[mcgsxr]

I know that this is an audio forum, and the basement will continue to have a 2 channel system in it, but for the most part, my questions will center around the addition of a pool table to my basement, and how to address reducing sound transmission from the unfinished basement, to the other areas of the house.

Room size - 25x35 with 7.5 feet from floor to bottom of 2x6 joists.
Flooring - concrete, with 30% coverage with carpet.  May increase to 50% if I can find a cheaper piece of carpet to go under where the table is expected to sit.
Walls - 1/2 covered with fiberglass pink, and 6mm vapor barrier
Ceiling - joists
L shaped stairwell, with builder grade hollow core door, with significant gap underneath the door when closed.

Goals - to be able to play pool, including the break shot, at all hours of the day and night, and not disturb my 2 young children (2 and 4) or my wife (otherwise known as the Boss!).

Budget - as low as possible... $500-$600? -  it is a stretch to come up with the $2000 for the table as it is.

Labour - mine, and at times helping hands - retired father, and friends who love pool, and would be willing to assist to get the place ready for play

My thoughts :

1 - change to solid core door with proper door sweep, set to floor level.  Masonite Safe N Sound door available at local Home Depot for around $105 for my 32 inch door space.
2 - install Roxul Safe N Sound between the joists - use finishing nails to level the 3 inch insulation so that it is below the bottom of the subfloor above, and will be above the drywall - please note, that for the purposes of this discussion, drywall is a future consideration, not expected to be included in this exercise.  So, for the short term, the ceiling will stay unfinished, but with insulation between the joists.
3 - the flooring above the basement ceiling is 70% ceramic tile, but is carpet with underpad in 2 areas.

Questions:

1 - does this approach hold water?
2 - what else would you suggest I consider, given the constraints and budget?
3 - how effective do you believe these measures will be?
4 - are there other, more effective, affordable measures I could consider?

I know that bass travels well through walls, floors and ceilings, and pool playing is less likely to have bass in it (I would think), so any thoughts would be appreciated.

Here is a shot of the space in question, to give some reference to what I am working with.  The pool table would be right at the front of this pic, when situated.  What appears to be a finished wall at the back right, is just a 10 foot piece installed floor to ceiling by the previous owner, for some lcd projector experimentation.  Most of the space looks like the left wall, with exposed concrete walls from floor to about 4 feet, then the vapor barrier and pink.



Thanks in advance,

[bpape]

Until you get the drywall up, you're still going to have transmission issues - sorry. 

Also, you'll have to deal with the HVAC ducting.  Box around it and drywall with insulation in the cavities of the framing and move the vents as far away from the pool table as you can get.  Preferably, by running flex duct over to a new location and tie into the tin.  The tin duct is just like an amplifier of mid/high frequencies and it will transmit all through the house.

Bryan

[mcgsxr]

Don't be sorry, this is what I NEED to understand!

By HVAC vents, do you mean cold air returns, or the actual hot air runs?  There are 4 heat vents in the basement, one in each corner, and the table will go in the middle, so there is distance built in there.

Or perhaps you mean the main trunk, that will run right over the table, and will resonate with sound, and THAT will go throughout the rest of the house?

[bpape]

I mean all of the lines.  All of them tie together and the tin just resonates and passes it along to the next duct.  That's why I said isolate them behind drywall and insulation (the insulation if packed a bit will also damp the tin resonance) and use the coiled plastic/insulation type flex duct to run your outlet and return to/from the room.  That way, it can't pass anything along.

Bryan

[JLM]

I tore out a cheapy suspended ceiling from an old basement years ago and the amount of sound transmission up and down increased significantly.

Tried to get the evil contractor to suspend the drywall ceiling in the current man-cave (audio room) from gage metal Z channels, but he refused.  Between the six recessed can light fixtures and the drywall attached directly to the bottom of the floor trusses, the sound transmission is significant (more noticable as the rest of the room is very well insulated even though batt insulation was installed above the cans/drywall).

For your budget, I'd replace all the ventilation lines from the main lines out, install a suspended ceiling (no penetrations), lay batt insulation on top of the ceiling (leave no gaps), and replace the door with a fiberglass exterior door (insulated with weatherseal).  Make sure to use lined ductwork to minimize exposure to fiberglass.  Finding the lined/fiberglass retangular duct might prove difficult and a bit expensive (using much of the coiled flexible duct really cuts down the air flow you can get).

[mcgsxr]

All the suggestions make sense, but I suspect that prices must be lower in the US!  Just to swap the door, and add the insulation to the ceiling will run me $600.  Any changes to the duct work, and or installation of a suspended ceiling will add at least another $400.

I guess another example of how everything in life costs more than you want it to!

I will take a few more pics of the space, because I am afraid I have not made myself clear.  The excellent suggestion of encasing the main HVAC trunk in drywall and insulation is likely made useless, due to the fact that the actual furnace is, and will remain short term, in the same room as that duct work...

I appreciate the suggestions, but it is sounding (no pun intended) more and more like "after hours" play will have to wait until the infrastructure of the basement can be upgraded.

[bpape]

Yes - that's a problem with the furnace.  If you want sound to stay in a room, you can't share it with something that has huge tentacles reaching all through the house.

IF you can DIY, redoing the ductwork can be done reasonably.  As for the insulation, I think you'd be better off with standard wall insulation and spend the balance elsewhere.  Safe'n'sound isn't needed.  The difference is not all that great behind sheetrock provided the cavity is full.  Price out some standard R-30 and see what that does to your budget.

If you can't completely redo the ducting, at least consider removing or decoupling sections of it so it can't propogate the noise through the tin itself.  Find some duct liner, cut 2" or so out of a joint, wrap the joint with silve HVAC tape to seal it, then wrap with duct liner to preserve the temperature difference.  You can even use something cheap like poly batting a couple inches thick.  That's a poor man's isolation method - but it will help.

Bryan

[mcgsxr]

My public learning about sound transmission continues, thanks for sharing your expertise Bryan, and others.

So, my attempts to insulate the ceiling would be in vain, without drywall?  Complete waste?  Won't reduce the sound of the break shot much at all to the floor above?

I understand about the furnace, and the tentacles throughout the house.  I plan to section off the room so that there are 2 rooms - one with all the HVAC and water heater, and storage, and the other the room with the stereo and the pool table.  At that time, there will be walls, and ceilings etc, so I will incorporate all the points listed here, as best I can.

I was hoping that there would be a way to make a difference in the short term, without committing to the 1000's that finishing the basement represents.

Here are some more current pics of the space in question.

Please note the pool table location is represented by the space between these 4 items on the floor - red milk carton, short white step at one end, and at the other end the short white table, and the other short white step.  Humpty Dumpty is readying himself for the break!



This shot is taken from where the stereo is, and represents the North East corner of the basement.



This shot is from the same corner, but I have turned to face straight South - you can see one of the tops of my OB speakers, in the lower right.



Now from the North West corner, facing the stairs that come down.



This shot is from the same corner, but now facing due South again.



Now from the South West corner, facing back down into where the last shot was taken.



This shot is from the same corner, but now facing back to the stereo corner.



Here is a shot of the main HVAC trunk, flanking the main steel beam - all this will eventually represent the bulkhead that will be boxed in, filled with insulation, and drywalled off.



Lastly a sample of how the HVAC lines INSIDE this room are tied into the main trunk.



I assume these represent the pieces that should be "broken" with the flexible ductwork section, to resist vibration going back into the main trunk, and then all through the house - I understand that if the main trunk is not boxed in and insulated etc, this is fruitless.

In order to understand how the whole room will become 2 rooms, you simply turn the baby gate seen near the furnace and water heater, into a wall.  That will wall off the HVAC, and storage, freezer, electrical and coldroom etc.  The resultant room will become the play area for kids and big kids alike.

A long way to go, but with your help, the end product will be worth the investment.

Thanks guys, I appreciate your sharing,

[ToddSTS]

As for the ducts, couldn't you slap up some high-temp mastic from McMaster-Carr (essentially Dynamat) to mass load it a bit and reduce the amplifying effect of the sheet metal?  I would think that would be better than nothing. Just a thought.

Todd

[bpape]

Insulating the ceiling will help some with the actual pool playing - not perfect but a help.  What you won't get a ton of is help with the vocal range - people talking and laughing.  Those are much lower frequencies and won't be stopped with just absorbtion - they require mass (drywall).

Also, in the short term, the other big weak point you have is the door at the top of the stairs.  Is that the one you're going to do with a solid door? 

Bryan

[mcgsxr]

Understood about the voices Bryan, I had not considered that - though truthfully it will be me often alone, my passion for billiards is impressive, I used to play every day, outside my home, so a captive table might very well see daily action too.  Friends in the evening would be once per week.

The door is the one I was thinking of replacing, with a Masonite Safe N Sound door, yes.

[Rob Babcock]

It's my understanding that many "soundproof doors" are simply mediocre doors that you get overcharged for.  A solid core exterior door with a regular exterior jamb might be a better & cheaper alternative.

[mcgsxr]

Good point Rob, I will consider that too, as an option.

As for the room, well it is reaching a critical state now!  The table arrived on Sunday, and I was able to keep the area relatively clear, but not get the light hung.  My very tall friend will have to come over soon for that.

For those interested, it is a Dufferin solid oak 4.5 x 9 table, with Simonis 860 cloth, and Aramith Premium balls. 

The sound transmission issues are not that bad.  Regular play seems not to bother anyone anywhere in the house.  The break shot does radiate throughout the house though, with the obvious issue being the HVAC trunk right over the table.

I will slowly address these issues as I progress, but for now am very happy just to have the table in, and playable.

The milk carton visible in the one shot is one of the items that my little girls use to stand on, to get a good view!