Hi All
We have two sennheiser EW2 radio mics and they are both set to the same frequency, will there be any problems when doing an interview with two people and having both mics using the same frequency.
Cheers Steve
You can have one mic and two receivers on the same frequency, and this even comes in handy sometimes, BUT you cannot have two transmitters on the same frequency - awful noises, strange results and a total mess result. One frequency per channel. Just change one to another frequency. Sennheiser provide build in sets of channels for exactly this purpose.
As Paul says - 'awful noises, strange results and a total mess result' - which is why, if you ever cover a wedding or similar event where someone (like the vicar) is already wearing a radio mic of their own it's imperative that you check frequencies with them before the event starts. Howling feedback is not something you ever want to deal with once things are underway.
robo
Confirming Robo's results - I forgot to do this the once. Ready to film the wedding and the groom coughed - came out through the church's pa system - A very quick freq change solved it.
I do lots of shows in theatres - On the seafront nearby were the National Lawn Green Bowls competition - loads of people in white, on a number of greens, with a PA system running to speakers all along the promenade. We had a Cannon and Ball show that evening, and the Bowls people went home about 6pm, but forgot to turn off their PA system, which was behind locked doors. Thousands of people got treated to 50% of the show - Bobby Ball's mic was on the same channel. We had started, so nothing we could do about it!
Sometimes, sharing channels can be handy - it lets you 'steal' audio from another persons system. So if there is already a radio mic being used, you can often set your receiver to their channel and record the audio.
Technically, there are small differences - mainly audio deviation, bandwidth and commander design - plus pilot tones, but you can switch this off, and get something. You will be told this is bad, and not to do it when talking of mixing brands or models, but I discovered many years ago that Trance receivers are complimentary to Sennheiser transmitters - the tech specs are similar apart from the companding ratio, but in this example, it works for you adding just a touch of compression, and sounds quite nice. The other way around is OK, but small differences in mouth to mic distance make a bit more difference as the commander is actually expanding the dynamics a bit - however, it's quite usable. It works well with Shure to Sennheiser too - but you need to look up the Shure channel number to frequency list, because the channel number isn't very helpful in telling you the frequency!
The absolute rule is that you must NEVER have two transmitters on the same channel - if they are reasonably close to each other then its a nasty warbling swoosh mess, but worse, if the two mics are separated, then the receiver tends to 'hear' just the strongest one, but then as the two mics move, the other suddenly cuts in and replaces the audio, when the other one becomes the weaker - you still get the swoosh noises in the background, but working out what is happening is difficult. Actually, once you have heard the co-channel interference noise, you will be able to recognise it instantly.
In my kit I have a scanner - programmed with all the usual channels I use, plus others from popular kit, and when I run multi-channel systems, this is a very handy way of being able to check each mic when you are wandering around.
Thanks everyone, I have moved channels on one of them.
Again this forum has come to my help. Keep up the good work.
Steve