relay for on/off speakers

David_AVD

Grandpa Elf
Community project designer
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Jun 12, 2010
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Victoria Point (Brisbane)
While gold contact may be nice, almost nobody uses them in any of the audio products with relay switching I've worked on. Signal relays are often optimised for low current / voltage, but any low cost relay will work just fine for this non critical use.

Switching the power on and off would not be a solution I'd recommend, especially with modern devices. Apart from the mute period each time it is switched on, accidental rapid power cycling can be a real issue. So many devices have SMPS (switch mode power supply) and switching them off then back on soon after effectively bypasses the NTC surge limiter on the mains input, leading to higher than desired current inrush.

The input impedance of the active speakers is usually quite high, even though they are designed to work with 600 Ohm balanced output. Impedance matching with balanced audio these days (the last 15 - 20 years) is not like the old method where the input impedance was really 600 Ohms. Even if you lose a few dB, this application doesn't need a lot of level so it's of no significance.
 

Mark_M

Annoying Elf
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Christmas Light world
I wanted the music to be where the lights are flashing. Therefore I have divided my layout into 4 sections and have one speaker for each section. Then program the speakers to be on/off depending on the show.
I've been looking on Facebook and came across this post about 7.1 channel audio. This basically means 7 speakers and a subwoofer.
Immediately I thought of this thread.
View: https://www.facebook.com/groups/xLights/permalink/3268031449899254


I know you're not wanting 7 speakers too all play at once, but have a look in the comments from @dkulp .
With FPP 4.x, remotes can run audio and sync with master. Thus, the "main" FPP instance can run the main stereo sound track and you could have separate remotes that have different stereo sound tracks for the props/speakers that they are near/connected to.
Another thing you can do with FPP 4.1 is define events for various sound effects that call the FPP "Play Media" command. Then use control channels in the sequence to trigger the commands. Thus, you could have event 01_01 call the "Scream.mp3" or something and whenever the appropriate channel is value "1", it would scream. You can run that on a remote or even have it bridge mode.
This FPP play media seems like an idea to use multiple speakers (and multiple sound effects).
Suppose it also means you can still have most speakers playing the song with selected ones to play a sound effect.

Maybe D.Kulp can chime in about this in FPP v5 :).
 

christophe

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Jun 5, 2019
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Melbourne
I've been looking on Facebook and came across this post about 7.1 channel audio. This basically means 7 speakers and a subwoofer.
Immediately I thought of this thread.
View: https://www.facebook.com/groups/xLights/permalink/3268031449899254


I know you're not wanting 7 speakers too all play at once, but have a look in the comments from @dkulp .


This FPP play media seems like an idea to use multiple speakers (and multiple sound effects).
Suppose it also means you can still have most speakers playing the song with selected ones to play a sound effect.

Maybe D.Kulp can chime in about this in FPP v5 :).
wow wow wow. This is even way better. It is exactly what I was looking for, just to have some subtle sounds here and there just to surprise the audience. Something that I can't get, how can I have different sound effects and have one main sound tracks and all running from one sequence?
 
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