Suggestions for integrating HS TTS with whole-house audio?

[DC]

I would like to start using the TTS features of HS. I want to feed the HS output into my whole-house audio system. I have speakers in every room and on the front and back porches so the entire house would be well covered. I have a dedicated Yamaha amplifier for the whole-house audio. The amplifier feeds a 10 way speaker distribution impedence matching transformer. (I have 13 pairs of speakers so 3 pairs are doubled up.) I currently have a satellite receiver and a CD changer connected to my amplifier. I have other inputs to which I could connect HS. But there are two problems:

1. If the audio system is on and playing another source, I would have to switch it via I/R to the HS input. That's probably doable but I'm concerned about the time-delay. I suspect I would miss part of the HS speech while the input switch is occuring.

2. If the audio system is off, it would have to be powered on first. Same problem but I'm SURE I would miss part, if not all, of the speech because the amp takes about 3 seconds to come on when the power on button is pressed (or I/R command is received).

What I would really like to do is have a dedicated amp for HS and feed it, and the music amp, into some kind of high speed electronic switch and feed the output of that into my speaker distribution system. I would like for the switch to normally feed the music amp to the speaker system but automatically switch to the other input (HS) whenever it detects a signal. Problem is, I can't find such a switch. I have to believe they exist but I don't know where to look.

Can anyone recommend a high-speed audio switch like this?

Anybody have any other suggested methods for accomplishing the same thing?

Thanks!

[This message was edited by DC on Saturday, 06 July 2002 at 12:43 AM.]

[Barry Gordon]

As long as you can control the Yamaha amp/preamp by IR I see no problem.

Take all the places where you want to speak and change the logic so that it always runs through a script. That is, where you wanted to speak using TTS, write the phrase to a HS variable (HS.savevar) and call a new function called the speaker function, or insert the speaker function in-line. In the speaker function, Power up the amp if necessary, wait an appropriate amount of time, switch the preamp inputs wait an appropriate amount of time, get what to speak (hs.getvar), speak the string, switch back the preamp to where it was. The basic logic would require that the only control of the audio system was from HomeSeer, or there was feedback so homeseer always knew the state of the preamp/amp.

It is definately doable, since I do a similar thing for my house but do not use homeseer. My whole house audio system makes anouncements like what playlist is playing, what Sat radio station is playing etc. It uses the HT control PC to speak the phrases. and does the switching as described.

[DC]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR> The basic logic would require that the only control of the audio system was from HomeSeer, or there was feedback so homeseer always knew the state of the preamp/amp. <HR></BLOCKQUOTE>

This would present a problem. HS can tell whether the amp is on or off because I have a small transformer plugged into the switched outlet that triggers an Ocelot input. The main purpose of this is so that HS can power it off when we leave the house.

However, HS does not know what input the amp is set to if it is on. I could have HS switch the input to the aux input for HS speech, but I don't know how HS would know what to switch it back to. That's a problem that had not occurred to me until I read your post. And it will not be possible to have only HS control THIS amp because I have several Niles wall-mounted keypads around the house that are used to control the whole-house audio system.

However, this is the reason I would like to have an amp that is dedicated to HS. But, I still have to have a way for two amps to feed the same set of speakers with an automatic switch to the HS amp whenever it presents a signal to the switch.

[sonypoolplr]

You could try using DPDT relays to attach both amps to the speakers. Just put the speakers on the common side of the relay. Then wire the speakers to the contacts, normal audio to NC and speech to NO. Then have HS open or close the contacts as needed. Here is a 16 relay panel and I think they have an 8 one is you don't need that many.
[URL=http://www.smarthome.com/2320.html

Rob

[George]

If you use the relay method, I really hope your amp has speaker blow impedance protection! Some amps dont like it when, under load, the impedance goes from 8 ohms to infinity.

[DC]

I would be afraid to use a simple relay to disconnect the speakers from the amp. Wouldn't that be essentially the same thing as running an amp with no speakers attached. I know that can damage amplifiers. Yamaha may well have built in protection for that but I'm not sure.

[Krumpy]

I have a amp for my Home Theater and another for the whole house audio. There is a line-level connection from each of the amps to eachother. The amp for the whole house audio is under strict HS control. I have created a system library script that manages all of its functionality and remembers its state. All of this is under touchscreen control.

DC, in your situation, you would have to purchase some device that can listen/sense all IR codes sent and then remember the current audio input on your receiver.

[collegeboyslive]

I too use the 16 relay switch box, however i solved the speaker inpiedance problem very simply
use and amp with a 70 volt speaker output

you basically use the same speakers just add a transformer at the spekaer.

presto, no more inpedance issues and no more volume issues, you can also set by using the transformers , differnt levels for differnt speakers, thus in a small room like the bathroom ( great for morning showers) you will set it to a lower leval than say the living room

any questions feel free to e-mail me

detail of setup in profile

[DC]

Collegeboyslive,

I don't understand how what you are suggesting would not cause a potential problem with my amps. If I use a simple relay to switch the speakers from one amp to the other, one of the amps will be feeding output to nothing. It would be just as if the amp were switched on with no speakers attached. Isn't that bad for an amplifier?

I have found this switch that might be a solution:

http://www.rdlnet.com/stssr1.htm

The web site doesn't say so, but I have to believe the switch is more than just a relay. It seems that it would have to have some kind of circuitry to "absorb" the audio signal from the amp that is NOT being routed to the speakers. I am going to call the company tomorrow and ask them.

[Barry Gordon]

My electrical engineering is a little rusty. I haven't dealt with it in 50 years. By opening the output of an amp (that is removing the speakers), the amp sees an infinite impedance. Therefore there will be no current flow. Now what is going to blow? I can understand why you would not want to short the output, then the amp would want to drive all of the current it can and something would blow if there is no protective circuitry. That I understand.

Something in the back of my mind since voltage source vs current source. On a device that looks like a current source, you do not want a shorted output. On a device that looks like a voltage source I do not think you want an open output, but it would have to be a perfect voltage source (no internal resistance) Too hazy, I am getting too old.

The RDL device you are looking at is a line level switch not a speaker level switch. It should do what you want but the amp would have to be on. It is just supplying another input source (line level) to the amp. It will not switch speakers, or I should say will probably die trying.

[rocco]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Barry:
By opening the output of an amp (that is removing the speakers), the amp sees an infinite impedance. Therefore there will be no current flow. Now what is going to blow?
<HR></BLOCKQUOTE>

You are correct, Barry, after a few microseconds. The problem is that a speaker is an inductive load, and therefore current will not cease instantaneously. If current is flowing when the circuit breaks, the di/dt will cause a large voltage transient for a few microseconds. That spike could blow out the output of the amp.

I would aggree with Barry's assessment of the RDL unit as well. It sould do exactly what DC wants, with the TRIG input controlled by HomeSeer. That way, HomeSeer does not need to know what input is currently selected to the amp. It simply reverts to what it was before, once HomeSeer de-asserts TRIG.

It's looks like a nice device. Thanks, DC. I will probably order one to play with.

mark

[DC]

So, if this is a "line level" switch, that means it switches the source going TO the amplifier, not the output FROM the amplifier, correct? If so, then it won't work for my situation. I think what I really need is TWO amplifiers feeding one set of speakers.

[rocco]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by DC:
I think what I really need is TWO amplifiers feeding one set of speakers.<HR></BLOCKQUOTE>

Really? Maybe I misunderstood (it would be the ninth time today), but don't you want only one amp working at a time? Would you ever be using both amps at the same time? If you do need to use both, like one amp feeding one room and homeseer talking in another, you are correct. But if one amp is switched out completely while the other is switched in, I would think that saving yourself an amp, and switching at the amp's input would be safer, cheaper and more reliable.

The only way I have ever seen speakers switched in & out is the way collegeboyslive mentioned, using an amp with a 70v output and a transformer at each speaker. But I'm still a caveman when it comes to audio equipment. I'm using old Phase-Linear and Heathkit stuff (anyone know where to get nixie tubes?) - mark

[Barry Gordon]

Rocco, Those damm transients!!! Forgot that the speaker is an inductive load.

[Barry Gordon]

DC, I am in general agreement with the posts. You are better off switching the inputs. I am also willing to bet that the RDL units may be cascaded. They are very fast so you will miss nothing if you issue the trigger commands just before speech starts. Two RDL switches would give you three inputs, the two audio you have and the one HS speechoutput. To do the triggers you could use a couple of X10 units, but I would prefer something like a lynxport or other source of voltage or contact closures. the only issue I see is amp turn on when it is off. But you said you could sense that, and therefore could put a delay in the script of 5 seconds while the amp turned on. The RDL solution is nice since it will go back when done to whatever it was at.