Axiom Home Page Forums General Discussion Home Theater Lets plan a theater space

From the couple books I have read:

Below 200-300hz the walls become less effective at blocking sound transmission. Room modes are thought to be augmented by bulking up walls, as you allude to, but they are best dealt with by dimensions and bass trapping. Planning on a single flimsy wall and beefing up others unfortunately is pouring money down the drain.

Square rooms are best set up in a corner firing along the diagonal. Parallel boundaries are bad news. But all in all, best avoided.

Curious to hear what square room folks have to say.

For what it's worth, I wasn't recommending beefing up the other walls to deal with room modes -- it's likely to happen anyways (based on where the thread is going) in order to provide some soundproofing and I figured it might be possible to get a free ride from that work...

... I was hoping there might be an interior wall where soundproofing could be skipped, reducing the impact of the room modes. Then again if it's a full blown HT build it might be possible to add some serious bass trapping without adding a serious pile of ugly in the process.


They mostly get snippy with me for outing them

sorry I assumed thats what you meant. Oh the interwebs...

[snippymode]Square rooms suck. The Axioms are the best I've ever had in there, but I gave up on trying to achieve excellence.[/snippymode]

Yeah, it would have been better to work a bit of context into my comment and say something like "I have this crazy idea you should leave one of the walls un-soundproofed...".

Found this that may be of some interest.

http://www.stcratings.com/assemblies.html

I am guessing my wall plan of 5/8 on channel with an insulated staggered stud wall will net me an STC at or near 50db. I think the weak link in my dividing wall will be the french door with a large glass area in each. Might look at custom making doors with spaced double panes. Prehung french doors would be so easy though....

Hey Nick, did you ever get your cooling scenario figured out? I stumbled on your thread while trying to find cooling and air turnover specifics. I'm thinking I may put a thermostat controlled motorized damper inline ahead of the main and second floor tee-off point. My thoughts are that if the room gets too hot outside air will be pumped in and out at the full CFM the HRV can muster. Theoretically, at max would turm the room over just over three times an hour. Hopefully its enough..... A dead vent will add another weak link in my wall.

New HRV and whole house replacement windows showed up friday (old ones were single pane when we bought ) Installed 5 windows today. HT on backburner... again. Poo.

Crappity crap crap crap.,..

I had a long post and accidentally closed the tab in Firefox and lost it.

Ugh.

Soundproofing... I spent probably no more than $600 more for extra studs, drywall, clips, hat channel, insulation, green glue, and the custom ordered door and sill plate. VERY cheap considering the enormous impact it had on soundproofing the room. I can play things pretty loud without disrupting my wife watching Dancing With the Stars.

Here is a video that I've shared before. Just watch the first few seconds of it. This was from a year ago. I had the movie Oblivion playing even louder than I normally watch movies, and start the video with the door shut. Yes, you can still here the video outside the room, but compared to when I open the door, it is a huge improvement.



My wife wanted french doors too. There are several problem with that. They aren't soundproofed at all, they rattle, they are pricey, and they let light in. In talking to my wife, she said, "just put a curtain over the window." Well, what is the point of having the glass door if you just cover it up. After going with the solid core steel exterior door, she is OK with it now because of the above mentioned ability to watch DWTS without me disrupting her.

As for the heat issue, I haven't quite figured it out. I know that I need to get air out of the room, so a few weeks ago when I finally did my equipment rack, I put in a 250mm fan above it to blow air out of the room. This *should* work when the A/C is running as it gives the A/C a place to flow towards, however the weather has been too nice to really have the A/C on. It won't help much in winter since there is no source of cool air.

I think that my final plan will be to change out the fan for a direct air return for even more exhaust pull from the room, then in summer when the A/C is running, it will work even better than my little fan that is just blowing into the basement ceiling joists. I then will need to be able to set up a powered fan setup to pull air from outside in the winter. That would give me my source of cool air for those months and I would just close the HVAC vents and put small covers over them to seal them better. Then for the hot and cold times of the year I will have cooling to the room and something to pull the hot air out. Spring and fall will become the issue at that point, but having something working the rest of the year is a big improvement. I really should get going on figuring the winter cooling out before winter is actually here.

Sounds like a great idea. Learn from my mistakes and make sure you have a *very* good screen to keep rodents & bugs out though...

I hate it when that happens.

Sounds like a great plan, Nick. I read through your other thread and others. Mini-splits are popular, but come on! Spending upwards of 1-2 thousand for a single rooms HVAC? Better planning could have saved those blokes $ considering a minisplit doesnt exchange air.... Some of them are pretty militant about it too.

I'm wondering about the need for heating in the space. If I am thinking right, I should be able to get away with heating the common area just outside of the room with hot water baseboards. I might try to find a big old rad. They are cool.

When we are in the space with the doors clsed it should be pretty toasty. When not in there I can leave the doors open and warm air should circulate through. I wish I knew more about HVAC.

bridgeman, the furnace in our house isn't a "high efficiency" one, so it needs a supply from outside already for fresh air. I doubled up the screen on the outside vent, and put a doubled up screen where it comes to the inside as well. I would do something similar for the theater.

Serenity_Now, for future resale, you might want some type of heating in the theater, just plan on never needing to run it. To date we have NEVER had the vents open in the theater when the heat is running. Even in a cooler basement when the door has been open and the temp is a touch cool. Fire up the projector, put some 3500 BTU/hour people in there, and you don't need heat. But having it for whenever the day comes to sell, or even if you get an appraisal, most places count finished square footage based on a couple of factors, including a heat source (they don't care about A/C oddly enough) in each living space.