Phantom power question

[jdsdj98]

I asked this question over in the Live Sound forum, but it never got answered, so I thought I'd try here.

I do live sound in a sports facility here, and for national anthems preceding games we use a pair of wireles Beta 87A's (hypercardioid) on the field, regardless of whether it's an individual or a large choir. Fortunately the powers that be realize that a hypercardioid mic is less than ideal for mic'ing a choir and seem open to the possibility of picking up a pair of LDC's (probably AKG C3000's) to be used for large groups. Obviously, these would have to be hard wired. All of my mixer inputs are in the patch bays, so I'd be patching from the input panel on the field at anthem position into 2 mic in's on the mixer. I feel like I should know the answer to this already, but how is phantom power handled in this situation? Can it be passed down patch cables through a patch bay to the mic's on the field? Or am I missing something obvious here? I've never had anything but XLR cable between my mixers/pre's in my experiences in the past, and this one has my scratching my head as I look at the patch bays.

 

[vinniesrs]

I don't think you should have an issue with phantom power, as long as you are using 3 conductor patching. If it's a very long distance, then you might have an issue with cable capacitance, but that probably wont degrade the sound bad enough to be noticed in your situation, unless you are recording or broadcasting.
I don't know what kind of length of cable you are using, but there could also be minor effects on the supply of power. Off the top of my head I don't know the answer to this last concern, it may even be too minor to worry about, but if you give me some info I'd be happy to let you know if it's an issue.

 

[Kurt Foster]

Yes it will work if you use a balanced patch bay and cables, however you are going to get on hell of a thump/pop sound when changing the patch.

 

[jdsdj98]

Thanks guys. Yes, the patch bays/cables are balanced. I'd guess there'd probably be 300-350 ft. of cable between me and the mic's. It's a new stadium, and everything was wired in during construction, so it's hard to know exactly. I'll know well in advance whether it's an individual or large group doing anthem, so I'll have the patch set way ahead of time, and then those inputs will be closed immediately following and will remain closed throughout the game, so thumps/pops won't be an issue at all.