Speakers & Acoustics with Audio Consultant, Tony Grimani, Part 1

Dolby Podcast Episode 52 - November 13, 2009

In the first of 2 discussions, Craig Eggers and audio consultant, Tony Grimani, from Performance Media Industries and Media Specialty Resources, Inc., discuss acoustic properties and performance characteristics of various speakers. In this episode, Tony and Craig cover:

1. The fundamentals of how speakers work,
2. Various types of speakers, including monopoles, dipoles, and bipoles,
3. The roles that front channels, center channels, surround channels, and subwoofers play, and
4. Comparisons of in-wall speakers to free-standing speakers.

 

[music]

Craig Eggers: Streaming to you from our headquarters in San Francisco, this is Dolbycast, the insiders guide to entertainment technologies from the experts at Dolby Laboratories. We are here to give you the straight talk and news on everything you need to know about technologies that excite your eyes and ears.

Craig: And welcome back to Dolbycast. This is going to be a very special Dolbycast. If you are interested in understanding speaker design, the performance of speakers, room acoustics, how to get the very best sonic performance from your home theater system and your home speakers, we have a very special guest you're going to be very interested in hearing from.

But first, some housekeeping. We've been receiving a lot of listener questions at dolbycast (at) dolby.com. Keep sending us questions. We will do a listener question show very, very shortly.

And in the future, coming up shortly, we're going to have a holiday guide show for those of you who are last minute shoppers who haven't made up your mind. It will be covering a wide variety of topics. Stay tuned for that.

I did get a listener question from a gentleman who is obviously an audiophile. His name is Stan. He said, "Hi. Recently Norwegian record label Two L released the world's first Blu-ray audio disc entitled, 'TrondheimSolistene: Divertimenti.'"

Stan says that this is encoded with Dolby TrueHD 5.1, 24-192 audio, and he says it's absolutely amazing. He says it's something every audiophile out there should check out. So, check it out. I know I'm going to grab that disc and give you a full report in the future. Hey, we've got a very, very special guest coming up, Mr. Tony Grimani.

[music]

Craig: And we are back at Dolbycast. Our guest today is a highly respected writer and industry consultant. He's an industry pro, and quite frankly he's an overall nice guy. Tony Grimani is the president of Performance Media Industries and Media Specialty Resources. Tony Grimani, welcome to Dolbycast.

Tony Grimani: Thank you. Thank you, Craig.

Craig: Tony, we're glad to have you here. I know we've been trying to get you on the show, the program, for at least six months.

Tony: It's been challenging to get together, but here we are.

Craig: We're here. Hey, Tony, tell us about Performance Media Industries and Media Specialty Resources. You're the president of both companies.

Tony: I am president of both companies, a terrible idea actually, but they're both companies that are involved largely in the acoustics space as it relates to media environments.

PMI, Performance Media Industries is a consulting company that I started 10 years ago now. Primarily what it does is designs high end home theater screening room, recording studios, and things like that.

Craig: Wow.

Tony: And Media Specialty Resources I started five years ago is a manufacturer and distributor of acoustics materials.

Craig: That's interesting. You're involved in all aspects then, from the recording studio all the way to the home.

Tony: Correct.

Craig: Interesting, cool stuff. I want to talk about acoustical treatment and some of the work that you have been doing with that later on in the podcast. Tony, for our listeners, tell us how you got involved in this industry.

Tony: Oh, it's a long story. Actually, I tell you frankly, it goes back to my parents. My dad's an electrical engineer who worked a lot around radio, TV, and audio, and my mom is a professional opera singer. And that was around the house.

Craig: Is that right?

Tony: Yeah. It was just kind of been in my life. I studied electrical engineering and was lucky enough right out of college to get a job here at Dolby.

Craig: So, tell us what you did. You know, when I first came to Dolby, they said, hey you've got a huge legacy to follow here. Tony Grimani used to work here. Tell us what you used to do.

Tony: That's interesting. I was hired originally to help design microchips for noise reduction for cassette decks. Remember those things, the little tape that went around?

Craig: I sure do. We're showing our age.

Tony: Yeah. But pretty soon, I got very interested in the surround sound program that was just beginning, back in '84, '85.

Gradually just got more and more involved in the technology development and the software developments and all of the things it took to actually get Dolby Surround up and running from source material all the way to products.

Craig: For the longest time, people in the industry associated you with a fellow company here in the bay area, THX. That's where I met you when I worked for Toshiba.

Tony: Right.

Craig: What did you do at THX?

Tony: After five years here at Dolby, working on maybe what we called the source material, the A chain of surround sound, I got interested in how does it play back at home? How does it play back in the theaters? How does it play back in studios?

And that drew me actually to the next phase of technology development, which is to get into the full system, figuring out how to put something together so that the consumer at home can actually hear a film soundtrack exactly how it was intended to be heard, and to work with manufacturers of electronics and loudspeakers to help them figure out how to do a surround sound system correctly, and that's really what THX did.

Craig: And right now you are also a writer for "Residential Systems," which is kind of an industry magazine for the CEDIA group.

Tony: Right.

Craig: So, what are you doing now? I mean, you're doing consulting. You have this acoustical company. You are still doing the consulting?

Tony: Absolutely. I would say if you look at one of my days, half the day is spent helping the team in my office design a screening room, a home theater, a recording studio. The other half of the day is working on the products we have been developing and selling throughout the world.

Craig: Any high profile screening rooms or home theaters you want to talk about?

Tony: Well, I could tell you, but I would have to kill you actually.

Craig: Oh, no.

Tony: Unfortunately, some of the high profile guys of course, don't want their names mentioned. But I will say that one of the high profile actors we did a theater for won the best theater at CEDIA last year, so that was gratifying. A good room, the client is very happy with it, and it was good to see that the CEDIA crowd appreciated it.

Craig: Given your history in sound and making sound better, I thought this would be a great opportunity to talk about speakers and acoustics and how we can maximize the experience and get the very best audio as well as video performance in our home.

Tony, we have had all kinds of listener questions about speakers, speaker placement, and acoustics. This is going to be a great podcast because I think we can address a lot of those things. I want to start all the way from the beginning, the genesis, if you will. What's a speaker, Tony? What's a speaker designed to do?

Tony: [laughs] In the beginning...

Craig: In the beginning...

Tony: A speaker is a device that takes typically an electrical signal and converts it into sound waves. I think you mentioned once that it was like a sound pump, an air pump. Well, it is, essentially.

It's a device that has a motor in it. It's a motor that does a very specific function, which is to actuate pistons or devices that displace air molecules and create waves that our ears can hear.

Craig: And there are all kinds of different speakers. We talk about direct radiators. We talk about bass reflex design. We talk about monopoles, dipoles. Let's talk about that for a second. What's a direct radiator?

Tony: That's a colloquialism or semantics, really. There are thousands of speaker topologies. The most common one that actually I guess to evolution has yielded the biggest market share is this box about 15 inches tall with a woofer and a tweeter in it. The woofer is a cone diaphragm and the tweeter is a dome diaphragm.

Craig: Right.

Tony: Sometimes people call that a "bookshelf speaker" because it was originally designed to be sitting in a book shelf, whatever. That's the most common thing and that's also known or thought of as a direct radiator. It's a speaker that radiates sound, generally, directly towards the listener.

Craig: OK. That's cool. So there are also speakers that are direct radiators that are bass reflex.

Tony: Right. So, the bass reflector concept is a way to extend the low frequency response of this little box.

Craig: How is that accomplished, Tony?

Tony: You take that little box as an air pump and there's a frequency below which it just can't go no more because there is not enough air to displace inside the box to actually get low frequency response.

There's a little trick, which is to put a little organ pipe inside the box, known as a bass reflex resonator. But this little organ pipe works together with the diaphragm of the woofer and the cavity inside the box and gives a little bit more sound coming out of it at the right frequency.

And the whole trick in designing those bass reflex speakers is to tune that organ pipe, also known as the port, to the box, to the driver so that it all works together. Main advantage is you get more bass out of a little speaker than you would otherwise.

Craig: More bass, so identify that speaker. Obviously we might have a dome tweeter, maybe a mid range speaker, and also a woofer, and then also a port or a hole, if you will.

Tony: A hole.

Craig: Sometimes, though, you do see sealed cabinets that don't have a port.

Tony: Yeah. I actually don't know what the statistics are, but I would venture to say that the majority of consumer speakers today are sealed. They are not bass reflex, they are sealed enclosure. They work fine. We've all in the industry figured out a way to make sufficient low frequency sound out of those, that they work fine.

And somebody may contradict me and go, no, there's more of those than the other. Whatever. I think by and large the acoustics suspension speakers, as it was coined years ago now, is the dominant force in the industry.

Craig: Interesting. So monopole, dipole, all those different poles. Talk about poles.

Tony: Tadpole?

[laughter]

Tony: This business of bass reflex versus sealed enclosure is about how to play back the bass of the speaker. Actually, before these things all came up, there were also other typologies for speakers.

Infinite baffles that were largely a box, not a box actually, a large plane with a driver in it, looks like an end wall speaker, actually. There were infinite ports. There were all kinds of different things, but those all have to do with the bass.

What you're talking about is the radiation pattern of the speaker, which is totally independent. I actually like to discuss this similar to a garden hose. You can take a garden hose and put one of those nozzles on it so that you can change the spray pattern on it.

You can have a really tight pattern or a wide pattern. You can have a pattern that sprays left and right. These are all different ways that the water comes out of the nozzle. Your experience in the middle of summer being soaked by that can be different dependent on the pattern of the nozzle.

Craig: Sure.

Tony: It's exactly the same thing with speakers. Some loudspeakers have a very focused sound directivity towards you, like a tight pattern on a nozzle. They hit you hard with their sound water, if you want to think of it that way.

Craig: Is that what you would classify as a monopole, then?

Tony: I would classify that not only as a monopole, but I would classify it as a speaker with a high directivity.

Craig: OK.

Tony: There's a lot of different ways those look, and I'll talk about that in a second.

Craig: OK.

Tony: Then there are other speakers that spray sound just very wide, all over the place, like the setting on your nozzle that would just give you a mist character. And just the mist feels smooth and cooling, those speakers have that same sensation. They actually sound very laid back and very enveloping and not very directive.

Craig: But it's difficult sometimes to really isolate a particular audio image, though, with that type of speaker, right?

Tony: Exactly. You have in one case a speaker that is spraying sound in all directions. It's giving you this relaxed sound field, and you can't really hear where individual musicians are in the sound field. You just have this big, huge symphonic sense.

On the other end of the spectrum with a very directional speaker, you have a thing as if the water was hitting you right on the forehead. You go, "It's right here."

Craig: Right.

Tony: What's really interesting, Craig, about this is that evolution has also gotten us in the middle of those two choices. If you go back many, many, many years ago, without stating brands, there's a company that got famous for selling horn-loaded speakers.

Then there was another company that got famous for selling these speakers that actually fired sound into the wall away from you, and sprayed the sound all over. Those were two opposite sound of sound religion, if you want to think of it that way, and they both competed on the market for, "mine's better."

What's really interesting is that the final evolution has led to this box I discussed earlier, which is the two- or three-way device with a woofer, a midrange, and a tweeter, that fires sound towards you but only towards you. It actually sprays a pattern that's probably about 120-130 degrees wide from left to right side.

So it's kind of a halfway point. It's not like anybody did analytical research on this going, "It's got to be this way." It's more like evolution. In the world of hi-fi, you make something. If people like it, they buy it. If they don't buy it, you go out of business or you make something different.

So natural market evolution has said, "Hey, we like this thing that's right in the middle better," and that's the ubiquitous speaker today most people have used. Surround sound brings in some new questions to that.

Craig: Especially the rear channels, right?

Tony: All the way around actually, I've found quite early on in messing with surround sound here that there's more to it than just the precepts that work for two-channel stereo.

Craig: What about dipoles and bipoles? Let's dig a little bit deeper here.

Tony: Right. One of the things that those of us involved in doing surround sound experiments back in the early days, if you want to call them that, in the early '80s, we found that you put signals into the surround speakers or the rear speakers we sometimes called them then, but they're surround speakers.

You turned them up to the point where you hear them, and then suddenly they sound like they're coming from a box on the wall. You have this very fine point between I don't hear them, I don't hear the sounds on one side, then you turn it up enough, not only do I hear the sound, but I'm actually distracted by this box over here to my side or to my rear.

A lot of work went into figuring what we do with that. Interestingly enough, some of that work actually went back to earlier research from the '30s and '40s about these perceptions of directions and directionality.

The bipole or dipole speaker was actually developed to help create a sound that comes from your sides or your rear that's more of a sound field than a directional poke at you coming from that box.

Craig: So more of a diffused sound, if you will.

Tony: A diffused sound, or a sound that, if I can go back to the garden nozzle analogy, is more of the spray mode than the really tight point, and the main idea being that you can actually create a sound field around you that still sounds like the sound is coming from the right or coming from the left, but doesn't say, "Oh, it's hitting me on the side of my head and it's coming from that box over here on the right or the left wall."

Craig: Is the philosophy behind that, for example in home theater, to create that illusion of a bigger, deeper room then?

Tony: Yeah, ultimately that's what we found was necessary. If you're going to do sound coming from speakers all the way around you and you don't want it to fall apart, falling apart to mean that it's coming from individual speakers around you rather than integrating.

If you want it to integrate all the way around, what we found is it's important to create a little more sound field, a little more diffuseness. In order words, light up more of the reflections in the room than a directional loudspeaker would normally do.

Craig: I've always been a fan of direct radiators. That's just the way I am. I'm getting the feeling from you that you're very much a dipole fan in terms of speaker design and function. Would that be wrong?

Tony: I actually wouldn't put it on a dipole or a tripole or a tadpole or repole. I would actually say that I'm a fan of a sound field coming from the surround sound speakers that doesn't say, "Hello! I'm a speaker over here!"

In a small room, like the size of this little studio, I'm finding that the way you get there is using either a dipole or a bipole speaker, one that's going to spray more sound over the walls than a normal two-way bookshelf.

If you go into a room that's big enough, if you take a room that's 30 x 25 like some of the screening rooms we design, a dipole is no longer necessary because there's enough room there to create the sound field.

Craig: A lot of home theaters are not only designed to listen to movies, where you want to create that very widespread, that very highly diffuse sound, but for example, my home theater, I listen to 5.1 music all the time.

I guess that's why I'm really a fan of sound that I can isolate instruments, as opposed to a more diffuse sound field. How do you feel about that?

Tony: I think it's a question of choice. It's a question of taste, and it's the same taste issue as happened in the early, mid '70s, when some manufacturers were making directional speakers and others were making wide-diffuse speakers. Some people liked one, and some people liked the other.

There was no standard other than, "Well, I like this" or "I like that." Ultimately, interestingly enough, it all met in the middle. So, I would say that I'm personally a fan of having a sound that's a little more laid back out of the surround channels, one that doesn't tap me on the shoulder, going "Hello! I'm here! Hello! I'm here!," however that is achieved.

Now, music, film, don't really know. I think it does come down to taste. Whether I'm listening to music or film, I don't like to hear that guitarist coming out of a box on the wall on the side of me. If in a mix, it's clearly positioned over here, it's going to distract me away from where I'm typically oriented, which is looking at the front speakers.

So, there are people who will go, "Well, music doesn't have to be bound to the front speakers. You can spin around on the chair and you can do this." Sure, you can certainly turn all the way around and follow a sound field.

That's not the way I'm used to listening to music. When I go to a concert, the stage is over here, and that's where it is. There are plenty of examples of music written for multiple locations, both for classical and modern music, so that's all fine.

I will say that when we're talking about home theaters for film, besides my taste for how I like to hear the surround channel to be smoother, I'm not saying very diffuse by the way, I'm just saying that it's not just poking you on the shoulder.

I will also say that in the cinema industry, in the movie theaters, they found many years ago that the best way to play back that channel was an array of multiple speakers that created a more spacious sound field than the front loudspeakers.

Craig: Right, but that's also because the room is much bigger.

Tony: It is two reasons. It's a way to get audience coverage that's even so that everybody gets to hear the same experience, but it's also something that was found very early on, that it allows a sound designer to put sounds there without distracting the audience away from the screen.

And there's a push-pull. If you go to a mix session where they're making a movie, there's a push-pull between the director and the sound designer. The director is a visually oriented guy. He wants to make sure everybody is paying attention to what's on the screen: that's where the actors are, where all the photography happens, where everything happens.

There's always this tug of war between the sound designer, who wants to put stuff sonically all the way around the room, and the director is going, "No, no. I don't want to distract my audience." Guess who wins usually? It's the director.

But very early on, it was found that by using an array of loudspeakers, something that spatializes the sound more, you give yourself more headroom in the sound level of the surrounds before you distract the viewer.

Craig: Some very interesting insights from our guest, Mr. Tony Grimani, industry consultant and now a president of a company who delivers acoustical treatments to the home. We're going to talk about that in just a little bit. But we take a break, and we will back to talk to Tony about speaker placement.

[Musical interlude]

Craig: Hi. This is Craig from Dolbycast. Hey, we love to get your questions. Send those questions to dolbycast (at) dolby.com, or give us a call, 1-888-6DOLBY-C. That's 1-888-6DOLBY-C.

[Musical interlude]

Craig: And we're back at Dolbycast with our very special guest, Mr. Tony Grimani. Tony, we've been talking about rear speakers in the home theater, but you know, quite frankly, the front speakers are probably the most important elements of our sonic experience, right?

Tony: Absolutely. It all comes from the front. I like to say that the most important channel is the center channel.

Craig: Oh, definitely, yes.

Tony: The left and rights are sort of satellites to that, and the surrounds are kind of icing on the cake.

Craig: It's interesting when you think about surrounds and how it's changed, though. Center speakers always reproduce dialogue; that's been the most important speaker in the home theatre in some respects. And then your left and right speakers have always been used to do musical swells and to show movement off-screen and onto screen.

But you're starting to see the surround speakers also being used to reproduce musical swells, too. So they're starting to take on some of the capabilities or the performance needs of the front speakers, aren't they?

Tony: Absolutely. The music mixers and sound designers are getting more creative with time, and they're trying more things. One of the exciting things that they're doing now is actually to pan dialogue.

Where dialogue used to just be anchored in the center speaker, in a lot of-especially animated movies, you'll hear dialogue moving from left to right and right to left following the actor, with the main idea being that the sound's following the picture.

Now, for that to really happen, well, you have to have good speakers in the front. The center speaker needs to be a good speaker.

I see a lot of people just chintz out on that one, and just get some really nice left and rights, and some little low-end speaker that lays down horizontally with the two woofers on the side and a tweeter in the middle, and the quality of sound coming from that is just not good enough.

Craig: And on Dolbycast, we've always been telling our listeners, really the performance of that center-channel speaker really needs to be matched to the left and right speaker, doesn't it?

Tony: Absolutely. If you actually look at the sound power coming out from that speaker, it dominates by a large amount. So you've got to have a good speaker there. What kind of speaker? Well, again, it depends a bit on your room and your taste.

By and large, I've found that if you go back to that, that speaker we were talking about earlier, which is the most classic bookshelf thing you get today, you know, the woofer and the tweeter in it, it has a pretty broad dispersion. I actually find that five of those around you in a room work fine. It's a great start.

If you want to go to the next step, I find that three identical front speakers that have a little more focus, that send a little more sound toward you and less into the room...

Craig: So a little bit more directional.

Tony: A little bit directional. Not alter directional. I'm not saying a horn-loaded speaker that's drilling you in the head, but something a little more directional for the fronts, and something a little less directional for the surrounds, yields a good result.

Craig: Interesting.

Tony: And that's a direction to go. Now, plenty of manufacturers make those things. They don't always know how to communicate the directivity, because it's not a spec that people really understand necessarily, but there's ways to find that. So if you see a speaker that has a horn in it, chances are it's more directional than one with a tweeter.

Craig: So, a recurring question here on Dolbycast, I wanted to get your input on this. When you're calibrating and consulting on a home theatre, how do you determine the best placement for the subwoofer speaker?

Tony: A very good question and very important question. Actually, the subwoofer placement is a very complicated thing, and it's actually chaotic. What I mean by that is a lot of math and a lot of physics can only give you a certain level of information on where the correct placement is.

And ultimately, the best way to place it is by trial and error. And trial and error, in this case, being to play bass sounds out of that speaker, and if you actually have an acoustic analyzing device that some technicians have, measure at the seating position how the subwoofer location in the room influences its sound. And it's radical.

Craig: Interesting.

Tony: This is not a tweak. Some people go, "Oh, you're an audiophile. You hear this stuff. I can't hear it." No, no, no. There are radical differences in the sound of a subwoofer whether it's placed here, there, or somewhere else in the room.

Craig: I have sat next to subwoofers in some rooms where you couldn't even hear the low frequencies.

Tony: Absolutely.

Craig: It's amazing.

Tony: Absolutely. The subwoofer emits sound waves that are so long that they pump the room with a wave that's bigger than the room, and at that point, you're like in the middle of a pipe organ.

And there's places in a pipe organ, or any instrument, where there's a cancellation. There are actually waves that have high pressure and low pressure in the room, and you can actually be sitting in a cancellation.

So, here you are. You bought this $800 subwoofer, and it's not doing anything for you. And all you've got to do is move it two feet, and suddenly you've got your $800 worth.

Craig: Lights up the room.

Tony: Yeah.

Craig: Interesting. So tell me your thoughts about in-wall speakers. That seems to be a trend. You're seeing a lot of spec homes with in-walls. You see a lot of high-end and mid-range companies now introduce, obviously, in-walls.

There's the whole spouse-acceptance factor, and in-walls certainly appeal to that. What's your thinking? What's your thought on in-walls?

Tony: Well, the good news is that there are some very good quality in-walls today. Early on, when in-walls came out, they were just a functional thing. They were largely just a car-audio speaker painted white and stuck in the wall.

Craig: Yeah.

Tony: And they got a bad rap from that. But today, there's a lot of very high-quality in-walls that rival, in terms of sound quality, anything you can do in the room.

So if they're placed correctly in a wall that's solid and is not rattling and vibrating away and you can put them in the right place and you don't put a plant in front of them, they can sound fantastic.

Craig: So some of the in-wall speaker systems actually have sealed cabinets, or sealed backs.

Tony: Yeah.

Craig: Any difference in performance you see there?

Tony: Absolutely, and the difference is consistency. By actually putting an enclosure in the back of the speaker, it will sound more predictable from room to room. Otherwise, you have this open baffle that's just really spraying into an unknown cavity that may be leaking out the back.

You don't know what it's going to do, the main effects being in the bass side. So the enclosure on the back of a speaker has two benefits. One, predictability. The other one is it sends less sound into the bedroom next door.

Craig: Gotcha. My biggest issue, though, is how do you prevent the speaker from, quite frankly, rattling the whole wall, causing the studs to rattle? I guess that has to be a consideration you take when you're building a room, right?

Tony: Absolutely. If you can be involved in building the room, the answer is more screws.

[laughter]

Tony: You can also glue the sheetrock to the studs using construction adhesive and screws. You can also put some soft materials between the studs and the sheetrock so that they rattle up against each other. Those are all considerations.

If you're just doing a retrofit, and you don't have the facility to go in there and do a wall, maybe you drive more screws into the wall and just refinish the wall.

Craig: Maybe if you can get into the studs and put in cripples between them to really reinforce those studs, that would obviously help, too, and probably dampening, any type of acoustical treatment, insulation, etc.

Tony: Absolutely. So step one is if you can actually choose a speaker that has an enclosure behind it, it will rattle because the air is not pumping the stud-bay behind it, it will rattle less. So step one.

Step two. Use insulation in the wall. Step three. You may have to go ahead and take down sheetrock and reinforce the wall.

Craig: So, to our listeners who are putting in a retrofit, look for a sealed cabinet. If you can get into there, put some insulation behind the speaker, and choose a good quality speaker.

Tony: Right.

Craig: Excellent. So I'm hearing now, and I'm seeing now, subwoofers that are actually placed into the walls. Talk about that for a second.

Tony: I actually love that. And the reason I love that is it's been known for a while now that the subwoofer conundrum, the one you mentioned, that you could be sitting right next to a sub and not hear it, can be resolved by putting more small subs around you.

And there's actually some very interesting work done on this, and it's found that four subwoofers in an X pattern around you, or in a cross-pattern around you, can yield very smooth bass. So with an in-wall subwoofer, you can do that.

Craig: Let's go back for a second - four subwoofers in a cross-pattern.

Tony: Yeah.

Craig: More detail.

Tony: So, one in the middle of the front wall, one in the middle of the left wall, one in the middle of the right wall, one in the middle of the back wall.

Craig: OK.

Tony: That's one configuration that gives you very even bass in the room, and will almost guarantee that you'll get good bass where your couch is sitting.

Craig: Now, is this applied to subwoofers in the wall or subwoofers in general?

Tony: Well, you can use four big subwoofers and try to place them in the middle of your living room and maybe go look for an attorney to control your divorce problems.

But I think in order to keep everybody happy as well as to keep the aesthetics of the room in check, choosing smaller, in-wall subwoofers and putting four of them in walls where they're hidden is a great way to go. Now, they all get hooked up together, they're in mono, and the results are stunning.

Craig: Very interesting. Tony Grimani, you know what, I began this conversation with you telling our listeners that we were going to talk about acoustical treatment and how to get the best sound in your room. Obviously, we're up against time, here.

I would love to have you come back and join us again to talk specifically about how we can optimize the experience we have in our homes and talk about some of the things that you're doing in the industry to bring better sound. So, will you please come back to Dolbycast?

Tony: I would love to.

Craig: Excellent. Ladies and gentlemen, another edition of Dolbycast. I hope you got some great stuff out of this. Tony's a real expert, really understands audio and audio reproduction. From in-walls to free-standing speakers to dipoles to monopoles, we've covered it all. See you next time on Dolbycast. I'm Craig Eggers. Thanks for listening.