Voice Select Between Elk and Sound Card

[BraveSirRobbin]

I'm in need of a way to have a common voice announcement speaker distribution used for the Elk M1 Gold announcements as well as voice announcements from a HomeSeer computer (via its sound card output).

I'm using an Elk-800 amplifier with its output connected to four Elk Echo Speakers (for a total of two ohm load which is at the rating of the amplifier).

I needed to somehow share the input of this amplifier with the computer's sound card output and the Elk Voice Output #1.

To do this I arranged a circuit to have Output #1 be at a pre-amp level (saw an Elk “How-To†on this somewhere). I then used the on-board single pole double throw relay (Output #3) to switch between the two sources (Elk preamp output and the sound card output). Refer to attached schematic below for details.

I then adjusted the sound output of both the Elk M1 Output #1 and the computer as well as the overall gain of the Elk-800 amplifier so both voices were uniform while achieving desired volume at the speakers.

Then whenever I want the computer to take over the announcement system I just turn output three on before sending any voice announcements (no big deal, since the computer voice announcements are done via script anyways).

This works well, but there are three problems that I need some input and advice on.

First, I'm using the my.elk script for turning output #3 on and can only find a command for turning an output on for a limited time. Is there a command to turn it on without a timeout?

Second, there is a distinguished (i.e. not loud, but noticeable) "pop" during the start and end of all the Elk announcements. I know it’s coming from the Elk output #1 as I connected headphones right to that output (with nothing else attached).

I played around with various capacitors in the amp, speakers, elk, etc... but could not get rid of this.

Third, is there some way to enable and disable the Elk voice announcements so they only occur for a certain time of the day? I know I can write a rule to do this, but would rather not (I'm using 45 zones for this house).

I was thinking about using output seven via a relay to control the power to the Elk amplifier so it was turned on during the "daytime and evening" hours only. Is there a better way?

How is everyone else interfacing their HA voice announcements with the Elk announcements?

Thanks,

BSR

 

[BraveSirRobbin]

Ok, got the "on" command to the amp solved:

sub main()

hs.RunEx "my.elk.txt","output_off","7"

hs.RunEx "my.elk.txt","output_toggle","7"

end sub

Then for the "off" command I just used:

sub main()

hs.RunEx "my.elk.txt","output_off","7"

end sub

So I can setup an event to run these scripts in the morning and afternoon. Output seven would be connected to a relay that controlled 12 volt power to the Elk-800 amplifier.

 

[WayneW]

Third, is there some way to enable and disable the Elk voice announcements so they only occur for a certain time of the day? I know I can write a rule to do this, but would rather not (I'm using 45 zones for this house).

I am not aware of a way without using a rule. How is the number of zones relative?

You can create a simple rule:
Whenever ....
Then enable/disable non-alarm voice messages

 

[BraveSirRobbin]

You can create a simple rule:
Whenever ....
Then enable/disable non-alarm voice messages

Ah, I like your method much better Wayne!

Now, how to fix that "popping" problem!?!

 

[Digger]

Are the grounds tied together for the different systems? Maybe that is the cause of the popping?

 

[BraveSirRobbin]

Are the grounds tied together for the different systems? Maybe that is the cause of the popping?

Do you mean grounds as in signal path return or actual "case" grounds of the equipment?

I'll try making sure AC grounds are the same. I'm also going to order a cable isolator for the sound card output as shown HERE (towards the bottom of that page. Part number SISOL8R).

 

[Guy Lavoie]

You mention using double throw relays, so are you switching both conductors of the sound source? If you tied the commons together and only switched the actual signal, then the signal ground mentioned by Digger would be always maintained and might minimize or eliminate the pop.

To test it, just use a piece of wire to connect the signal commons together and leave the relay connections the way they are.

 

[BraveSirRobbin]

You mention using double throw relays, so are you switching both conductors of the sound source?

Per the attached schematic, I'm only switching the signal via one SPDT relay and have all commons tied together.

The problem is with the Elk itself. I can connect headphones (mono of course) to the new preamp output with nothing else connected and hear this pop.

How come I'm the only one having this problem? Surely all of you Elk M1 fans/experts have tried something like this! <_<

Curious how everyone else is using the Elk in conjunction with their HA machines.

 

[Spanky]

If you are capacitively coupled to the amp, you are hearing the voltage level shift when the output 1 on the M1 turns on and the relay closes.

Try shorting out the capacitor or taking it out of the circuit in the diagram you show. This may help the pop.

 

[BraveSirRobbin]

If you are capacitively coupled to the amp, you are hearing the voltage level shift when the output 1 on the M1 turns on and the relay closes.

Try shorting out the capacitor or taking it out of the circuit in the diagram you show. This may help the pop.

Tried that, the pop is coming directly out of the Elk Output (via the headphone test), but I will try to play around with various cap values.

I also tried shorting out the cap (in the schematic) with the same results.

 

[Spanky]

BSR:
Experiment with adding an 8 ohm speaker to Output 1, to see if that makes any difference with the pop.

 

[BraveSirRobbin]

BSR:
Experiment with adding an 8 ohm speaker to Output 1, to see if that makes any difference with the pop.

Tried it, but same results, pop still there (at same level) on the amplified speakers.

Of course the pop is not present on the newly added output one speaker.

 

[Digger]

I still think you have a problem with the grounds. Did you try tieing the system commons together so they are all referenced to the same point? I used to see this happen when putting differrent types of devices as inputs to a preamp or mixer years ago (microphone on channel 1, cassette deck on channel 2, and tuner on channel 3). If the commons werent tied together you heard a very crisp "pop" when switching the microphone on etc. Tied the grounds or sheilds together from the 3 devices cables and it would stop the "pop".

 

[BraveSirRobbin]

Did you try tieing the system commons together so they are all referenced to the same point?

Six posts up, first sentence in the "reply".

 

[Digger]

BSR,

Sorry I missed that. Wierd that it is ok with a regular speaker and not with headphones etc.

There are a few audio engineers where I work and if I have time tomorrow I will ask them.