Couple of questions about lectern mics

[tastewar]

1. Pickup pattern. We have a couple of older mics currently (unknown vintage, etc.) that don't work too well, esp. with untrained speakers who might be off-axis. Looking around, I see very few Omnidirectional lectern mics. Should a reasonably good Cardioid mic be able to pick up most all speakers?

2. Condenser vs. Dynamic. I understand that condenser are generally preferred in this application, and my mixing board (Soundcraft MFXi) has phantom power capability, so I should be able to use Condensers. But reading the warnings in the manual gets me a little nervous. Specifically, it says, "DO NOT use UNBALANCED sources with the phantom power switched on. The voltage on pins 2 & 3 of the XLR connector may cause serious damage. BALANCED dynamic mics may normally be used with phantom power switched on (contact your microphone manufacturer for guidance)" Is there an easy electrical test (like with a multi-meter) to determine this?

[Ray A. Rayburn]

Originally Posted by tastewar

Looking around, I see very few Omnidirectional lectern mics.

They are rare because in many cases a directional mic gets you greater gain before feedback. If the mic is made with interchangeable capsules like the Shure MX418 and MX412 series, you can buy omni capsules to fit them.

Originally Posted by tastewar

Should a reasonably good Cardioid mic be able to pick up most all speakers?

Yes. An ideal cardioid mic will have a pickup angle of 131 degrees (-3 dB).

Originally Posted by tastewar

I understand that condenser are generally preferred in this application

Everyone wants a mic with a small head, and condensers are easier to make with a small head. With a few exceptions, dynamic gooseneck mics are only made for the very low cost market.

Originally Posted by tastewar

Specifically, it says, "DO NOT use UNBALANCED sources with the phantom power switched on. The voltage on pins 2 & 3 of the XLR connector may cause serious damage.

What they are warning about is plugging an unbalanced source like a guitar or other musical instrument (MI) output into a input with phantom power turned on via a simple wiring adapter, as opposed to via a direct box like you are supposed to.

It is also possible they are warning you that they cheaped out in the design of their phantom power circuitry and that the console itself might be damaged if an unbalanced source is connected with phantom power turned on. I hope that is not the case.

Originally Posted by tastewar

Is there an easy electrical test (like with a multi-meter) to determine this?

If a modern mic has an XLR male output connector you can be virtually certain it is balanced. The only exceptions I can think of are some 50 year old very rare mics.

[tdangelo]

Originally Posted by tastewar

1. Pickup pattern. We have a couple of older mics currently (unknown vintage, etc.) that don't work too well, esp. with untrained speakers who might be off-axis. Looking around, I see very few Omnidirectional lectern mics. Should a reasonably good Cardioid mic be able to pick up most all speakers?

Omni mics generally will not work in a sound reinforcement / PA application due to feedback. For sound reinforcement / PA cardiod is more common.

Originally Posted by tastewar

2. Condenser vs. Dynamic. I understand that condenser are generally preferred in this application, and my mixing board (Soundcraft MFXi) has phantom power capability, so I should be able to use Condensers. But reading the warnings in the manual gets me a little nervous. Specifically, it says, "DO NOT use UNBALANCED sources with the phantom power switched on. The voltage on pins 2 & 3 of the XLR connector may cause serious damage. BALANCED dynamic mics may normally be used with phantom power switched on (contact your microphone manufacturer for guidance)" Is there an easy electrical test (like with a multi-meter) to determine this?

Phantom power should only be used for balanced mics requiring it. These will typically have a three-pin XLR connector on them. Your cable to the console will then be FXLR to MXLR.

[tastewar]

Thanks for the good info, gentlemen.