TV PRODUCTION Phasing Problems

Joined
Aug 23, 2004
Location
Canton, OH
I'm the Audio Engineer for a TV station in Canton, Ohio. I've been with this station nearly four years, and prior had a few years experience with FOH mixing for bands. Anyway, we've been using ECM-77s for our interview sets, but I've always had problems with the host mics picking up the guests talking nearly as well as it should the host (and vise versa). They sit facing each other approx. 6 feet apart, and often the host will bring his wife as hostess (another ecm-77) sitting in a chair next to the host, and often the guests do the same (total of 4 ecm-77s). All of the mics follow the 3 to 1 rule, and I've been using an Alesis 3630 comp/gate to help with this, but even properly set, the gate nearly clips off softly spoken guests (and the gate switching between open and closed is audible due to line hiss noise and is often distracting). I've also had the same problem with our audience monitors being picked up back in the mics, even when barely audible to the audience (of course this sounds like a reverberating echo). It seems like I should be able to use phase cancellation to totally eliminate these problems, right? How do major network talk shows pull off a huge audience that can obviously hear plenty well enough, but not show up in the "to tape" mix? Is there anything I can to eliminate the mics from picking up the other guests that you should only hear from there own mics?? Any advice would be a great help, thanks

Jonathan G. Phillips
Live Broadcast Audio Engineer
WDLI - DT39 Canton, Ohio
Trinity Broadcasting Network
www.tbn.org

PRODUCTION GEAR LIST:

Live Console: MACKIE 32.8
EQ: (Main EQ) Behringer DEQ2496 Main output, EQ, Limit.
I have a few others, one 16 band is on the audience monitors with ALL of the mid-low to low freqs. rolled off to compensate for little-NO studio acoustic treatment
Pre-amps: Yamaha PM2000 console (mic channel in, submaster out per mic. - this console also provides the phantom power for each mic)
Snake Length: 400ft Studio to Audio Both
Interview Mic type: Sony ECM-77
DSPs: Alesis 3630 comp/gate (one comp/gate per mic inserted, one comp/gate for submaster, one comp/gate inserted for main console out, Alesis 3630 to the Behringer DEQ2496 return to main out insert - mono out to tape / air)
 

mbenonis

Wireless Guy
Administrator
Premium Member
Joined
Sep 1, 2003
Location
Chicago, IL
That's a tough one. There are a few people here who might have some ideas on this problem (I sure don't :)), but you might also want to try asking the theatre-sound mailing list the same question. The list is filled with pros who have years working with sound and who might have some ideas as well.

http://www.brooklyn.com/theatre-sound/index.html
 
Joined
Apr 25, 2004
Location
Kelowna, BC. Canada
Two problems come to mind when I hear ECM-77 and the problems your having, both to do with your choice of microphone I'm afraid. The ECM-77 is an omni-directional condenser. Which in other words means it's designed to pick up everything from every direction.

Getting a new mic (A one minute browse of Shure's website and I came up with this: SM7 it has mainly what you're looking for: a cardoid polar pattern, and it's dynamic. So it will only pick up what it's pointing at, at fairly close range.

It's a matter of preference between dynamic and cardoid (better rejection versus lots of gain) but phone up a local music/audio shop and test different types out for a day.

Hope I helped, if I think of anything else I'll jump right back in.
 

Nephilim

Active Member
Joined
Jan 10, 2004
Location
Australia
RelativeMischief said:
It's a matter of preference between dynamic and cardoid (better rejection versus lots of gain) but phone up a local music/audio shop and test different types out for a day.
I think you mean directional and cardioid.

Dynamic is a type of element electronics, as opposed to condenser.

#1 think you want to do is get that studio acoustically treated STAT. (Well, after losing the omni lavaliers - take a look at the Countryman lineup, they're very shweet).

If you're getting line hiss, either lose the gate or soften its attack up by changing the depth or attack rate.

Consider not having room PA during recording until you can get the back wall treated. Once it is, use the absolute minimum PA to reach the back row, even less if you don't particularly care about the nosebleeds.