Locally muting a PZM-11

[Bill Brower]

I am delving into whole house VR (thanks to Paul) and I have 3 PZM-11s on the way. I haven't decided on 'leave them on always' (probably not), 'attention command', or 'Enterprise style' (push to talk).

Either way, I think I should make it so I can locally mute each PZM-11.

Should I interrupt the + AUDIO, - AUDIO or the GROUND?

If I had them I'd just try it. I experiment with caps if I get the BUMP sound over the speakers.


Thanks everyone, Bill

[CaymanIslandCarpediem]

This doesn't really answer your question and you may already be aware of this, but here goes anyway ;-)

What are you connecting these mics to? I've just purchased a Gentner AP800 off Ebay for about $100 (likewise because of Paul's posts on VR). I'll have to play with this to see how well it all works but my plan was just to use its mic gating features so the AP800 would basically automatically mute the mics.

I'll be following this thread though as knowing how to physicially mute the mics locally would be interesting if my plans don't work quite like I was hoping ;-)

[Bill Brower]

I have an MPA II.


Gating only mute mics if the threshold at that mic isn't reached. TV and radio will sometimes trip that threshold and obliterate other mics.

[CaymanIslandCarpediem]

I am hoping to feed my home audio into the AP800 so it can cancel out that noise but again I have NO idea how well it will work ;-) I don't know if that cancelation happens before the gating (in which case it may work) or if the gating happens first (in which case its probably going to have issues). I've got a feeling my hopes for having this fully automated may not be that realistic. If you find how to mute the mics locally please post it as I'm sure I'll end up needing something similar ;-)

Cheers!
Tony

[jon00]

Bill,

IMO, the best way to mute mics is to short together +Mic & -Mic for a balanced system and Mic & Ground if unbalanced. This will prevent any induced noise entering the microphone stages of the pre-amp.

[gcyeaw]

Bill,
The phantom power is supplied by placing the + voltage on both the + and - leads and the negative power on the ground/shield. If you open the ground at the mike end you will cut the power and effectivly cut the mike output. I don't know, however, if there will be a pulse (bump) when you energise the mike.

A second alternative, although I don't know enough to suggest trying it wihtout more information, is to short the + and - audio leads together (not to ground) at the mike. This should silence the mike output. But as I said, don't try it until you have verified it will not damage the mikes internal preamp.

[Bill Brower]

Here is what I surmise based on the little experimenting I have been able to do:

I have one mic hooked up now to a backup HomeSeer. It mis-triggered on a lot. That is with the accuracy cranked to max.

1) If you crank up the gating threshold to very high, you will have to speak within 2 feet of the microphone.

2) If you use attention phrases (which is what they seem to do on HA shows), that takes longer to do simple things.

3) You can use Enterprise style with an enable button at the mic.

I think I will be using a combination. During the night when everything is off, I'll us an open mic in the bedroom since the house will be silent.

[jon00]

A second alternative, although I don't know enough to suggest trying it wihtout more information, is to short the + and - audio leads together (not to ground) at the mike. This should silence the mike output. But as I said, don't try it until you have verified it will not damage the mikes internal preamp.

No damage will result. The majority of pre-amps are AC coupled (via a capacitor). Even if it was DC coupled, the offset voltage would have to be virtually zero, otherwise the diaphragm of the Mic would be polarised in one direction and it would not work!

[Bill Brower]

PZM-11s run on phantom power provided by the MPA II mixer so I am shying away from shorting.

I'm not worried about the bump since when the Windows mixer volume out of the line out is muted I don't think it'll bump.

Plus, maybe bridging a capacitor across will mellow the bump but let the signal pass.

Bill,
The phantom power is supplied by placing the + voltage on both the + and - leads and the negative power on the ground/shield. If you open the ground at the mike end you will cut the power and effectively cut the mike output. I don't know, however, if there will be a pulse (bump) when you energize the mike.

A second alternative, although I don't know enough to suggest trying it without more information, is to short the + and - audio leads together (not to ground) at the mike. This should silence the mike output. But as I said, don't try it until you have verified it will not damage the mikes internal preamp.

[jon00]

Bill,

The Phantom power +ve is fed up both the Mic+ and the Mic- while the negative is sent on the ground. If any voltage is placed across the mic capsule, it would be destroyed.

Shorting is the correct method...I spent around 5 years in the audio field - just did not want to admit it!

[Bill Brower]

Shorting is the correct method...I spent around 5 years in the audio field - just did not want to admit it!

OK, now I'm convinced, thanks for your help sir.

Bill

[Bill Brower]

Bill,
The phantom power is supplied by placing the + voltage on both the + and - leads and the negative power on the ground/shield. If you open the ground at the mike end you will cut the power and effectivly cut the mike output. I don't know, however, if there will be a pulse (bump) when you energise the mike.

A second alternative, although I don't know enough to suggest trying it wihtout more information, is to short the + and - audio leads together (not to ground) at the mike. This should silence the mike output. But as I said, don't try it until you have verified it will not damage the mikes internal preamp.

Thanks for your help too, it'll be a couple of weeks then I'll hopefully have an update.

[gcyeaw]

Bill,
Here is a site with a 'popless' solution for shorting the pins.
http://www.prosoundweb.com/install/s...poponoff.shtml