Problems with Sennheiser EW 112p G2 wireless mics.
 

Hello.

I've just bought the Sennheiser EW 112p G2 wireless mic system and have a couple of questions.

The receiver has a RF meter as well as a green light that goes on when an RF signal has been received, but nowhere in the manual does it say what significance is to be drawn from viewing this meter. What am I to draw from the fact if only two or three of its seven blocks are lit up? What if one or seven? Is it just sufficient that some reception is shown on the meter, etc.?

I've also found the manual confusing in other areas. I can adjust the receiver's "AF OUT". Here the manual says the default is "+18" but suggests "Lev -24" for "EK 100G2 +2...0...-30dB" (which is the receiver that comes with this system). What is it saying? What do these numbers mean exactly? What is the relationship between numbers, like +18 and -24 and setting a level for "EK 100 G2 +2...0...-30dB"? As it is, I'm just adjusting this setting till the reading on my camera's meter peaks in the -12dB range.

I'm having the same problem with the "SENSIT" adjustment on the transmitter. Here the manual says the default is "-10dB" then seems to suggest one set this number to "-30dB" to match "SK 100 G2 0...-30dB" (which is the transmitter that comes with this system). So what is this number on the Sensit screen supposed to mean? Is it supposed to mean the lowest level of sensitivity?

As with "AF OUT" all I've been able to do here is ignore these specific numbers and just adjust this figure up or down till the peak on the transmitters AF meter is at about the fourth block. (Even figuring that out took a little detective work. On the transmitter there is just a meter with seven blocks. No values are assigned to them. The manual I have attempts to simultaneously be a manual for the whole Sennheiser 100 series. In one place it shows the transmitter of another model. It has its seven blocks numbered -30, -25, -20, etc. It was on this basis that I've concluded that between the fourth and fifth block would be a peak of -12dB.)

Can anyone answer my questions? Is there any place on-line where those answers can be found.

Thanks.

John

John, it is a reference manual and not much of an operation manual at all.

Here are the general guidelines of setting up gain structure on wireless, they apply to the EW100 and to most analog wireless systems. Yes, I've used these methods on the EW100 and EW500.

1) Transmitter gain - typically, you do want loudest peaks to momentarily reach full scale on the transmitter meter (or, for some wireless, momentarily light an led). Notice carefully the word "momentarily". You don't want sustained full scale or a continuously lit LED.

There is inherent noise in the wireless signal chain, analog transmission wireless deal with this by a trick known as companding. For it all to work at its best, you want hot audio at the start, otherwise, you'll get less signal-to-noise.

2) Receiver RF meter - strangely little-known is the fact that the receiver will see more RF signal if its antenna is in the same orientation as the transmitter's. With the transmitter on a belt, this means that the receiver is optimally placed on a bracket that puts it vertical.

2a) Receiver RF LED - this indicates that the receiver is seeing enough signal to turn squelch off. Squelch is another trick typical of analog wireless systems. It's like a little automatic volume control. If it sees enough transmission strength it turns on the receiver AF output. If not enough signal, it turns off AF output ("squelches" it). This helps to prevent sound ops and camera ops from ripping off their headphones when an RF hit occurs and results in a huge burst of static on the channel.

3) Receiver AF output - usually, you'll start with this as hot as possible and see if your camcorder can accept this signal. For the EW100, which can put out line level, that means setting the camcorder to line-level input, placing the camcorder volume trim at about 50% and see if you're in the ballpark with peaks somewhere in the -6 to -15 range on the camcorder display. If too hot, start lowering the receiver output. Once you have the receiver output roughly set, you'll do further volume trims at the camcorder.

Some camcorders only have mic-level input, the EW100's output can be reduced to mic level, the same guidline as above should be used. If you have to crank the camcorder input volume way down and it seems touchy this is a sure indication that you're feeding it too hot a signal.

3a) Camcorder with autogain - sigh. Some camcorders don't offer manual gain control. Some operators are seemingly allergic to manual control, and if auto doesn't produce great results in all circumstances, they think that means there is something wrong with the camcorder. Sigh. I personally am very much opposed to such operational philosophies because the best autogain can't decided which audio it is that you really wanted, and, you don't really know what's going on tape. Those cam ops also never use headphones...

*If* autogain must be used, that usually means cranking receiver output down as you listen for overmodulation.

4) Finally, you need to do some reality checking - do the settings you've completed provide a good signal-to-noise ratio, how does the mic sound on headphones plugged into the camcorder? Most receiver/camcorder combos should sound better at line-level, but sometimes better signal-to-noise is found at mic level. You gotta' try it, and try several different settings to benchmark what settings will work best with your equipment.

Repeat as needed - try some other settings, get familiar with how it sounds when it sounds good, get equally familiar with how it sounds when it sounds bad, and always monitor with headphones!

See if this little video tutorial I threw together helps: http://link.brightcove.com/services/...bctid187745393

Also, try pointing your antenna's downward, on both transmitter and receiver. You can flip the clip as shown here http://vimeo.com/441881

A company by the name of bracket1 has a cool bracket for mounting the receiver vertically.

This tutorial saved my life couple of months ago. Thanks a lot Guy, yo da man!
Chris

Guy:

Thanks for the informative and helpful tutorial.

cheers

Thanks! Brightcove is no longer offering free hosting for small business so the above link is down. Only the big boys get to play at Brightcove "with plans starting at just $6000!" You can now find the Sennheiser wireless tutorial video now at

youtube YouTube - Sennheiser Wireless Evolution G2 Tutorial
vimeo Sennheiser Wireless Tutorial on Vimeo
dvcreators Sennheiser Wireless Tutorial at DVcreators.net