Here's the goal:
I have one large room.
On one axis I have a projection screen.
On another axis I have a plasma.
My various sources (audio part of it) travel through a pioneer 59txi en route to the speakers.
I have sufficient speakers for a 6.1 system on the plasma and 5.1 on the projection. The projection system uses all the same speakers as the plasma system (with an additional centre channel).
I need some way of switching the speakers based on whether I'm using projector or plasma.
So, said another way...imagine I have speakers A,B,C,D,E,F,G (forget about subs for now). When I'm watching the plasma:
LEFT = A
RIGHT = B
CTRE = C
SL = D
SR = E
SB = F
Now, when I'm watching the projector:
LEFT = D
RIGHT = A
CTRE = G
SL =F
SR = E
In an ideal world, I'd love a third option - when I'm listening to stereo:
LEFT = D
RIGHT = E
Now, if I wandered behind my amp and replugged all the speakers every time I switched modes, this would be easy --- but who wants to do that!
In an ideal world, I press a button on the remote and all the speakers switch to their correct functions.
Someone out there must be:
a) Bright enough to understand the above
b) creative enough to know how I cd achieve this
- oh, and it probably goes without saying - I want to keep the sound quality high...so an array of crappy speaker swicthers may not cut it - if they drop sound quality.
(P.S. I do have an AMX control system - with relays and such - if that helps..)
I have one large room.
On one axis I have a projection screen.
On another axis I have a plasma.
My various sources (audio part of it) travel through a pioneer 59txi en route to the speakers.
I have sufficient speakers for a 6.1 system on the plasma and 5.1 on the projection. The projection system uses all the same speakers as the plasma system (with an additional centre channel).
I need some way of switching the speakers based on whether I'm using projector or plasma.
So, said another way...imagine I have speakers A,B,C,D,E,F,G (forget about subs for now). When I'm watching the plasma:
LEFT = A
RIGHT = B
CTRE = C
SL = D
SR = E
SB = F
Now, when I'm watching the projector:
LEFT = D
RIGHT = A
CTRE = G
SL =F
SR = E
In an ideal world, I'd love a third option - when I'm listening to stereo:
LEFT = D
RIGHT = E
Now, if I wandered behind my amp and replugged all the speakers every time I switched modes, this would be easy --- but who wants to do that!
In an ideal world, I press a button on the remote and all the speakers switch to their correct functions.
Someone out there must be:
a) Bright enough to understand the above
b) creative enough to know how I cd achieve this
- oh, and it probably goes without saying - I want to keep the sound quality high...so an array of crappy speaker swicthers may not cut it - if they drop sound quality.
(P.S. I do have an AMX control system - with relays and such - if that helps..)
This would be very easy to achieve using a DPDT relay for each speaker, actuated (via diodes) from a 'mode switch' (rotary or pushbutton bank as you prefer). If you wanted to be really clever, you could derive the control signal from the video source power-up signal.
As far as quality's concerned, it would be dictated by your choice of relay.
As far as quality's concerned, it would be dictated by your choice of relay.
First thing that comes to my mind is that probably you'd want to switch the audio inputs to the power amp as that is much simpler, less power etc than switching the speakers.
As to the switching, what you really need is to rotate the total stuff one click clockwise and back, isn't it? From east-west to north-south. So you need a 7-in, 2 x 7 out switcher, user in reverse: you put all channels in each of the 7 'output' jacks, but offset one click. Then the 'input' row actually goes to the power amp. By selecting one or the other setting you rotate one click or back.
Now the hard stuff: I have no idea this is a standard product, but the Behringer MX882 might fit the bill at just over a 100 bucks. Check their website for the manual.
Jan Didden
As to the switching, what you really need is to rotate the total stuff one click clockwise and back, isn't it? From east-west to north-south. So you need a 7-in, 2 x 7 out switcher, user in reverse: you put all channels in each of the 7 'output' jacks, but offset one click. Then the 'input' row actually goes to the power amp. By selecting one or the other setting you rotate one click or back.
Now the hard stuff: I have no idea this is a standard product, but the Behringer MX882 might fit the bill at just over a 100 bucks. Check their website for the manual.
Jan Didden
Thanks for the two directional suggestions.
Let me take them in reverse order.
a) Use Line Level...
This is a good idea, but would mean I'd have to swicth out my receiver (VSX-59txi) to a pre + power amp scenario and then route the pre-outs iinto a matrix switcher like an extron crosspoint. In addition, I wonder how much signal degradation would transpire? I wonder (thinking out loud) whether its possible to grab the 7.1 signal from my receiver do my maytrix stuff and then shove it back in...(kind of like an insert on a pro mixing desk) - anyone know the answer to this?
b) Relay based solution.
This is interesting, though I can't quite wrap my head around how it would actually work? Signal comes into an array of relays. I don't think one can connect the speakers to the output side of the relays as one would end up cross wiring all the speakers....so I think the relays would have to feed additional groups of relays...in fact, to handle 7.1 (forget the .1), one would need 7 + 49 + 7 relays ( I think). Is this what you had in mind?
Ugh - my brain hurts thinking about it. Please advise...
and thanks everyone for your input - this is great.
s.
Let me take them in reverse order.
a) Use Line Level...
This is a good idea, but would mean I'd have to swicth out my receiver (VSX-59txi) to a pre + power amp scenario and then route the pre-outs iinto a matrix switcher like an extron crosspoint. In addition, I wonder how much signal degradation would transpire? I wonder (thinking out loud) whether its possible to grab the 7.1 signal from my receiver do my maytrix stuff and then shove it back in...(kind of like an insert on a pro mixing desk) - anyone know the answer to this?
b) Relay based solution.
This is interesting, though I can't quite wrap my head around how it would actually work? Signal comes into an array of relays. I don't think one can connect the speakers to the output side of the relays as one would end up cross wiring all the speakers....so I think the relays would have to feed additional groups of relays...in fact, to handle 7.1 (forget the .1), one would need 7 + 49 + 7 relays ( I think). Is this what you had in mind?
Ugh - my brain hurts thinking about it. Please advise...
and thanks everyone for your input - this is great.
s.
You could make a simple matrix with relays or buy one and control it from the AMX. The most expensive part is programming the AMX. I would use a line level switcher, connect the best amps to the best speakers and route the signals that way. Much better than speaker switchers.
There are connercial matrix switchers available for the pro market and for the industrial market. I had a stack of HP switchers that I dumpes a few moths ago when the project they were intended for fizzled. They are too expensive but the interface and programming would be.
This is an option and the AMX should be able to control it:
http://www.extron.com/product/product.asp?id=matrix3200-6400&subtype=108
Or
http://www.extron.com/technology/archive.asp?id=joel85
Shop on eBay or wherever for similar products.
-Demian
There are connercial matrix switchers available for the pro market and for the industrial market. I had a stack of HP switchers that I dumpes a few moths ago when the project they were intended for fizzled. They are too expensive but the interface and programming would be.
This is an option and the AMX should be able to control it:
http://www.extron.com/product/product.asp?id=matrix3200-6400&subtype=108
Or
http://www.extron.com/technology/archive.asp?id=joel85
Shop on eBay or wherever for similar products.
-Demian
1) Line level- Better if you can do it- no power through the relays. This is what kills relays. But you must check your receiver for pre out and line in. Possible on upper level receivers.
2) Speaker level relays, you need a relay for each speaker at each combination or 7 X3 or 21 2 form A contact relays rated for 5A minimum.
3) Switch- 14 pole three position. Again possible. I don't have the patience to wire it. You could use the switch out of an old printer selector switch. (26 pole switch in many of them).
Check your receiver. It may be time to make or buy seperate amps for all of the speakers and use the receiver as a processor.
Or possibly re-arrange your room?
Have fun- -Demian
2) Speaker level relays, you need a relay for each speaker at each combination or 7 X3 or 21 2 form A contact relays rated for 5A minimum.
3) Switch- 14 pole three position. Again possible. I don't have the patience to wire it. You could use the switch out of an old printer selector switch. (26 pole switch in many of them).
Check your receiver. It may be time to make or buy seperate amps for all of the speakers and use the receiver as a processor.
Or possibly re-arrange your room?
Have fun- -Demian
Another way would be a line-level gold plated patch bay using RCA cables.
With good connectors and cable, it will be "relatively" inexpensive and very high quality. It also provides an easy way to lock out the system from unintended ears, just by plugging into "dead" ends.
You'd still have to be (un)plugging cables, but at least it will be on the front of your rack.
🙂ensen.
With good connectors and cable, it will be "relatively" inexpensive and very high quality. It also provides an easy way to lock out the system from unintended ears, just by plugging into "dead" ends.
You'd still have to be (un)plugging cables, but at least it will be on the front of your rack.
🙂ensen.
Maybe I'm missing something, but it seems to me that it can be done with six relays (speaker or line as you prefer). I've shown SPDT, but you could of course use DPDT if you want to switch the earthy side as well.
The bottom diagram is an add-on to enable the 'ideal' stereo option. In this case, the main relay bank should be in the 'plasma' position, so that the auxiliary relay can select 'home theatre' or 'stereo'.
Relay coils can be controlled by a simple switch, a switch / diode matrix (more elegant), or an automated system.
The bottom diagram is an add-on to enable the 'ideal' stereo option. In this case, the main relay bank should be in the 'plasma' position, so that the auxiliary relay can select 'home theatre' or 'stereo'.
Relay coils can be controlled by a simple switch, a switch / diode matrix (more elegant), or an automated system.
Attachments
This can be done simpler. But hazards exist-
1) You can't always use common grounds on speaker applications. The amp may have bridged outputs. There may be other complications if the return lines from the speakers get crossed.
2) If three different layouts are desired three speaker relay arrays are needed. Leaving unused speakers connected may not work if the channels are used differently. Some reduction in relay count may be possible.
-Demian
1) You can't always use common grounds on speaker applications. The amp may have bridged outputs. There may be other complications if the return lines from the speakers get crossed.
2) If three different layouts are desired three speaker relay arrays are needed. Leaving unused speakers connected may not work if the channels are used differently. Some reduction in relay count may be possible.
-Demian
dnsey --- this is fantasic...
I'm thinking I should go with speaker level as I don't then have to rejig my receiver set-up.
your diagram seems to work for all my use cases...and I'm not quite sure why I was so convinced that I needed a much more comprehensive array of relays -- maybe I was drinking something that I shouldn't have been!
Now, my questions get more granular...
a) It seems that I need DPDT Relays (speakers are AC so I need both sides) that are two-pole and capable of handling speaker level signals - without degradation....any ideas on where I might find such a beast ... and what it's called.
b) I have an AMX control system that is capable (via Remote) of triggering 8 independant 12V, 200mA outputs as either a toggle or pulse - perhaps I can use this as the relay actuator? Alternately, it also has 8 relays that I could use.
c) When you say a 'switch diode matrix' what do you mean?
Thanks so much folks -- for the guidance on this...amazing!
I'm thinking I should go with speaker level as I don't then have to rejig my receiver set-up.
your diagram seems to work for all my use cases...and I'm not quite sure why I was so convinced that I needed a much more comprehensive array of relays -- maybe I was drinking something that I shouldn't have been!
Now, my questions get more granular...
a) It seems that I need DPDT Relays (speakers are AC so I need both sides) that are two-pole and capable of handling speaker level signals - without degradation....any ideas on where I might find such a beast ... and what it's called.
b) I have an AMX control system that is capable (via Remote) of triggering 8 independant 12V, 200mA outputs as either a toggle or pulse - perhaps I can use this as the relay actuator? Alternately, it also has 8 relays that I could use.
c) When you say a 'switch diode matrix' what do you mean?
Thanks so much folks -- for the guidance on this...amazing!
1audio ---
I think your point (about circuit integrity) is why I was imagining an array of relays.
One wouldn't use a common ground as the speaker signal is an AC signal -- so one would definately use a DPDT relay...I guess the issue comes down to how the relays work....if they move from position A to position B in one movement, then there is a risk that a given relay gets there ahead of its sisters and we create a dangerous loop that could blow the amp.
So, we would need to (ideally) switch each relay to an OFF position prior to moving it to its destination position...does this mean we need a three pole DPDT with the middle position being not connected --- or am I babbling incoherently and inventing imaginary dragons?
I think your point (about circuit integrity) is why I was imagining an array of relays.
One wouldn't use a common ground as the speaker signal is an AC signal -- so one would definately use a DPDT relay...I guess the issue comes down to how the relays work....if they move from position A to position B in one movement, then there is a risk that a given relay gets there ahead of its sisters and we create a dangerous loop that could blow the amp.
So, we would need to (ideally) switch each relay to an OFF position prior to moving it to its destination position...does this mean we need a three pole DPDT with the middle position being not connected --- or am I babbling incoherently and inventing imaginary dragons?
skavan said:
No, you just realised another good reason to switch the inputs instead of the speakers. What's the problem with 're-configuring the receiver' ? It's exactly the same concept as switching the speakers. Its even easier, just line-level wiring no thick snake-type cabling for 7(!) speakers going to and from your switch box...
Jan Didden
janneman -
The issue is that I would need to either ditch the 59txi receiver I have OR skip its amplification section.
Basically, I would need to grab teh pre-amp output --- put it through the relay stuff (or external matrix switcher like an Extron) and then return it to an amplification stage.
My receiver (and most other high end units that I know of), do not allow you to grab the pre-amp outs and then return them for amplification - they let you do one or the other. In other words, you can grab the pre-amp outs, but when you ask the amp to use the power amp inputs, it presumes you want to bypass the pre-amp part of the amp and your selected-amp-input becomes 'external multi-channel-input'!!! So the only way to deal with this is to buy $2k worth of external amplification and just use the 59txi as pre. Pretty expensive way forward!
If I'm missing a solution here - please tell me!
The issue is that I would need to either ditch the 59txi receiver I have OR skip its amplification section.
Basically, I would need to grab teh pre-amp output --- put it through the relay stuff (or external matrix switcher like an Extron) and then return it to an amplification stage.
My receiver (and most other high end units that I know of), do not allow you to grab the pre-amp outs and then return them for amplification - they let you do one or the other. In other words, you can grab the pre-amp outs, but when you ask the amp to use the power amp inputs, it presumes you want to bypass the pre-amp part of the amp and your selected-amp-input becomes 'external multi-channel-input'!!! So the only way to deal with this is to buy $2k worth of external amplification and just use the 59txi as pre. Pretty expensive way forward!
If I'm missing a solution here - please tell me!
skavan said:
Right, I get it. I presumed, wrongly, that the preamp outputs and poweramp inputs were totally uncommitted. I'm getting too old for this newfangled stuff, really...
Jan Didden
I agree with the other correspondents that line level switching would be better than LS level. For this, you need to look for relays with e.g. gold plated contacts, ideally specified for audio signal switching. Browse a supplier's catalogue, and the choice is yours (there are some nice telecoms relays easily available which would suit well).
Yes, that would work OK - I'd use the trigger O/P to run relays as above rather than the inbuilt ones, which I presume are meant for power switching and might degrade the signal.
If you go for manual switching, you can use simple SPST switches to operate all the relays, but each relay coil should be isolated from the others by a series diode. In this particular case, it doesn't matter too much, but providing this isolation means that if you want to expand your system later, you can switch individual relays without triggering the others.
Yes, it's an AC signal, but (in simple cases) it's referred to ground, so you could get away with SP switching. However, for the good reasons outlined by 1Audio, it's well worth investing the few extra pennies in DP types. In any case, it would be good practice to power down your amps before reconfiguring the speakers, to avoid potentially damaging transient spikes (clicks and pops) if for no other reason.
Do you have a tape loop? If so, that would achieve the same thing. Use the 'tape out' as your preamp O/P, and 'monitor in' as power I/P. Set the amp to 'tape monitor' of course.
Good idea -- only problem is that the monitor outputs are stereo only and therefore would result in no 7.1.
mmmmh it seems, so far, that the only viable solution is to use speaker level relay based switching.
so that begs the question - where do I find such beasts...I have searched the internet high and low, and am not sure how to identify relays that would fit the bill and be acoustically transparent.
One other thought just popped into my warped brain --- hi-fi stores have auditioning rooms where they can direct a source amp/receiver towards different speakers....the salesguy punches in a 2-digit source code and a 2-digit speaker code and voila!
Anyone know what these are called and/or who makes them?? Seems like they might do the trick??? Did an internet search but came up with lots of line level stuff and no speaker matrix selectors.
ugh - so near yet so far!
s.
Anyone know what these are called and/or who makes them?? Seems like they might do the trick??? Did an internet search but came up with lots of line level stuff and no speaker matrix selectors.
ugh - so near yet so far!
s.
Hi!
Your BEST choice is speaker level good quality DPDT relays. But BEWARE - there IS a huge difference how you connect! I assume you would like to do it in a fashion that does not put your amplifier nor your speakers at risk.... heres how:
You need ONE DPDT relay per speaker to be switched (in your case 6 relays).
Connect the C (common) terminals on one relay to one speaker. Yes - you must connect both wires of the speaker to be 100% sure your system works as intended - this approach works best and with ALL types of amplifiers - bridged or not.
Connect the NC (normally closed) contacts to the amplifier ouputs normally used for this speaker. Make sure that you keep the polarity (+ an -) the same.
Connect the NO (normally open) contacts to the alternative amplifier output.
Do this same for all speakers involved. Make sure that there is no phase reversals in your connections.
Connect the coils of all relays parallell. It is prudent to connect a diode in parallel to kill the back emf and make sure your control switch works properly in the long run. The diode should NOT conduct when the realys receive DC power... Put the cathode towards the positive end of the coil. An 1N4001...1N4007 would be fine.
Apply power to the relays when you want to have the alternative setup selected.
I would suggest to use 24VDC relays and a suitable readily made DC power supply for powering them. Simply switch this power on and off by either unplugging it or arranging a switch.
By placing this realy block in close proximity to the amplifier(s) you can minimize the wiring. There are suitable high current automotive relays with 6.3mm spade contacts to make the wiring easier and achevable even without soldering. Automotive relays are otherwice good since they have a good current handling capacity and can easily be mounted.
Let me know if you need a schematic to clarify my idea. It is essential that you use the realys to select to wich amplifier the speaker connects - and not vice versa. Othervise you risk connecting amp outputs together - an unbearable situation that could cause smoke output.... With this suggested approach the worst thing that can happend is that one amp has momentarily two speakers connected - but just for a couple of milliseconds during the switchover. A thing that any amplifier can take.
Best regards,
Christian
Your BEST choice is speaker level good quality DPDT relays. But BEWARE - there IS a huge difference how you connect! I assume you would like to do it in a fashion that does not put your amplifier nor your speakers at risk.... heres how:
You need ONE DPDT relay per speaker to be switched (in your case 6 relays).
Connect the C (common) terminals on one relay to one speaker. Yes - you must connect both wires of the speaker to be 100% sure your system works as intended - this approach works best and with ALL types of amplifiers - bridged or not.
Connect the NC (normally closed) contacts to the amplifier ouputs normally used for this speaker. Make sure that you keep the polarity (+ an -) the same.
Connect the NO (normally open) contacts to the alternative amplifier output.
Do this same for all speakers involved. Make sure that there is no phase reversals in your connections.
Connect the coils of all relays parallell. It is prudent to connect a diode in parallel to kill the back emf and make sure your control switch works properly in the long run. The diode should NOT conduct when the realys receive DC power... Put the cathode towards the positive end of the coil. An 1N4001...1N4007 would be fine.
Apply power to the relays when you want to have the alternative setup selected.
I would suggest to use 24VDC relays and a suitable readily made DC power supply for powering them. Simply switch this power on and off by either unplugging it or arranging a switch.
By placing this realy block in close proximity to the amplifier(s) you can minimize the wiring. There are suitable high current automotive relays with 6.3mm spade contacts to make the wiring easier and achevable even without soldering. Automotive relays are otherwice good since they have a good current handling capacity and can easily be mounted.
Let me know if you need a schematic to clarify my idea. It is essential that you use the realys to select to wich amplifier the speaker connects - and not vice versa. Othervise you risk connecting amp outputs together - an unbearable situation that could cause smoke output.... With this suggested approach the worst thing that can happend is that one amp has momentarily two speakers connected - but just for a couple of milliseconds during the switchover. A thing that any amplifier can take.
Best regards,
Christian
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