Dealing with echo/large room

Deaden the walls with absorption materials, like sound blankets, or moving blankets.

Anything that breaks up big flat hard edges will cut down echo. High ceilings are actually a bit of a blessing because you can hang a bunch of blankets and whatnot staggered around the room up above out of sight.

If you're not seeing the floor, throw blankets or carpet remnants under the actors too. You probably won't be able to totally eliminate the echo -- nor will you want to because then you'd be all the way at the other extreme with a lifeless dead sounding room. Worst case scenario, get the best quality recording you can on set, then do some ADR work to rerecord the audio in a better sounding room, and apply reverb as needed to make the ADR sound like it belongs in the picture.

I'm not sure if it's still a current model, but the Audio Technica AT-3031 microphone is good to use in reflective rooms. It has a nice "dead spot" when it comes to reflections coming back from anything but the front. It is my echo room mic. Originally recommended to me by a sound guy.

If that doesn't work out, the suggestions by Will and Indietalk are excellent.

Anything that you can use to deaden the room will be a help - carpeting on the floor, sound/moving blankets (even quilts/comforters), pillows, curtains, couches; anything that will absorb sound. Hang the blankets, whatever, on C-stands as close to the shot as you can. If your shots permit it try to work in corners to minimize the amount of acoustic "bounce".

Although its contrary, you may want to boom from underneath to avoid the hard floor reflections, and to take advantage of the high ceiling which probably has acoustic panels.

Your best option would be lavs on the talent, or as Scoopicman suggested a non-shotgun mic, as shotgun mics actually make the roomy/echo sound worse than it really is due to their off-axis rejection.

All good advice here...but one if i had no other chose because of being lit out of a shot, would i boom from below...if its not in shot...throw a mat under the actors...

using a shotgun indoors is never your best chose...there are too many reflections for a shotgun to work indoors...the ports on a shotgun are there to allow sound in and cancel it, but in a room when it will be reflected sounds it will only amplify the reflections make your situation worse...just go with a hyper indoors if you have one. While lavs will give you signal to noise...they are not going to give you better quality.

your problem in an echo room is not noise...but the actual sound of the actors and other than deadening the room, there is not much more you can do.

now given that you are shooting in a big room and this is what big rooms sound like...its really not a big deal if you see that its a big room on camera...i would do what ever i can do and then live with it...if you are using a good mic and recorder...when get to post...i dont think you will hate it as much as you might think you do now. of course if you are shooting very wide and cant get the mic close...those shot are not going to be great...but maybe you can lay sound from a closer shot over it...you'll just have to see...

if you had a matched pair of mics i can teach you a trick that sometimes works, but not always...but i have a feeling that you just have the one...so wont go into it unless you do.

Thanks for the advice. Unfortunately there was no way to set up any sort of blankets the way the room was set up or how we were shooting. However one thing we did was record alot of the audio from below as someone suggested. It came out better than I thought it would.

There was another room with the same dimensions except w/ carpet on the floor (couldn't use it because of the heating system noise). But I couldn't believe how much a thin carpet cut out the echo. I'm gonna think twice before throwing large carpeting away.

Thanks