Well unfortunately I was going to post pics but somehow I have deleted them from my camera's memory stick. <<<<THAT SUCKS>>>> Anyways, we have just completed our rehearsal studio build using the great resources from this forum. John had given us a great design all of which was used for our actual build...everything except the inside out walls. Now I am kicking myself.
http://www.johnlsayers.com/phpBB2/viewtopic.php?t=8939
We're still experiencing some bass bleeding at certain frequencies into our neighbors space! Very minimal but still enough to be an annoyance. There is no kick drum or any guitar bleed so I have a feeling it has to do strictly with the high SPL of the bass cabs. What should we do next? Here is what we have....
We started by doing the standard "beefup" on the shared wall with our neighbor (two layers of 5/8 sheetrock between joists, cleats, sound caulking etc....) There is a 3" space between existing wall and new wall. (2x6 + 3" + 2x4). The total 12" air space between walls were stuffed with two layer of OC r-19 unfaced fiberglass. We used two layers of 5/8 sheetrock on the inside walls of the studios, applying ISO SC-175 sound sealant along every exposed seam. (same as the beefup). For the ceiling we used 2 layers of 5/8 attached to RC-1. Between the joists we used OC r-38 faced insulation. Everything was hung, mudded, taped and painted according to the suggestions found on this site.
We were pretty sure that the ceiling was not short circuited during install.
Each room is pretty small under 280 sq ft. and the sound pressure levels are enormous.
Am I expecting too much by wanting no sound transfer at all? How at this point should I go about reducing the transfer even more? Will adding another layer of sheet rock to the wall closest to our neighbor help any? How do I test to see if it is a possible short curcuit? Will adding a few more bass traps help? Auralux? I'm desperate...LOL. Any suggestions would be much appreciated.
Thanks
BEN
Should I add more mass?
Originally posted at johnlsayers.com, topic 9578.
Well I for one am happy that you did not do an inside out double wall as a part of a unit seperation partition.Well unfortunately I was going to post pics but somehow I have deleted them from my camera's memory stick. <<<<THAT SUCKS>>>> Anyways, we have just completed our rehearsal studio build using the great resources from this forum. John had given us a great design all of which was used for our actual build...everything except the inside out walls. Now I am kicking myself. http://www.johnlsayers.com/phpBB2/viewtopic.php?t=8939
What are your sound pressure levels within the roon when you're playing? What are the ambient levels in the neighbors when you are not playing- and when you are playing?We're still experiencing some bass bleeding at certain frequencies into our neighbors space! Very minimal but still enough to be an annoyance. There is no kick drum or any guitar bleed so I have a feeling it has to do strictly with the high SPL of the bass cabs. What should we do next? Here is what we have....
ALl of this sounds pretty much by the book- BTW - you have to be carefull when dealing with neighboring party walls - If the wall is shared it is a party wall - and party walls have requirements to have and maintain particular fire ratings........ IN the states there are a couple of testing labs that certify these walls - one is UL (Underwriters LAb) and another is FM (Factory Mutual) - neither of those include any of the reversed walls that John uses in his designs - and to the best of my knowledge they do not esist in any test data anywhere. They are designed as acoustic assemblies to be used within a studio environment - but not as a part of a rated fire wall assembly. (John - please correct me if I am wrong on these being tested - perhaps in your country they have been). Anyway - the point I am trying to make is this - the removal of a fire rated assembly - replacing it with a non rated assembly - is a criminal offence in most states - and (if ever there was a fire) could be cause for criminal arrest including homicide charges if ever there was a death related to the failure of the wall to meet required ratings. In addition - the movement of the wall face from it's original location to another location inboard of it's original face (even if the wall design itself is able to be rated) has most probably compromised the rating at the wall/ceiling assembly - by creating a direct path into the wall cavity through the floor decking (which isn't rated) I would have to see some drawings on exactly what you did and what existed - and how the 2 dovetailed together.We started by doing the standard "beefup" on the shared wall with our neighbor (two layers of 5/8 sheetrock between joists, cleats, sound caulking etc....) There is a 3" space between existing wall and new wall. (2x6 + 3" + 2x4). The total 12" air space between walls were stuffed with two layer of OC r-19 unfaced fiberglass. We used two layers of 5/8 sheetrock on the inside walls of the studios, applying ISO SC-175 sound sealant along every exposed seam. (same as the beefup). For the ceiling we used 2 layers of 5/8 attached to RC-1. Between the joists we used OC r-38 faced insulation. Everything was hung, mudded, taped and painted according to the suggestions found on this site.
Absolute - you are way beyond realistic......... I have measured just drums in a band room at 110 dB - it could easily be 120 - 125 for a full band - to expect perfect isolation is nowhere near realistic. Galaxy - the quietest srudio in the world doesn't meet the standard you are asking about - and that's when building it from sxcratch - not trying to set it inside of someone's house with a neighbor on an attached wall..........Am I expecting too much by wanting no sound transfer at all?
It all depends on what is the weak link - if it's flanking - then you can just throw money at it forever and never make it any better...........How at this point should I go about reducing the transfer even more?
At this point you don't test - because you don't have either the experience nor the equipment to pull of the testing. The way for you to handle it is to hire a pro to do some testing for you - and let them give you the best advice for the situation - anyone here would be making a blind guess - which may or may not be any better than yours......... and this will only work (the testing) if your neighbor is willing to give them access to their apartment as a part of the process - they can't do it from just one side....... BTW - just for future reference: BASS TRAPS DO NOT CREATE ISOLATION BETWEEN ROOMS.... get a good strong picture of that in your minds eyes - they only help to attenuate that which exists in the room due to the level of isolation you have. RodWill adding another layer of sheet rock to the wall closest to our neighbor help any? How do I test to see if it is a possible short curcuit? Will adding a few more bass traps help? Auralux? I'm desperate...LOL. Any suggestions would be much appreciated.
Rod. Thank you for your post. I really appreciate the honest feedback. I will take those db level measurements and repost.
I understand the bass trapping not being part of room isolation but I was hoping that by adding more absorption I could effectively tune the room, thus minimizing the "MUD" factor. If the musicians don't have to compete against their own reflections then maybe the volume levels wouldn't need to be so high. Thanks again for all of your help Rod it's much appreciated.
BEN