Can you use two wireless transmitters with one receiver?

R

richmondfloyd

Active member
Hi,

I have a Sennheiser evolution wireless G2 set - inc one receiver and one transmitter. I've been searching online, but it is unclear whether I can buy another Sennheiser wireless transmitter and use one receiver for two transmitters.

I will be filming a training session shortly, where the delegates will be too far apart to use just one wireless mic. I have considered a omni-directional mic, but as I won't have a dedicated sound man, I think a wireless mic is the best option.
 
short answer.
no.


Only receiver to my knowledge out there that does
2 transmitters 1 receiver is the lectro SR


at least in the "pro" level
maybe there is a cheaper company that makes such a thing..but the G2 no.
 
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Two transmitters on the exact same frequency are going to fight with each other. The only thing the receiver will pick up is noise from the battle.

There are units from several manufacturers that house two receivers in one chassis (Audio Technica 1800-series, for example), but that's the only way to pick up two transmitters within a single "receiver" (even though that's technically two receivers).
 
Hmm, I suspected as much.

Although I did have a glimmer of hope as in the manual for the G2 it says...'when using several transmitters simultaneously, interference can be avoided by maintaining a minimum distance of 20 cm between two transmitters'

So if the problem is not that that receiver won't pick up two, but that the noise would be bad, then this might mean that the G2 is capable...?
 
No, it is not capable. Period.

The 20cm reference in the manual speaks of having multiple systems in operation... complete systems, each with transmitter and receiver. Again, the only way to receive two separate transmitters in one receiver box is to have the transmitters on separate frequencies and two receivers contained in the same chassis.
 
richmondfloyd said:
Hmm, I suspected as much.

Although I did have a glimmer of hope as in the manual for the G2 it says...'when using several transmitters simultaneously, interference can be avoided by maintaining a minimum distance of 20 cm between two transmitters'

So if the problem is not that that receiver won't pick up two, but that the noise would be bad, then this might mean that the G2 is capable...?
Click to expand...


No this means you dont want to use 2 transmitters on top of each other like it mentions. They are talking about if you have multiple systems running at once.
Easy example is 2x G2's on 1 person. Say there is a PA feed using a mic on him..
you put a mic on him for your recording. Put the packs on opposite sides of the guy.


More of an issue with a unit like the G2 would be a transmitter near a receiver.
IE: 4 receivers in the bag with 2 transmitters in the same bag for camera hops.
They aren't trackin front ends and would get a ton of interference.
 
Two radio transmitters on a single frequency would create a carrier wave interference problem where one transmitter will "step" onto another. The result is a weird tone laying over both transmitters.

That's why air traffic control and pilots keep transmissions short and sweet. More people can transmit their info in a given amount of time because only one transmitter can work on that frequency at a time.

You'll definitely need two separate receivers, or use the ATW-1800 which has two receivers built into a single unit. I've been using a couple of those for more than a year and it's been working great.
 
Ha, yes you can. But I have yet to see a TDM ( Time Domain Multiplexing) configuration for wireless audio applications. You really don't hear a CW tone with FM transmitters on the same freq. More of an AM condition.
Old time ham radio operator and broadcast engineer here....
 
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I know this is an older thread, but this is relevent to my situation today. I am doing audio for a tv pilot on a last minutes notice. The audio person who originally began the shoot ordered 1tx and 2rxs on block 24 and likewise for block 25. Now my thinking is that he/she did this since they had planned to use these two blocks for audio hops to two seperate cameras. Would this be a logical assumption? I am 99% sure this is possible. Can someone verify this for me?
 
richmondfloyd said:
Hmm, I suspected as much.

Although I did have a glimmer of hope as in the manual for the G2 it says...'when using several transmitters simultaneously, interference can be avoided by maintaining a minimum distance of 20 cm between two transmitters'

So if the problem is not that that receiver won't pick up two, but that the noise would be bad, then this might mean that the G2 is capable...?
Click to expand...


This is an RF question, and the setup would have two receivers for the two transmitters. The power emitted by the two transmitters can be so 'powerful' that they mutually pick up each other's transmssion, and fold the extraneous signal in to their own transmission, despite operating on different channels...

The result would be cross talk between channels.

Don't know how this would affect 'kissing/singing' duo performance on stage... but maybe they all just lipsync anyway...

In a digital system, don't think this is gotten to the audio wireless world yet, one could have a time division multiplexed (or CDMA...) transmitters and have the receiver separate things out...



... oops got sucked into an ancient thread...
 
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You'll be fine.

One receiver from each Blk would go directly to each camera so that each camera has both the Tx feed.

Cedric Akins said:
I know this is an older thread, but this is relevent to my situation today. I am doing audio for a tv pilot on a last minutes notice. The audio person who originally began the shoot ordered 1tx and 2rxs on block 24 and likewise for block 25. Now my thinking is that he/she did this since they had planned to use these two blocks for audio hops to two seperate cameras. Would this be a logical assumption? I am 99% sure this is possible. Can someone verify this for me?
Click to expand...
 
Thanks Alan. That's what I thought. I just needed to hear it from someone else. Now I'll just have to tell them there was no need to order to extra lavs unless they get two additional blocks of wireless systems.
 
Cedric Akins said:
Now I'll just have to tell them there was no need to order to extra lavs unless they get two additional blocks of wireless systems.
Click to expand...

It's potentially confusing if you just say "wireless systems." That implies that they need both transmitters and receivers. If they want to use those systems as four individual wireless lavs, they just need two more transmitters (one on block 24 and one on block 25, naturally). Or course that's assuming that the models you're using are frequency agile (meaning that you can have the different tx and rx operating on separate frequencies within the same block).
 
Hi richmondfloyd. I think also NO. Because it is not applicable to use two transmitter in only one receiver. But you have a good idea. I hope that there is someone who can invent two transmitter in one receiver. :D
 
pablowest said:
Hi richmondfloyd. I think also NO. Because it is not applicable to use two transmitter in only one receiver. But you have a good idea. I hope that there is someone who can invent two transmitter in one receiver. :D
Click to expand...

Digitally this has already been 'invented', there are a number of methods that could maintain a high bit rate, and have multiple mics with digitizers transmitting. The 'receiver' would be more than just a receiver, but more like an orchestrator of the ensemble...

The problem is that people seem to like maintaining the analog signal until it is received and processed perhaps via a mixer/pre-amp, then digitized...

One could also do some stuff in the analog world, but the additional circuitry would probably not be worth it, relative to just selling two boxes... Heck, TV just ended analog broadcasts which essentially had a 4 Mhz signal for the luminance, 2 MHz for chroma, and the 50K FM for audio... took up 6 MHz channels... and of course separate circuitry to process the respective signals...

As I recall the wireless mics use 100K FM bandwidth, or thereabouts.
 
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Simply - every transmitter needs a receiver and you cannot have more than one transmitter on a frequency without having serious nasties.

However, you can have as many receivers as you like listening to a transmitter.

An easy reason for having two receivers per transmitter is to record the signal simultaneously on two cameras.
 
There is not problem using a 2 TX with 2 Rx on a camer or with a double camera receivers.

I am assuming you are using professional stuff (means a super-etherodine or double conversion receivers).
In pro stuff you have nice ceramic filters with a bandwidth of more or less 200/250 KHz.

So the only thing is just put the 2 frequencies at least 300 KHz distance.

As per market availability:

Sennheiser 2000 (just a modified IEM) --> www.sennheiser.com
--> 1 channel antenna diversity - 75 MHz bandwidth
Sennheiser 3241 --> www.sennheiser.com
--> pro case with slot in - 1 channel TRUE DIVERSITY - 36 MHz bandwidth
Lectro SR --> pro case with slot in http://www.lectrosonics.com/Receivers/sr-series.html
--> 1 channel TRUE diversity or 2 channel antenna diversity - 25.5 MHz bandwidh
Wisycom MCR42 --> pro case with slot in http://www.wisycom.com/product.php?ID=48
--> 2 channel TRUE diversity - 240 MHz bandwidth - analogue and digital output
 
maxpolo said:
There is not problem using a 2 TX with 2 Rx on a camer or with a double camera receivers.

...
Click to expand...
True, but the original question was whether one could operate two independent transmitters on the same frequency sending to one, single-channel receiver. Not possible.
 
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