Brainstorming for Space Next Door

General
41

In sound isolation work I’ve done, you’re looking at

  1. lots of money
  2. tons of weight
  3. diminishing returns in a building as old as ours

Fiberglass insulation does jack squat below 2000Hz. Double studs on rubber springs & 2 layers of drywall with vinyl, acoustic caulk, and a 4" air gap would do, but you’d have to do the walls too, not just the ceiling.

Dave is right about the talking issue. Even legally. A healthy conversation is 70dB SPL within 3 feet or so. Noise laws and regulations are vague in most cases, but even the most stringent only start above 90dB, which is 8x the power level of conversation.

If you really want to research, Steve Klein has good info on his site: http://www.soundcontrolroom.com/plans-info-advice/details-plans

L

42

I keep a decibel meter at the hive if anyone is ever curious how loud they or something is as well.

43

In sound isolation work I’ve done, you’re looking at

  1. lots of money
  2. tons of weight
  3. diminishing returns in a building as old as ours

Thanks, that’s a better summary, though I would be clearer on “lots of money” to be in the tens of thousands, assuming you hire it done.

Fiberglass insulation does jack squat below 2000Hz.

Oh, fiberglass is a crappy solution, but it’s a quick, cheap, and easy to install solution. Everything else starts to get into serious money and effort. Also most people have their hearing fall off after about 5kHz, so it’s not the worst thing in the world.

In this case the ceiling matters because that’s the only shared wall with Josh above us. I think there’s effectively an L shaped space with a high wall and then the ceiling/floor that’s shared.

44

I still wonder about where the tenant is upstairs, the ‘Space Taco’ (insulated area above the wood/small tools area) was installed when the Hive Got that space (for noise abatement to the tenant)… If noise from people talking outside the fablab or lounge is a problem now, Why wasn’t it THEN?, Why wasn’t the agreement to have space taco stuff installed there as well?
I suspect those areas were not in use when the Hive moved in there but they are now.

I know you can look up and see between the floorboards, especially where the knotholes are… So there is NOTHING but a wooden plank between us. Air and sound pass easily through the gaps. (Trent is heating part of his space)

What about we talk with Josh and try laying in some carpet foam (or the thicker puzzle mat stuff) and putting a carpet on top of it on the floor upstairs? We can ask him about color or design, I’m not advocating installing the carpet, but laying it in place to test. and he gets a nicer floor, If he really wants woodflooring, we could instead lay wood on top of the foam. Lots of people lay carpet in without installing it.

I don’t know the size of the rooms up there, but it might be possible to purchase carpet remnants of the right size, and it would cost less to try this than some of the other solutions. Even purchasing carpet and foam at normal prices will be cheaper, We could lay some thin plywood down first (luon, maybe)

In the past I did some reading on soundbooths for music recording, it’s a matter of how MUCH you want it to isolate sound, we probably don’t need a complete cut off, just reduction, The carpet and foam and wood each absorb different frequencies, it will make what is called a ‘comb filter’ but it ought to dampen and block enough to make Josh happy.
He’s going to be colder, though. but that may also help with heat going up there in the summer time,

A quick check of Lowes (website) shows carpet ranging from under a dollar per square foot up to a few, (yes you can get VERY expensive but we aren’t buying that stuff) We could try doing one room and see if it helps, Any idea how big the rooms are up there?
I don’t know if that price includes the mat under it or not. I would definitely lay down thin plywood or chipboard first.

Nancy

45

IT"S CALLED A SKY BURRITO NANCY!!!

46

Burrito, Schmerrito, (grin) but my question stands about the upstairs apartment,…

"Is the tenant using an area for living quarters that was not previously in use?

And, Would putting down a carpet with a matt and maybe plywood under it be enough to curb the noise issue for the tenant?

47

"Is the tenant using an area for living quarters that was not previously in use?

Not sure it matters. As long as we’re making reasonable use of the space, in the manner it was intended, I don’t think we’re crossing any lines.

You could make a similar argument for having a the house next door to your house sit vacant for years. Then a new family moves in, and their dog is always barking. It’s annoying, but they haven’t done anything wrong.

And, Would putting down a carpet with a matt and maybe plywood under it be enough to curb the noise issue for the tenant?

It would help, but probably not significantly would be my guess. This is because the material is fairly thin, though all the folds inherent in cloth will help. Further I don’t think anybody would know until it was tried. Lots of different things effect noise and it’s transmission. It’s a very inexact science at the best of times.

48

Doing things in another person's apartment is pretty much a no go. Ever. That is a dune sand worm level can of worms.

I plugged in 250sqr feet into an online calculator for added a dropped ceiling. That quote said ~700 in materials and ~700 for labor. Which also matches with estimates of $2-$5 per sqrft.

I imagine we would have the skill to put a drop ceiling in, assuming we had people willing to do the labor. (I would not due to my back injuries and that being that high up would cause a constant stream of poop to come out of me.)

So that is at least a rough number to start from in a discussion. And assuming my random guess if 250 sqrft is close.

49

Okay, Andrew, here’s your justifications:

Trust me, my professional field of specialization is acoustics, electroacoustics, and psychoacoustics. Please excuse me if I get touchy in this area, but I didn’t study it for 10+ years, publish, and become a professor without some god-damned effort.

First, I think you meant that our hearing drops off above 15kHz, not 5kHz. Human hearing can extend into 20+ kHz in young people / children, however pressbycusis due to exposure to loud noise and resulting ear damage causes this high frequency loss.

The most sensitive range of hearing in humans is 4kHz to 6kHz. So, we actually hear 5kHz as 2x as loud as any other frequency. See the equal loudness contour –

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=imgres&cd=&cad=rja&uact=8&ved=0ahUKEwji_4_Q4_vRAhWIKCYKHfA_BBMQjRwIBw&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FEqual-loudness_contour&psig=AFQjCNGr5v1ur1mNKKOoZsS8J5upSPxmRQ&ust=1486481064897910

This is the critical band for speech ineligibility. Humans evolved to have high sensitivity in this region to communicate. It is also critical band for masking phenomena, and intra-aural localization.

If we’re talking about material only, we need to find the attenuation in sabins. A sabin is the amount of energy converted to heat across a barrier of dissimilar material of a given boundary area. Because sabine’s equation requires knowledge of air volume, absorptive surface area, and time (RT60), we can’t just get a convenient percentage value or any sort of useful sound proofy-ness indicator that makes sense in multiple situations.

But, yes, sound absorption is related to a material property (absorption coefficient). The misconception is that the absorption coefficient is a percentage of the sound absorbed by a material. For instance, the absorption coefficient of 2.5" of R8 fiberglass batt is about .92 at 1kHz . This does NOT mean that 92% of the sound is absorbed. It simply means that .92 is factored into sabine’s equation.

That means that in one 32ft roll, we’ve got about 13.8 sabins of absorption.

For fancy, 10cm thick acoustic foam it would be 14.85 sabins

What does this tell us? It ONLY tells us that acoustic foam works better than fiberglass batt, but not by a whole lot, except that we only need 1cm of foam vs 2" of batt.

I STILL don’t know how much the sound is deadened in our case. I’d have to know volume of the space, surface areas, average sound pressure level, current absorption of surfaces, resonances, and time variables.

I’m actually trying to say is that this is not so simple, and is virtually impossible to predict. Furthermore, the absorption of any given material means very little, actually. Much less than the structure of the building we can’t change.

Finally, I’ll put it this way. In order to significantly deaden sound between the two spaces, we would also have to eliminate heat loss between the two spaces. The two are related, and I think everyone can grasp that we’re not going to make our space or even a part of it LEED certifiable any time soon.

Finally, sound is not heat. ANY air gap, whatsoever, even just an inch, that is not sealed will negate most of the work. Hence, Nancy’s point that there are gaps in the floor / ceiling. Ever single one would have to be closed with caulk before any insane amount of batting would do much.

So, my estimate would be to decouple the ceiling and shared walls with floating rubber mounts, double stud and frame (not drop ceiling). 16" air gap. Double gypsum acoustic grade board. Packed sand and rubber at floor couplings, and vinyl seal with acoustic caulk. So, the answer is so expensive that my conclusion is:

Screw it, it’s hopeless.

If you really wanted a number, we’d probably be looking at more than $70k (DIY cost) to be able to run the bandsaw at night. At the very least, the cost of make a new timber framed ceiling for our ENTIRE ceiling space, not just the area under this dude’s apt., and two layers of sheetrock.

If folks want to put up insulation, I won’t stop you, but there is no significant return on investment.

Lorin

P.S. I went way too overboard here, but I think my point is made.

50

Sorry, meant 2-4k is most sensitive. 5k is adjacent knee area, so also sensitive, but not most sensitive.

51

Okay, Andrew, here’s your justifications:

Trust me, my professional field of specialization is acoustics, electroacoustics, and psychoacoustics. Please excuse me if I get touchy in this area, but I didn’t study it for 10+ years, publish, and become a professor without some god-damned effort.

Sorry, I take it all back. Lorin can clearly guess. Insert the wayne/garth we’re not worthy. I bow to your authority. (And no sarcasm here)

If you really wanted a number, we’d probably be looking at more than $70k (DIY cost) to be able to run the bandsaw at night. At the very least, the cost of make a new timber framed ceiling for our ENTIRE ceiling space, not just the area under this dude’s apt., and two layers of sheetrock.

If folks want to put up insulation, I won’t stop you, but there is no significant return on investment.

Okay, my mistake, I thought there might be a slight amount of return, for a slight investment. Thanks for posting a more in depth analysis, I appreciate it.

52

Lorin, LTDR Version?

In your opinion, what level of investment would be required to make it so we could have people in that new area and block enough sound that exited conversations will not disturb the resident above that space?

53

I’ll bring in my meters and equipment and make an assessment of the space today. That helps a lot.

Making it a meeting area is not the biggest deal in the world. Simply putting stuff in the room will do more than any amount of padding on the walls. Furniture absorbs and breaks up sound well, especially couches.

Also, I’m with Dave B on the “conversation” issue. If I live in an apartment in an old building, I expect not to have a neigbor who uses a radial arm saw at 1am. However, the occasional party, argument, etc – I do expect that.

Lorin

54

This may sound odd, but I could make a sound meter that flashes lights or other indicator (non-loud) if the dB RTA goes above a threshold at a given hour. Not being loud may be the best answer, and reminders don’t hurt.

Lorin