means, air, spreading it. But that’s not all. If you measure a bass speaker in the open, in the middle of a field, and then leant against a large wall, you realise that the sound pressure increases – in the second position – by 6 dB. The sound energy is quadrupled. We can expect sound energy to double.
expanding display experiences La massima flessibilità per montare uno schermo al soffitto Connect‐it è un sistema modulare esclusivo. Con pochi componenti standard si possono ottenere quasi tutte le soluzioni di montaggio. Le caratteristiche principali delle Serie Connect-it sono: sistema modulare flessibile interfaccia modulare per schermi per un adattamento perfetto installazione semplice e veloce montaggio di più schermi utilizzando componenti standard
Filmato Connect-it www.connessioni.biz
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