Orientation of listening position & null/peak question

[matthiasmax]

Hi all,

I'm in the process of planning the listening position & acoustic treatment of my future studio room.
I can't do any building operations like gypsum walls etc. Only hangers on the walls & ceiling is what I have in mind.

I have 2 questions: 1) Does the concrete piece in the middle of the room (32 cm deep on the side and 59cm from the ceiling) affect the way i have to create the image for the nulls & peaks or is it of such small size that i can neglect this?

2) I wonder which direction is the best of placing my speakers and listening position. It seems it would make sense to place everything towards the longer side of the room because there are these big sweet spot possibilities in the middle of the room.

On plan to do 1-2 big hanging absorbers from the ceiling if this is of any importance.

The room is 7m long, 3,69m wide and 2,75m high.

Thanks for any ideas!
Matthias

[Ethan Winer]

1) Does the concrete piece in the middle of the room (32 cm deep on the side and 59cm from the ceiling) affect the way i have to create the image for the nulls & peaks or is it of such small size that i can neglect this?

Probably not, as long as it's not at a reflection point.

2) I wonder which direction is the best of placing my speakers and listening position. It seems it would make sense to place everything towards the longer side of the room because there are these big sweet spot possibilities in the middle of the room.

The speakers should be set to fire the longer way down the room. Full explanation here:

How to set up a room

You'll probably do best to set up at the right side of your drawing, so the cement thing is toward the rear of the room.

You also need plenty of corner bass trapping in as many of the outer 12 corners as you can manage.

--Ethan

[matthiasmax]

Hi,

Ethan, thanks for getting back. That's some helpful feedback. I was about to do some measuring today on the naked room without any treatment. Maybe that will also add some more info to finally make decisions and the positions.

Apart from the positions I'm making thougths about the ceiling. It's 2,75 meters high and also concrete. Again, as I'm not the owner of this room I can't do any building operations. I had in mind to hang a panel with an angle downwards to the listening position here. The panel would not be as wide as shown in the picture as the bass traps in the corners would be on the outside of the. But you get the idea...

Or would these hangers that I saw in a lot of John's studio work as well (see picture 2)?

BTW did I mention that in the front of the room there is this big window almost as wide as the entire room (seen right in the picture). No treatment possible here. Will this be a problem?

have a great weekend everybody !
Matthias

[Ethan Winer]

A flat cloud is fine, and there's no need to angle it. Use rigid fiberglass at least 2 inches thick if not four, with an air gap of at least two inches if not four.

--Ethan

[matthiasmax]

Ethan: thats great info from an experienced (saw the exhausted video ) man!

I really think I have to do some treatment first. Tried to do some measurements but I almost found no position in which the sound was near to a satisfying starting point. The rooms just too empty---


Cheers!

[matthiasmax]

Hi,

a quick one: Is it better to have a panel absorber angled 45 degrees in the corner or fill the corner up with triangle insulation ?

Also is the celing-wall or floor-wall corner more important when bass trapping?

Anyone got experience with the german Isover Akustic TP 1 insualtion? Not sure whether its the right material for bass traping....
The product sheet says its "at least" 30kg/m³. The streaming resistance is ≥ 5 kPa·s/m².

I was thinking of 15cm deep absorbers with a width of 62,5cm. 8cm (almost half of the depth) insulation the rest air gap for the panels.

[ThomasT]

Anyone got experience with the german Isover Akustic TP 1 insualtion? Not sure whether its the right material for bass traping....

Just pragmatical: If a material absorbs not so good, you simply need a little more ... so dont worry much, as long as it is in the range of 20-60kg/m³.
I used Rockwool Sonorock 80 mm think for super chunks. 80 mm Sonorock has the lowest price per m³ (less than 40 Euro). 100 mm Sonorock cost nearly 60 Euro per m³! Sonorock has 30kg/m³. Isover TP 1 seems to be lighter than 30kg/m³ but Isover was unable to tell the mass per cubicmeter!

I build full super traps because they are easier to build. Just stack some triangles of sonorock.
A sheet 45° in the corner must be mounted somehow.

[matthiasmax]

Hi T,

yes, if it the Isover stuff was, say 40kg, I would have had no doubt. But if it has 25kg it really is on the lower limit that I want to achieve.

I'm really thinking about the triangles but I cant to much building to the walls and therefore everything has to be standalone. The absrobers have to be removable without any harm to the wall. I think the triangle solution then becomes more difficult to realize.

We'll see

Thanks for your ideas!

[matthiasmax]

Hi T,

me again

How many m² is the 1 m³ you mentioned for 40,- €?

I have an offer for 40kg/m³ material with a m² price of 8,81 €.

Thanks!

[ThomasT]

Hi T,

me again

How many m² is the 1 m³ you mentioned for 40,- €?

I have an offer for 40kg/m³ material with a m² price of 8,81 €.

Thanks!

Hmmm...how do build a studio if you are not able to do such simple calculations?

80 mm thick Sonorock cost 3.60 Euro per m² at Obi (cheapest source).
100 mm thick Sonorock cost more than 6 Euro per m² at Obi (cheapest source).

I have an offer for 40kg/m³ material with a m² price of 8,81 €.

Sound like Thermorock if it is 100 mm thick. The price would be ok, but is not a Schnäppchen.
Will work, e.g. for Broadbandabsorber.
For superchunks Sonorock was the cheapest I found.

[matthiasmax]

Ok ok Sorry for being blind (or is it a lack of self confidence after reading so many other people's numbers??)

I bought 9.5m² of sonorock 100 for about 40 € today which seems to be a good price!

Now, on to the corner trap building. I really would love to have cleared the question of how to build my corners. Like I said I can't do much building operations to the walls. So the Traps would have to be "standalone". I have attached a pictuer of how i want to built the bass traps.

The facts:
15cm deep frames
10cm sonorock insulation at the front
100cm wide
200cm high

Standing in the corner the triangle of wall-wall-panel would be 70-70-100 cm.

Do I need the frame to be 5 deeper than the insulation when its a corner trap?

Will these be bass traps actually or more like broadband absrobers? Before I start building....

Thanks!

[ThomasT]

I build my superchunks with two roof battens (Dachlatten 24x48 - cheapest timber here) srewed vertical on the cornersides. One 625 mm from the corner, the other 500 mm. Since Sonorock is 1000x625 you get 4 triangles with 625x500x800 of each sheet.
On the top, on the bottom, and one half hight I screwed diagonals, connected to each vertical batten. This is the frame holding the sonorock and where I stable the fabric.

Superchunks are broadband absorbers. They act as high absorber, too. To prevent this, you can cover it with foil. But how think he foil has to be fpr what frequency can only the experts tell. I can tell the influence of foil and the fabric itself when I measured again.

[matthiasmax]

Hi,

So are my corner panels to wide? Should I go for the second approach and make them less wide but instead deeper?

BTW: DO I need to seal these panels. I hoped I didn't have to as I just want them to stand on the floor. No mounting.

Would appriciate a quick feedback.

Thanks & enjoy your evenings!

Bye

[jbassino]

Panel absorbers dont need to be sealed
Its the fiberglass that does the job

[matthiasmax]

Hi

@jbassino: Thanks for the quick reply back then. Helped me a lot !

For all others: I post some of the pics today I made during the building process of my corner bass trap panels.

They are 129cm high, 15cm deep and 79cm wide. I used a 2-layered rockwool method to get a total of approx. 14 cm rockwool layer.
I made 8 absorbers. Cost are as follows:

Rockwool 100,- €
Wood 65,-
Fabric 20m 60,- (IKEA "Patricia" - got it for 3,- instead 6,- € per meter!)
Skrews 10,-

After you have calculated and prepared what you need to buy and have the metarial at your place it goes really fast! I made 4 absorbers last night in about 4 hours.

Cheers!

Cheers