Sound for lobby

[Ech725]

Here is my scenario. My university is getting a lobby added on to the theatre. I've been asked for some advice regarding sound needs in the lobby. I know that a sound installation company should be consulted but the higher ups never acknowledge my suggestions. I've been talking with IT. I've attached a quick sketch of the lobby. So I've been told that all the conduit will be run to the storage closet. IT is trying to figure out where they will run video and data. As far as sound needs, the lobby will have a speaker at the podium. While I would love permanent speakers, I think they may be cost prohibitive. Also the ceiling is 20' high and the walls in front of the podium are all glass. So at the very least, I would want some inputs for speakers and some mic inputs. I'd really prefer all this to be run in the conduits to wall/floor panels. Now the IT guy wants to put his network gear and sound rack in the storage closet. Now if I want to be able to control the levels of the audio with say a mixer, is that doable? I would prefer to adjust things in front of the presenter than have to walk over to the storage closet. The IT guy did not have a solution. I'd appreciate any other info/tips.

 

[AlexDonkle]

If the front wall is all glass and the ceiling is 20', I'd also be concerned about the acoustics of the space.

From what you're saying though, I'm assuming that the drawings have been finalized already? (based on your comment that all the conduit home runs to the storage closet). Also keeping in mind that all mic/line cable have to be put into separate conduit from loudspeakers.

 

[museav]

If the IT guy wants to design it let them, otherwise nicely suggest that they stick to IT.

I'll give my usual input, you need to start over with first determining what it is you are trying to do and achieve. What I often find with similar situations is that the University has campus standards for IT and thus the IT may already be pretty clearly defined, but campuses rarely have standards for AV outside of classrooms and thus what is desired and expected probably needs to be defined before getting into the related solutions and infrastructure. How will the systems be used? What type of events does it need to support? Who will be operating it? The basics of first defining the desired results and then figuring out how to achieve them, not the other way around.

 

[Ech725]

Yes drawings have been finalized. As far as use, it will be used for gatherings-lunches(there will be a small prep kitchen area), presentations (2 large monitors will be behind the podium), and open houses for recruiting students. I imagine there would be 50 to 100 people at the gatherings. Either I would run or a student so simplicity is key. I know nobody has thought about sound. They are more concerned with picking out tiles and colors. (I could only imagine the acoustics with all the glass and tile) I am hoping to avoid having a new lobby and having to run cables everywhere to have sound or having conduit seen throughout the lobby.

So data cable can't run in the same conduit with speaker cable or mic cable?

 

[marmer]

Your lobby sounds similar to my lobby. Glass walls, high ceiling, very reverberative, small gatherings. Very hard to do sound reinforcement. This may not be the answer you want, but we do entirely portable. Run the wires and set the speaker stands or small columns as close to the guests as possible. Put the mixer where you want depending on the setup for the event. No need for conduit. In that reverberative space if your speakers are in the walls it's going to be very hard to manage intelligibility and it's going to be easy to get too much noise into the room to be able to control it. And get some absorption or at least diffusion on those walls where you can. That hard surface rectangle looks like it will have a lot of flutter echo. And, I wouldn't be too committed to having permanently mounted display screens if you have a lot of glass and no way to control light. Frankly, the architect should have consulted an acoustician but if they haven't you need to strongly recommend that they do because it sounds like this place will need some help.

 

[Ech725]

Your lobby sounds similar to my lobby. Glass walls, high ceiling, very reverberative, small gatherings. Very hard to do sound reinforcement. This may not be the answer you want, but we do entirely portable. Run the wires and set the speaker stands or small columns as close to the guests as possible. Put the mixer where you want depending on the setup for the event. No need for conduit. In that reverberative space if your speakers are in the walls it's going to be very hard to manage intelligibility and it's going to be easy to get too much noise into the room to be able to control it. And get some absorption or at least diffusion on those walls where you can. That hard surface rectangle looks like it will have a lot of flutter echo. And, I wouldn't be too committed to having permanently mounted display screens if you have a lot of glass and no way to control light. Frankly, the architect should have consulted an acoustician but if they haven't you need to strongly recommend that they do because it sounds like this place will need some help.

Yeah I can only imagine that it will be tricky to reinforce sound. I know our department chair is trying to convince the higher ups to not go with terracotta tile. Oh yeah the display screens are going up but the shades are being cut At least, they decided to install the housing for a later date. It's frustrating because I know that I'll have to deal with all the problems that could be alleviated by hiring the right professionals and at least consulting with the people who will primarily use the building.

 

[marmer]

And, you mentioned tile. Funny you should mention that as I'm working on a feasibility study of putting a hard surface floor in our lobby for esthetic and durability reasons. We have an architect and an acoustician involved. If the slab of your new lobby contacts the structural columns or slab of your existing building without some kind of expansion joint, and you have some kind of hard floor without a resilient underfloor, you will very likely get impact sound inside your theatre from people walking or moving stuff in the lobby. Do you have double-door vestibule sound-lock entryways into your theatre? If not, you may need that as the lobby will build up sound if there are enough people inside it and I don't know how careful the original designers of your theatre were with sound isolation, pre-lobby. There might not have been much of a concern with those doors if there was no real lobby. And just to reiterate: the best way to handle audio is to get the speakers as close to your audience as possible and keep the gain really low. Reflections from all those walls will make your intelligibility a real challenge if the system gets too loud. Just tape the wires down with appropriately colored gaff tape and be done with it.