What should i get?

[JuliánFernández]

...........

[RICK FITZPATRICK]

but i really want to know how many dbs will be outside if i´m playing a drumkit at 100db... any help? ThankS!

There is only one way to know the absolute truth. Measure it with a Sound Level Meter. Have someone take some readings with one while you play. The level inside doesn't matter. Also, this may or may not matter either, if who ever it is you are trying to keep from bothering, hears it regardless.

[RICK FITZPATRICK]

Forgot to add, where you measure at relative to the exterior wall will give you a reading. Move out untill the reading drops 6db. From that point, it will drop 6 db for every doubling of the distance. BTW, I'm surprised you didn't get an answer from Knightfly
fitZ

[JuliánFernández]

Thanks Rick! I´ll be back with new questions!

[RICK FITZPATRICK]

Hey Julián. Man, I'm certainly no expert on this stuff. I just try to use some common sense, but sometimes this stuff doesn't make "common sense" I've read your posts over at Johns site, and thought Steve had pretty much covered the bases. Anyway, don't know if this really helped, but it seemed like the only thing that would tell you the truth. But, wouldn't that be a little late if your transmission loss wasn't good enough? At least if your studio is finished. Kind of hard to add more mass etc after the fact isn't it?

Anyway, glad I could help. That is, if it really did any good.
fitZ

[JuliánFernández]

Hey man! I´m really grateful for you and every people who shares their time to help someone you don´t even know...
Adding mass is not a problem, really. I can put more layers of gypsum if i want...
Anyway, i´m kind of anxious to see it working... is only that.
Again, i appreciate your time... thanks for that!

In a couple of weeks i´ll let you know how the studio is working!