Sennheiser EW300 Transmitter two mono sends

L

Lionel Miller

Freshman
Jan 18, 2011
20
0
0
United Kingdom
Hi,

I sure I read somewhere that you can run in to trouble if you are using one transmitter in stereo mode with to mono sources and the receivers are set to focus on left or right only. Something along the lines of if you get RF interference the signals can converge back together again?

Anyone running this successfully? Just thinking about using this technique to add a couple more mono mixes to an IEM system.

Cheers
 
Re: Sennheiser EW300 Transmitter two mono sends

The basic theory is that the second channel for stereo is kind of squeezed in upside down - and the way it's set up in standard stereo is that the regular channel is L + R, while the second channel is L - R. That way a mono receiver (which doesn't know about the second channel) gets summed mono, while a stereo receiver does a little summing math and ends up with separate L and R channels to give to the user.

The side effect of this is that if the transmission is somewhat compromised, the second (L-R) channel gets lost first. So that's the "it converges to mono" thing. In a hostile environment it's sometimes necessary to switch the IEM system from stereo to mono for more reliable operation.

As Andrew said, in practice it generally works just fine. You'd have stereo IEM users complaining a lot if there was a problem like that anyway. The rest of the question is just to be sure that your antenna situation is correct and that you've done your homework for frequency coordination.
 
Re: Sennheiser EW300 Transmitter two mono sends

Thanks for the replies guys. I have a four way rack of G3 300 IEM with the AC3 and an A2003 Paddle. Options would be buying another Transmitter and Receiver and using it with standard stalk antenna or getting two more beltpack receivers and keeping everything through the combiner. Good to know that it works successfully!

Cheers
 
Re: Sennheiser EW300 Transmitter two mono sends

Overall the biggest issue we have is users bumping the pack and changing the panning.
That said I was having a quick play with one of our systems yesterday and found that when I had a really strong signal sent a mix on one stereo side t would also show up in the pack of mix on the other stereo channel. Nowhere near full strength, but definitely enought to be annoying. Need to have more of a play with it though.
 
Mike Bakere is absolutely spot on, there is definite cross talk between Left and Right, make sure the signals have similar gain structures and levels and you can get away with it, great little cheat to get onto the EW300 system.
 
Almost all bases are covered with the previous answers.

It all comes down to a 2-mono-focus-setup being a last resort.

There are hostile environments that keep disturbing the stereo transmission, resulting in the receiver getting only a mono mix and "swishes" that are not nice.

I would recommend using another transmitter, even when it can't be used through the antenna combiner. I would put that extra receiver on a distant frequency (maybe even in another band) and seperate the antenna from the main Tx antenna.
 
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