studio foam

[mixaholic]

is it necessary to cover each inch of the walls in a room with studio foam? cause i see pictures of studios and i only see foam in different areas. why do they only have it in those areas and how do i find out where i should place my foam or is it jus bettter to cover each in of the room with it? thanks

 

[Massive Master]

Covering a room in foam normally causes more problems than it fixes -

A few sheets to control flutter here and there, fine.

If you get the LOW end under control, which foam isn't going to do, THEN work on the other stuff. If you don't control the low end, you control nothing. When you DO control the low end, you control everything.

Personally, I wouldn't even try looking for flutter and comb filtering problems until the low end is addressed. Once it is, it's a piece o' cake to tackle the rest.

 

[Robert D]

What Massive said......

To expound, foaming up the whole room just sucks the highs out of the room, and kills any sense of space. Low frequencies have little to no directionality, and the frequencies that do give spatial information are the ones sucked up by all that foam. And since only the upper half of the spectrum is affected by the foam, the frequency response of the room gets skewed like a low pass filter.
The right approach, disregarding bass trapping, is to strategically place some good acoustical foam at the first refection points (use a mirror to find them) and generally to break up any large flat reflective surfaces, AND to mix that with some diffusive surfaces. Diffusion gives complex reflections that give the room a sense of space. There are diffusers that you can buy that have mathematically calculated shapes, but even a bookshelf with various sizes of books in it serves to create diffusion. The main thing is to find a combination of absorption and diffusely reflective surfaces that gives an even response, not to create a big life sucking low pass filter.

 

[Ethan Winer]

> how do i find out where i should place my foam <

See this Acoustics FAQ:

www.ethanwiner.com/acoustics.html

--Ethan

 

[SouthSIDE Glen]

The right approach, disregarding bass trapping, is to strategically place some good acoustical foam at the first refection points (use a mirror to find them) and generally to break up any large flat reflective surfaces, AND to mix that with some diffusive surfaces.

Bingo! There's a whole lot more to quality room acoustics than just this, but Robert has hit the simplified main points very well on tops correct emphasis on bass trapping.

- Bass trap the corner joints between the walls and the walls and ceiling.

- Throw some diffusers (special purpose diffusion panels or natural like a bookcase) on the walls and ceiling at points where if you put a mirror there, you could see your monitors in the mirror from where you sit.

- Throw some heavier absorbtion on the wall behind your monitors at the key reflection points.

- If you have wall to wall carpeting in your control room, break it up with some plastic anti-static mats or portable plyood sheets. Too much carpet can leave a room too attenuated-sounding. OTOH, if you have harwood or concrete floors, break that up with some soft furntiure and or thick pile area rug. In other words, find a balance between reflecting surfaces and diffusing surfaces for the floor.

- Set up your desk/console symmetrical to the room. Place it along the middle of the longest wall, if possible, but not right up against the wall. Do NOT set up in a corner of your room if you can at all aviod it. That will medd with your bass response terribly.

G.