Hi everyone, Dennis Foley from Acoustic Fields.
Today we're going to talk about room pressure balance.
A lot of you when we talk on the phone during the week and emails that you send me, we're
always discussing areas of high pressure, high-low frequency pressure in your room.
So I kind of come up with this idea of helping you measure that.
It's not real technical way but it'll give you a way to get a feel for what's going on
in your room and I think the more time you spend in the room, the more time you walk
around the room, obviously the more time you measure different positions in your room,
the more comfortable you get with it, the more knowledgeable you become about it and
then you can assign the appropriate treatment.
So always in music the key word we have to use is balance.
Everything inside of a room has to be balanced.
If you think about the chain that we're listening to, when the mix engineer records, he is about
balance.
When the mastering engineer gets the mix, he's about spectral balance.
So when we release the energy into the room, we should also be about balance.
We should be able to hear everything equally, not a huge amount of energy below a 100 Hertz
and maybe less above.
So we want to kind of have a good balance in there.
So here's a little simple test that we can use to get you more familiar with the room.
Just get a standard sound pressure level meter, there's a tons of them available.
And then get an RTA that has an FFT function on it so you can look at the individual frequencies
and there's plenty available in the app store, you can get them.
So let's divide our room into thirds and take just 6 measurements.
Stay away from the boundary surfaces about 3 feet and do some measurements.
Play a song, play a sign wave, a steady tone at a certain frequency if you want to, stay
below a 100 cycles and take some measurements around your room and then plot.
Maybe here, it's going to be 85 dB SPL, okay?
Maybe over here where our speakers are, maybe it's going to be 90 SPL, okay?
Just do a little investigative work.
Do a little bit of measurement in your room and try to see where the hot spots are in
the room, okay?
The hot spots are areas of high pressure that we don't want.
If the front end of your room is real high pressure and the back is not so high, that's
an uneven balance.
So you're hearing less, because it's being smothered here, than you would be at the listening
position here.
So let's just do some measurements, let's get used to our room a little bit, try to
figure out how it's behaving.
And then if we see a big difference in SPL readings at below a 100 cycles, then we can
assign a treatment to that particular part, okay?
So what should we shoot for?
Just a rough idea, plus or minus 2 dB less than a 100 cycles throughout the room and
plus or minus 1 dB above a 100 cycles throughout the room.
That should be a goal that you shoot for.
Our Sacred Ground studios in California is actually – well, we won't do that – but
actually it's less than 1 dB across the board from 30 cycles all the way to 20,000.
But that's a special room, that's my personal room and I've spent a lot of time getting
it that way and a lot of money.
But as a general rule, we want balance throughout the room.
So use this simple procedure and see what your pressure levels are in the room and then
call me and tell me what you have and then I can tell you how much square footage of
treatments you'll need in that area to balance things out.
Thank you.