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POSITIVE FEEDBACK ONLINE - ISSUE 2
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2001 Audio Engineering Society (AES)
by Scott Dorsey

Why is a high end audio journal reviewing a pro audio trade show? The high end community seems to believe that pro audio folks have tin ears and are obsessed with loudness, while the pro audio community seems to believe that high end people are tweako cultists who care more about cables than music. While there are people like that in both camps, I don't think either group has any real understanding of the other, and neither understands that there are important points on which the two camps overlap. In the interest of cross-cultural fertilization, I’d like to report on the 2001 Audio Engineering Society (AES) show from a high-end-audio viewpoint.

This show had to be rescheduled due to the unfortunate events in New York in September, when it was originally to take place, and a lot of the vendors pulled out. A lot of the makers of cheaper equipment decided to attend the NAMM musical instrument show when they were forced to choose between the two, while few makers of higher-end gear sell to that market. As a result, the AES show had a much higher percentage of high quality gear on display this year. While the trade show section was about a third of its normal size, it was a lot more pleasant. It's been a long time since I could cover the entire show floor in two days, and it was very nice to be able to do so. Surprisingly, none of the folks on panels or giving papers pulled out. I will review a few of the papers that I got to see, and I will include preprint information, so you can order papers from the AES web site (www.aes.org).

I was surprised not to see as much international press as I normally do. I didn't even see the Studio Sound crew this time around. However, I was happy to meet Philip Spencer from Asia Pacific Audio Technology, an Australian magazine that looks quite interesting. I also got to talk with Paul Cogan, editor of Stage Directions, a magazine oriented toward theater technicians, and check out his magazine. A lot of the fun of being press at these events is seeing different magazines from different countries.

DSD and high sampling rates were all the rage this year. It seemed like everyone had new product out. SADiE was showing an editing system based on dedicated hardware and software for editing SACDs, giving full equalization and dynamics control in the DSD domain. It's a very slick piece of hardware, and it’s reasonably priced, to a point that would allow smaller mastering houses to get into the SACD business. SADiE joins the Merging Technologies Pyramix and Sony's Sonoma system in offering this.

Mytek Digital was showing a hard disk recorder that can also record to a SCSI tape device, which records DSD format data for SACD mastering. It also does simultaneous downconverting, to convert DSD bitstream to PCM at 44.1 or 96 k, so that DSD recordings can be issued as CDs.

Tascam was showing something called the DSD-96, which allows recording of two-track DSD on 8mm tape, but which can also be used as an eight-track PCM recorder to record and play standard DTRS tapes.

Sony was exhibiting all sorts of SACD and DSD stuff, including their XA-777ES SACD player, which can also play CDs, and they were showing off a large catalog of SACD releases from Sony Music, UMG, Virgin, and EMI. They were also getting all wound up about ZTT Records releasing the Frankie Goes to Hollywood best hits compilation on SACD. I didn't go to the SACD demo this year, but having heard a lot of SACD demos, I will say that the format can sound really good, but that demos have not shown its capabilities. Oh well, it's a trade show.

Digital Audio Demark was showing their ADDA 2408, an 8-channel, 24-bit/96k A/D and D/A unit with a wide variety of interfaces available as options, and with the provision for external computer control. This is pretty typical of the new generation of high grade, high-speed converters that are now showing up.

Prism Sound was showing their AD-2 and DA-2 converter and processor units. The DA-2 looks like a hell of a box for high grade home systems. Prism has always made some of the cleanest, best-sounding converters around, and these latest offerings are 24/96 ready, but have internal dither so they can be used with 16-bit recording formats as well as with 24-bit gear.

Even the low end of the market is getting into the high sampling rate thing. Ego-Sys from Santa Clara introduced a computer soundcard for $199 that does 24/192. How does it sound? Who knows? But it will sell, because even the bottom-of-the-line home studio folks are jumping at higher sampling rates and longer word lengths.

There was a lot of DSD discussion in the papers sessions. J.D. Reiss and M.B. Sandler from King's College, London, gave a talk called "Efficient Compression of Oversampled 1-bit Audio Signals," in which they described a method to compress DSD data by a 1:4 ratio. Although the method is slightly lossy, all the loss that occurs is well beyond 20 KHz. Does it affect the sound? Is the improved sound of DSD the result of the high frequency response or something else? Nobody knows, but listening tests might help us get an idea. See Preprint 5472.

James Angus from the University of Salford in Manchester, UK gave a talk called "Effective Dither in High Order Sigma-Delta Modulators," in which he describes a method for comparing the effectiveness of dither in linearizing PCM vs. 1-bit DSD-like converters and gives guidelines for achieving optimum linearity. See Preprint 5478. Then, Stanley Lipshitz and John Vanderkooy from the University of Waterloo gave a talk called "Towards a Better Understanding of 1-bit Sigma-Delta Modulators, Part 2," in which they extended the general discussion of one-bit converters to what they call 1.5 bit converters, i.e., converters that have three output states but use sigma-delta style encoding, like DSD. They then predicted the idle-tone behavior and spectral linearity of these theoretical converters, and showed how the same math applies. They used this to give a more generalized model of sigma-delta converters and talk about dither in the converters, specifically refuting some of the things that James Angus said earlier. I have not been able to follow the math well enough to know who is correct, but my attempts to do so have helped me understand a lot about sigma-delta methods.

For the last couple of years, everyone has been talking about wide-bandwidth recording, but this year it's gotten all the way down to the microphone level. Manfred Hibbing from Sennheiser pointed out, in "Design of Studio Microphone with Extended High-Frequency Response," that extended recording frequency range requires extended frequency microphones, and talked about a way to do this by moving the resonant point of the microphone down and using internal equalization to get a flat response, much like Sennheiser has done with their MKH series RF mikes for three decades, but with an additional octave of response. See Preprint 5465.

C. Buergel, et al., from the Fraunhofer Institute, gave a paper called "Beyond CD Quality: Advanced Audio Coding for High Resolution Audio with 24 bit Resolution and 96 KHz Sampling Frequency." These folks are designing lossy compression systems for high-resolution wide bandwidth channels, which to me seems like missing the whole point. See Preprint 5476. On the other end of the scale, Markus Erne from the AES Technical Committee on Audio Encoding gave a talk called "Perceptual Audio Encoders: What to Listen For," which began with an overview of how perceptual encoding, lossy compression schemes like ATRAC and MP3 work, then went into detail about what kinds of artifacts occur when they don't work. Erne not only talked about obvious effects like birdies and swishing sounds, but about subtler effects like image degradation, and he pointed out that the perceptual mechanisms for imaging weren't very well understood. If you're curious about why MD sounds the way it does, and why radio stations sometimes sound funny, check out Preprint 5489.

Denon was showing off all sorts of home audio receivers and DVD changers, as well as a solid state video player and a dual-disc CD-R recorder for dubbing, but didn't have any of their simpler and better-sounding gear on display. They make some great CD players that are sold for broadcast use, but have very solid, bulletproof transports and generally good sound, but they didn't show them this year.

Webber Tapes Ltd from the UK was demonstrating their WAVEcomp software, which allows differential comparison of two audio files on a computer system, much like performing a nulling test on a stereo component. This is a valuable tool for checking computer software, anything from the very obvious changes wrought by lossy compression software to subtle changes that may occur in mastering and editing. It produces a difference between the two sources, and not only displays them on the screen but plays the sound back so you can get a sense of what is getting lost in the transformation. This could be very handy for anyone involved in computer audio, and these days it's getting hard not to be involved in it. The WAVEcomp software is also a handy tool for determining error rates on CDs, and the company provides an optional instrumented CD player that hooks to the computer to provide information about how the CD system is interpolating. Very handy for checking premaster CDs.

I was hoping to stop by the Soundforge booth and complain to the folks there for their constant barrage of spam e-mail, but they had pulled out of the show.  They keep removing me from their mailing lists and adding me again a week or two later. Isn't marketing wonderful? This is one company I won't be buying from.

Quantegy wasn't there this year, so the only media vendors were Emtec/BASF and Maxell. Emtec was showing off their usual line of mastering tapes in various open-reel formats, but they were also pushing some of the newer computer media. I couldn't tell what Maxell was selling, except that they were giving away free CD-Rs, cassettes, and batteries, and when I asked about their 1/4-inch open-reel UD tape, I was greeted only with blank stares.

George Massenburg gave a talk in the When Vinyl Ruled area, discussing the production techniques and equipment he used on Earth Wind and Fire and Little Feat albums. I was only there briefly, but the conglomeration of hardware they had on display—from a Scully lathe and Neumann mastering console to a pair of Altec A7s which were being used to play the demos—the hardware was as fascinating as the talk. Throughout the show, this exhibit was completely packed, and it was almost impossible to get a seat inside.

The Groove Tubes folks were showing off their ViPre, which is a mike preamp with an input transformer with multiple taps, so you can adjust the load impedance that the microphone sees. Nicely designed tube gear. They were also showing off their line of vacuum tubes.

D.W. Fearn was showing off some very high-grade tube preamps, and using a headphone amplifier based on a 5080 tube. Upon further inspection, I found that he had built my headphone amp project from Vacuum Tube Valley and was using it for his demos. I am incredibly flattered, because he is the sort of designer that I have always wanted to be, and to have him use my headphone amps for demos is a huge ego boost.

John Hardy was showing off his mike preamps based around an input transformer followed by a Jensen JE-990 discrete op-amp design. What was most interesting was that he was giving away copies of the original Deane Jensen paper on the JE-990, which not only shows the schematic but goes into excruciating detail about how the op-amp circuit was designed and what design constraints were used and compromises made. His preamps are great, but even if you have no intention of ever using one, the JE-990 paper is worth reading just to see some lovely design work. (You can use the JE-990 in all sorts of other circuits, since it is basically a discrete circuit that can replace almost any op-amp, monolithic or not.)

Dick Sequerra from Sequerra Labs was also showing off an IC-based mike preamp, fully differential throughout, with adjustable input impedance, although since his design was transformerless, adjusting bridging resistors on the input sets the input impedance.

Even Prism, the British company mostly known for their high grade A/D and D/A converters, was showing off a new mike preamp. Their MMA-4 has four channels in one rack space, switched attenuators, and extremely low noise and wide bandwidth. They were also showing off their MEA-2 mastering grade equalizer and MLA-2 mastering grade compressor, all with stepped controls and very precise channel matching.

On Saturday morning a number of folks dropped in to see Robert Orban present a paper he wrote with Frank Foti of Omnia Audio, called "What Happens To My Recording When It's Played on the Radio." Unfortunately he didn't show up, but the preprint is very interesting. The authors talk about what broadcast processing does to program material that is already clipped, and try to dispel the myth that outrageously loud and abusive processing in CD mastering will make CDs sound better on the air. They point out that the phase rotation hardware most broadcasters use to get cleaner and louder voices without added compression tends to do bad things when presented with clipped source material. Get Preprint 5469 if you're curious.

Piotr Kieczkowski from the Technical University of Mining and Metallurgy in Poland gave another interesting paper about compression, "The Reduction of Distortion in the Dynamic Compressor." He showed what compression does to various waveforms, and analyzed the resulting distortion, then demonstrated how the control function of the compressor affects that distortion. Nothing earth shattering, but an interesting way to analyze an effect that most engineers have only thought about subjectively. See Preprint 5445.

Mike Spitz from ATR Service Company was demonstrating the Aria electronics package for Ampex ATR-100 tape machines. This is an all-discrete, record and play electronics unit designed by David Hill of Crane Song, and is magnificently constructed. It was a clear improvement over the original ATR-100 electronics which, though impressive in their day, are now somewhat dated.

Nearby, JRF Magnetic Sciences was showing off head kits for those same ATR-100 machines, to convert them to half-inch two-track operation (which is currently becoming very fashionable due to the lower noise floor) and even one-inch two-track operation. They were also showing their own reproduce amplifiers and a 2-inch 8-track headstack for these machines.

Jerry Bruck from Posthorn Recordings, who sells a lot of neat gadgets for field recording work, is now importing and selling Stabilant-22 from the Canadian manufacturer. This is the same stuff that Sumiko rebadged as Tweek, and it's a long-chain polymer that is conductive over short paths. Very fine for improving connections on low level signal paths like phono cartridge leads, and for dealing with worn edge card connectors.

The Museum of Sound Recording in New York was showing off photographs of the equipment they have collected, and lamenting that they don't have space to display it all. They had a Nagra III and an RCA 74b in the booth, both products I use pretty regularly, and my girlfriend was mildly amused to see stuff she recognized (and has seen in use regularly) in a museum booth. If you have an interest in old recording gear, or you happen to have a large amount of office space in the New York area you'd like to donate to a deserving organization, check out www.lovesphere.org/mosr for more information.

DK Audio had some high grade metering, with digital as well as analog inputs, as well as phase scopes that can give you some sense of how a recording images in conditions where playback is doubtful. Dorrough was also showing off a line of less expensive but still high-resolution meters.

Field Production Items

Cooper Sound was showing off their tiny field recording consoles intended for motion picture use. Beautifully machined and hand built, they are little eight-to-four mixing consoles with all the features you’d expect in a large-scale console, except that they will fit in a briefcase. Very quiet and neutral sounding, with transformer coupling in order to reduce RF noise problems in bad environments. Dan Dugan from Dan Dugan Sound Design was showing the things off.

Sound Devices was showing a much simpler and more stripped down field mixer, the MixPre, but they were also showing a digital USB interface called the USB Pre, which allows you to use a laptop for field recording work. These were both transformer coupled with high grade Lundahl transformers, and looked to have quality electronics, as well as features like tone generation and bright meters that could be read in sunlight, which is important for field recording work.

Acoustics

I didn't see any of the usual acoustical material manufacturers, but there were quite a few papers on acoustics. For example, Miomar Mijic spoke on "Design Requirements for Sound Reinforcement Systems in Serbian Orthodox Churches," making the point that the traditional Serbian church buildings had acoustical problems due to the materials used, and that newer churches were required to use the traditional materials. This was combined with the particular problems of the Orthodox services, which involve multiple preachers speaking from different positions while moving around the room. If you're curious about how this affects PA requirements, check out Preprint 5487.

Avi Makivirta and Christophe Anet from Genelec in Finland went to 164 studios using Genelec monitors to measure room response and positioning, which they summarized in "A Survey Study of In-Situ Stereo and Multi-Channel Monitoring Conditions." They found a wide variety of noise levels and a correlation between the noise level and how close the listening position was to the speakers, but they also found a lot of room resonances and notches and wide variations in symmetry. Preprint 5496 has the information if you want to show people that your listening room is better set up than a typical studio.

There was another very interesting paper from the folks at Genelec. It is painfully obvious to anyone who has tried that it is futile to use a conventional equalizer to fix room problems because you are trying to fix a time domain problem with a frequency domain solution. Aki Makivirta et al. have tried using digital delay in combination with frequency-specific filtering to fix low-frequency room modes, and while the results were far from perfect, they looked a lot better than any I've seen without making physical room changes. Check out Preprint 5480, "Low-Frequency Modal Equalization Of Loudspeaker Room Responses" if you are interested in the math.

Speakers

Foreign speaker manufacturers who are normally present, like DAS, Selenium, and Tannoy, and American companies like Community and Radian, missed the show, which I found quite disappointing.

A.D.A.M. showed their powered monitors, based on drivers that are similar in principle to the old Heil ESS driver, with conventional bass cones. The demo didn’t sound very good, with harsh sound and rather exaggerated surround effects, but I know that the speakers are capable of much better. I liked the A.D.A.M. speakers a lot at the show two years ago, before they had gotten representation in the U.S., but I am pleased to note that McCave is carrying the line and has it available to dealers for demo and purchase.

The demo at the Truth Audio booth was even worse than the one from A.D.A.M., partly because they were on the show floor, and partly because they were using a dreadful old Crown IC150 amp. They didn't have anything approaching acoustic music on their CD changer, just overprocessed pop, and couldn't play my demo CD. I have heard good things about these speakers, and would like to hear a demo that shows what they can do. The demo here did not. On the other hand, they had Bootsy Collins endorsing their product, so how bad can it be?

Westlake Audio had a number of larger monitors on display, from the LC4.75 to their very large horn systems, but none were available for demo. I haven't heard the newer, smaller Westlakes and was rather disappointed, but because of the rescheduling of the conference, they weren't able to get demo space.

NHT was showing their A20 monitor speaker system with an amp specifically designed for the speakers, but had some of their home speakers on display as well. They also warned me that the home product line would be changing early in 2002.

Earthworks had a very interesting speaker on display, their new Sigma 6.2 reference monitor. This is a stepped-face box with a single woofer in the main box, a recessed area for a Vifa tweeter on a baffle, and then a wide vent on top which doubles as a carrying handle—a very slick design. It looks like they took a lot of time thinking about how monitor speaker should sound and how people use them. Eric Blackmer of Earthworks spent a lot of time talking about how they voiced it to get something that sounds neutral and measures fairly flat. I only got a very brief chance to listen, so can't say more, but what I heard was pretty good.

FAR Audio in Belgium had a booth where they were showing their line of powered monitor speakers (by powered monitors, I mean speakers with internal amplifiers). They had a smooth top end, free of the spitty dome tweeter resonances that I find very annoying, and a decent midrange, but I couldn't tell much more under show conditions. Also definitely promising, but they do not have U.S. distribution. They also make some nifty remote-controlled preamplifiers, and Pierre Thomas was very happy to demo with my material and let me play with the positioning of his products.

Blue Sky also had a small satellite-sub system, with built-in amplifiers in all the boxes and internal bi-amping on the satellites. Very smooth but accurate top end, and a clean transition between the satellites and the sub, much better than I have heard in a long time. I didn't get to hear the system under better conditions, but it's worth looking into, and is THX-approved. (This is a big deal, since it's hard to find stuff that is both THX approved AND good sounding, in my opinion, and a lot of folks are doing installs that require THX approval.) Imported into the U.S. by Group One, Inc.

Embracing Sound Experience from Sweden was showing off a very strange gadget built by Emes in Germany under their patent license. It was a pair of speakers in a single box with a front baffle between them, and a processor with some shuffling, with the intention of getting a full stereo image from a single box. It wasn't a deep and broad image, but it was definitely better than any of the previous gadgets I have seen that attempt to use closely spaced speakers to get a wide image. Definitely not high end, but it does have a place in small, portable systems. Most listeners honestly have no clue about what stereo is and what a soundstage should be, and anything that improves soundstaging on low end products will probably help them to understand what they are missing. At the very least, this is an interesting bit of engineering even if the concept seems misguided.

SLS Loudspeakers used to make large PA speakers employing high-output ribbon tweeters from Stage Accompany, which sounded absolutely amazing, but they had problems getting the tweeters in quantity, so they started manufacturing their own ribbon drivers. They showed a small studio monitor, the S8R 2-way, which had a very clean sound and great imaging, although a very small sweet spot, but they also make enormous ribbon driver line arrays for narrow-dispersion stadium sound systems. Stage Accompany makes cabinets using their drivers, but they missed the show this year because of the rescheduling, so I did not get a chance to compare the SLS and Stage Accompany systems, which would have been very interesting.

The folks from Frances Manzella Design took a group of us uptown to the Masterdisc mastering studio, where we got to listen to some of their Griffin mastering monitors, designed by Stig Erik Tangen in Norway. This demo was done with a Sony CD player driving a Krell D/A into a Neumann mastering desk and the Griffin crossover. They used Crown Studio Reference amps on the top end and Chevyn Research amps on the bottom, and it sounded pretty damn good. We played a lot of material, including my usual Glenn Gould demos, and the imaging was tight, the overall sound solid, and the things could play at much higher levels than was prudent and still remain transparent and clean. I was impressed. They had a D'Appolito midrange pair with a Stage Accompany ribbon driver and a 15-inch bass driver. The bass was a bit odd, but it sounded more like a room problem than a speaker problem. I suspect the room was voiced more for hip hop than for solid, flat low-end response.

Juha Merimaa and others were giving a talk called "Measurement, Analysis, and Visualization of Directional Room Responses." These folks built a multiple microphone array that can measure not only sound intensity but the direction the sound wave is propagating. They measured level and direction at thousands of points within a room with a fixed stimulus source. This is another small step toward understanding room effects, which I think everyone will agree are still largely mysterious. See Preprint 5449.

On the PA side, everyone and his brother was showing some sort of line array. McCauley had a huge one called the Monarc MLA5. Line arrays are a way of getting some degree of directionality and pattern control for large rooms and are currently very fashionable, although many of the companies that made them fashionable were not exhibiting this year. Part of their advantage is that they are fairly foolproof to set up in bad rooms, and anything that makes concerts sound better is okay by me. The McCauley system is being used by Jo Dee Messina, King Crimson, and Queensryche, and I can't think of a more diverse group of customers.

Martin Audio was showing off a line of large flyable speaker systems under the Mach name, as well as some small in-wall speakers, though they had nothing available to demo.

There were a number of companies selling speaker diagnostic equipment, most of it a bit expensive for home speaker builders, but not all. Klippel GmbH was showing a very nice distortion analyzer for loudspeaker systems. Mr. Klippel was also to be found presenting a paper entitled "Prediction of Speaker Performance at High Amplitudes," in which he attempted to model nonlinear interactions and thermal effects in loudspeaker drivers using two-tone excitation signals, measuring the response at high levels, and building a model around the measurements. See Preprint 5418.

The EAW staff had two very interesting papers. The first was by William Hoy and Charles McGregor, on "Loudspeaker Complex Directional Response Characterization." Their premise was that with line arrays becoming very popular and with attempts to model speaker imaging becoming possible, it is now important to get more accurate information about speaker directionality than the simple polar plots that most data sheets have. These folks detailed a method to get very high-resolution plots of frequency response at points in a sphere all around a speaker, and store that information in a file format that can be transferred into modeling software. See Preprint 5439. Following this was a second paper form David Gunness entitled "Loudspeaker Transfer Function Averaging and Interpolation," in which he discussed an improved mathematical model to represent the response of a typical speaker using time delay functions and the data from the measurement method described above. See Preprint 5440.

Mario Di Cola from the Laboratorio Musica in Italy gave a paper called "Analysis of Directivity Anomalies in Mid and High Frequency Horn Loudspeakers," about modeling radiation patterns of horn speakers from the very different perspective of pressure waves themselves. His English was not so good, but he got the relevant points across and Preprint 5432 is available if you are curious. Looking at his crude but effective measurement system is worth the price of admission.

The best speaker paper was probably the simplest one. J.R. Wright from KEF gave a paper called "The Virtual Loudspeaker Cabinet." From the title I assumed it was another paper on speaker simulation, but in fact it was about putting activated charcoal into speaker cabinets. The high surface area and adsorption effects mean that the impedance to air motion at lower frequencies is reduced, and the proper application of activated charcoal blocks effectively increases the internal volume of the speaker. Strange, neat, and effective. See Preprint 5421.

Microphones

The big microphone news is that AKG is reintroducing the old AKG 451 electret condenser mikes. Unfortunately the new version, unlike all the old ones, has the capsule permanently mounted to the body. With the older 451s, you could put extension tubes between the capsule and the body and keep the microphone body out of view, for a very low profile. The new mikes won't do this, which I think defeats most of their advantage. 

Richard Barnett from AKG gave a talk, "Modal Improved Condenser Microphones," in which he demonstrated a finite element model (FEM) of a microphone diaphragm and showed solutions for the equations of motion of the diaphragm. This is exciting, in that it helps manufacturers build a model for how a given capsule design will work before building it, and it's the first FEM capsule model I have seen. Using techniques borrowed from the civil engineering field, audio folks have been using FEM techniques for years to look at tonearms and cartridges, and it is good to see more difficult elastic models being applied to microphone design. See Preprint 5466.

Martin Rausch from the University of Erlangen-Nuremburg talked about "Computer-Aided Design of Electrodynamic Loudspeakers Using A Finite Element Method." In this case, the FEM model was the important part of the study, not a generalization made from that model. He detailed how a model was made of both the magnetic and the mechanical influences of individual drivers (ignoring cabinet issues) and how the model could aid optimization of driver design. See Preprint 5420. Similar work was being done by Ryan Mihelich of Harman/Becker, who talked about "Loudspeaker Nonlinear Parameter Estimation: An Optimization Method," which started with an FEM model and them built a nonlinear electrodynamic model to match. See Preprint 5419.

AKO Pacific was showing their line of IEC measurement microphones and capsules. These are very high-grade measurement mikes, for considerably less than B&K charges for similar configurations. Since I tend to like measurement mikes for recording as well as for actual measurement, I was quite interested in the line. Their higher-end Type I capsules and preamps looked an awful lot like the B&K stuff.

Minoru Kobayashi from Sanken was showing off some of their microphones, but I was unable to understand much of his English, nor did he have any literature. He was also unable to tell me who had the U.S. distribution for Sanken. I like the look of a lot of their mikes, and they make some spectacular-looking small diaphragm condensers.

Scott Jones from G-Prime had the Microtech Gefell line on display, which contains a lot of small-diaphragm mikes. He was very helpful, telling me about service literature on their older microphones.

Taylor Johnson was showing THE mikes, made in Argentina for the Sound Room. Nice manufacturing quality, and very fine design work. I liked the look of them.

Curtis Technology was showing off an externally polarized miking system for drum kits, consisting of their AL-2 microphones and OPre2 preamplifier. I couldn't get any information about what was inside, except that the AL-2 uses 12AU7 tubes, but the sound was somewhat rolled off on the top end.

Baltic Latvian Universal Electronics (BLUE) was missing from the show. They had planned on rolling out their new set of microphones at the show and bringing much of the Latvian factory staff, but when the show was rescheduled this became impossible.

I checked out the Audio-Technica AT895 adaptive-array microphone. This is an array of seven microphone capsules going into a DSP box, with software that nulls out off-axis signals. This gives you the ability to get a very tight pattern that sounds a little funny off-axis, but less so than a normal shotgun mike. I spent some time picking voices out of the crowd with it, and found it was both more natural and more directional than any conventional shotgun I have used.

Wes Dooley at AEA was showing off his replicas of RCA 44BX ribbon microphones and replacement parts for the RCA 77DX microphones. Nothing new, and he hadn't started making the BK-11 replicas that I wanted to see, but he was giving out some very good chocolate, and it's hard not to mention someone who gives you chocolate.

Cables

Whirlwind was showing off their line of industrial grade cables and connectors. They also had prepunched boxes, fanouts, and rack mount panels which could be ordered in any configuration, great for everything from home theater to remote trucks. You can use your own high end wire and connectors or order them with their wire and connectors.

Marshall Electronics was showing off the Mogami line of cables. The only new ones they had at the show were installed system cables with shields, not really suitable for high end gear, but they also had their usual line on display, everything from tiny coax and balanced pair cables for internal equipment wiring to serious interconnect cables at reasonable prices to speaker cables. These folks spend a lot of time engineering cables both to measure well and to sound good, and at a reasonable price. I was surprised to see that they also make computer cables, but they say they have been doing it for years, and it's clear that they are very well constructed, especially when compared to the usual cabling on the market.

Gepco was showing their line of high-grade cables. They make a cable designed for S-VHS consisting of two 75-ohm cables bundled together in a Siamese pair, which is great for unbalanced stereo audio. I really like their products.

Belden had their customary booth, with Steve Lampen holding court. Belden makes some good stuff and some not-so-good stuff, and Steve knows which is which. This year I was mostly interested in a very small star-quad cable that was available in bundles within one sheath. I ordered a sample, and we will see how it sounds. 

Sommer Cable is a German firm that was founded by a group of musicians to make high-grade audio cables, and they make impressive-looking materials of various sorts. They have fancy gold and silver-plated Litz wire cables, available on special request, but even the off-the-shelf items looked impressive. When was the last time you saw anyone outside the high end selling cables specifically designed for phono signals? These folks are definitely worth checking out. They have been in business only three years, and are only now getting U.S. distribution.

Other Stuff

There was a fellow running around the trade show floor screaming about how all Arabs were "damn murderers," how some Arab guy had an Arab hat with a crescent on it right there in his booth, and how all those damn murderers at the AES show made him so mad. Upon investigation, it turned out that Fletcher of Mercenary Audio, making fun of the Pro Tools Alsihad thing, had a Shriner fez reading "Shah of Alsihad" at his booth. Some people just didn't get the joke, or are too full of hate to even try. Fletcher also had his usual "Shit on a Stick" exhibit, with an Adat recorder and a Mackie 1202 mixer impaled on a post. Legend has it that the last time this was displayed at an AES show, Greg Mackie came over, looked at it, laughed, and said he bet that it still worked. It's good to see that some people actually do get the joke.

Ralph Henry from Equi=Tech was showing off their line of balanced power systems, and while I shudder at their advertising, I have to say that balanced power can reduce noise floor caused by chassis leakage in equipment, and balanced power sources are great to have around. I take offense at the pseudoscience and the claims of outrageous noise floor improvements that they promise, but it just goes to show you that this sort of thing isn't strictly limited to the high end. It might be worth trying one of their balanced power boxes on your high end system; for all I know it might make it sound better. They are certainly well constructed, and appear reliable.

There was a paper given by Ralph Glasgal of the Ambiophonics Institute, entitled "Ambiophonics: Achieving Physiological Realism in Music Recording and Reproduction." Ambiophonics appears to be a combination of a speaker system, a process for storing the room impulse response when a recording is made, and the Ambiovolver, a software shuffling system that directs the room ambience from the main pair to additional speakers. I wasn't able to take the trip to New Jersey to hear the demonstration, but it looks like an interesting way of trying to model the original room sound. See Preprint 5426.

Digidesign wasn't at the show this year, and was very conspicuous in their absence. However, someone found an empty booth in the back of the hall, wrote "Digidesign" on a cardboard square, and put it on a table in the middle of the booth. I liked it.

THAT Corporation was showing their THAT 1510 microphone preamplifier chip. This is a drop-in replacement for the SSM 2017 chip that is in all kinds of mid-grade equipment, and should offer an upgrade path. It might also be worth trying as a front end to a phono preamp, but the notion of having a good upgrade for inexpensive preamps and consoles is enough to make me interested. THAT also makes some great transistor arrays and gain control elements.

Vistek Corporation was showing off their line of connectors, switches, and potentiometers. The connectors looked a bit cheap, but the switches and pots looked pretty solid. It is hard to get good quality potentiometers in reasonable quantities, and this might be a good resource for folks building their own gear.

Neutrik and Switchcraft were both showing their lines of connectors, though both were mostly pushing the more inexpensive, crimp-type connectors this year, for some reason.

Lots of companies were showing toroidal transformers. Plitron had an enormous 500 KVA unit on display, as well as their normal line. Keen Ocean Industrial from Hong Kong was showing a nice line of power toroids. They said they had often made wideband audio toroids for output transformers as well.

Lundahl was not there to show their line of audio transformers, but sent mail to attendees explaining that they weren't going to make the show, and why.

John D. Paul from Schott Corporation gave a talk about measuring jitter through the pulse transformers used for digital audio signals, and a new method of directly measuring phase error through the transformer, in "Characterizing Digital Audio Transformers with Induced Jitter Histograms." See Preprint 5448.

In the past few years I have heard a lot of papers on Class D amplifiers, and a lot of folks were discussing theories of linearizing them. This year I saw actual products. Hegel AS from Oslo, Norway was showing their SoundEngine SE-2090 thickfilm hybrid module, which is a complete 100W switching amplifier on a module that a manufacturer can drop into a receiver design. They also had information on home stereo gear sold under the Hegel name in Europe. The Hegel H2 and H4 amplifiers are built around these Class D modules, with large dual-mono power supplies in one case. They also make a very slick, minimalist preamp called the P4, and a variant with a simplified output stage called the P2. Phono modules are available. They also have CD players—the CDP4, which is HDCD-ready, and the CDP2, which has a conventional sigma-delta converter. This gear it looks very nicely built and deserves attention, but as far as I can tell, it has no U.S. representation. Powerphysics was also showing off a Class D amplifier module that they sell as an OEM product to manufacturers wanting to embed a high power amplifier into powered speaker systems.

Johan Gaboriau, Xiofan Fei and Eric Wallburger from Cirrus Logic gave a paper entitled "High Performance PWM Power Audio Amplifier," in which they discussed a high speed switching amplifier based on sigma-delta conversion methods, did a full error analysis on it, then showed how converter nonlinearity could be optimized. This is very different from the dual-PWM systems that most class D amplifiers use, and has the promise of sounding a lot better if the operating speed can be high enough. If you're into the whole Class D thing, look at Preprint 5428.

Somehow I also found myself listening to "Spectral Approach to the Modeling of the Singing Voice, " by some people from the Pompeu Fabra University and a fellow at Yamaha. They talked about ways to morph one voice into another voice by identifying phonemes and replacing them with sampled phonemes in such a way that voice inflection was preserved. Its intended purpose is for karaoke systems, but I can imagine a day when this technology will have far scarier implications. See Preprint 5452.

As always, the House Ear Institute had their truck there, testing hearing and giving free advice on hearing conservation. They issued a press release saying that hydrocodone/acetaminophen pain relievers like Vicodin may be responsible for partial hearing loss, which is a disturbing thought. The people from Ear, Inc. were showing off their web site (www.freehearingtest.com), which provides a simple and approximate hearing test of frequency vs. audibility and provides a pointer to an ear doctor in your area. H.E.A.R. (Hearing Education and Awareness for Rockers) was also doing hearing tests, and was making custom ear molds for high-grade earplugs and in-ear phones right there at the show.

Nearby was the John Lennon Songwriting Contest Educational Tour Bus, which travels to high schools and music expos to provide remote recording services. It grew out of a song contest, but seems to have become more than that.

Finally, the Society of Motion Picture and Television Engineers were not only selling their standard documents and a variety of great books and trying to get folks to sign up for SMPTE memberships, but were selling great T-shirts with projector alignment test patterns and video bars.

I really enjoyed this year’s show, and think that the quality of both exhibitors and attendees was much better than usual. The show was definitely more pleasant than the sprawling shows of the recent past.

Best Sound In Show

Frances Manzella Design was taking people up to Masterdisk to listen to their large scale mastering monitors. Each Griffins, made for them in Norway, has a D'Appolito midrange driver, Stage Accompany ribbon drivers, and a15-inch bass driver. While the bass in the room was a bit strange, the speakers had a very clean midrange with good vocal quality, and were a very refreshing change from the show floor. These speakers are voiced to sound neutral at reasonable levels, but also to be able to operate at outrageously high levels and stay clean. That's a difficult and expensive thing to do.

Worst Sound in Show

The Songwriter's Showcase in the lobby of the Javits brought in some very fine young local musicians to perform in a horribly reflective glass-walled room with a reverb time so long that none of the words were intelligible. The PA crew tried valiantly, but just couldn't overcome the horrible effects of the location. It's very sad when the worst sound at the show is live.

Loudest Sound in Show

What with Cerwin-Vega and Full Sail not being at the show this year, the loudest sound I heard was at the Truth Audio booth. I understand that it's hard to do demos on the show floor, but listening to a Crown IC150 amp playing processed pop music at high levels was not a good way to show off loudspeakers.

Best New Company

Sommer Cable, a German firm, has only been in business for three years and is just now breaking into the U.S. market with a line of very nice-looking high-flexibility cables.

Hottest New Product

The Cadac Type R console on display at the show was hot, hot, hot. You could feel the heat coming off of the top panel. It would keep your fingers warm at those fall music festivals, and it sounds good, too.

Best Old Product

Posthorn Recordings is now distributing the Stabilant-22 contact enhancing fluid in the family that Sumiko used to distribute as Tweek. Great stuff for keeping old gear with worn connectors operating.

Best Giveaways in Show

Mercenary Audio, H.E.A.R, and the House Ear Institute were giving out free earplugs, which were very much appreciated and useful. Although the show was much quieter this year, it was still pretty loud.

Worst Giveaways in Show

This award is tied between Genelec, which was giving out light-duty cloth bags which ripped when crammed full of marketing literature, and Neutrik, which was giving out samples of their solderless XLR connectors, which frankly don't seem very reliable. On the other hand, I'll try them, and if they do turn out to be reliable they might be the best giveaways.

Best Papers in Show

This year I am splitting the Best Paper award between people who cannot agree, because I found listening to them discuss their differences very enlightening. James Angus from the University of Salford in Manchester, UK gave a talk called "Effective Dither in High Order Sigma-Delta Modulators," in which he described a method for comparing effectiveness of dither in linearizing PCM vs. 1-bit DSD-like converters and gives guidelines for achieving optimum linearity.

Then, Stanley Lipshitz and John Vanderkooy from the University of Waterloo gave a talk called "Towards a Better Understanding of 1-bit Sigma-Delta Modulators, Part 2," in which they extended the general discussion of one-bit converters to what they call 1.5 bit converters, i.e., converters that have three output states but use sigma-delta style encoding like DSD does. They then predicted the idle-tone behaviour and spectral linearity of these theoretical converters and showed how the same math applies. They used this to give a more generalized model of sigma-delta converters and talk about dither in the converters, specifically refuting some of the things that James Angus said earlier. I have not been able to follow the math well enough to know who is correct, but my attempts to do so have helped me understand a lot about sigma-delta methods.

Silliest Paper in Show

"Beyond CD Quality: Advanced Audio Coding for High Resolution Audio with 24-bit Resolution and 96 KHz Sampling Frequency," by C. Buergel, et al. This is paper was on the design of lossy compression systems for high resolution,  wide bandwidth channels, which to me seems to be missing the whole point.

Best Satellite/Subwoofer Combination

The Blue Sky satellite/sub combo actually sounded like a pair of speakers, with much better integration between the satellites and the sub than I have heard in ages.

Best Suit in Show

The spotted-pony-pattern suit worn by Clive Kavan from the UK was definitely a hit, beating by a long shot the pink hairy thing that EveAnna Manley wore this year.

Best Ego Boost

Discovering that D.W. Fearn built my DIY headphone project from VTV and liked it.

Most Compacted Booth

This year, Tascam managed to fit their entire product line in a booth that could not have been more than 100 square feet, tops. The rumor was that they had pulled out of the show when it was rescheduled, and when they decided to come,  the booth space was no longer available.

Best Sofa

The folks in the booth next to the Little Labs booth pulled out at the last minute, leaving the booth unused. Someone from Little Labs decided to put an inflatable couch in the space, which was very gratefully appreciated by many tired people. Not only this, but the couch had a black hairy cover, almost as hairy as that pink thing EveAnna Manley was wearing.

Best Butt

The guy in the dreadlocks with the Spandex bike pants wandering around on the show floor. I didn't see him, but our official butt inspector was very impressed. The photograph she took, though, sadly does not include his badge, so he cannot be identified.

 

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