7.1 Surround Speaker Controller?
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Posts: 46,084
I've been watching this group for a few months, and quite impressed
with its diverse knowledge base. My current gig is high-end surround
sound audio, and I'm looking to design and build a Stamp driven
speaker controller for 7.1 surround-sound monitoring. It's been a
while since I programmed a Basic Stamp, but it looks like all the new
tools will make this a fun (re)learning project.
Here's the basic idea. In a surround mixing environment for audio
engineers, it's helpful to be able to mute and solo individual
speakers. This gets quite complicated with surround-sound systems,
where we have speakers in front as well as behind us. And while it's
possible to buy an inexpensive home-theater receiver for a few
hundred bucks that will hook to our mixing consoles and drive the
monitor speakers directly, there's no commercial product that can
mute/solo the individual speaker-level outputs of the amp. So I need
to build such a device for my classes.
Looks like the simplest way (in terms of blacksmithing time) would be
to get something like the TFS-1 ROBOIFACE board, use its output
transistors to drive big relays, and put some switches and LED's on a
remote pod to sit on the console. A few questions come to mind as I
think about the layout. Big relays and sockets can cost $10 to $20
each, and I need 8 of them for the project. But from MCM Electronics
I can get automotive relays for a buck a piece. Does anyone see any
cons to using 12-volt DC rated relays to switch speaker level signals
of a 100-watt amplifier driving 8-ohm loads? These relays are rated
for 40 amps, and have 12-Volt DC coils. Of course, I wouldn't be able
to drive the coils directly from a BS, but certainly the transisor
outputs of the TFS-1 ROBOIFACE would have no problems, right? Of
course I would put a diode across the coil for the kick-back, etc...
Any comments on relay selection? Also, the relays should be down at
the amplifier rack, while the controller up on the console... so I'm
considering using a standard DB-9 cable to run a common ground and 8
relay-coil leads back to the controller. I know it's not a elegant as
running an RS-232 interface, but in this case simpler is better.
Also, any thoughts on input switch de-bouncing? I'm guessing a simple
resistor/cap array would do the trick. I could accept a small delay,
since this isn't like playing a music keyboard.
Thoughts? Comments? Suggestions?
Thanks....
with its diverse knowledge base. My current gig is high-end surround
sound audio, and I'm looking to design and build a Stamp driven
speaker controller for 7.1 surround-sound monitoring. It's been a
while since I programmed a Basic Stamp, but it looks like all the new
tools will make this a fun (re)learning project.
Here's the basic idea. In a surround mixing environment for audio
engineers, it's helpful to be able to mute and solo individual
speakers. This gets quite complicated with surround-sound systems,
where we have speakers in front as well as behind us. And while it's
possible to buy an inexpensive home-theater receiver for a few
hundred bucks that will hook to our mixing consoles and drive the
monitor speakers directly, there's no commercial product that can
mute/solo the individual speaker-level outputs of the amp. So I need
to build such a device for my classes.
Looks like the simplest way (in terms of blacksmithing time) would be
to get something like the TFS-1 ROBOIFACE board, use its output
transistors to drive big relays, and put some switches and LED's on a
remote pod to sit on the console. A few questions come to mind as I
think about the layout. Big relays and sockets can cost $10 to $20
each, and I need 8 of them for the project. But from MCM Electronics
I can get automotive relays for a buck a piece. Does anyone see any
cons to using 12-volt DC rated relays to switch speaker level signals
of a 100-watt amplifier driving 8-ohm loads? These relays are rated
for 40 amps, and have 12-Volt DC coils. Of course, I wouldn't be able
to drive the coils directly from a BS, but certainly the transisor
outputs of the TFS-1 ROBOIFACE would have no problems, right? Of
course I would put a diode across the coil for the kick-back, etc...
Any comments on relay selection? Also, the relays should be down at
the amplifier rack, while the controller up on the console... so I'm
considering using a standard DB-9 cable to run a common ground and 8
relay-coil leads back to the controller. I know it's not a elegant as
running an RS-232 interface, but in this case simpler is better.
Also, any thoughts on input switch de-bouncing? I'm guessing a simple
resistor/cap array would do the trick. I could accept a small delay,
since this isn't like playing a music keyboard.
Thoughts? Comments? Suggestions?
Thanks....
Comments
12 volt relays. The board already has diode protection on it so no external
diodes are required across the relay coils.
jim
http://www.geocities.com/jimforkin2003/
Original Message
From: jmsokol [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=y8myPIiZEQvTv4fBEz_hNAdk-t1C3AVCRcEP8Lp-966ZjmHn12_-Kl2MaB5-nt2WLlO4MDux7UwrSGbKtqw7]mikes@m...[/url
Sent: Tuesday, June 10, 2003 9:11 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] 7.1 Surround Speaker Controller?
I've been watching this group for a few months, and quite impressed
with its diverse knowledge base. My current gig is high-end surround
sound audio, and I'm looking to design and build a Stamp driven
speaker controller for 7.1 surround-sound monitoring. It's been a
while since I programmed a Basic Stamp, but it looks like all the new
tools will make this a fun (re)learning project.
Here's the basic idea. In a surround mixing environment for audio
engineers, it's helpful to be able to mute and solo individual
speakers. This gets quite complicated with surround-sound systems,
where we have speakers in front as well as behind us. And while it's
possible to buy an inexpensive home-theater receiver for a few
hundred bucks that will hook to our mixing consoles and drive the
monitor speakers directly, there's no commercial product that can
mute/solo the individual speaker-level outputs of the amp. So I need
to build such a device for my classes.
Looks like the simplest way (in terms of blacksmithing time) would be
to get something like the TFS-1 ROBOIFACE board, use its output
transistors to drive big relays, and put some switches and LED's on a
remote pod to sit on the console. A few questions come to mind as I
think about the layout. Big relays and sockets can cost $10 to $20
each, and I need 8 of them for the project. But from MCM Electronics
I can get automotive relays for a buck a piece. Does anyone see any
cons to using 12-volt DC rated relays to switch speaker level signals
of a 100-watt amplifier driving 8-ohm loads? These relays are rated
for 40 amps, and have 12-Volt DC coils. Of course, I wouldn't be able
to drive the coils directly from a BS, but certainly the transisor
outputs of the TFS-1 ROBOIFACE would have no problems, right? Of
course I would put a diode across the coil for the kick-back, etc...
Any comments on relay selection? Also, the relays should be down at
the amplifier rack, while the controller up on the console... so I'm
considering using a standard DB-9 cable to run a common ground and 8
relay-coil leads back to the controller. I know it's not a elegant as
running an RS-232 interface, but in this case simpler is better.
Also, any thoughts on input switch de-bouncing? I'm guessing a simple
resistor/cap array would do the trick. I could accept a small delay,
since this isn't like playing a music keyboard.
Thoughts? Comments? Suggestions?
Thanks....
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>Any comments on relay selection? Also, the relays should be down at
>the amplifier rack, while the controller up on the console... so I'm
>considering using a standard DB-9 cable to run a common ground and 8
>relay-coil leads back to the controller.
You don't need any smarts for this - the whole thing can be done with the
relays mounted at the amplifier rack and some switches / LEDs mounted at
the console. DB-9 serial cables are a good choice - just make sure that
the ones you purchase have all 9 pins wired through. Some inexpensive
mouse extension cables have only 3 or 5 wires.
Use multi-pole relays if possible - this allows you to use one pole to
latch the relays on when selected.
Contact me off list with a fax number if you want a sketch of how to use
momentary switches to control the relays - its way too much effort to do it
with ASCII art.
The versions I built for the recording studios around here do all the
switching at the amplifier inputs rather than the outputs. Just seemed
easier at the time. But your way will work just fine.
dwayne
--
Dwayne Reid <dwayner@p...>
Trinity Electronics Systems Ltd Edmonton, AB, CANADA
(780) 489-3199 voice (780) 487-6397 fax
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