Pale blue cloud  



Building a saxophone practice room


This article is about the building of a small practice 'room' in my attic. It first appeared as a series of posts on the Sax on the Web forum.

I live in a 1950s town house which is build well enough, except for the fact that they soundproofing is not of a very high standard. I am a witness when someone three houses down the block is drilling a hole in a concrete ceiling, or when the neighbours are frolicking in their bedroom.

Needless to say, playing a saxophone (especially practicing top tones, and scales) or learning to play the trumpet, is not always amusing to listen to for someone else but me.

So I decided to build myself a small practice room in my attic. It only needs to house one person, and it does not need to be 100% soundproof since its not a recording studio. Just enough to be able to play at any length of time at any part of day without upsetting the neighbours.

The attic roof is slanting, which limits the height of the box, as I shall call it for short, and it needs to have 10 cm clearing from the walls all around, for soundproofing reasons. I also need to leave room in the attic for other 'lounging' activities, as well as a bed for friends to stay over, and a desk.

Taking all this into account, I decided on the layout below (picture not to scale).

The long side is 2.15m, the short side on the left (where the door will come) 0.95 m wide and the side on the right (which will come under the slanting roof) is 1.15 m wide. The right hand side starts slanting in at 1.50 m, and the highest part will be 1.98 m.

The base frame is constructed from 44 x 75 mm pinewood beams. At the corners where the beams meet, I employed lap joints which are held together by heavy metal braces. I don't use glue or nails because I want to be able to take the whole thing apart in case I want to make modifications or if I ever move house.

The lap joints are partly made on my tablesaw. But because I don't have dado blades, I have to do part of the work manually, i.e.: use the table saw to cut the edges of the joints to the right depth, then use a chisel to cut away the wood.

At each corner, metal brackets will hold the corner posts vertically in place. Initially I thought about attaching them with nails, but later I decided on screws (I prefer a good screw over a nail anytime ). The screws make the metal brackets about 5 mm high, so to compensate for that, and to ensure that the corner posts are actually resting on the base frame and not on the screw heads, I employed a router to recess the brackets into the wood.

A central beam provides additional stiffness as well as support for floor panels. This one is held in place by a half lap joint and a 60 mm long screw. The stiffness is required because the base frame will not be placed level on the floor: it will be supported by a couple of vibration insulators. More about those later.

The little wood block on the left provides additional support for the door frame.

This is the completed base frame, looking from the part where the door is, to where the slanting roof is:

There is a little extra space on the far left, this fits nicely between the chimney and the wall, to create some extra space. The whole thing is not exactly spacious so I want to use as much real estate as possible

The two diagonal beams near the front are supports for the door frame. They are firmly glued to the base frame with construction glue, held in place by just one screw.

This is the unfinished doorframe.

It is made of the same 44 x 75 mm beams as the base frame, and held in position by two metal brackets at the bottom, diagonal braces at the rear and eventually by a couple of horizontal 'stringers' linking the corner posts to the other vertical posts that will be made along the long sides.

The booklet I read about making a sound-proofed room mentioned that the door should be as small as practicable. So I partitioned the front side: the left and bigger part will be the doorway. The one on the right will form part of one of the soundproofed boxes that form the ventilation system.

I could not use the metal corner brackets for the central vertical posts, but by glueing it to the one on the right using a little crossbar it should stay in position. The central post is resting on a little wood block that I glued on, since it is 31 mm wider than its support beam (75-44 mm). This little wood block can be seen in one of the earlier pictures.

Because my attic is quite small, and I'm making part of this thing up as I go, I have to go out regularly to buy more hardware for my little project.

So, I bought four couple of sheets of triplex (122 cm x 60 cm x 4 mm) and four multiplex panels (122 cm x 70 cm x 12 mm). The triplex will be screwed to the underside of the support frame, and the multiplex will be placed on top of it, to function as the floor I'll be standing on. The original plan was to use underlayment, but the stuff sold at the DIY was so warped that I thought better of buying it. I just hope that the 12 mm multiplex, supported by the central beam of the baseframe, will not bend too much under my weight.

The purpose of the double layers of panelling is twofold: it provides extra sound proofing, and if needed I can fill the space between the two with insulation material (like Rockwool) for extra soundproofing.

I ordered neoprene mountings (from this company, via a local dealer) to counter contact sounds, they should arrive here next week.

There's a whole range of them (they are the 'RD' type of mountings), and you pick the type you need based on the load it is to bear (Newtons). I bought seven for a total of EUR 135,- including VAT and P&P. The amount you need depends on the type of construction you're making (think stability), and the load that your floor can bear.

Before they arrive there is little I can do because I have to be able to put the base frame on its side to fit the mountings.

Here the underside is attached to the base frame. I used 4 mm triplex because it's cheap and it does not have to bear any load apart from maybe some insulation material.

There are four sheets of triplex. At the sides where the sheets meet each other, I removed a strip of material about 4 mm wide, 2 mm deep along the entire length of the sheet. That way each side is overlapping its neighbour, adding a little to the soundproofing and preventing any Rockwool particles from 'leaking' out over time.

I'm not quite sure yet where the electrical conduits for light and inside wall outlets are going to be, but in preparation I drilled two 17mm holes through the beams in the area where the whole thing will be closest to an existing wall outlet:

Top left one can see how a metal corner support has been let in into the wood to cater for the height of (support + screws).

The mountings arrived by mail. They feel very sturdy and smell rubbery. Each comes with a 3 cm long bolt which can be screwed into the top. Since the bolt is too short to go through the baseframe beams (which are 75 mm), and it's not metric thread so I cannot buy longer bolts either (easily), I am going to screw them upside down underneath the baseframe, with two bolts per mounting.

Things are going pretty well so far. This one was taken after fitting the vibration mounts to the base frame. After that I put a sheet of hard carton on the floor, and placed the thing on it.

All the posts and longerons fit surprisingly well *pat on back*, although the wood, being pretty cheap and probably not so well cured, is a little bent now and then. The pine is pretty coarse, which means the cuts are kind of ragged. Lots of tiny splinters

The longerons are placed at a 60 cm separation (vertically), which should provide sufficient stiffness (hopefully) and enough 'meat' for holding the gypsum plates later on. Less separation would be better, but requires more wood, money and tim

The walls are almost finished now. Only the bit where you see the clamp (center of picture) still needs to be fastened, and the diagonal brace that ties the back wall to the left side wall.

Next: the horizontal beams connecting the left and right side wall, which will also provide the support for the roof gypsum plates.

By the way: it's not my bad cropping, but there's not enough space in my attic to fit the entire box on the picture.

This is the first time I use 'lubricated' screws; they have some kind of red stuff on the first 1.5 cm of the thread which makes it easier to drive them into the wood.

I'd never seen them before, and thought I'd give them a try, since pre-drilling each and every screw would just be too much of a hassle.

Let me tell you: these are great! No pre-drilling required and little pressure on the drill that I use as a screwdriver (with phillips bit holder). I finished the first box of 200 today, and got myself 200 new ones. They're more expensive than 'regular' screws, but worth the time and hassle they save.

Eventually I decided on using styrofoam for the floor insulation, in stead of Rockwool. Basically because I don't like to work with Rockwool: kind of difficult to cut those sheets to the right size, and very messy. The little fibers get everywhere and they itch.

Here's the floor with the styrofoam in it; two of the three floorpanels removed.

Styrofoam is very easy to work with. I used panels 4 cm thick, which can be sawed to size with a normal (hand operated) wood saw.

The only drawback of the stuff is that it creates lots of little scraps and crumbs that are static and stick to everything: hands, pants, saw, workmate, shoes. Use the vacuum cleaner before walking through the house, or the stuff ends up everywhere :-/

A switch to the left of the door will switch on/off the power to the. I plan on using one of those switches with a red light built in, so it's easy to see from the outside if I left the light on on the inside.

Because the wall outlet is at the left rear of the box, I first have to route the power to that switch, along the top of the box.

From the switch it goes back to approx. the middle (at the point where you can seethe little plastic distribution box mounted to the frame), where it enters the box to power the air extraction fan, light and a power outlet inside.

I thought about running the electricity under the floor because it looks neater out of sight, but decided not to because of the risk of an electrical short circuit in case drinks are spilled.

The light that is hanging from the ceiling will have to make way at some point, because it's partially hanging over the box now. Need to find me something new there.

Finally - it's time to start with the dry wall!

I bought 12 panels of 2.60 x 0.60 m, 12.5 mm thick, which have been sitting downstairs, blocking traffic in the hall. They are just short enough to fir through the stair wells, a kind of difficult to maneuver because they are heavy, and have to be held in such a way that they don't crack from bending too much. So far so good.

I use a jigsaw to cut the panels to size, taking care not to exert to much stress, lest they break.

In the picture below you can see that I fitted a small strip of wood to the baseframe just above the floor. It has the approximate thickness of the dry wall panels, and serves as a support for fitting the panel: I just let it rest on that strip of wood, use one or two heavy clamps (that I can operate single-handedly) to hold the panel to the box frame, and then I have both hands free to screw the panel to the box.

One of those clamps can just be seen on the far right in the picture below, hanging from the frame.

Got to start thinking about how I'm going to build those baffles for air in/out...

Two baffles will take care of the fresh air: one is equipped with a fan that sucks the air out. The other one has no fan and just lets the air in. I am located in between.

I made with the first one today of 18 mm MDF left over from another project. It measures about 65 x 16 x 16 cm.

You can see the fan at the bottom of the baffle. It's an ordinary bathroom ventilation fan, which runs on 230 V. The outside diameter is 100 mm. I fitted it at an angle to the exhaust opening because it does not run very silent. In this way, by applying some extra sound insulation underneath, I hope the noise of the fan, outside of my box, will be muffled a bit.

Above the fan one can see four small MDF boards which partly block the way of the air in such a way that there is not straight path from the top of the baffle to the bottom. The air has to zig-zag past the planks. This provides the damping of the sound waves.

This MDF box will be closed by one plank, having an air inlet at the very top.

Here's the baffle again, half an hour later, with sound proofing foam applied to the inside.

The foam is about three centimeters thick, and glued it place with styrofoam glue. The foam is really easy to work with; I just cut it to size with a pair of scissors.

I regret not making this box a bit deeper: when the back panel is on there won't be much clearance for the air to flow through, unless I don't put the foam on the back panel. And without the additional foam the soundproofing will be just a little less.

Close-up of the air exhaust, looking in and up.

I closed the wall where the exhaust baffle is, and applied sealant to most of the seams between the panels, to prevent noise seeping through.

Next up will be the air inlet baffle. Here are two images, the first one is from the outside looking in, the second one is from the inside looking out.

This baffle too will be treated with the black egg-carton foam, like the outlet baffle, but it won't have a fan to force the air through.

You can clearly see the 4 cm styrofoam I use for sound insulation.

I'm done with the electrical stuff now. The only thing that can be seen on the inside is the rectangular connection box (top) and the power strip for various appliances (iPod, external speakers, cooling fan, etc.). Electrical wires enter the rectangular bit through the wooden panel from behind. Inside I can make as many connections as I need, and then feed them outside through push-out holes that have the same diameter as the PVC pipes used for wiring.

I hope today's was the last run I have to make to the DIY store. Spent another €150,- on stuff:

  • four packs of 4 cm styrofoam
  • tube of styrofoam glue
  • tube of sealant (got the black variety, oh well *shrug*)
  • 18 mm hardwood plywood for the door (65 x 175 cm)
  • hinges plus screws for the doors
  • electricity stuff (connection box, wire, plug)
  • wood for doorframe
  • plastic strip to protect edges of gypsum plate from vacuum cleaner bumping into it

And best of all: spotlights!

I don't like normal halogen bulbs. For one because they use a lot of power but also because they become extremely hot. And in the limited space of my box I can't have that because temperature control will be difficult as is, and I don't want to burn myself on them (small enclosure).

So I bought the LED bulbs, which will replace the standard bulbs that came with the armature. The power consumption of these LEDs is only 1 Watt as opposed to the 50 Watts of normal halogen bulbs. And they don't get warm.

If it turns out that the colour temperature is nice I may decide to use the elsewhere in the house, too.

The box is ready to be played in! Yesterday my holiday started, and I completed the box by fitting a couple of weather strips around the outside of the door. Apart from dressing up the inside (putting some nice cloths on the wall so I don't have to stare at the styrofoam) and finishing the seams in the gypsum board on the outside, it's done.

I cut an old rug to size, which makes the inside more friendly.

First impressions: when standing outside the box, one can hear what is going on inside, music-wise, but at a much reduced level. The attic is now near-empty, so I expect noise levels to go even more down when there's a futon, furniture, etc. On the ground floor, very little can be heard. I think that the neighbours won;t hear anything at all, or only so little that it does not raise annoyance levels  

Inside, the reflected sound is less loud than I anticipated. To be completely sure that it does not harm my hearing I'd probably need to borrow a decibel meter (is that what it's called?), but there are less reflections than in a normal room with a hard wooden floor and near-bare walls.

The two 1W LEDs give of enough light, the hum of the ventilator is barely audible and there is a noticeable continuous supply of fresh air. There's enough space for a little table and a chair, but two of those triple-legged saxophone stands would take up too much space, so I'm debating making a duo-sax stand out of wood myself.

Conclusion: I'm very pleased with the results of this project!

© Palebluedot