Cutting down the noise. HELP!!!

[Russell Nash]

I'm in the middle of a trio of row houses.  I don't share walls with the neighbors, but there is only 20cm (8 inches) between the houses.  Some noise and a whole lot of vibration makes it over to the house next door.  I want to put in acoustic tiles and rubber matting. 

Do any of you know a website with detailed advice on how to best do this?  I could just go and spend thousands of Euros, but I'd rather save as much as possible to buy "fun" stuff.  Also any help from Germans on the best places to buy the materials would be greatly appreciated.

[David Jupp]

If it's vibration rather than noise, acoustic tiles etc might not do any good at all.   Vibration can travel down into the ground, and depending upon ground conditions can travel a surprising distance.  I used to work at a site where we could feel certain pieces of equipment in operation hundreds of metres away.

It might be worth considering resilient mountings for your machines (or even bench) first to isolate from the floor/walls.

[lordedmond]

got to agree if its vibrations then you need to put you machines on anti vibration feet and go from there


as an indicator when I used to work they had a steam hammer ( converted to 100 psi air ) not a big one about 12 inch dia ram when they were really giving it some welly you could feel it half a mile away, but then it was so controllable you could put a egg on the anvil and it would just kiss it not break it

something like this would help
http://www.gmt.gb.com/products/machine-feet.php


as you have a air gap the sound should not be a problem


Stuart

[andyf]

I would imagine that houses so close together are built with common foundations (perhaps on a single concrete raft) which might be transmitting vibration and noise. The resilient mountings which have already been suggested look like being a good starting point.

If you are still on speaking terms with the neighbours, you might set a machine running and then press your ear to their floor, to check my foundations theory. Before investing in resilient feet, you could  temporarily try three or four layers of bits cut from old carpet under the machines, to see if that makes any difference.

Andy

[Russell Nash]

A few more details and some clarification.

1) The acoustic tiles were a throw in.  I figured if I'm doing other stuff, I might as well cut down on the echo and make it quieter for me. 

2) I'm not dealing with any big machines.  This is why I was thinking about rubber matting.

3) My workbench is our old kitchen.  All the old cabinets and counter tops are setup along two walls.  I have the thing all put together very securely, and I get almost no vibration in my coffee cup on the counter top.  Before I start ripping the whole thing apart, I wanted an idea of how isolated it needs to be.

4)

[lordedmond]

first of all Kitchen cabinets are very resonant devices like a drum, you have them fastened to the wall that will transmit the noise/vibs to the house structure ( have you got cavity walls or are they solid )   here in the UK the older type of what we call terraced houses ( row of houses ) the kitchen or then known as the scullery was only a single brick wall


is it machine noise or you filling and hammering again a free standing structure will transmit less


as other have said run the machines and go next door and listen


Stuart

[Russell Nash]

It's a single slab foundation.  THe house walls are solid stone with about 20cm between the separate houses. 

The bench holds my power miter saw, bench sander, drill press, and scrollsaw. 

Does anyone  know of a website that discusses this in detail?

[lordedmond]

Ahh its the brown stuff butchering devices that are causing the problem along with the common foundations

thats why you always see workers in the brown stuff wearing ear defenders 


IMHO they are noisy machines and create a lot of high frequency noise , metal working do dahs work at a much lower speed and produce less intrusive noise


If you had stated the type of equipment in your first post you would have got a more useful answers

sorry but I do not know of any site that would be able to help  try googling for workshop sound suppression equipment


Stuart

[BillTodd]

Having endured 16 months of hell from a noisy neighbour (had to threaten to sue him to fix the problem!), my sympathy lies with your neighbours ;)


First  - engage your neighbours, talk to them ask them to help you solve the problem.

Second - it is not the level of noise that will be the problem, it will be the duration and repetition that causes them grief. If you can limit your noisiest periods to day-times and weekends it will keep them happier.

Third - it's much nicer to work in a quiet environment so, making sure your machines are not too noisy is always best .


It is possible to keep anything quiet; I've been on a film-set standing next to a truck mounted multi-kW generator and not been aware that it was even running. I've been in sound studios watching a drummer through a window beat the hell out of his kit in perfect silence.

There's only one way to stop noise - Mass and Isolation (I know that's two things, but they are intrinsically linked).

There will be both vibration and air-borne noise from your machining.

Fixing the airborne noise is about  stopping it escaping and absorbing it, so double/triple glazed windows (that are shut while you're working ) and doors that are heavy and well sealed (look for 1/2 hour fire-check doors). 

Carpeting, soft furniture curtains all help to absorb the noise (not all are conducive to machining so do what you can).

To stop vibration, mount your light-weight gear on heavy plinths (something like a couple of layers of granite work-top) float the plinth on rubber matting (e.g. carpet underlay - with more between layers.  200kg of granite takes a lot of energy to vibrate so, your small lathe/mill will not move it much and the rubber will stop that small movement being transmitted to the neighbours 

As Stuart says, cabinets can act like resonators and make the sound louder - and open frame with shelves may be a better option.

I happy to suggest more if you need it

[edit]

I have the thing all put together very securely, and I get almost no vibration in my coffee cup on the counter top.  Before I start ripping the whole thing apart, I wanted an idea of how isolated it needs to be.

That suggests to me that the floor and wall is adding mass to your workbench - not what you want! Pull the cabinet away from the wall and separate the bench from the floor with rubber mat.  If possible add mass to the top of the bench (assuming it is strong enough) . How about a couple of cheap paving slabs under the work top ?

[andyf]

I'm pretty sure it will be noise and vibration transmitted through the structure which is the cause, Russell. Barring open windows etc, airborne soundwaves would have to vibrate your stone wall, which would have to vibrate the air in the gap between the houses, then that would have to vibrate the neighbours' stone wall, which in turn would have to vibrate the air inside their house. Given the relative density of air and stone, the attenuation would be enormous.

I think the only guidance you are likely to find on the Web is advertising material like this very fancy system, which needs a compressed air supply: < http://www.globalspec.com/FeaturedProducts/Detail/BRDNoiseVibrationControl/Lower_Noise_Levels_Protect_Machinery_Foundations/199536/0 > .

Simple resilient rubber-type mounts would be easier on the wallet, and I'm sure they would greatly mitigate the transmission of noise and vibration if used beneath the feet of your benches and to secure your benches to the wall. Come to think of it, it would be easier and less disruptive to put them between your machines and the bench tops. That would have the added benefit of reducing the noise within your shop because the benches would no longer act as sounding boards.

As I said before, experiment by standing your machines, without bolting them down, on layers of old carpet or on rubber car mats to see if that helps, before spending real money.

Andy

[BillTodd]

As I said before, experiment by standing your machines, without bolting them down, on layers or old carpet or on rubber car mats to see it that helps, before spending real money.

All good advise  but, if you try to float a light machine it will need soft rubber to work well, so it'll be wobbly . if you bolt the light machine to something heavy, the pair can be 'floated' on stiffer material which does not wobble as much.

You'll also be pleasantly surprised when the machine performs better as a result

[Lew_Merrick_PE]

Russell,

1) Make reasonably stout, hollow bases for your machines.  Fill the hollow with sand.  I use fairly large diameter screws through the sides of my base to fill/empty the sand.  Mount the base on a pair of short (3 in/75 mm) I-beams (S flange).  Get some 2 inch (50 mm) fire hose the length of the I-beams.  Bond a tire valve stem in place as far in from the end as you can reach.  Seal the ends (good contact cement) and fold them over such that the "folds" stick out a bit from the ends of the I-beam.  Drill a hole through the I-Beam flange for the tire valve.  Bond the hose to the underside of the I-beam.  With everything assembled, inflate the hose sufficient to lift the base (with tool installed) about 1/4 inch (6 mm).  The mass of the unit should keep everything from "walking" while the air reduces the transmission of vibrations.

2) Hang several layers of indoor/outdoor carpet an inch or so from the walls with an inch or so of spacing between each layer.  I also did the same thing above & below my installation using "stretchers," but I did this when I had my lathe, milling machine, bandsaw, and grinders set-up in a dorm room in college (back in the dark ages).  I was in a 3rd floor dorm room and could run my machines at 4 AM without my neighbors complaining.

The standard I-3 X 5.7 lb/ft S-flange I-beam is 2.375 inches wide on the flange.  At current prices, new beam would run (US) about $6/ft.  It should be available from stock at any steel "service center" distributor.

[hopefuldave]

[quote Lew_Merrick

1) Make reasonably stout, hollow bases for your machines.  Fill the hollow with sand.  I use fairly large diameter screws through the sides of my base to fill/empty the sand.  Mount the base on a pair of short (3 in/75 mm) I-beams (S flange).  Get some 2 inch (50 mm) fire hose the length of the I-beams.  Bond a tire valve stem in place as far in from the end as you can reach.  Seal the ends (good contact cement) and fold them over such that the "folds" stick out a bit from the ends of the I-beam.  Drill a hole through the I-Beam flange for the tire valve.  Bond the hose to the underside of the I-beam.  With everything assembled, inflate the hose sufficient to lift the base (with tool installed) about 1/4 inch (6 mm).  The mass of the unit should keep everything from "walking" while the air reduces the transmission of vibrations.

[/quote]

I've seen similar setups using (what looked like) tyre inner tubes between doubled 3/4" ply boards - the boards had 2x4 timber "walls" with 4" of concrete poured in. This was in a recording studio drum booth, drums sat on a nice reflective surface (the concrete/ply sandwich) so their racket sounded right, but the "thump" from the bass drum etc. didn't transmit to the floor structure - seemed to work well, the difference in low frequency noise between in and out of the booth was (wild-assed-guess) 60dB or so (in real numbers, about a millionth!) - the booth walls were *heavy* though, window was three layers of 1" glass separated 6" or more, inner and outer separately attached to inner and outer 8" concrete block walls, middle layer of glass "floated" in a steel frame with rubber mounts to the inner wall - sound engineers sometimes have to do a lot of work for isolation!

I reckon something similar but a bit simpler would work for machine noise, like Lew suggests, if filled with concrete instead of sand you'd find it easier to bolt the machines down? In the world of noise isolation, there's no substitute for mass!

Dave H. (the other one)

[Russell Nash]

Update

The wall seemed to be my biggest problem.  I had originally wanted to have my machines against the wall, so I could have pegboard behind the machines.  Looking at my cabinets, I realized I could set them up with a few drawers under the machines.

I decided to create a machine and heavy hand tool island.  All of my machines will be there along with my power tools.  I'll also do my heavy work like hammering on the island.

I bought machine feet for the five cabinets I wanted to use, and raised the tops to over a meter (approx. 43") with steel cabinet legs from Ikea.  I followed some more of your advice by trying to make the whole thing as heavy as possible.  All of the cabinets are bolted together, and I have some paving stones lined up to put inside the cabinets if I need more weight. 

I will hopefully finish attaching the counter tops today and can start bolting down the machines after that.