Isolated basement room

[DasProductions]

Hi,

Goal: Best as possible isolated basement room, play live guitar(voxAC30’s) with backing tracks(PA speakers) and hopefully not disturb my wife and son on 1srt/2nd floor(hopefully ). No neighbors close by so that’s one bonus.
Room dimension: 21.6’feetX 12.8feet X 7.4’feet(height)
After researching this is what I’ve come up with for best isolation, room within a room design shown below, please any recommendations and comments are very welcome, thank you.

roominroom.jpg(attached)
1.Can new walls be nailed to the cement floor with a rubber padding in between? I looked into John’s floating floor design but I don’t think I have enough height in the room.
2.Placing new 2X8 beams in between the existing 2X10 ceiling beams, 2 inches below original ceiling height for air gap, not sure how to insulate so it won’t be touching both existing ceiling and new floating ceiling?
3.Since room in room structure and no RC channels needed, can I mount tv etc to walls, mount screws thru the sheet rock and studs?

roominroomFireplace.jpg(attached)
1.Can the wall 2X4 studs be touching the fireplace bricks, or leave ¼ gap filled with green glue? or rubber padding?
2.Sheetrock will be flush with the fireplace, not touching it, ¼ gap will be filled with green glue.
3.Will use the space behind walls for heat/vent silencer boxes

Thank you very much,
Jim

[DasProductions]

Hi Everyone,
Checking to see if i'm missing any critical information in my drawings above, I apologize if I do and not being clear enough. Trying to see if this would the best way to isolate the room.
Thank you,
Jim

[Gigalittle]

Hi Jim,

I am also a new member on the forum, so any veterans out there please chime in and correct any errors or ommisions.
Your plan looks pretty good, but a few suggestions...

Green glue is not used for caulking / sealing - it is used for damping between layers of drywall. For caulking and sealing use standard acoustic caulk - which is a lot less $$$. You may or may not need green glue depending on how much isolation you need but it is applied between the layers of drywall to help dampen vibration and increase low frequency isolation. Despite its name green glue is not an adhesive its just this gooey stuff that remains elastic to help dampen vibration - you also need to be sure the drywall is properly secured with screws.

Your basic inner framing idea is sound but you should consult with a structural engineer to verify 2x8 joists will be sufficient.

You may also need to "beef up" your outer leaf with additional layers of 5/8" drywall. Specifically in the ceiling (between the joists) and the existing 2x4 wall on the right side of your diagram separating your practice space from the rest of the basement. On that wall you may have the luxury of just adding the drywall on the other side (rather than having to cut it up into little pieces to fit between the studs) which would be a lot less work for you. No additional mass should be required on the walls that are concrete, but you need to be sure the entire outer structure is air tight using acoustic caulk.

To really make a recommendation on how much mass you need on your inner and outer leaves it would be good to know how loud you play in decibels. If there are no live drums (just backing tracks through the PA) you may be able to get away with less isolation and less cost on materials. In fact the whole room in room construction might not be necessary at all. If you ever want to add live drums in the future, however, serious isolation will be required and it would be best to build it right the first time.

1. The new walls can be nailed directly to the concrete. Rubber padding will not be needed unless the floor is uneven in which case it could help to ensure there is an airtight seal. Be sure to use pressure treated for anything that is touching concrete.

2. Your air gap in the ceiling will be more like 10 inches. You can place insulation bats between the joists. It is OK if it is touching the new ceiling and the new joists as long as it is not over compressed. If it is too compressed it could create a flanking path so you don't want it packed in tightly.

3. You could mount a TV to the walls but remember any holes you make in your inner leaf could compromise your isolation if they are not well sealed.

1b. The new 2x4 walls should not be touching the fireplace bricks or anything else that is attached to the existing structure (other than the concrete floor). Otherwise you are creating a flanking path for sound. What type of fireplace is this? You may need to get rid of it. If there is a chimney that is connected to another fireplace on another floor you will need to seal it off with something massive and build your new wall in front of it.

[DasProductions]

Hi Steve,
Thank very much for taking the time and providing great detailed information, I really appreciate it.
Great advice and information, now makes a lot more sense.
Regarding the fireplace, you are correct, there is another fireplace above it on the 1rst floor but they have separate flues enclosed in one chimney. Does it help having separate flues? Or doesn’t make a difference?
If having separate flues helps my situation than maybe my plan can still work?(after sealing the fireplace door?)
Thank you,
Jim

[Gigalittle]

Hi Jim,

I think the most important thing you need to do now is figure out how much isolation you actually need. The best way is take a measurement with an SPL meter to figure out how loud you play.

If there are live drums in your future (typically 115dB), I think you would need to give up the fireplace. Basically you would need to brick in the opening so it is air tight, then build your new wall out in front of it (with no opening for the fireplace). Otherwise the sound is going to just travel straight up the chimney and into the rest of the house. Your isolation will only ever be as good as your weakest link, and the chimney is a direct opening to the rest of the house. The flue and damper and any standard glass doors you may have in the front of the fireplaces now would be pretty inconsequential for stopping the sound.

On the other hand if there are no live drums in your future, you do not need to go to such extremes for sound isolation! Let's say your peak level is only 80 dB, then you would only need to isolate 40 dB so it is not so noticeable upstairs. Maybe some heavy sealable glass doors on both the upstairs and downstairs fireplaces would be sufficient. This also means you wouldn't have to build the whole room in room design like you are planning. There would be much less expensive ways to build your practice space! That's why it is so important to get some actual measurements - so you don't under or over design it. You can get a decent sound level meter online for around $40.00

http://www.cnaweb.com/analog-sound-leve ... 4AodiAcAlw

It really makes no sense to go the trouble and expense of building a whole room in room like you are planning but still leave that opening for the fireplace. I guess that's why you don't see a lot of fireplaces in pro recording studios

I hope this helps, and apologize if it is not what you were hoping to hear.

[DasProductions]

Hi Steve,
No need to apologize at all, knowing now all this information you have provided me is exactly what I wanted to hear and I appreciate it very much, thank you. It totally makes sense now. I will start with a decent sound level meter(thank you for the link) first and then decide which direction I should approach. Planning the right way is the most important and I thank very much for letting me know before I completely screw it up.
Thank you,
Jim

[britune]

You could build a removable plug for the fireplace. Just pop it in place when playing loud. Remove when you want to use the fireplace.

I made a couple isolation rooms in my basement. You can see what I did here. http://www.johnlsayers.com/phpBB2/viewt ... =2&t=14136

[DasProductions]

Great building thread britune! I've learned a lot already just by the pictures you have, thank you, i will spend more time reading the details, lots of great information.
I was also thinking of making some type of plug for the fireplace door like you said, even if not removable, but i will complete some more research since one wall of the room within the room will be touching the fireplace transfering the sound to the rest of the house, as stated by Steve which makes sense.
Time to do some more studying