[LAU] Jamin for FOH (was: Re: JAMin updates?)

Jack O'Quin jack.oquin at gmail.com
Wed Aug 5 11:38:47 EDT 2009

On Wed, Aug 5, 2009 at 7:53 AM, Fons Adriaensen<fons at kokkinizita.net> wrote:
> On Wed, Aug 05, 2009 at 10:18:57AM +0200, Arnold Krille wrote:
>> Some kind of PA-managment that does:
>> a.1) Frequency-X-over and EQ (and phase and that)
>> a.2) If EQ is to simple nowadays (as some Fons guy tells me:), sophisticated
>> digital filters...
>> b) Multiband-compressor (one per output or with independant frequency ranges)
>> and limiters for the outputs.
> The Lake (later Dolby) processors used to be one of the
> standard solutions for this (and are still used today),
> see <http://www.dolby.com/professional/Live_Sound/>.
> They are no longer sold AFAIK, one of the reasons being
> that manufacturers of PA systems are integrating this
> sort of technology, see e.g. <http://www.labgruppen.com/>
> and <http://www.qscaudio.com/products/dsp/dsp30/dsp30.htm>.
> Integrating xover filtering, EQ, and limiting and sometime
> even the power amp brings some important advantages - it
> removes many connections, gain controls and other things
> that could be done or set wrong and render such processing
> completely useless, and it allows to adapt the processing
> to specific speaker units and combinations, usually selected
> from a menu on the user interface, or by networked remote
> control apps. A big PA system today is completely set up
> and monitored via network connections, and this can include
> things such as amplifier and even speaker temperatures.
> You can do all of this on a PC, but it's a shaky solution
> unless you do some further integration - for one there will
> be far too many gain controls after the processor, making
> nonsense of any carefully set limiter levels and exactly
> matched xovers. One other problem is to find the proper
> settings for your hardware, and that is one reason why this
> job is today done mostly by the speaker manufacturers who
> have precise information about the electrical, mechanical
> and thermal limits of their products.
>> c) Automatic (and live!) comparison of the input signal that is routed to the
>> outputs and the signal from one or more measurement microphones to adapt to
>> the room with only a mouse-click. And to re-adapt to the room when the crowd
>> is in.
>> d) Feedback-destroyer (which will probably be hard to do while c) is running
>> its adaption.
> Not so simple but certainly possible and much more suited
> to software based solutions.

That sounds like an interesting, fun (and difficult) project.  But,
well outside the problem domain of jamin.

Jamin has been stable and useful mainly because it was always focused
on one specific task.

No reason not to reuse any useful parts of jamin for this new
application, of course.  That has already been done once for a DJ

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