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#23511 - 04/24/13 12:39 AM SpeakEasy speaker buzz on every X10 command.
John Warner Offline
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Registered: 01/09/03
Posts: 834
Loc: Port Perry, Ontario, Canada
I have a buzz in the speakers attached to my SpeakEasy that I just noticed corresponds to every X10 command. It's fairly faint so is only noticeable at night. If a sting of X10 commands is issued, you can hear each one of them - buzz, buzz, buzz, buzz.

I'm not 100% sure when this started but I don't think it has always done this? My setup is now 13 years old.

The speakers are regular amplified PC speakers connected to the SpeakEasy MON OUT jack and are AC powered so I suppose the buzz could be unrelated to the SpeakEasy? Since there are 3 pairs of PC speakers located throughout the house and all of them buzz that seems unlikely?

None of my other AC powered PC speakers (attached to PC's) do this.

I've always just assumed the buzz was coming from the SpeakEasy perhaps due to a bad capacitor but as I think about it more there could be other possibilities? The SpeakEasy is also AC powered so it could be a power supply issue there as well?

Any suggestions on how to isolate the cause?

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#23512 - 04/24/13 05:56 AM Re: SpeakEasy speaker buzz on every X10 command. [Re: John Warner]
Guy Lavoie Administrator Offline
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Registered: 12/21/02
Posts: 6548
Loc: Montreal, QC, Canada
Hi John.

To know if it's the Speakeasy you could try disconnecting the speakers from it (but leave the speakers turned on) and then see if you still get the buzz.

Are your X10 commands being transmitted as RF too with some kind of transceiver? That's a type of rf interference that an amplifier could pick up as induced noise. If it really appears to be the Speakeasy, you could try adding a 0.1 uF capacitor across the DC power in the Speakeasy (after the built-in rectifier diodes) to see if that helps.
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#23513 - 04/24/13 08:39 AM Re: SpeakEasy speaker buzz on every X10 command. [Re: Guy Lavoie]
John Warner Offline
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Registered: 01/09/03
Posts: 834
Loc: Port Perry, Ontario, Canada
Hi Guy, long time!

Thanks for the advice, I'll give it a go!

These X10 commands are coming directly from the Ocelot via one of Jeff Volp's XTB's.

This buzzing has been going on for a long time but I only noticed last night that it coincides with X10 commands. I just happened to have my Elk ESM1 plugged in beside me for another problem I was looking at and noticed the connection.

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#23514 - 04/24/13 09:13 AM Re: SpeakEasy speaker buzz on every X10 command. [Re: John Warner]
John Warner Offline
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Registered: 01/09/03
Posts: 834
Loc: Port Perry, Ontario, Canada
I unplugged the audio from the SpeakEasy to the speakers and the buzz goes away so it appears to be originating with the SpeakEasy.

Since I assume there is nothing put on the ADICON Bus for X10 commands I guess it must be coming via the SpeakEasy power supply? As you probably know the SpeakEasy, unlike most modules, uses a 12vac supply

This SpeakEasy was just in for repair at ADI less than a year ago (May 2012) for a different problem. I do know the buzz has been there for many years but I don't know if it was resolved temporarily after the repair or not?

Is this likely to be a capacitor in the SpeakEasy that's gone bad or could it be the AC wall wart?

Without a circuit diagram it's not obvious to me where I would insert a 0.1 uF capacitor across the DC power in the SpeakEasy?

This problem is mildly annoying but not enough so to be without my SpeakEasy for another 4-6 weeks to ship it off to ADI again.

Canada Post also seems to like to penalize us with exorbitant shipping cost to the US. Between the repair costs and shipping costs last time I could have purchased a new SpeakEasy for just a few dollars more.

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#23515 - 04/24/13 09:48 AM Re: SpeakEasy speaker buzz on every X10 command. [Re: John Warner]
Guy Lavoie Administrator Offline
Beyond All Hope
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Registered: 12/21/02
Posts: 6548
Loc: Montreal, QC, Canada
It comes either through the power supply, or is picked up as rf interference. Since you mention using the XTB, that device might be the source of it. It amplifies the X10 signals to beyond normal levels and might not have the complete rf shielding that would be required for a UL type approval. But since the XTB is a straight plug in unit, just try removing it temporarily and test again for the noise. If that solves it, then try relocating the XTB or the Speakeasy farther away from each other...
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#23516 - 04/24/13 11:03 AM Re: SpeakEasy speaker buzz on every X10 command. [Re: Guy Lavoie]
John Warner Offline
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Registered: 01/09/03
Posts: 834
Loc: Port Perry, Ontario, Canada
Hi Guy!

The XTB is hard-wired into a dedicated double pole breaker so it covers both sides of the split phase. It also repeats any X10 commands it sees from other sources.

I turned off its breaker and the buzz goes away but, of course, so do all the X10 commands generated by the Ocelot.

With it still off, if I generate an X10 command from an RR501 or an old CM11A there is no buzz.

The XTB is located in the basement next to the Breaker Panel and the SpeakEasy is upstairs and at the opposite end of the house so I don't think it's an RF problem?

So, clearly it is the XTB causing the SpeakEasy to buzz along with every X10 command!

That explains why it just seems to have started several years ago for no apparent reason. The reason is now apparent, I added an XTB.

I just tried inserting a plug-in X10 filter ahead of the SpeakEasy AC Walwart and that does not appear to have made a noticeable difference?

So, I guess the question remains, is there a solution or do I just live with it?

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#23517 - 04/24/13 11:37 AM Re: SpeakEasy speaker buzz on every X10 command. [Re: John Warner]
Guy Lavoie Administrator Offline
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Registered: 12/21/02
Posts: 6548
Loc: Montreal, QC, Canada
 Originally Posted By: John Warner
...The XTB is located in the basement next to the Breaker Panel and the SpeakEasy is upstairs and at the opposite end of the house so I don't think it's an RF problem?


Well, think of the what the XTB is doing: amplifying a 120 kHz signal and superimposing it on the power line...so your whole house wiring becomes a broadcast antenna. I think the XTB is a great device and keeps X10 usable in an otherwise hostile electrical environment, but if I remember right the original X10 signal levels were limited by some regulatory requirement, which the XTB is likely not observing. This leaves you to finding a suitable workaround. I'm 90% sure that the Speakeasy is picking it up as rf noise. One thing that should be easy to try: wrap the speakeasy in tin foil and then ground the foil. If that eliminates the noise or audiably reduces it then you're on the right track to pinpointing the source.
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#23518 - 04/24/13 12:10 PM Re: SpeakEasy speaker buzz on every X10 command. [Re: Guy Lavoie]
John Warner Offline
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Registered: 01/09/03
Posts: 834
Loc: Port Perry, Ontario, Canada
Makes sense...

I'll give that a go another day since everything is mounted neatly in a hidden wiring closet so it will take a little effort and I'm out of time for today.

I wonder if it's the SpekEasy itself that's picking it up or if some of it is coming from the AC Walwart & wire that is powering the SpeakEasy? I guess I could run it off a 12 volt battery as a test if the tinfoil doesn't work...

Thanks again Guy for the great (as usual) advice!

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#23519 - 04/24/13 12:44 PM Re: SpeakEasy speaker buzz on every X10 command. [Re: John Warner]
Guy Lavoie Administrator Offline
Beyond All Hope
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Registered: 12/21/02
Posts: 6548
Loc: Montreal, QC, Canada
\:\)

Let me know what you find out!

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#23520 - 04/24/13 03:25 PM Re: SpeakEasy speaker buzz on every X10 command. [Re: Guy Lavoie]
JeffVolp Offline
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Registered: 01/26/03
Posts: 185
Loc: St. George, Utah
John just contacted me regarding this, and I thought I should respond here.

The 120KHz superimposed on the home wiring is well above the audio range, so I'm having difficulty understanding how RF radiation of that signal could cause the problem. Since the noise is a "buzz", it is likely the envelope of the signal bursts that are coupling into an input stage somewhere. That requires the 120KHz to be rectified somewhere.

If any signal wires for SpeakEasy run adjacent to 60Hz powerlines, try separating them, and crossing at 90 degrees to minimize coupling. You also might try some small capacitors (1000pF or .01uF) to ground on the SpeakEasy signal inputs, but that might also effect the audio quality.

I assume your SpeakEasy uses shielded cables for signal runs. Make sure the shields are properly grounded.

The XTB does pull more power when transmitting, but I don't see the mechanism for that to couple into the SpeakEasy.

Jeff
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X-10 automation since the BSR days

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#23521 - 04/24/13 05:20 PM Re: SpeakEasy speaker buzz on every X10 command. [Re: JeffVolp]
John Warner Offline
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Registered: 01/09/03
Posts: 834
Loc: Port Perry, Ontario, Canada
Thanks Jeff, I'll let you know if I figure anything out!
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#23522 - 04/24/13 06:44 PM Re: SpeakEasy speaker buzz on every X10 command. [Re: John Warner]
Guy Lavoie Administrator Offline
Beyond All Hope
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Registered: 12/21/02
Posts: 6548
Loc: Montreal, QC, Canada
Hey, thanks to Jeff for chiming in.

Yes, my thinking is that the signal envelope gets demodulated somewhere in the speakeasy's amplifier circuit and sound like intermittent 60 Hz buzz. An unshielded amplifier in an ungrounded plastic box such as the Speakeasy would be prone to picking up this type of noise, much like high powered CB radio signals would get picked up by audio devices when CB radio was popular.

The thing with the Speakeasy is that there are no external "signal inputs" as such (other then when recording the original messages), since it generates an internal audio message from digitally recorded sounds. Adding small capacitors would involve soldering them between two chips in the unit itself (doable, but a bit more work).

I'm eager to see what the shielding tests with foil will show us.
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#23523 - 04/24/13 10:01 PM Re: SpeakEasy speaker buzz on every X10 command. [Re: Guy Lavoie]
JeffVolp Offline
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Registered: 01/26/03
Posts: 185
Loc: St. George, Utah
 Originally Posted By: Guy Lavoie

The thing with the Speakeasy is that there are no external "signal inputs" as such (other then when recording the original messages), since it generates an internal audio message from digitally recorded sounds.

I am not familiar with Speakeasy, and thought it was something like the DCS intercom system I installed here. (That doesn't pick up any X10 buzz.)

Since there are no external signal connections, moving away from any 60Hz power cables or enclosing it inside a grounded metal case are probably the only options.

I know about RF pickup. Back in the 70's a neighbor "Piledriver" had a linear amplifier on his CB rig, and his transmissions came in clear as a bell on our real-to-reel tape deck.

Jeff
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X-10 automation since the BSR days

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#23524 - 04/25/13 04:53 AM Re: SpeakEasy speaker buzz on every X10 command. [Re: JeffVolp]
Guy Lavoie Administrator Offline
Beyond All Hope
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Registered: 12/21/02
Posts: 6548
Loc: Montreal, QC, Canada
Jeff, the Speakeasy is a self contained adicon expansion module that allows you to record voice quality digital messages (either from an external audio source or a built-in microphone) and then play them back on command using the Ocelot's or Leopard's program logic:

http://www.appdig.com/adicon_new/html/modules.html
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#23525 - 04/25/13 01:47 PM Re: SpeakEasy speaker buzz on every X10 command. [Re: Guy Lavoie]
John Warner Offline
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Registered: 01/09/03
Posts: 834
Loc: Port Perry, Ontario, Canada
Thanks to both of you, I'm hoping to get a chance to try the tin foil tomorrow. In the mean time, I thought you might like to hear it?

SpeakEasy Buzz on X10 from XTB.

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#23526 - 04/25/13 06:30 PM Re: SpeakEasy speaker buzz on every X10 command. [Re: John Warner]
Guy Lavoie Administrator Offline
Beyond All Hope
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Registered: 12/21/02
Posts: 6548
Loc: Montreal, QC, Canada
That's pretty well what I was expecting, a few raspy bursts of 60 hz buzz.

But just think John... you might be the first person who has ever heard X10 commands!

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#23527 - 04/26/13 07:21 AM Re: SpeakEasy speaker buzz on every X10 command. [Re: Guy Lavoie]
John Warner Offline
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Registered: 01/09/03
Posts: 834
Loc: Port Perry, Ontario, Canada
So, here's the scoop!

Wrapping the SpeakEasy in tinfoil did not seem to make an appreciable difference in the volume of the buzz.

So, I experimented a little more and found that removing the SpeakEasy audio input cable which connects it to my old PC cuts the volume of the buzz by about 1/2. The audio input cable is only used on rare occasions when I need to change a SpeakEasy recording so leaving it disconnected is no big deal.

Note too that the PC it is connected to is rarely powered on as I only keep it around to connect to the Ocelot since it has a serial port.

It would appear that much of the noise is coming from the audio input cable or the powered-off PC it is connected to.

Bottom-line is I won't know for sure until I'm in bed tonight and all is quiet how noticeable the buzz still is but given it was only mildly annoying before I'm pretty sure it will be at an acceptable level now?

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#23528 - 04/26/13 07:40 AM Re: SpeakEasy speaker buzz on every X10 command. [Re: John Warner]
Guy Lavoie Administrator Offline
Beyond All Hope
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Registered: 12/21/02
Posts: 6548
Loc: Montreal, QC, Canada
Yes, any external cable would certainly be prone to picking up rf interference like an antenna. You might even try making a shorted plug that you could put into the audio input jack when it is not in use to see if it helps a bit more.
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