rob aylestone
Moderator
I bet it's annoying having a phone free recording studio!
Isolation wall without rockwool (bass blocking)
- Thread starter spitzer
- Start date
miroslav
Cosmic Cowboy
Not sure what you mean...?
I've got a phone in there (or will have)...but like all my other phones...usually turned off, no ringers on anywhere.
Maybe that's some English humor I'm missing?
jamesperrett
Active member
This is turning into an interesting thread now...
My studio building 'career' started with a 15'x10' shed in the garden with chipboard lining and carpet on every internal surface. To my teenage surprise, with a band playing the sound outside was nearly as loud as the sound inside but fortunately we were nearly 100m from the nearest house and the neighbours were understanding. The acoustics inside were fairly dead and the poor soundproofing probably helped by letting all the bass out.
The next two studios were small commercial rooms that were used for both rehearsals and recording. The first of the two had studs screwed to the walls, then old doors (which we found cheap) and then a layer of carpet. Fortunately the outside walls were fairly thick so they provided most of the soundproofing. We made some great recordings in there but I don't think the acoustics really helped. The second of the two was in a modern office building where we actually did very little soundproofing apart from adding an extra stud wall on the wall next to our neighbours and a second ceiling in the downstairs room to reduce the sound travelling to the upstairs control room. Our immediate neighbour could hear when we had a band in but there wasn't too much leakage outside.
When the commercial studio finished I wanted a decent space in the house and this time I had a bit of a budget so I brought in a studio building company. That was interesting as they were obviously used to working on BBC projects (they'd been working on a World Service studio before mine) and I learned about things like Camden Partitions and magnetically sealed doors. While we were only 20m away from a fairly busy road, we rarely heard anything in the studio and a band playing in the room could be hardly heard outside although a little more sound travelled to the room above.
For the current studio I decided to do it all myself taking on all the lessons I'd learned with the previous 4 studios. I was on a tighter budget this time but I hoped to avoid the issues with the previous places - even with the professionally built room I noticed that they'd taken a few shortcuts which probably reduced the effectiveness of the soundproofing. I had a local builder build an outer shell with 150mm heavy concrete blocks (they call them medium density but they're much heavier than standard blocks) and I then built a completely separate inner shell with a few tips from an acoustic consultant that I know. I'm fairly happy with the way it turned out although I think I probably should have used thicker glass in the windows and my door hanging skills are nowhere near professional. About the only sound that gets in is that of a low flying Chinook nearly overhead and very little, if anything, gets out. There are construction pictures on my Facebook page if you click on the link in my signature.
My studio building 'career' started with a 15'x10' shed in the garden with chipboard lining and carpet on every internal surface. To my teenage surprise, with a band playing the sound outside was nearly as loud as the sound inside but fortunately we were nearly 100m from the nearest house and the neighbours were understanding. The acoustics inside were fairly dead and the poor soundproofing probably helped by letting all the bass out.
The next two studios were small commercial rooms that were used for both rehearsals and recording. The first of the two had studs screwed to the walls, then old doors (which we found cheap) and then a layer of carpet. Fortunately the outside walls were fairly thick so they provided most of the soundproofing. We made some great recordings in there but I don't think the acoustics really helped. The second of the two was in a modern office building where we actually did very little soundproofing apart from adding an extra stud wall on the wall next to our neighbours and a second ceiling in the downstairs room to reduce the sound travelling to the upstairs control room. Our immediate neighbour could hear when we had a band in but there wasn't too much leakage outside.
When the commercial studio finished I wanted a decent space in the house and this time I had a bit of a budget so I brought in a studio building company. That was interesting as they were obviously used to working on BBC projects (they'd been working on a World Service studio before mine) and I learned about things like Camden Partitions and magnetically sealed doors. While we were only 20m away from a fairly busy road, we rarely heard anything in the studio and a band playing in the room could be hardly heard outside although a little more sound travelled to the room above.
For the current studio I decided to do it all myself taking on all the lessons I'd learned with the previous 4 studios. I was on a tighter budget this time but I hoped to avoid the issues with the previous places - even with the professionally built room I noticed that they'd taken a few shortcuts which probably reduced the effectiveness of the soundproofing. I had a local builder build an outer shell with 150mm heavy concrete blocks (they call them medium density but they're much heavier than standard blocks) and I then built a completely separate inner shell with a few tips from an acoustic consultant that I know. I'm fairly happy with the way it turned out although I think I probably should have used thicker glass in the windows and my door hanging skills are nowhere near professional. About the only sound that gets in is that of a low flying Chinook nearly overhead and very little, if anything, gets out. There are construction pictures on my Facebook page if you click on the link in my signature.
rob aylestone
Moderator
Miro - Sorry, it related to the lead lining - Faraday Cage and a phone free zone, or at least a phone call/text free zone!
ECC - There's no door to put the bolt on - just a weak spot in a perfectly normal looking wall. I know I can get out in an emergency!
ECC - There's no door to put the bolt on - just a weak spot in a perfectly normal looking wall. I know I can get out in an emergency!
miroslav
Cosmic Cowboy
That topic came up when I started my construction...but here in the USA, most contractors rarely use block for anything more than the foundation portion.
Not saying it's not ever done, it's just not part of their normal structure building unless it's something commercial, etc.
I'm sure I could have gone that way too if I wanted to...the contractor would not have refused...but it got to a point where I didn't want to get anymore complex than what was really needed, so I adjusted my initial ideas.
When I finish treating the inside, I will know then if it all meets my expectations...but like I said, 100% soundproofing was never part of the plan, just some level of sound control...and I also never intended to build a commercial grade studio structure, since I have no plans to run any 24/7 recording sessions.
Well I meant, mate! FIT a freaking door THEN put a glass bolt on it!
Re phone. You could run a land line in and have a lamp? I dare say someone makes an app to get a smart phone to drive a LED? Just have a long wire.
Dave.
rob aylestone
Moderator
Do people have land lines with phones anymore - I must admit, I'm noticing none of my actual work comes in by old fashioned phone any longer - they always ring the mobile?
I don't want a door! I have things hanging on the wall and a door for an emergency exit would never be opened, and if I did make a door, I'd just have a handle. Admittedly, it would be useful for storage, but that room is really just junk rather than a proper store. That's at the other end.
I don't want a door! I have things hanging on the wall and a door for an emergency exit would never be opened, and if I did make a door, I'd just have a handle. Admittedly, it would be useful for storage, but that room is really just junk rather than a proper store. That's at the other end.
miroslav
Cosmic Cowboy
I still have a landline at my house...and I ran a bunch of landlines into the new studio too.
I would never give up my landline to switch only to a cell. My cell is off like 95% of the time...only have it as an emergency phone when in the car, but at home I never use it for anything. I go out of my way to avoid cell phones or any WiFi. All my network is hardwired, even though my router has WiFi as an option.
High frequency radio waves are evil...but people are too addicted to their WiFi gadgets to ever give them up, so no one wants to hear about the WiFi evils.
With my phone landline...when the cell service is down in a storm, or when power is out...the landline still works just fine.
Also, when the cable network goes out, I can switch to DSL on my landline...so it's my backup network.
Nope...I will never give up my landline.
rob aylestone
Moderator
Ha! If we lose power here it’s a Facebook event and we’ve never lost cell signals for a long time. It’s rare here.
May not be so rare in the future Rob? Was it 100,000 homes lost power in the two recent big blows? Then floods mean no juice.
I went over to FTTC a year or so ago and get 25-30M up 9.5M down. I have DECT phones but they need a charger (as do mobiles/cells of course) I have a bog s keypad phone that works on the line if needs be. But maybe you have a 50kW genny 'oot'back'?
Dave.
miroslav
Cosmic Cowboy
There are a lot of trees here, and only some areas have underground wiring...like my street is underground wiring, but the street that feeds mine still has wries up on poles...all it takes is one tree to pull down lines, and we have no power.
I have a whole house generator for those situations...so I can stay up and running, power my routers, the landline provides phone and DSL (unless it too gets ripped down)...so in most of the big storms of the last several years, it really wasn't a wild experience for me here...just a PITA.
spitzer
New member
I don't remember ever losing power AND cell at the same time. I did make a call with a landline phone about 10 years ago, just for fun. "Heya... you noticed the power is down in about 10 blocks here?" -"It is? Wait, but you're calling from home? What?". There's even a cell tower less than a mile from here but I think it was just outside the blackout, and of course there are other towers around. The much more serious problem in the long run would indeed be that a cell signal is useless without power, sooner or later your batteries for stuff will run out. I have a car charger for my phone that I could use for a while in a situation like that, but not for anything else.
That got me thinking though, aren't phone lines ALSO up on poles? Like you said "unless it too gets ripped DOWN". Depending on things. Would think it's simply too expensive to get them underground for millions of miles for everyone in the countryside for example. Never really paid that much attention to what exactly is up on the poles and what's in those huge insulated cable things I've seen even just running overground in ditches etc. (I think).
That got me thinking though, aren't phone lines ALSO up on poles? Like you said "unless it too gets ripped DOWN". Depending on things. Would think it's simply too expensive to get them underground for millions of miles for everyone in the countryside for example. Never really paid that much attention to what exactly is up on the poles and what's in those huge insulated cable things I've seen even just running overground in ditches etc. (I think).
I am NO expert on the telephone system Spitzer but even in the worst storms we have have had in my 74 years I have not experienced a loss of land line phone service. Power yes but not the Dog.
In my particular street the there is a green cabinet 50mtrs maybe from my house and that is served by underground cables and fibre (I am FTTC) The copper goes u/g to a substantial pole just across the road from me and drop lines go to maybe ten houses.
'Cell' phones (we call them "mobiles") rely on 'king great masts which might be vulnerable to wind. I assume the traffic comes in almost all u/g but there might be the odd pole in the mix?
And of course those mast transmitters need power. I am sure they have backup batteries but they can only last so long.
Dave.
spitzer
New member
To go back on-topic again for a bit...
This is the interesting part. Perhaps I expressed myself poorly as I was interpreted as "arguing against basic acoustic princples", don't know, but if there even is some particular point I was going for it is related to this exactly.
We all KNOW that only a little bit of chipboard and some carpet is not NEARLY enough to help against the 120 dB of a band playing in a small space. Actually we all probably know that a little bit of drywall and some rockwool won't do it either. I think the wall behind me right now is some sort of drywall-fiberglass-drywall kind of construction (it sounds hollow when you knock on it), and I can very clearly hear people just walking and talking in the hallway there so the reduction is hardly even 20 dB. (slighlty off-topic fun fact: the inner doors here are so thin, that I once accidentally when opening, swung one completely open, the handle hit another door in the same corner and punched a hole clean in it. It looked like some sort of chipboard, but I was surprised to see it was only maybe 3-5 mm thick. And I didn't see anything inside the door to cushion anything, would've expected there to be fiberglass or something at least)
Regarding what's "conducted straight-through" a wall... that requires the wall to be flexible enough to vibrate at the frequencies in question, right? I can easily picture that being a problem with something different, however if you imagine a 10-layer wall of let's say 4 x 2 x 0.2 metres, built with 700 kg/m3 fibreboard... it would weigh 1120 kg. Like I mentioned at one point before, I don't have the numbers, but my guess is that rivals the weight of brick/concrete block walls depending on their thickness and construction. And with a wall SO heavy... I personally have to guess, but my guess is that it would NOT function as a "membrane" practically at all unlike a thinner wall. (Sort of how the solid mass body of a regular electric guitar also DOES resonate, but nowhere near at the same intensity as a hollow-body)
The question THEN is, will it BLOCK (and I mean simply block, not absorb, not anything else) high SPL sound, including very low frequencies from going through?
As miroslav pointed out early on (I didn't think there was any disagreement here?), this kind of construction indeed would practically result in a room basically like one where ALL four walls were solid concrete, and there would be no way for the bass frequencies to get OUT. Which presents a different set of problems, as the bass then stays inside the room.
I'd like to say that among many others, for example the comments about "the idea" about making isolation walls part blockers, part absorbers by design, using soft materials as dampers (and possibly also allowing it to leak air on purpose) because of the bass build-up problem were extremely welcome. I had never, never before in my life heard anyone say THAT is the reason or justification. So thank you for that.
I don't know if you care, but that's at the same time something that explains well why I ask so many questions here. I've spent countless hours during many years researching this stuff, reading different forums, research papers etc. But, still I had NEVER heard anyone mention that anywhere. Note that I'm NOT rejecting it, I trust that it is true. What I'm saying is simply that things like that aren't something you just trivially know, and the answers are in fact very difficult to find or figure out.
Best regards,
This is the interesting part. Perhaps I expressed myself poorly as I was interpreted as "arguing against basic acoustic princples", don't know, but if there even is some particular point I was going for it is related to this exactly.
We all KNOW that only a little bit of chipboard and some carpet is not NEARLY enough to help against the 120 dB of a band playing in a small space. Actually we all probably know that a little bit of drywall and some rockwool won't do it either. I think the wall behind me right now is some sort of drywall-fiberglass-drywall kind of construction (it sounds hollow when you knock on it), and I can very clearly hear people just walking and talking in the hallway there so the reduction is hardly even 20 dB. (slighlty off-topic fun fact: the inner doors here are so thin, that I once accidentally when opening, swung one completely open, the handle hit another door in the same corner and punched a hole clean in it. It looked like some sort of chipboard, but I was surprised to see it was only maybe 3-5 mm thick. And I didn't see anything inside the door to cushion anything, would've expected there to be fiberglass or something at least)
Regarding what's "conducted straight-through" a wall... that requires the wall to be flexible enough to vibrate at the frequencies in question, right? I can easily picture that being a problem with something different, however if you imagine a 10-layer wall of let's say 4 x 2 x 0.2 metres, built with 700 kg/m3 fibreboard... it would weigh 1120 kg. Like I mentioned at one point before, I don't have the numbers, but my guess is that rivals the weight of brick/concrete block walls depending on their thickness and construction. And with a wall SO heavy... I personally have to guess, but my guess is that it would NOT function as a "membrane" practically at all unlike a thinner wall. (Sort of how the solid mass body of a regular electric guitar also DOES resonate, but nowhere near at the same intensity as a hollow-body)
The question THEN is, will it BLOCK (and I mean simply block, not absorb, not anything else) high SPL sound, including very low frequencies from going through?
As miroslav pointed out early on (I didn't think there was any disagreement here?), this kind of construction indeed would practically result in a room basically like one where ALL four walls were solid concrete, and there would be no way for the bass frequencies to get OUT. Which presents a different set of problems, as the bass then stays inside the room.
I'd like to say that among many others, for example the comments about "the idea" about making isolation walls part blockers, part absorbers by design, using soft materials as dampers (and possibly also allowing it to leak air on purpose) because of the bass build-up problem were extremely welcome. I had never, never before in my life heard anyone say THAT is the reason or justification. So thank you for that.
I don't know if you care, but that's at the same time something that explains well why I ask so many questions here. I've spent countless hours during many years researching this stuff, reading different forums, research papers etc. But, still I had NEVER heard anyone mention that anywhere. Note that I'm NOT rejecting it, I trust that it is true. What I'm saying is simply that things like that aren't something you just trivially know, and the answers are in fact very difficult to find or figure out.
Best regards,
jamesperrett
Active member
As I said before...
The answer to your question is in one of the linked papers (though I can't remember which one off the top of my head).
The answer to your question is in one of the linked papers (though I can't remember which one off the top of my head).
spitzer
New member
I'm sure it is.
Suitably, it's not that long ago when I wrote here that "the answers are in fact very difficult to find".
"RTFM"... sigh.
mjbphotos
Moderator
If the wall sounds 'hollow' when you knock on it, and you can hear people on the other side, there is NO insulation in the cavities at all. The door described is called a 'hollow core' door. Typical cheap construction method, and no, they do not block any sound either. Half the price of a solid wood door, of course. Maybe 1/3 these days with the ever-increasing cost of wood products.
spitzer
New member
Interestingly, it does NOT ring "hollow" from the opposite side. So I guess there's insulation on one side only, and obviously not enough. It's also interesting that the hollow sounding side is plastered, with presumably the same plaster as the solid sounding wall next to it, and the total thickness of the wall is at least 25 cm. No idea why exactly it's constructed in the (unknown) way it is. Can only make assumptions based on that since it's an outer wall, it's probably required to be fireproof.