Media Reports

Disc Rot, Wireless, Customer Confusion
By Barry Fox

In the early days of Laservision, CD, and DVD there were reports of “laser rot.” Some discs, sometimes poorly pressed or stored in high humidity, let oxygen from the air seep through the protective lacquer and erode the aluminum reflective layer. This caused data errors which made the player stutter or stop playing. Now there are reports of a few early Blu-Ray Discs showing signs of grey dot spotting.

BVHE’s “The Prestige” was the Blu-ray title most often cited on Internet postings as having problems. Others said BVHE’s “Gone in 60 Seconds,” Sony Pictures Home Entertainment’s “Stranger Than Fiction,” and Warner Home Video’s “The Departed” were also affected, but to a lesser extent. Most of the affected discs appear to have been released within a short time of one another, and at least some pressed by Sony DADC. But Sony says it has not received any complaints.

Disney’s BVHE is now asking customers with a problem to call its Consumer Relations hotline “for forensic examination.”

BVHE’s hotline told a caller that so far only one disc had been returned and the disc appeared to have been cleaned with a caustic substance, such as bleach or ammonia.

If the problem is real, and does not affect HD-DVD, it could be related to BD’s use of a 0.1mm coating layer. Sony DADC has been using a transparent adhesive film, but has now switched to the spin coating process used by most other replicators.

There was no Internet when Laservison, CD, and DVD rot was discovered, so awareness was slow. Now any problem will be publicized and addressed far more quickly.

WIRELESS
License-free wireless technology on the 2.4GHz ISM (Industrial, Scientific, and Medical) band has changed the face of home computing and could now do the same for hi-fi. Crystal Audio’s new “high-end wireless, THX certified loudspeaker package” claims to “remove all the cable clutter associated with home cinema speaker systems.” But taking the wires out of hi-fi will not all be plain sailing.

The family of IEEE 802 WiFi standards has made it (relatively) easy to connect computers and printers in a wireless network on the 2.4GHz band. The same system can be used to stream compressed audio and video, as in Philips’s Streamium products. Range is a few hundred meters.

The Bluetooth system works on the same 2.4GHz band and is used for cellphones and portable players because it pulls less power, so does not drain batteries so quickly. The new A2DP standard (Advanced Audio Distribution Profile) lets a Bluetooth link carry stereo. But audio quality is iffy, range is only a few meters, and the signal won’t pass through walls.

The very heavy compression and decompression used for WiFi and Bluetooth adds a significant delay or “latency” to the signal—20 milliseconds or more which makes the system useless for some applications, especially TV sound because the sound lags horribly behind the picture. Mixing wired and wireless components exposes the delay, too.

The ISM band is very crowded, not just with data communications systems but also analog “videosenders” and heavy-duty interferers such as microwave ovens. The WiFi and
Bluetooth standards were designed to make the best of this bad job.

The band is divided into up to 14 channels (11 or less in most countries) but they overlap, and the WiFi system can use only three at the same time without one interfering with another. “Collision avoidance” rules are permanently stored in every WiFi transceiver to stop it sending data while another transceiver is using the channel. Once a channel is free, every unit in the area tries to grab the airspace. So each generates a random number, and uses it to set a “back off” time before trying to occupy the channel. This ritual dance keeps each transceiver waiting for unpredictable periods.

Microwave ovens, analog Video senders, and even out-of-range WiFi units don’t stick to the dance rules, so just blast away. So WiFi data is sent in bursts or “packets” and an acknowledgement signal returned for every packet successfully received. If there is no acknowledgement, the packet is sent again. This adds unpredictable delays.

Bluetooth works differently. Each device independently hops 1600 times a second between slightly different frequencies after each packet of data is sent. WiFi can swamp Bluetooth.

Three years ago Sharp launched a 15″ WiFi TV. The company admitted that interference could cause “interruption of the image” and the owner should manually select one of three channels “to alleviate such symptoms.” Computer users found it swamped WiFi. The product is no longer available outside Japan.

When you read past Crystal Audio’s headline claims, the only wireless connection is to the rear speakers. The key technical advances are the use of uncompressed 16-bit, 48kHz audio and latency of just 2ms.

The wireless technology is proprietary, not an 802 WiFi data system. The digital signal is modulated using DSSS (Direct Sequence Spread Spectrum), with error correction and control data that increases the audio data rate of around 1.5Mbit/sec to 4Mbit/sec.

The only latency comes from the analog to digital converters, 1ms for code and 1ms for decode.

Crystal admits that “if the wireless system interferes with another Bluetooth or Wi-Fi system, the sound coming from the speakers might pause for a minimum fraction of time but this disappears when we change the transmission channel.”

The transmitter can be switched manually between three channels; in some models the receiver switches manually, while in others it switches automatically.

Many industry eyes are now on new 802 standards for higher rates in the higher 5GHz band, where (so far) there is less clutter. But 5GHz technology is not yet mature.

And nothing can alter the easily forgotten—or camouflaged—fact that wireless speakers need either giant batteries or mains wires to power them.

CUSTOMER CONFUSION
When the Head of Philips Consumer Electronics, Jeremy Ling, spoke at a London trade conference, he told how he had joined Philips a year ago with no experience of consumer electronics. So he spent a week working as a salesman in a Comet store to get a feel for the industry.

“Do you know what the retail return rate is for WiFi Routers?” Ling asked the audience. “10%? 20%? 30%?

“No; 40% of all home wireless networking equipment is returned because people cannot make it work. And of the Philips equipment that is returned we find that 98% has “no fault found.”

I can well believe this. I tried a dinky little Philips Streamium Internet WiFi radio a year ago and it was a pig to set up. The product managers can never have watched someone struggle to make the product work.

Perhaps thanks to Ling’s stint on the shop floor, Philips is learning. A recently launched WiFi Skype DECT phone was as easy to set up as any computerish product like this can ever be.

People used to complain about computer instruction manuals the size of phone directories, and full of gobbledegook jargon. The computer companies solved the problem by no longer printing manuals. They just printed a Getting Started Guide and put the gibberish on a CD-ROM for the owner to print out. Frequently Asked Questions on a website seldom answer the questions people want to ask.

The audio industry is going the same way because modern equipment is more like a computer than an AV product. It will get worse as HDMI with HDCP encryption becomes obligatory for high quality digital audio and video connections. Because equipment is software-based, it can be rushed to market before it is ready, and updated with software upgrades that must be downloaded by Internet connection. Wireless networks rely on WiFi routers which are tricky to set up.

UK company Morphy Richards is promoting a new “easy to use” Internet Radio. “All you need is Wi-Fi” promises the blurb.

I borrowed one and it worked fine with a Netgear Wi-Fi router, but not with a Belkin. I wasted hours trying before asking Morphy Richards the very simple question. “Have you actually tested the radio with Belkin DSL modem/routers?”

After several months and many reminders Morphy was still ducking my simple question. Draw your own conclusions.

Modern AV amp beasts are computers in disguise, which need composite, component, and S-video inputs and outputs, along with analog and digital HDMI, optical and coaxial audio inputs and outputs, all assignable to a dozen different functions. That’s before the user starts worrying about the myriad of Dolby and DTS decode choices, and the video up-scaling and digital audio sampling options that may work only if there are HDMI connections.

The badly written and illogical manuals, often sourced from Japan, only make sense when you already know what they are trying to say.

What’s needed, and all too often missing, is a manual which is carefully structured to deal first with basic practical essentials and easy options, and then offer more detail on specialist options. There should also be some practical examples of typical setups (how to connect a multichannel DVD player, and so on) that the user can follow and modify.

The best example I ever saw was from a few years ago, for the RC3200 universal remote control from Marantz. There were readable examples of what components Mr. and Mrs. Average might want to switch with a single macro button push.

The Marantz manual was written in the UK. I’ve no idea whether newer products from Marantz have such helpful instructions. But I am currently encouraging Denon to try a similar approach.

The moral of this story is simple. Before buying anything that is going to need a manual, ask to see it. A quick flick through will tell you what level of misery you are in for. M3

Barry Fox reports on the audio industry as columnist for the British publication Hi-Fi News. His commentary appears in every issue of Multi Media Manufacturer.

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