Small Room Acoustics upgrade

[Simon AdamsParticipant]

Hi John,

Thank you SO much for your time! I have a small room (8.5 ft wide, 11 ft long, 9ft tall ish) and it's my tracking and mixing room. I have room corrective software (ARC) and Sonarworks 3 corrective software for headphones. I record mainly vocals and acoustic guitar. Most else is either direct or VI.

I've treated the room a fair amount. I have the walls covered mainly with 2 levels of 1 inch absorption.

What should I concentrate on now? Bass traps? If so where? Or should I go for panels that I can move for mixing and tracking? I am using a Reflexion Vocal Screen for recording everything and even putting it behind my head for mixing at the moment.

Thank you John!

Simon

• This topic was modified 8 years ago by Simon Adams.
• This topic was modified 8 years ago by Simon Adams.

[John BrandtParticipant]

Simon,

Your question is very common and I hope that many people will read this:

1 and 2" treatment on the walls can reduce the RT-60 (reverberation time) quite substantially, but only effectively from about 1.6 - 3 kHz and up. This leaves the rest of the musical spectrum untouched. 8" deep 1/4 wave trapping works down to 423 Hz!

Bass trapping is critical in order to be able to hear the bass that is on your track. Otherwise the frequency response will be very lumpy around the room. Boomy here, thin there, etc.

The most important part played by bass trapping is that the trapping added to a room reduces or eliminates the diffuse field which, in turn, broadens the ‘sweet spot’. The free field that is created by trapping has everything to do with the Critical Distance of a room.

Critical Distance (Dc):

The ratio of direct sound to ambient sound is dependent on the distance between the source and the listener, and upon the reverberation time in the room. At a certain distance the two will be equal. This is called the "critical distance." So this is basically defined as; the distance that a sound ceases to fall off at -6 dB per doubling of distance from the source. (Inverse square law) The source sound goes constant volume at the Dc (Critical Distance) of the room. Once the listener is at the Dc from the source sound, the perceived level is the same everywhere in the room. This point in space can translate to ‘MUD’ in a studio room where you must record many instruments at once.

Control Rooms are heavily trapped to create a large free field. A control room being trapped is not an unusual thing and most people assume that it must be done, but tracking rooms – often called ‘live rooms’ – also need good low frequency trapping. You won’t be able to work multiple instruments or vocals in the room at the same time unless you have to have a decent amount of trapping in the walls and ceiling. Without the trapping, you will need to use close-miking techniques, and then why do you need such a large room?

Note that the term ‘live room’ is not so named because the room is ‘lively’ or ambient. It is simply the room where ‘Live Performance’ occurs. I prefer to call them ‘Tracking Rooms’ so as not to confuse.

I hope this is helpful.
Cheers,
John

[Simon AdamsParticipant]

Thanks so much John. Much appreciated info!

Can I ask, what kinds/size of bass traps would you recommend and where would I get the best bang for my buck putting them in the studio? And... are bass traps preferable to panels I could move etc.. I would like to spend somewhere in the 200-300 range if possible, but perhaps the better question is, how much should I spend?

Thanks again

Simon

[John BrandtParticipant]

Simon,

You could probably do pretty well with $200-$300.

It seems that most of you guys have a temporary setup and it probably wouldn't be practical to make new 'acoustic treatment' walls, but if you can, do it. Since boundaries are the best place for trapping and treatment, remember that you have 12 corners in a rectangular cuboid. 🙂

4 - wall/wall corners
4 - wall/floor corners
4 - wall/ceiling corners

So if you have treatment in all of those corners, you are doubling your efforts! Traps are more effective where boundaries meet.
And... if you place treatment where THREE boundaries meet, it's adding another boundary to the equation making the trapping that much more efficient.

That's why we go floor to ceiling.

If you go with panels, you can stack them. Vertical room Corners: trap them top to bottom.

Simon, you could use a 4 - 6" thick cloud trap overhead. Cover about 1/3 of the room, from forward of the mix position where the speakers are to the back.

----

Build incrementally, as you can afford it. Begin with the things that you will see the most results first, like vertical corner trapping. - Make that as deep as possible but no more than 24" deep. Use the cheap lightweight insulation.

Cheers,
John

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