Moderator: What educational resources can you recommend to learn more about gain structure? For someone who is fairly good at math, but not necessarily and engineer, I think Yamaha's “Guide to Sound Reinforcement” is an excellent tool. I think I have read this three times now, and each time this stuff becomes easier to follow and understand. A step up from this would be Don and Carolyn Davis' book on “Sound System Engineering”. This is a bit more engineering based, but if you can get through the math part, it is a great reference.

Tim Mc: I used the Davis' "Sound System Engineering" got lost a little at first, but learned more every time I opened it.

Brian: Even with an engineering background, I can say that there are parts that are difficult to follow. Being persistent and determined with the reading helps a lot.

Moderator: OK... shifting gears a bit...

Jon Bannan: Brian, I have heard that you are involved in the new Philadelphia Eagles Stadium. Can you talk about that since it is right across the river? What kind of issues are you dealing with currently?

Brian: The stadium is being built quickly. The primary things that we are dealing with right now are all the little details such as: How does the conduit terminate in the wall when there is a recessed TV? Where exactly does the power need to go? Can the ceiling go a little lower in a room to coordinate the mechanical ductwork? etc. This is a very time-consuming point of the process right now. But the attention to the detail now will pay off with a successful project.

Moderator: Is the main system distributed?

Brian: Yes it is. One of the main goals is achieving good pattern control (read as "big horns"), while maintaining good sightlines from the suites. Since the speakers need to throw all the way down to the field, but only being 10' to 15' above the heads of the people at the Club Seating level, you need to have the good pattern control.

Moderator: Do you find that distributed systems are the dominant choice these days?

Brian: You see them in a lot of facilities, and they do work rather well in trying to minimize late arriving reflections. They are the preferred system of choice, but...
there is some newer technology they can provide great coverage from a central cluster. We designed a large EAW KF900 center cluster for LA Dodgers and the intelligibility and punch it delivers from 400 feet away is amazing.

Tim Mc: Or perhaps distributed clusters? What are the trade-offs involved with them?

Brian: We have a distributed cluster at the Buffalo Bills stadium. The reason we went for this approach had an extremely deep field seating section, and we couldn't get it loud enough at the field seats on the 50-yard line (not that these seats are important :-)

Brian (continued): We looked at a central cluster, and because of the clubhouse at the opposite end, we would have had far to many reflections off of the clubhouse. So we chose to use distributed clusters on one side of the stadium. I can say that there are pros and cons about all three design concepts. The design challenge is knowing which design is the right one for the job.

Moderator: It's also a choice of the client, and a budgetary question as well, no?

Brian: Money often plays a big factor. A high-quality distributed system will be the most expensive, but provides the most consistent tonal quality and sound levels to each seat. A high-quality center cluster or distributed cluster system would be next, and then a low-quality center cluster will always be the least expensive option.

Moderator: How do you control the energy sufficiently from a high-power cluster like the one at Dodgers Stadium?

Brian: The great thing about the KF900 is that it has amazingly tight pattern control as a result of its multi-cell design. With the multi-cell design you can collapse and expand the pattern while maintaining equal tonal quality. Dave Gunness at EAW has developed some great tools in predicting the correct filters to apply to the cells to give you the pattern control that you need.

dbl: What design problems do the newer louder (regarding crowd noise) stadia create with regards to local noise ordinances?

Brian: We have been fortunate in that with all the outside stadiums we have worked on, we have not had an issue with outside noise ordinances, however, we are always internally concerned because we know the day will come when we will be asked if we did everything possible to control the noise.

Brian (continued): The way to address this always comes back to the question of pattern control, and how far down in the frequency spectrum you have good pattern control. For instance, a small horn that may be 12"w x 6"h can only have good pattern control down to about 1KHz in the vertical plane.

Brian (continued): So when they say it is a 90-deg x 40-deg horn, that is only until 1KHz. Below that, the pattern begins to open up. So using as large of horns as possible on devices is one of the best ways you can achieve keeping the noise from the speakers within the bowl.

dbl: Does not the required SPL due to the louder crowd make that LF control more of a problem?

Brian: Low frequency energy often is found to be lacking in many stadiums, simply because of the large volume that you are trying to fill. However, many stadiums are willing to pay to have extended low frequency. This is an important element at the Philadelphia Eagles’ new stadium.

Brian (continued): With the extension and the increased level of the low frequency, it is just as important to try to address this with regards to noise leaving the stadium. One of the ways we try to do this is with dipoles. A dipole will help reject low frequency energy +/- 90 degrees off axis.

Lee: I think dbl's question was more about the crowd noise, in arenas designed to emphasize the crowd noise.

Brian: I want to try to make sure I understand the question. Are you asking what is being done to control the crowd noise that exits the stadium, when stadiums are being built to reinforce crowd noise?

Moderator: Yes, I believe that's the crux of it, also concerning indoor arenas where this seems to be done frequently...

Brian: I honestly can't say that I have been in a meeting when the issue of designing a stadium to reinforce crowd noise was an issue. The big issues are always how do you get as many people into a facility with the best sightlines to the field, to the ad panels, and to the video displays. In order to achieve these goals, it lends itself to a circular design, which will inherently reinforce crowd noise, but I don't believe it is the intent, at least not on the projects that I have been involved with.

Tony Mah: Brian, being at one of the most well-known firms, I am wondering if you get many requests for Johnson- or Beranek-level acoustics from modern churches. Does anyone ask for a room with an EDT of 1.4sec, a RT60 of 2sec with high envelopment these days?

Brian: Tony, some members of our team have spent a great deal of time in evaluating the real value of some of these measurement techniques. What we have concluded is that reverb time is a good measurement, but is not the sole indicator as to the intelligibility of the room. The more important factor is the level of the late arriving reflections. We will always fight hard to deflect, absorb, or scatter energy, but our techniques will seldom affect the reverb time.

Moderator: What traits do you find all good contracting firms possessing?

Brian: Experience, Experience, Experience. The quality of installation is almost always associated with how much experience in a particular type of project an individual has. There are exceptions, sometimes people with great experience make mistakes, and sometimes people with just a few years experience will do a great job. But these are the exceptions.

Dave L: And the ability to hang speakers with the horns down as specified in the drawings?

Brian: Someone must have been working on a project in Minnesota.:-)

Moderator: Brian - what's the most interesting project you've worked on, and why?

Brian: There have been lots of interesting ones, but the projects I've enjoyed the most are the ones that have pushed my knowledge and experience to a new level. One that sticks out is Universal Studios CityWalk. I have never worked on a project that demanded so much attention to detail. Although the design process was a painstaking experience (in terms of time), watching how smoothly the installation process went as a result of the design process opened my eyes to the value of paying attention to the details.

Moderator: Allll-righty... last question of the night:

Tony Mah: Brian, any secrets you want to share?

Brian: Honestly, I think we all do what we do because we have a passion for the sound industry. It's the kind of job that you can strike up a conversation with anyone and they listen intently. At the same time, we all want to increase and grow in knowledge. I think my secret is to realize that everyone I meet has something that I can learn. My goal is to know a lot more 10 years from now than I know right now.

Moderator: On behalf of PSW and our audience, Brian, we sincerely thank you for sharing your time and knowledge this evening. We very much appreciate it!!!

Brian: You're Welcome!