My go to have a rant

[dfinn]

[RANT]Hi,

 

Can I just ask is it normal to run an active speaker off an internal battery on a gig, in my opinion thats quite a daft thing to do.

 

The reason I'm asking this is because a couple of months ago I was asked to do sound for an awards evening which, being a budding young technician agreed to. I was told all the kit would be set up ready for me by the in house techs which was fine by me.

 

So I arrived and sorted myself out, I was told by the event manager I could move bits and bobs around like the outboard rack and mixer so it was layed out how I liked which I did. I immediately got hassled by the in house tech asking me what I was doing, I explained and he went off in a bit of a huff, never saw him again.

 

The setup was run with 4 mackie tops (passive) off one amp daisy chained down the hall so there was two each side (used sort of like repeaters but with no delay unit) and then another pair of active speakers at the back (mains powered) with wireless receivers on.

 

then as a monitor I had a small full range cab with a transmitter on to give me something to hear and also to send signals to the speakers at the back of the hall. I was positioned on stage, in the wings so I couldn't hear what was actually coming out of the main speakers, only a monitor feed.

 

So we got halfway through the gig and during a singers piece my monitor begins to cut out intermittently, it sounded just like a radio mic but also the backing track was cutting out as well so it must be something else. I looked on the back panel of the speaker only to find no power lead and it being powered off it's internal battery, this battery was also powering the transmitter meaning the back speakers will also be cutting out.

 

I can believe this is the correct thing to do, I would never leave anything that could be mains powered sun off a battery.

[/RANT]

 

Thanks,

 

Daniel

[Hambone]

I really wish I could sometimes battery power my rear PA powered speakers. I'm going to use a Carlsboro Liberty system to get the signal there, but it's sometimes a hassle to find power.

[Bobbsy]

I'm sure your question is rhetorical...but obviously it's not normal at all!

 

The one time I ever resorted to battery powered speakers was once when I worked on an outdoor "promenade" performance of "A Midsummer Night's Dream" and hid some active, RF-fed "home hi-fi" type speakers hidden in trees. These were designed to work off a 12V supply from a wall-wart adaptor, but I found I could get a couple of hours from them using 4AH PAG camera batteries. They weren't being used for reinforcement purposes; rather to play some spooky effects at the audience from surprising angles.

 

But...for your application....HUH?

 

Bob

[Hambone]

Is there a reliable and safe inverter-style source to power my RCF ART-310As and Carlsbro Liberty receivers? (this, or something similar, with appropriate battery, for example.)

 

It's rear-channel source material, so the volume isn't huge in comparison to FOH.

[Bobbsy]

Well, from my hobby of narrowboating on the canals (rather than anything to do with theatre) I can recommend the Victron Energy range of inverters ( http://www.victronenergy.com/ ).

 

One thing to watch: a lot of cheaper inverters do not output a proper sine wave; rather, they give you a square wave. Square waves are acceptable in some applications but are not suitable for others....I don't know what the situation would be with your equipment, but I'd check if I were you.

 

Bob

[Hambone]

Perhaps this one would be more suitable.

 

It seems like I could build a case with the inverter and a battery to power each speaker and receiver.

 

Anyone using batteries/inverters for PA?