Stereo Mic
 

I'm thinking about getting a MKH 418-S Sennheiser stereo shotgun mic to use on my XL1.
My question is how do I end up with a stereo signal with one mic going through one channel?

Michael,
It will actually be using two channels.

Doesn't the MKH 418-S require phantom power? You will need an appropriate accessory to power the mic.

As a point of information, there are battery powered single point stereo mics available as well. Thay can connect directly via the MA-100/200. Some modest cost models come with a stereo mini-phone plug.

Stereo Mic
 

Thanks for your responses.

Ken,
Yes but how does it do that with only one connector?


Don,
Mabey, but I know that some mics have internal compartments for AA bateries as their power source. I looked at the specs but could not determine this.

Michael Hamilton
 

OPPS!
Sorry Don
I was'nt paying attention to the 2nd line in your post.

Check http://buy.sennheiserusa.com/ASP/Sen...df/mkh418s.pdf
Looks like it requires 48-volt phantom power with no battery option. Polar pattern is very tight above 4 kHz.

How do you get two channels out of one connector?

The connector used for that purpose is a 5 pin XLR.
I'm not sure about this mic, but its a good guess. You will have to
buy or make an adaptor cable that goes from a 5 pin female to two 3 pin
male XLRs. You may also need stereo phantom power if 418 doesn't
have on board batteries. If so, I suggest the beachtek DXA-6.

My AT-825 has a 5-pin XLR on the mic and came with a cable that has the 5-pin on one end and a pair of 3-pin xlrs at the other end.

That's also how the AT822 is configured. One 5-pin XLR goes to the mic, two 3-pins lead to single-channel XLR connections.

Thought the AT822 was the single ended version of the AT825 with an unbalanced 3-pin XLRM output at the mic body, a 3.5mm stereo minin phone cable and a two mono miniphone output cable inthe package?

Sorry, you're correct Don. The 822 mic connects to a 3-pin XLR which then feeds two 3.5mm plugs. I've had XLR adapters on these plugs so long that I've forgotten that that's not how they were supplied.

Thank you for the corrections.

Hello,

Just a note, that the MKH-418s does not provide true L&R stereo putput but is actually a Mid/Side microphone. What that means is the mic has a cardioid capsule (mid) and a bi-directional or "figure of 8" capsule (side). To get tre L&R stereo, the microphone's outputs need to be connected to a "decoder" box which takes the two outputs(M&S) and converts them into a true stereo (L&R) signal. The benifit of the M/S technique is that it allows the user to widen or narrow the stereo field by varying their ratio. (I use two studio microphones in this configuration to record concerts with excellent results and great stereo seperation.

If you are looking to get a true Left and Right stereo sound (like that of the XL1s' on camera mic) on camera, you will need the decoder box. Sound Devices among others make this box.

An alternative would be the Audio-Technica AT835ST stereo shotgun mic. This mic contains an internal decoder circuit (switch selectable on the mic) that provides a Wide and Narrow Stereo pattern along with the M/S output. It does require phantom power to operate so a Beachteck or other XLR adapter will be requuired to power the mic. (Note to Canon... A Phantom Powered MA... adapter is badly needed!)

As far as the AT825 and AT822 are concerned... The AT825 is a stereo mic with a 5 pin XLR output that fans out to two 3 pin XLRM connectors (all balanced audio), whereas the AT822 haas a three pin xlr output connector to provide unbalanced outputs to feed either two 1/4" plugs or an 1/8" TRS connector. This mic is ideal for connecting directly to the stereo mic input on a cmcorder and the cable length can be extended by using a standard XLR mic cord. (However I would not go much beyond 25' of extension as it is high impedance signals and long cables are susceptable to interference.

Hope this long winded post helps.

Cheers

> ...(However I would not go much beyond 25' of extension as it is high impedance signals and long cables are susceptable to interference...

Actually, unbalanced does not mean a source is high impedance, although most high impedance sources are also unbalanced.

The AT-822 has a low impedance output (about 200 ohms).

The length issue relates more to the opportunity for pickup of stray electrical noise.

Thanks Steve,
Your reply was very informative.

Can anyone tell me; are stereo mics used for dialogue on narrative (dramatic) shoots? Seems to me that I'm hearing mono for dialogue on most of the movies I see. And if so, why ?


Michael

I would guess because of the surround sound mixing that's involved with movies. As your accustomed to hearing, dialogue comes out of the 'center' channel, while ambient and F/X are directed to other channels during the mixing process. The idea is to have your audio relative to the visual space being presented. Since most of your dialogue is coming from visual sources that are in the visual frame of the shot, it makes sense that you would also want the dialogue to project from that same source.

This is my best guess for this situation.