Wireless drop-out? at DVinfo.net

Bob Harotunian · October 27th, 2006, 12:17 PM

We've been using Samson UM32s for several years and they have performed flawlessly. However, at a recent wedding, we had a few drop-outs from the groom's mic. I noticed that they happened when he turned away from the camera even though he was maybe 25' away.

I was wondering if his size had anything to do with it since the guy was very wide, so to speak. Does this sound normal or could the unit be failing?

Thanks for any thoughts,
Bob

Waldemar Winkler · October 27th, 2006, 06:02 PM

Possibly. I know from experience body density can impede radio frequency transmissions just like any solid object. However, I would guess there were a number of factors that in combination caused your dropouts. The density of one human body usually isn't enough to cause your malady.

Some of these culprits could be:
1. Worn out cable. Lav mic cables are very thin and subject to a lot of twisting and turning and stress. Eventually a cable weakens and the wires within begin to separate. You can't see this because the cable wrapping is far more flexible than the wires. Eventually a wire will completely break and you have a dead mic. Until this happens you are subject to intermittent breaks that re-connect as the body wearing the mic breaths and moves. The wires almost never break at the ends where they have stress relief connectors. It is always some where in the middle.
2. Transmitter gain set too low. Receiver mute/squelch set too high. I always set my transmitter's gain to maximum output. Mainly because that setting reduces the number of failure points I have to troubleshoot when a dropouts do occur (assuming I spot them during sound check). Receiver mute/squelch is there to narrow the receiver's sensitivity to radio frequencies just above and just below the specific frequency to which your reciever is set. Too narrow limits reception of signal drift. Too wide is an open invitation to infection from nearby broadcasts.
3. Antenna position. Since most wireless lav mics use the mic cable itself as an antenna it is a good idea to route the mic cable beneath clothing so only the cloth of the jacket/shawl is between the antenna and the antennas of your receiver.
4. Insure the antennas of your receiver are above the heads of the audience when seated. The combined body density of a hall full of people can indeed disrupt a wireless signal if the receiver's antennas are one to three feet above floor level. I've had it happen to me.
5. Then there are the odd things: Someone near you is broadcasting something on the same frequency, in the next building, perhaps? A mobile phone within a few meters of your location? A heating/air conditioning electric motor just start up?

The problem with wireless is that it is without wires, and other people nearby are using the same technology. Just about anything is possible.

I'd replace your mic cables first, then wait and see what hapens.

Bob Harotunian · October 28th, 2006, 06:56 AM

Thanks Waldemar...great answer. Because of this groom's "robust" size, I was thinking that the antenna may have been bent a little in his inside pocket. I hope it's not the mic cable since I've had a hard time finding a good 3 pin replacement lav for the Samson in the past.
Bob

October 27th, 2006, 12:17 PM	#1
Bob Harotunian Major Player Join Date: Mar 2003 Location: Somerville, MA Posts: 360	Wireless drop-out? We've been using Samson UM32s for several years and they have performed flawlessly. However, at a recent wedding, we had a few drop-outs from the groom's mic. I noticed that they happened when he turned away from the camera even though he was maybe 25' away. I was wondering if his size had anything to do with it since the guy was very wide, so to speak. Does this sound normal or could the unit be failing? Thanks for any thoughts, Bob

October 27th, 2006, 06:02 PM	#2
Waldemar Winkler Major Player Join Date: Aug 2004 Location: Durango, Colorado, USA Posts: 711	Possibly. I know from experience body density can impede radio frequency transmissions just like any solid object. However, I would guess there were a number of factors that in combination caused your dropouts. The density of one human body usually isn't enough to cause your malady. Some of these culprits could be: 1. Worn out cable. Lav mic cables are very thin and subject to a lot of twisting and turning and stress. Eventually a cable weakens and the wires within begin to separate. You can't see this because the cable wrapping is far more flexible than the wires. Eventually a wire will completely break and you have a dead mic. Until this happens you are subject to intermittent breaks that re-connect as the body wearing the mic breaths and moves. The wires almost never break at the ends where they have stress relief connectors. It is always some where in the middle. 2. Transmitter gain set too low. Receiver mute/squelch set too high. I always set my transmitter's gain to maximum output. Mainly because that setting reduces the number of failure points I have to troubleshoot when a dropouts do occur (assuming I spot them during sound check). Receiver mute/squelch is there to narrow the receiver's sensitivity to radio frequencies just above and just below the specific frequency to which your reciever is set. Too narrow limits reception of signal drift. Too wide is an open invitation to infection from nearby broadcasts. 3. Antenna position. Since most wireless lav mics use the mic cable itself as an antenna it is a good idea to route the mic cable beneath clothing so only the cloth of the jacket/shawl is between the antenna and the antennas of your receiver. 4. Insure the antennas of your receiver are above the heads of the audience when seated. The combined body density of a hall full of people can indeed disrupt a wireless signal if the receiver's antennas are one to three feet above floor level. I've had it happen to me. 5. Then there are the odd things: Someone near you is broadcasting something on the same frequency, in the next building, perhaps? A mobile phone within a few meters of your location? A heating/air conditioning electric motor just start up? The problem with wireless is that it is without wires, and other people nearby are using the same technology. Just about anything is possible. I'd replace your mic cables first, then wait and see what hapens. __________________ Waldemar

October 28th, 2006, 06:56 AM	#3
Bob Harotunian Major Player Join Date: Mar 2003 Location: Somerville, MA Posts: 360	Thanks Waldemar...great answer. Because of this groom's "robust" size, I was thinking that the antenna may have been bent a little in his inside pocket. I hope it's not the mic cable since I've had a hard time finding a good 3 pin replacement lav for the Samson in the past. Bob