Topic: question about phantom power for mics....

[heyitsmejess]

can a mic that says it requires 48v phantom power run on less?

specifically, the mics are cascade m-39.

thanks in advance!

[DSatz]

Well, 48-Volt phantom powering allows for a tolerance range of +/- 4 Volts, but I suppose you mean voltages even lower than that. The answer is that many 48-Volt microphones will still put out a signal of some kind at lower voltages, but their headroom and dynamic range may well be compromised--in some cases quite drastically. You might find that the microphone seems to have lost sensitivity, gained noise, and that it overloads badly on loud sounds. During a live performance is NOT when you want to be finding that out.

There are plenty of microphones that can operate on any of a wide range of voltages (e.g. 9 - 52) without loss of performance, though generally those are really 12-Volt phantom-powered microphones that can tolerate the higher voltages, and that simply throw the extra energy away as heat.

In any event no sane manufacturer would ever claim that their mike needs 48 Volts if it really doesn't, since that would be to their disadvantage in terms of sales. So if they say it, I suggest that you believe it (or act as if you believe it) unless there is solid evidence to the contrary.

--best regards

[John Willett]

can a mic that says it requires 48v phantom power run on less?

DSatz said it.

The normal tolerance is +/- 4V - but don't even try it on less.

Yes, they may work (of a sort) at a lower voltage, but you lose the transient response and the quality drops.

[ghellquist]

There are a three standards for phantom power that I know of, 48V and 12V and the very rare 24V. These standards gives the working conditions for the mics as a range of allowed values. It is sort of like comparing to the fuel you put in your car -- unleaded down to 85 Octane might be ok but the car will be hurt be beeing fueled with diesel.

From that point it is rather easy to understand that no mic manufacturer will specify that "this mic will work with non-standard voltages" as how could anyone really know what these non-standard voltages really will be.  Sometimes this can be "read" out of the schematics of the mic by an experienced person rahter easily. There is a quite often used schematic which will work down to about 20V without large problems, but will definitely not work on 12V. There are other mics that will start behaving really unpredictable (no sound or oscilattions) below around 40V. The only way to find out really is to test it with the mic in question, using the actual voltage you want to test with.

Regardless, with most mics (not all though) a gradual decline in sound quality as the voltage is decreased. This might show up as increased noise and/or lowered maximum sound level befor clipping or simply as increased distortion. Distortion can be perceived by people in different ways, some even preferr a distorted sound to a clean sound so nothing is really simple when it comes to sound.

Sometimes these tests has been done by other people -- so if you state what equipment you want to run those Cascades with perhaps someone has that specific answer.

Gunnar