Hi everyone, Dennis Foley from Acoustic Fields. Today we're going to talk about the barrier
treatment process. Now normally we don't think of a barrier as treatment, we think of absorption
and diffusion as treatment, which they are, but we're really treating noise with a barrier.
So it's a form of treatment and thus there's a process involved. If anything could be more
true in this case with barrier design is to measure twice and cut once. carpenter adage
that guys in my shop use constantly and say it to me because I forget to but you've got
to really have numbers here because everything depends on those noise numbers. The material
type, the cost, the construction methodology, everything is dependent on that. So we must
measure for all noise, frequency and amplitude. We've got to. We've got to do it over a week
because we want to see what's going on in the whole week. We want a seven day picture of
what's going on each day. So then we can look at each day. We can look at the time of the
day, the largest amplitude and the lowest frequency, because that's the one we have to design for.
That's why we have to have seven days of data, because we're looking for a specific Number,
we're looking for a specific relationship. The relationship is the lowest frequency of noise
and the highest amplitude or strength. So that's why we have to have this seven day map. There's
a big difference in design if our noise is below 125 Hz or if our noise is above 125 Hz. Huge
difference in design. It's night and day.
below 125, it would be easy for you to do because it would be thicker. But if they were both
of equal thickness, you wouldn't be able to tell the difference. And that's one of the
differences in this range. So just that difference shows you there's less material, there's a
different construction methodology, there's different densities, and the materials are
arranged differently. Laymen are not going to be able to understand this. I'm sorry, but
it's too complicated. I built a lot of rooms and measured them for noise. So we understand
the relationships that go on between density, materials, noise, frequency and amplitude.
We've studied this. So the barrier that we build in any room is always a ratio of what's going
on in the neighborhood. Let's say this is a room in a neighborhood. What's going on in
the neighborhood? In most neighborhoods, 70-75 dB SPL, steady constant range, we're going
to produce 100-100 plus SPL in the room. So we have a 30 dB, say, range of energy that
we have to look at. We want to keep this 100 dB, we don't want to leak any more than 70,
we really designed for this. We don't want to leak any more than 60 into our 70 number. We
stay under the radar at 60, nobody hears us. See, there's a science to this. So the barrier
we build is the ratio between how much energy is going to be in the room and how quiet the
neighborhood is. We have a sandwich technique. We use a wood frame, we build sandwiches based
on the noise numbers and you insert them between the studs. So you got a stud frame here, you
build the sandwich and you insert it in the stud. Now the sandwich from the side will have
multiple layers. You can see here in this example one graphic of a particular barrier for a particular
frequency noise problem, not yours. a particular one that we worked on. I don't remember what
the one was at the time. Excuse me. You can see here in the graphics, different barrier
sandwiches for different frequency and amplitude of problem. Look how different they are. So
you turn the wood frame into the barrier. Each design is frequency and amplitude specific.
The sandwich that you build is directly based upon the noise numbers. That's why you got
to have them. They're critical. We won't do a noise project without them. You can guess
on your own. You won't guess right. And then you're going to call me and say, how can we
fix it? And then I'm going to tell you probably not in all cases, but 90% tear it out and start
over. Boy, people love to hear that. Well, don't guess in the beginning if you don't want that
response in the end. because that's just foolishness and wasting time. So barrier and CW, we have
our C-A-W process where we build our low frequency management with our carbon technology between
the studs. You're all familiar with that. Well there's a way to incorporate the barrier and
the C-A-W into one stud design. You need 2x12 stud frame but we can do it. We have drawings
to help you do that. If your noise falls within the space that we have to work with to stop
it with the sandwiches. Got to stick a carbon filter in there too that's four inches deep.
But it all can be calculated and designed for. Barrier treatment process, I think you can
see the process, starts with the noise measurements, then the barrier design, then the sandwich
build, then the sandwich install, then you seal the whole thing. Because we're building a boat.
We're going to put it in the ocean. It's got to be strong enough to handle the pressure
of the ocean slapping against it, the low frequencies. It's got to, can't leak. Barrier treatment
process. Hope this helps. Thank you.
and we'll give you real answers on a regular basis so that'll help you. Thank you.