Boundary microphones and a USB mixer

[GHarris]

Hi there,

This is going to be a long post, but basically I'm looking for any suggestions people can offer on what boundary microphone and what USB mixer to buy.

 

There's a pretty good chance that some the background info I give in order to guide the suggestions won't appear to make sense - where that happens please accept that it's probably just because I'm trying to give you the short version of the story!

 

Working as an IT Technician within a secondary school, we have, a few times a year events that take place on a stage in the main hall which need to be video linked to the gym at the other end of the school site.

 

The way this is done at the moment uses a network camera at the back of the main hall. A cheap, poorly suited microphone is plugged into it (1/8th inch jack). The microphone hangs down over the front of the stage and a long unbalanced cable is fed from it, along the length of the hall, to the camera. The audio we get from this setup includes a loud buzz and does not pick up sound from anywhere except the centre of the stage very well.

 

As a way of improving this we are looking to stream the audio separately from the video, so that we can use some different hardware and aren't restricted by the limited connections on the back of the camera. E.g. so that we can use phantom power and XLR connectors. So I am looking to buy a USB mixer and a couple of microphones. The USB mixer would connect to a PC and that PC would stream the audio over the network, separately from the video stream. (the video feed itself is adequate at the moment)

 

We don't have room in front of the stage, and in the instances where we need this Hall --> Gym video link we can't practically attach a microphone to everyone involved. The hall has a high ceiling and there's a large-ish gap between stage and walls. So we really have pretty much no choice but for the microphones to be hanging down from the ceiling.

 

An ex music teacher has suggested hanging two boundary microphones from the ceiling, mounted on two-foot-square Perspex screens (to provide a surface). So I'd welcome any suggestions for suitable boundary microphones.

 

I have been browsing this forum and, apart from the no-longer-available Crown PCC-160 being overwhelmingly recommended, I see mentions of this inexpensive boundary microphone coming up quite a lot. Is it really any good? The price seems too good to be true.

 

The music teacher also suggested the AKG C542BL:

http://www.studiospares.com/mics-other/akg...ic/invt/439860/

But this seems to have been discontinued, so I was wondering whether the cheaper (but seemingly otherwise identical) AKG CBL 99 would be an option.

 

Previously a local sound-and-lighting shop had recommended the Peavey PV-8 to us as a mixer. The music teacher I've been discussing this with recommended against it and said that there were better alternatives. But it appears that the one he suggested, the Behringer XENYX 1204USB, is out of stock here in the UK (and will be for a month or two). So I could use some suggestions of similarly priced (~£150) USB mixers that would have a similar feature set.

 

The quality level required from all this is not stellar. This equipment is only used a few times a year. While it's considered important on the occasions when it's used, it's primarily a matter of having something that *works* reasonably allowing those sitting in the gym to keep up with what's happening on stage in the hall... rather than it being a matter of trying to convey the best quality sound possible (though if it ends up sounding quite good it would be no bad thing!)

[paulears]

The Peaveys, Mackies and Behringers should do fine - the only thing to watch doing it this way is time aligning the final destination - these mixers have a quite short, but measureable delay, coupled with the natural delay of using distant mics (and I've got three of those cheap ones and they have been extremely good and VERY tough).

 

For this application - ultimate quality isn't the issue - so all you're really after is phantom power? so all the mixers you mention should be fine.

[GHarris]

Thanks for the quick reply. As it happens there's a pretty big delay on the video feed - about half a second - so there is plenty of headroom for any audio delays. I can use the software I stream the audio with to match up the delays in the audio and the video.

 

And yes, basically the mixer will be used to provide phantom power and connect two microphones with XLR connections to the PC (and possibly more connections on top of that, such as a direct feed from the main mixer in the hall for anything played on the speakers there).

 

I am pleased to see someone say that the Pulse microphones are good enough. Given that one part of the problem with the current setup is the sheer cheapness of the microphone we are using I was wary of spending too little this time.

 

Regarding the mixer, the music teacher had said that it can be frustrating not having linear faders (one reason he suggested the Behringer over the Peavey). Though I am not sure how much it would bother us for the limited purposes we have in mind.

[paulears]

You will be VERY surprised with the audio quality - for the price it's just silly, really.

[Unfathomable]

Regarding the mixer, the music teacher had said that it can be frustrating not having linear faders (one reason he suggested the Behringer over the Peavey). Though I am not sure how much it would bother us for the limited purposes we have in mind.

 

 

In my opinion, not having linear faders is only frustrating if you are operating it live, for a "permanent" set-up, pots are fine.

[bruce]

I'd look at capturing the audio using boundary mics, and taking the output from the mixer, padding it down a bit, and feeding it into the network camera. That way you avoid the need to configure a delay for synchronisation, and the video and audio will be available in the same stream rather than 2 separate ones. Make the front-to-back run balanced, and use a transformer to unbalance at the webcam end.

[GHarris]

You will be VERY surprised with the audio quality - for the price it's just silly, really.

 

Do I gain anything by choosing the AKG CBL 99 instead, then?

 

(Other than the convenience of being able to mount the boundary microphone using screws)

[paulears]

Just the gratitude of CPC for spending more dosh!

 

The thing with microphones that get used close in is that they have 'character' - while those optimised for distant pickup tend to have flatter responses, and the differences tend to be quite small - often just a nudge of the HF pot is enough to make them sound almost indistinguishable.

[ojc123]

To run a similar setup in school I have an ancient camcorder stuck on a bracket.

 

The AV out is ok for the purpose. It just goes through cables to the Green Room (though CAT5 is an option). It was put there as a temporary measure years ago and it's still there. The audio is compressed to bits but sounds ok. It copes with loud and quiet. The video quality is quite watchable. If we want to we put an operator on to follow the action. It certainly works well enough for what you describe.

 

Not perfect but perfectly simple.

 

BTW, the CPC boundary mics are VERY good value.

[GHarris]

Ah, I knew there was something I was forgetting to ask about.

 

I had been puzzled by how some boundary microphones are advertised as being cardioid (sometimes "half cardioid") and some are said to be omnidirectional.

 

I don't really understand how the difference between them would work in a boundary microphone. I thought that, generally speaking, boundary microphones were supposed to pick up sound in a very wide arc in front of them regardless.

[bruce]

Like all mics, they have polar patterns.

 

Omnis pick up sound equally from all directions. They're ideal to sit in the middle of a boardroom table to pick up all participants.

 

Others can be more directional - typically cardioid - and are ideal for front-of-stage.

[intyra]

I too have used the CPC boundary mics in question, and they are definitely good for the price.

 

Also, to add to your list of small mixers is the Allen & Heath ZED-10 - I'd probably (much) rather use it over the Behringer despite it having rotary pots rather than linear faders - the entire ZED series are very good value for money.