Vance Dickason | 
Patrick Turnmire | 
Jason Kemmerer |
1. How did you get started designing speakers? School, apprenticeship, etc? Is institutional education pivotal to becoming a good speaker engineer/designer? And what advice would you give to a young aspiring speaker engineer, maybe some key points...
V.D.: My involvement with electronics began at the tender age of 9 when I built a Heathkit five-tube shortwave radio with very little adult supervision ... and it actually worked! I got my Novice class amateur radio license at 12, my Technician class radio license at 14 and was president of my high school Ham Radio Club. In the vernacular of the day, I was a serious nerd. Loudspeakers started coming into the picture when I was 16 and built my first speaker enclosure, a Carlson type, for a mono hi-fi. However, like many engineers in audio, most of what I know was self-taught or mentored to me by others. For those of you starting out and thinking that a career in audio is where you want to be, my advice would be to get at least an electrical engineering degree (BSEE) with as much emphasis on mechanical engineering as possible. Beyond that, there really is not much in the way of formal education about audio or loudspeakers. Dr. Marshall Leach, who teaches courses in applied electromagnetics and electronic design at the Georgia Institute of Technology, has probably the most speaker-oriented program available in the U.S.
J.K.: Long story, but basically it goes way back to my IASCA days and years of installing. There was definitely some luck involved, but I pretty much knew I'd always end up being an engineer somehow. When I was managing an install bay at a shop in the late '80s, I had an opportunity to shift from retail to the manufacturing side for a while. Even though there was a cut in pay, I figured the experience would pay off in the long run. From then on the fuse was lit, and that ultimate goal of designing car audio gear helped me persevere through the tough times of engineering school. It took a while, but I eventually finished my EE degree, despite stopping several times along the way with various installation, sales and design jobs in both home and car audio. I suppose that without my passion for audio and hands-on experience, I probably wouldn't have ended up where I did, even with a degree.
It's just such a specialized thing, and unfortunately, there really isn't all that much in the way of formal education for loudspeaker design here in the U.S. Most of the classes available at the university level seem to be more generalized towards acoustics or recording engineering rather than specific to loudspeaker design itself. AES (Audio Engineering Society) is a really good resource for where to look for available programs, and there are a lot of good books and papers out there. Basically though, you really have to want to learn it on your own and maybe even come at it as a hobbyist first like I did. Speaker Builder magazine was it back in the day!
Some kind of engineering degree is really important to grasp the science behind it and also a prerequisite to get in the door with most manufacturers unless you have a lot of experience already. But the best thing about loudspeaker design is that it involves many disciplines, so you can really come at it from several angles (physics, electrical, mechanical, etc.). As with any engineering job though, you'll never feel like you know it all and usually end up specializing a bit. I'm actually primarily a product planner, so I wouldn't consider myself to really be a pure loudspeaker engineer quite yet. Fortunately, my background gave me the opportunity to also do loudspeaker design at the same time with some emphasis on subwoofers. It's a never ending learning process, and it's difficult to find time to continually educate myself with all the other things going on. Often, it comes from just working through the next development and exchanging ideas with other engineers along the way.
P.T.: I built my first cabinet when I was about 14. I was playing in a band and wanted to build a horn speaker for the keyboard player. It was a really heavy folded horn and I am sure it sounded just awful. I went to North Texas State University to study jazz (a drummer). I played in bands while growing up and thought I would be a professional musician. During the summer of '77, I took a part-time job as a car audio installer and salesman and was turned on to using component speakers in cars by SRC Audio in Dallas. They were one of the first companies that were selling high-end parts for car audio systems. After three years of college, I decided that I really didn't want to spend my life on the road playing music, so I took at job at SRC Audio building speakers. As I got more into speaker design, I found Vance Dickason's Cookbook and then the AES journals and anthologies. I took several college classes to help me through the math and engineering; basically to understand more of what I was reading. Eventually I taught myself the art of speaker design.
SRC actually manufactured drivers and systems, so I had a unique opportunity to experiment. I was also lucky to have several mentors during this time: Dave Seymore from TI; Bob Caudle, who wrote one of the first programs for speaker design; and Dave Cranfil, among others.
After I left SRC Audio, my long stints at Orion and then at the Chinese speaker manufacturer Sonavox were my "finishing school" in driver design. In those 10 years I designed over 500 products that made it to market. During this time I also created SpeaD and ReverseSpead software, which have become standard tools for transducer design. Working on this with Dave Blore (now at Bose) gave me a much deeper understanding of how a speaker really works.
I still find myself wishing I had spent the time to take the classes required for an engineering degree. If I had it to do over, I would probably have gotten an EE or ME. I think these are good tools for an aspiring loudspeaker engineer. Georgia Tech. is probably the best place in the U.S. to go for these. Marshall Leach has several classes on loudspeaker engineering (and one of the best books: Introduction to Electroacoustics and Audio Amplifier Design.
2. Will computer software eventually take the creativity out of speaker design?
V.D.: I have been lecturing to other engineers about loudspeaker CAD software for a lot of years and have lectured to engineers at Harman (JBL, Infinity), Klipsch, Kenwood, Samsung, EastTech and many others. There is no question that software simulation of loudspeakers is an extremely valuable part of design, both with transducer engineering and system design. However, as much as I use this technology, I do not believe it will ever take the creativity out of speaker design. I say this mostly because I don't think we will ever be able to create computer programs that will be able to describe and quantify the subjective timbre of a loudspeaker in a way that will allow the eclectic combination of drivers to produce a more musical loudspeaker. That takes human ears, human perception and a musically creative mind.
J.K.: I highly doubt it. Sure modern development software has really elevated the science to the point where we can try many new things first before building it, but you still need an imagination to push the envelope. There have been some recent papers on being able to actually predict good performance and subjective listening results, but I would submit that simulations and modeling programs will never get you all the way there. Maybe there's someone out there who knows how, but I haven't found it possible to measure everything I hear, and conversely, can't hear everything I measure.
P.T.: Just the opposite-they free us to be more creative. Rather than building endless iterations of trial and error design, they let us model new ideas quickly and get to the final product faster.
3. What effect, if any, will the manufacturing of speakers overseas, specifically China, have from an engineering point of view on the quality of the products we'll see.
V.D.: China today is capable of producing virtually any quality level desired from low-cost to very expensive high-end loudspeakers. However at this point in time, this cannot be done without the close supervision by the European or American engineers that are guiding these products through production. However, that is only because China is relatively new to high-quality audio. They can manufacture nuclear weapons, nuclear reactors and jet aircraft and I don't think it will be that long before they are able to competently take over all the audio engineering as well.
J.K.: We'll all earn a lot more frequent flyer miles! You have to look on the bright side sometimes. Actually, it will allow us to use materials and processes that simply weren't possible for any reasonable cost before. I mean, CNC machining, complex tooling costs and labor-intensive assembly often meant some concepts simply weren't practical for all but the extreme high-end or experimental. Of course, there are many challenges in educating and communicating with suppliers, but as long as you know what you want and have time, the end result is as good as you want it to be. I think if anything, it will help make better performance accessible to more people and broaden the possibilities for unique products and brand differentiation-if there is desire beyond just bringing cost down. I tend to use overseas sourcing to add more value and performance, rather than just making the same thing cheaper.
P.T.: Asian manufacturing is inevitable. I have been going there for 12 years and have seen the incredible growth and improved quality. This is only going to continue and in fact accelerate. Like it or not, in our market the vast majority of speakers, including "high-end" product, is already made in China. I think the key point for U.S. brands and prospective engineers to realize is that the Asian market will eclipse the U.S. market in 10 years or less. This means that establishing a U.S. brand in Asia is critical to long-term success. The speaker engineering opportunities in the next decade will also be found in Asia or at U.S. companies doing business in Asia.
4. Is speaker efficiency much of a factor in your designs?
V.D.: It really depends on exactly what you are designing. For multi-way component systems, it is critical to match the efficiency of the drivers. You can't have a woofer that is 100dB/2.83V and match it up with a tweeter that is 89dB/2.83V. This is less of a concern when dealing with bi- and tri-amplified powered systems with electronic crossovers.
J.K.: While it might not always be the #1 issue with every design, it must always be taken under consideration at some point. It is especially important now that designs are tending towards more linear excursion, which can often be a trade-off with efficiency. If efficiency is your main goal, then you'll usually end up trading off bandwidth or sound quality, though there are exceptions. For multi-element systems, it definitely ends up as an issue. Besides all that though, it depends on the application and the retail environment for the particular product. In general, I suppose one could say it's more important with full-range drivers than with subs ... at least for car audio. Subs are always driven with outboard amps and power is pretty cheap. Full-range drivers, on the other hand, may be running off of deck power and certainly can't be 6dB down or something from others on the demo-board. Either way, you'll always have to be careful to educate your dealer base on proper use.
P.T.: Really it's just one part of the overall product design goals. It funny every year, the marketing people give us higher and higher efficiency targets mostly with no understanding of the relationship it has to other performance goals. Every year we have to tell them, "Without changing the laws of physics, you can't get 98dB sensitivity from a 6" speaker that plays down to 25Hz and handles 250 watts."
All that being said, I am constantly on the lookout for new materials or technology that reduce mass and potentially increase efficiency. (In fact, I am a partner in an IP company, STEP Technologies, that has filed many patents designed to do just that.)
5. With improving technology, is there too much of a similarity in the quality of speakers regardless of price (within reason)?
V.D.: I would have to say that the range of good to bad is not as great as it was maybe 10 or 15 years ago. I would like to feel that I had some small part in bringing up the overall level of competence in the industry with my books. However, I still see a lot of very mediocre engineering in audio, and all that separates great-sounding speakers from just OK-sounding speakers is engineering integrity. Let's face it, generally the best and brightest engineering talent doesn't end up in audio, and as audio has a good supply of mediocre engineers, there will never be "too much similarity" among different designs.
J.K.: Certainly the gap is narrowing, but it still takes a lot of commitment to insure both build quality and performance. There are some great-sounding inexpensive drivers out there now, but surprisingly, also some quite poorly performing expensive ones. Like I mentioned before with overseas suppliers, the product is only as good as you want it to be, so there is still wide variation even within similar price ranges. Some companies simply source off-the-shelf stuff, which can be pretty bad if not double-checked. I'd say it's similar to the old saying for high-end home audio, [in which] double the price usually gets you part of that last 10 percent. Those $3 automotive OEM speakers are simply not as crappy as they once were, so even the low-end aftermarket has to step up to be viable in the replacement business. Aftermarket companies that just end up causing their own price erosion without improved performance will eventually have to face the reality that OEMs will always have better volume purchasing power. It's all about added value in my opinion.
P.T.: I think there is still a wide range of quality and performance, although it doesn't always follow the cost of a product. There are a lot of really expensive products that don't perform proportionally to their price, and some very inexpensive products that are among the best in overall performance. (Read CA&E to find out which is which!)
6. Does having a musical background help in what you do?
V.D.: Absolutely! I played music professionally for five years and still have a studio in my home and write and play music. I have a number of friends in the industry, those I consider the best and brightest, who are musicians: Bill Bush at Cerwin Vega is a bass player; Rich Coe at Eclipse plays a mean Gibson Les Paul; Pat Turnmire, CEO of Red Rock Acoustics, is a great drummer and guitarist; and Steve Irby and his guys at Kicker always have a company band. Musicians listen very attentively to the sound coming out of a speaker and so do loudspeaker engineers, at least the good ones, so definitely I think being a musician makes you a better speaker designer.
J.K.: It definitely helps with listening skills, as long as you didn't blow out your ears in the process. While I probably wouldn't consider myself to be one of those "golden ears," having a natural sense of pitch and timbre seems to be a distinct advantage. Plus just knowing what instruments are supposed to sound like is critical in taking loudspeaker design closer to the ultimate goal: realism.
P.T.: Absolutely. I know that I can clearly hear problems with a speaker that I can't easily measure. I am certain this is a result of many years of playing music. In fact, many of the most successful speaker engineers in the business are also musicians.
7. Are there any innovations still left? For instance, what types of materials might manufacturers utilize to improve on technology?
V.D.: The loudspeaker industry is a pretty mature one. That generally means that the innovations tend to get fewer and farther between as time goes on. However, I am constantly amazed at the innovations that keep coming. You can see this in the subwoofer reviews I have done for a number of years in Car Audio and Electronics. As to what new materials will contribute to improving loudspeaker technology, it is difficult to predict. Some kind of temperature invariant super conducting wire would certainly have a major impact on voice coil technology.
J.K.: Absolutely. It might not seem like much has changed for many years from the outside, but there really is a lot going on under the surface. Much of my patent focus has been on motor structure and thermal management, but recently I've been discovering there's still a lot that can be done with soft part materials and shapes. Injection molding and co-molding techniques, material compounds and adhesives are getting better all the time. Things like thermally conductive polymers and other exotic materials can take things in new directions, but the fact remains that even some of the old standbys can be optimized much further. With modern FEA (finite element analysis) software/hardware, you can try things that would have been impossible with the old cut-and-try methods.
P.T.: Absolutely. The best is yet to come. Sometime the innovations are small and sometimes they are mind blowing. Just look at the speaker sections of the patent office filings and you can get some idea of just what is going on. Materials, new magnet geometries, changes in the way we judge sound quality, integration of amplifiers and speakers, new software tools for design, new manufacturing methods ... the list goes on and on. (Without getting everyone to sign a non-disclosure agreement, I can't give specifics, but give me a call if you want more details.)
8. Do you still need real-world testing of products? And to your knowledge, how many companies do that? Have you ever designed something that didn't perform pretty much as expected?
V.D.: You will always need real-world testing for products that produce sounds. I don't know any company that doesn't put its speakers in a sound room and find out how they perform. And no, frankly, I can't remember developing a product for any manufacturer that didn't perform pretty much the way I expected.
J.K.: I'd say at least 50 percent of my evaluation time is spent with real-world testing, but it varies. You get to a point where you mostly use measurements to make sure nothing is really wrong to avoid wasting time, and then you listen. Sometimes I listen first, then measure. Personally, I think every engineer has designed something that looked good on paper, but didn't live up to expectations. That can be tough when you're on a tight development schedule, but there are things more important than rushing to delivery, like customer satisfaction and brand image. Without naming names, there are definitely a few companies out there that would appear to have never actually listened to it or beat on it hard enough before slapping on their logo.
P.T.: "Real world" is really the only place that matters. Computer models and lab tests only get you to the starting gate. The real test it how it works in the consumer's car or house. I hope that every engineer has designed something that didn't work like they planned. It's like the clich, "The more I learn the less I know." There are a couple of monuments to my education still on the market. It's a really exciting time in speaker engineering. Many of the things that were the foundation of our craft are now being questioned: T/S parameters (small signal) are really not that valid for system design, distortion may not be all that important, in fact it might even sound better, and separate speakers, amplifiers and D/A conversion may soon give way to hybrid converting speakers that process the digital source and plug right into the wall with no power supply.
9. Which approach do you use to design? That is, do you start with an aesthetic idea and solve the engineering problem, or do you figure out the mechanics and then try to develop the cosmetics?
V.D.: This is sort of like asking songwriters if they write the melody or the words first. The answer to that question is both for songwriting and both for speaker engineering as well. Sometimes I have done prototypes that were in plain black boxes and the cosmetics were added later. Conversely, I have also done projects in which the cosmetic design was done prior to the engineering.
J.K.: I might be different than others in that area, but basically I do both in parallel. You have to have a general idea of your performance target and what it'll take to get there before you start painting yourself into a corner with cosmetics. If it so happens that there's no way to keep the cosmetic concept without sacrificing performance, I'll always give priority to performance. Of course cosmetics are important for demo-board impact and an integral part of brand image, but performance is what will keep customers coming back over time.
P.T.: Both. If the design is driven by new technology, then the cosmetics are designed around the technology. If the design is based on a new "look" then the performance is made to work within the cosmetics. It's interesting; this year I was involved in projects at the far edge of these two methods. From a sales standpoint, the cosmetic-driven product is outselling the technically superior product. What does this mean? Maybe we have reached a point where the level of performance is good enough for the average consumer, and what they really want is aesthetics.
10. What is the biggest obstacle in designing a speaker from an engineering point of view?
V.D.: For the vast majority of designs, there really aren't any obstacles, just a few challenges along the way. If there are any obstacles, it's just time and available funds for the project.
J.K.: Probably time, with a close second being cost. Time helps you solve problems, but cost is almost always a constraint if you've analyzed the market correctly. Even with budget, time limitations can keep you from being able to try risky new things.
P.T.: Finding ways to reduce the price without compromising performance. It's easy to design the perfect speaker; doing it on a budget is the trick.
11. If you could change anything in the 12-volt industry as it relates to speakers, what would you change?
V.D.: I have some product concepts that I would like to develop, but if I told you, I'd have to shoot you!
J.K.: I'd probably have to say power-handling ratings. They're heavily abused and very confusing to the customer. I was on the CEA working group that established the CEA-2006 amplifier measurement standard and am now on a new one for loudspeaker-rating standardization. It's not easy to find agreement on something that takes away the easy route for marketing/sales folk or brands prone to cheating, but it's great to be a part of change for the better. Along those same lines, I wish there was an easy way to educate consumers about clipping and distortion, including the fact that the gain control on amps is not really a volume knob. Please stop the needless burned voice coil carnage! But who's to blame really when no one understands the ratings anyway? When the customer asks, "How many watts does that speaker got?" they should really ask what it'll take to get the best performance out of it.
P.T.: The SPL push. I love the rush of big bass and loud, loud music -I played rock 'n' roll for a lot of years, so I get it. The price we pay in loss of hearing just isn't worth it. In the industry, we all talk about listening safely. The truth is that every Friday night on a hundred stretches of cruise, a bunch of kids that love music are losing their ability to enjoy it. I hate the fact that something that I design could be responsible for that.
12. What do you think of the popularity of SPL competitions and the woofers made explicitly for that?
V.D.: I have been to a number of dB Drag competitions and I think it's a gas. The only thing I keep mentioning in reviews is that the emphasis on very high SPL can be dangerous for your hearing (hey, a lot of pro sound mix engineers and rock musicians have gone deaf). It's not that anybody ever sits in a dB Drag car at a competition, but I think some guys may be buying those products to install in street cars and that has a potential problem. Music is great, and losing the ability to perceive it is tragic.
J.K.: Since I got my start with IASCA and SPL competitions, I'd have to say it's pretty cool. Although on some level I think it was more challenging to try to balance SPL and SQ with the same system, I definitely have to respect some of the engineering that goes into pushing the physical limits of everything ... even if you would never listen to a system like that for pleasure. Of course there are a lot of guys out there that don't have a particularly valid scientific reason for some of the things they try or even why they think it works, but certainly do come up with some really innovative ideas. I'm a bass freak at heart anyway, and sometimes it really is just about how hard it pounds.
P.T.: SPL just for SPL's sake doesn't make sense to me. Do we really care if a car can hit 180dB at 57Hz for 5 seconds? A car audio system shouldn't be a weapon. Maybe it makes sense to let the Guinness book thing go and put a cap on points for SPL.
13. In your opinion, what's more important in the market, sound quality or output?
V.D.: I guess it's both. Some people are more tuned in to detail and definition (sound quality) and some just like to rock out.
J.K.: Unfortunately, for probably 80 percent of the market, it's output. Of course, there's a breaking point where there has to be at least a basic level of SQ to avoid instant irritation, but the overriding factor in consumers' minds seems to be, "How loud will it go?" Now getting to those high output levels with linearity and sound quality is all in the engineering, and it is possible to do both, just not many do. Hey, it's my job to show people the way through superior product anyway, right? I suppose one of the biggest problems is with the change in consumer experience, which explains the reason why SPL competitions seem to get more interest now than SQ. It's easy for most people to tell which sub hits harder, but not nearly as obvious as to which speaker has more detail or images better. Basically, MP3s and multimedia speakers are ruining civilization.
P.T.: Sound quality.
14. What acoustic problems specific to the car do you always take into consideration when designing product?
V.D.: It's different for different types of speakers. Car subwoofers are definitely different from home subwoofers. Car subs can take advantage of the acoustic "lift" from a small compartment and only have to play loud down to by 40Hz - 50Hz. Home subs really need to play loud at 20Hz and that takes some different design techniques. As far as component systems in the car, I tend to design those the same way as a home speaker. You can't predict which acoustic car environment the speaker will end up in, or even if the woofers, mids and tweeters will be phase correlated, so trying to compensate [for] the environment in the design of a product that operates from 100Hz - 20kHz is not really practical.
J.K.: Coming at it from the installer's side, a big thing to tackle head on would have to be the effects of mounting vs. listening position. Add into that the often leaky/flimsy baffle (e.g., factory door location), cabin transfer function, boundary loading effects, road noise and hard, reflective surfaces, and you've got yourself a challenge. While the old school home audio guys would tell you there's no point to even try, there is actually a lot you can do, even from just the loudspeaker design side. Things like driver Q and dispersion, system lobing pattern and frequency response, just to mention a few, are all considered in designing specifically to do well in a majority of installs. One of my major design philosophies though is to put in enough installation flexibility and tuning capabilities to provide installers the best tools to optimize performance as efficiently and effectively as possible. You can certainly overdesign things, so simplicity is also key.
P.T.: Environmental extremes (not acoustical but unique to car audio), off-axis response (mounting locations usually suck), and balancing mounting depth and performance (mounting locations usually suck).
15. What fundamental points in terms of sound do you think we should be reminded of-for instance, are there basic problems that you see in speaker design that manufacturers make the mistake of over and over again?
V.D.: Clarity, musicality and intelligibility are prime directives for me when I design a product for a company. Getting this to the greatest degree possible for the cost of the product is the goal. All I can say is that some companies and engineers are better at that than others.
J.K.: There are a few, but I'd have to say indifference to network design is one of the bigger mistakes most car audio manufacturers make. Speakers are not resistors, and just sticking a cap on a tweeter and a coil on a mid does not always work out. Anyone can design a fairly decent set of components/coax to sound good on-axis at equal distances in a demo-board, but that's not reality in the car. If you don't account for off-axis positioning and differences in relative distance to each component of the system, you'll not only get poor imaging, but also a ragged frequency response in the actual vehicle. Although there's no way to fix early reflections, there's a lot that can be done in the driver design itself, as well as the crossover network. Achieving phase linkage between individual drivers is the difference between background music and being part of the music. A good analogy would be that speakers are the muscles and crossover networks are the brains. You can't add back in something that's missing from the loudspeaker itself (e.g., dynamics, detail, etc.), but with a properly designed network you can certainly give each driver what it needs to function as a complete system in the planned environment. Until someone designs a perfect speaker that goes from DC to light, networks will always be an integral part of good system design.
P.T.:That squiggle at 19kHz probably doesn't matter.A 5 1/4" component woofer that plays to 25Hz is ridiculous.Tweeters that are 6dB hotter than the component woofer don't make sense. (The crossovers never have more than 6dB of pad and the tweeters are usually closer than the woofer)Titanium plating on a plastic cone does not improve the cone strength-no matter what the marketing hype says. (By the way, almost all titanium-coated cones are really just aluminum with an overcoat of color.)Diffraction from a coaxially mounted tweeter is by far the biggest contribution to response errors. Components will always sound better.
16. Has the emergence of surround sound for the mobile environment in any way affected the way you think about speakers?
V.D.: Not for me. I have been designing home theater and THX-certified home theater products for years, so this is nothing new, just a new application.
J.K.: Only in trying to come up with practical center-channel solutions. Center-channel installation is the single largest roadblock to multichannel sound in the vehicle. Until more cars come with center channel provisions in the dash, convincing customers to hack their dash will be a hard sell. On another side of things, some people are focusing on the extended frequency response of DVD-A/SACD and trying to design tweeters that go up to 80kHz. I'd have to say it's a waste of time if you end up sacrificing the audible range to get there.
P.T.: Nope.
17. Is there any difference any more between OEM and aftermarket systems, especially as it relates to speakers? (Be careful how you answer!)
V.D.: There is no question that OEM systems have improved vastly over the last five years or so. But, it's no different than in home audio. You have boom boxes and you have $100,000 per pair loudspeakers. OEM systems are good mid-fi plus products, but there will always be a high-end and always be an "aftermarket" solution to improve and or replace an OEM system.
J.K.: Absolutely. Although they've improved, OEMs still grind speaker suppliers to reduce cost and weight to the point where you can only physically reach a certain level of performance. The sound system isn't as much as an afterthought for car designers as it once was, but it still seems more emphasis is placed on the electronics and DSP side rather than the weakest link (speakers). That's good and bad news for the aftermarket. Undoubtedly, the aftermarket has the edge on loudspeaker performance, but just replacing speakers is no longer as easy as it was. Some OEMs seem to enjoy making all sorts of complicated enclosures that require rebuilding the entire door, and others put in so much EQ/DSP upstream that there's no way to get an undisturbed signal to the speakers without replacing the whole source structure. The advantage OEMs have is that they know exactly how/where the speakers will be installed and can design accordingly. Aftermarket installers essentially have to work with what they're given, and it's not practical to redesign the car interior every time.
P.T.: Aftermarket is still a few years ahead in the raw components technology (head units, amps, speakers), but OEM is way ahead in integration. In my opinion, the best OEM systems sound better than most midpriced aftermarket systems. The reason is that most aftermarket installs are not done with critical fine tuning (measurement) and listening evaluation like OEM systems.
18. Do you have a different approach when you're designing, say, component speakers as opposed to subwoofers, and how do the approaches differ?
V.D.: The two, subwoofers and component systems, cover very different frequency ranges and require entirely different approaches to the design. Hey, buy my book if you want to know the answer to that question! [Interested readers should look for The Loudspeaker Cookbook.]
J.K.: Kind of. There are some things you can simply ignore with subwoofer design, and others you have to pay much closer attention to. The basic design process approach is similar, but you can't really evaluate subs the same way as full-range drivers. Only a few companies have anechoic chambers big enough for good low-frequency measurement resolution, so you end up doing more near-field, quasi-anechoic and real-world testing with subs.
P.T.: No difference really. They are all fall into the same type of price categories and have the same kind of performance and cosmetic directions. The parts are different but it's kind of like a chef making prime rib or a souffl-it's still cooking, just different ingredients and processes.
19. Is there an absolute "best" or "true" sound? Or is it too subjective to say?
V.D.: This is a great question. So many people I have encountered in the loudspeaker business over the years seem to be striving to create that best sounding speaker, which is pretty much like Don Quixote going after windmills, you know, dreaming the impossible dream. There isn't a best sounding speaker and there never will be. The best sounding speaker would require everyone who listened to it to agree that it's the best sounding speaker ever, and human perception and hearing is too varied to ever come to agreement on that. Replicating the original acoustic event is a very elusive goal. The best we can do is come up with a good approximation, and that includes both the recording and playback process. It's like asking who makes the world's best vodka. (It's the Russians; they drink the most vodka, so it must be the best). All events that require human perception, and all events require human perception, are subjective and that's all there is to it.
J.K.: For "best" probably not, but you can get close to pleasing most of the people most of the time. There been a lot of studies about cultural and demographic differences in sound taste, and I agree with some of that. If by "true," you mean accurate, I suppose yes. The problem is that with loudspeakers, everything is a tradeoff and they are far from perfect. Plus an "accurate" speaker may not necessarily sound good to everyone. At some level, you run into the limitations of the original recording where complete accuracy reveals previously masked imperfections. Of course, I have my own "best" and "true" sound, but sometimes you have to put aside your own personal taste to design what you think will be best for the target consumer.
P.T.: "The best sound" is where you are taken away from the gear and the environment [and] into the music. If you forget for a moment or an hour where you are and get truly lost into what the artist created for you, then you have found it.
20. What do you prefer Hypnotiq or Courvoisier-no, seriously what do you prefer, paper or plastic?
V.D.: Hey, I'm a retro man-Courvoisier and paper.
J.K.: Probably still paper, unless you're talking about some of the esoteric hybrid or multi-layer poly blends. I should probably clarify though that by paper, I'm including a lot of types such as wood fiber, hemp fiber, etc. There are some highly fibrulated pulp blends that can simply amaze and astound. Aramids (e.g., Kevlar) have a lot of promise too, but by themselves don't solve everything.
P.T.: Tsing Tao on tap in Shen Zhen. Paper and plastic suck in equal but different ways.
Vance Dickason is a legendary speaker engineer and, fortunately, a contributor to the magazine. As he points out, he is also the author of the Loudspeaker Design Cookbook. | 
Jason Kemmerer is the senior engineer of the product planning division at Alpine. This issue features his handiwork in the test report of the Alpine SPX-SW124D subwoofer. | 
Patrick Turnmire is CEO of Redrock Acoustics and creator of the SpeaD loudspeaker-engineering program, now used around the world. He also does reviews for CA&E. |