easiest and most cost efficient way to soundproof?

Roxul is an insulation....it goes IN the wall.

And Roxul is sold at every Home Depot and Lowes I've ever been to. Although the Corning stuff is cheaper (same price, more than 2x more material in the bag) and works just as well.....Roxul is more of a marketing ploy.

Read the acousticians posting measurements and reviews saying it basically doesn't matter what your dampening material is, most insulations perform the same.

I think the most cheapest way that is still mostly effective is carpet the walls with old shag carpet scraps or use egg cartons. But i must say that, it takes a bit more work. Otherwise you can put up plasterboard walls in front of existing ones.

I've researched this topic to the end of time - there is more misinformation out there than you can imagine - lots of it repeated in this thread.

So, let's talk some facts:

1) Insulation (such as Safe n'Sound) is only minimally effective.
It's better than an uninsulated wall, but not by much. I'll quote the National Research Council of Canada's Institute for Research in Construction:
[QUOTE]Using sound-absorbing materials in a rigidly connected assembly is a waste of money.[/QUOTE]
Source: http://www.nrc-cnrc.gc.ca/eng/ibp/irc/ctus/ctus-n1.html

Why is this? Because the sound is just transmitted through the solid wood studs. The insulation just prevents the wall cavities from making the situation worse (they can become bass chambers) but not making it better. Note: Sound insulation in a metal-stud wall is worth it since metal stud walls are not as rigid as wood stud. Metal stud walls do better all-around, and are really easy to work with if you buy a good set of tin-snips. So just filling a wall up with SnS doesn't work.

I know lots of people swear by the stuff - but the facts are what the facts are. I think many people have put SnS in a new wall, and are happy with the performance but have nothing to compare it to. I've taken down lots of walls in my house to do other renos and "while I was at it" stuffed SnS in it. I've never found it provided any benefit. I should have listened to the research and not wasted my time and money.

Spray or expanding foam insulation will be worse - it'll make the whole wall assembly MORE rigid, not less and because it won't add any mass, it won't help.

2) Egg Cartons don't work.
Google for yourself "Soundproof myth egg cartons" and see for yourself.

3) QuietRock works but is expensive.
See their own STC ratings on their website: http://www.quietrock.com/educational-re ... quiet.html

4) NRC-IRC has recommendations based on facts:
Here are the offical NRC-IRC recommendations (from the same link as above):

[QUOTE]To reduce sound transmission through gypsum board walls:

• use double studs, staggered studs (with or without resilient channels), non-load-bearing steel studs, wood studs with resilient channels or load-bearing steel studs with resilient channels;
• increase mass by increasing the number of layers of gypsum board on each side from one to two;
• increase the depth of the cavity;
• fill the cavity with insulation;
• space studs at 600 mm; and
• space resilient channels at 600 mm.

[/QUOTE]

I know it's funny they have "fill the cavity with insulation" - but they mean in combination with one of the other approaches from the first bullet point (again, the non-rigid structures).

5) More facts
These sites also have good reference lists of various wall assemblies:

• STCRatings: http://www.stcratings.com/assemblies.html
• UGC: http://www.usg.com/rc/system-catalogs/a ... -SA200.pdf - skip to page 15.
• Full NRC-IFC data: http://www.nrc-cnrc.gc.ca/obj/irc/doc/p ... /ir761.pdf

Finally...bottom line:
So, cheap solutions that will actually work in order of performance (Note, for reference, you wall should have an existing STC of about 30 right now):

• Add another of layer 5/8 firecode drywall to each side of the exisitng wall: Single-Stud wall with 2 layers of 5/8 on each side: STC of ~55
• Add another layer of drywall attached using green-glue to one side: STC ~52 according to the mfg (http://www.greengluecompany.com/
• Tear down one-side of the drywall and re-install w/Resilient channel: STC ~45. (NOTE: Do NOT add resilient channel on-top of the existing drywall thinking "more-is-better' - it isn't in this case, since it creates a "triple leaf effect")
• Build another entire wall in front, w/1" separation: STC ~45
• Add another layer of 5/8" drywall to one side of the wall: STC ~35

...don't forget to caulk with acoustical caulk around the whole perimeter and pretty well anywhere else you can stick the stuff. Any air gaps will just make the whole effort a waste of time.

My own personal conclusion for how to retrofit a noisy wall? Go with green glue and another layer of drywall. I haven't used it yet, but I've not found anyone say that it isn't effective - they just complain about the cost.

...sorry, in addition to all that information above, if you want a less-permanent and easier solution you can try:

1) Sound Curtains:
Adding a layer of heavy fabric in front of the wall (needs to seal nicely against the ceiling, walls and floor) but not touching the wall (space it an inch or two in front) will reduce the sound but depends on the fabric being very heavy. Industrial quality sound blankets have mass-loaded-vinyl in them. Your chances for DIY success are mixed, but at least it's not hard to try.

2) Build a temporary wall
See this guy's solution: http://www.oohub.com/Soundproofing_wall.htm

"The insulation just prevents the wall cavities from making the situation worse"

...which is why you should do it. But....there's nothing really special about SnS versus other insulation as I posted previously. The links are easy to find on Google. It really just has to be SOME kind of insulation. SnS is overpriced marketing hype.

Drew_W wrote: ↑"The insulation just prevents the wall cavities from making the situation worse"

...which is why you should do it. But....there's nothing really special about SnS versus other insulation as I posted previously. The links are easy to find on Google. It really just has to be SOME kind of insulation. SnS is overpriced marketing hype.

I agree, but the OP should do it as part of a larger solution. If he goes through the trouble of opening the walls to add it, or to blow in cellulose, but then does no more then he will be disappointed. My low opinion on using insulation for sound reduction doesn't stop me from using it either (as I said, "while I'm at it") but only as an add on to something else. Never as a project onto itself.

lets talk doors!

What do you guys think would be better for a single door in the basement for a jam room- an exterior steel door, a solid wood door, or a Safe n' sound door? Ive googled but haven't gotten a definitive answer.
The door is a big concern for me, because right outside the threshold is a stairway to upstairs. followed by another stairway to the bedrooms.

^ I would say they are pretty equal. I would be more concerned about the gap at the bottom of the door.

Smoothie wrote: ↑^ I would say they are pretty equal. I would be more concerned about the gap at the bottom of the door.

Thanks that was my gut feeling too...which I suppose gives the edge to the exterior door, as a prehung one will come better sealed than any interior door. downside is of course, the style/pattern for an exterior door is going to be more limited/less likely to match other interior doors, unless you spend big bucks.