Sennheiser wireless frequencies - expert advice needed!!!

[jim_bass]

I have 2 Sennheiser EW100 radio mics and 2 x Freeport radio mics that i am trying to run in the channel 70 range.

The 4 recommended frequencies for the EW100 are:

channel 1 - 863.1
channel 2 - 863.5
channel 3 - 864.3
channel 4 - 864.9

The 4 fixed frequencies on the Freeport systems are:

channel 1 - 863.1
channel 2 - 863.7
channel 3 - 864.1
channel 4 - 864.9

I have tried manually tuning the EW100 to the same recommended frequencies as the Freeport to run them all.

i currently have set:

mic 1 (Freeport) - 863.1
mic 2 (EW100 belt pack) - 863.5
mic 3 (Freeport) - 864.3
mic 4 (EW100 handheld) - 864.9

Mics 1, 2 and 3 play nicely but when I turn on mic 4 it get picked up by mic 3's receiver and causes feedback.

My guess is that the EW100's have a wider frequency spread than the Freeports!?! So does anyone know how to calculate a frequency that will be far enough apart and will not go outside of the channel 70 band or interfere????

[crez5150]

The frequencies are too close... it won't work. What generation system are the EW100? If they are G3 you can get six frequencies at a push running in the de-regulated band (I'll need to dig out a chart) but if they are G2 or G1 then you're out of luck. you can still run 4 frequencies on de-reg band 70 but that's it. You'll need to re-tune to channel 38 if your kit allows but you'll still need licensing

[jim_bass]

The EW100's are both G1. They won't run on channel 38 as they are too old I believe.

So am i right in thinking that 4 EW100's will run on channel 70 or 4 freeports will run on channel 70. BUT I can't use a mixture of the 2 and still have 4 mics running?

[crez5150]

you are correct.