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Speaking of Radio…

I was talking to a friend from Russia about history, my job and various other things that are going on in my life. I received this reply, which I thought was interesting on a number of levels:

I’m glad we are on the same page about the era of the ‘cold war’. We were interested in your life even more than you in ours. We had almost no sources of information except for ‘The morning star’ which is a newspaper of the Communist party of Great Britain. The Voice of America and the Liberty (or Freedom, I have no clue because for us it was ‘RADIO SVOBODA’) were extremely hard to tune on. All foreign broadcasts were jammed. So to listen to the station you should maximize the volume up to the limit which was dangerous. Soviet houses are not at all soundproof and your neighbors could easily rat on you. Since that time I’d been dreaming of a small radio with could receive a clear signal from abroad. Of course we have the Internet broadcasting now but they often use old recording instead of live air and the signal depends on your data carrier. You should be online, you should have an app and unlimited data on your contract, your phone should be charged all the time. Too many conditions. Unfortunately a lot of foreign sites are banned here and the trend is to make this number bigger and bigger.

I find that perspective interesting.  We take for granted our ability to listen to information and listen to different points of view, even those we don’t agree with.  There are still trouble spots in the world and some people are not as fortunate.  It is very easy to block internet traffic and there are several countries that currently block access to some or all of the internet, for the safety of their citizens, no doubt.  Ideas are dangerous.

VOA/RFE transmitter site, Biblis Germany

VOA/RFE transmitter site, Biblis Germany. Photographer: Armin Kübelbeck, CC-BY-SA, Wikimedia Commons

In the last ten to fifteen years, many large government shortwave broadcasters have reduced or eliminated their programming favoring an internet distribution model.  This is a mistake.  It is very difficult to successfully jam terrestrial radio broadcasts.  Shortwave Facilities are expensive to develop and maintain, there is no doubt about that.  However, as the Chief Engineer from Radio Australia (ABC) once told me “HF will get through when nothing else will.”  Ironically, ABC has eliminated its HF service on January 31, 2017.

It seems to me that a sort of “Shortwave Lite” version of broadcasting might be the answer.  Use more efficient transmitters with lower power levels closer in to the target areas.  Such transmitters could be coupled to rotatable log periodic antennas to target several listening areas with one system, thus greatly reducing the number of towers and land required.  Solid state transmitters with a power of 10-50 KW are much, much more efficient than their tube type brethren.

DRM30 (Digital Radio Mondiale) has not gained wide spread use in the MF and HF bands.  Like it’s HD Radio counterpart, lack of receivers seems to be one of the adoption issues.  As of 2017, there are only four DRM30 capable receivers for sale not counting software plug ins for various SDRs.  That is a shame because my experience with DRM30 reception has been pretty good.  I have used a WinRadio G303i with DRM plug in, which set me back $40.00 for the license key (hint for those nice folks at the DRM consortium; licensing fees tend quash widespread interest and adoption).

CFRX, Toronto coverage map, average HF propagation conditions

CFRX, Toronto coverage map, average HF propagation conditions

Finally, I have advocated before and still advocate for some type of domestic shortwave service.  Right now, I am listening to CFRX Toronto on 6070 KHz.  That station has a transmitter power output of 1 KW into a 117 degree tower (approximately 50 feet tall) using a modified Armstrong X1000B AM transmitter netting  a 15-32 µV received signal strength some 300 miles away.  That is a listenable signal, especially if there is no other source of information available.  The average approximate coverage area for that station is 280,000 square miles (725,000 square kilometers). That is a fairly low overhead operation for a fairly large coverage area.  Perhaps existing licensed shortwave broadcasters should be allowed to operate such facilities in a domestic service.

The point is, before we pull the plug on the last shortwave transmitter, we should carefully consider what we are giving up.

iBiquity sale to DTS

DTS, Inc (NQ:DTSI) is to acquire iBiquity for $172M USD.  This was the headline about the middle of last week.  With that announcement, we get to see some of iBiquity’s financials; revenue of $40-50 million this year with a margin of 30-36%.

My question is, who or what is DTS?  DTS was initially known as Digital Theater Systems, Inc.  They specialize in digital surround sound technology, by developing or acquiring companies that created various CODECs and surround sound technology.

35mm film audio macro

An image of 35 mm film showing four audio formats, from left to right: SDDS (blue area to the left of the sprocket holes), Dolby Digital (grey area between the sprocket holes with the Dolby “Double-D”), analog optical sound (the two white lines to the right of the sprocket holes), and the DTS time code (the dashed line to the far right).  The DTS time code syncs picture to a CD-ROM that contains the surround sound sound track.

DTS continues to develop surround sound technology and makes money by licensing that technology to consumer and professional audio clients.  According to their 2015 Q2 financials, they are on track to make $140-145 million this year with a 25-30% margin.

My next question is, what does this mean for HD Radio?  It is much harder to answer this question, but here are some general observations:

  • DTS is a publicly traded company.  Financials and other information are a matter of public record.  It seems likely that the operation will be more transparent.
  • DTS operates with higher revenue and lower margins.
  • DTS has a high interest in mobile markets; devices and dashboards.
  • DTS has a history of continued development and marketing of technology it owns.

There are a couple of different scenarios possible; the first is business as usual. I think this is the least likely situation.  IBiquity as a company and HD Radio as a technology basically flat lined ten years ago.  A successful company like DTS would not likely purchase something that does not have growth potential.

Second possibility, DTS will keep the same licensing structure, but upgrade the HD Radio technology.  From a audiophile’s perspective; HD-1 sounds good, HD-2, 3, and 4 channels not so much.  This is especially true as more channels are added and the same size pie (aggregate digital bandwidth) gets divvied up into smaller and smaller pieces.  One area where HD Radio could shine is to get rid of the HD2-4 channels and create an IP multicast system.  IPv6 has greatly improved multicast performance which might enable a free data stream download, minimal data back haul via mobile data for an interactive, low data usage digital experience.  That would free up a lot of translators.

Third possibility, DTS will reduce the licensing fees for broadcasters and consumers and accept a lower margin on existing technology.  DTS will use HD Radio as a route to get their technology into dashboards, which is where they see their future profits.  Remember, the self driving car is only a few years away and mobile entertainment will be all the next rage.

As far as AM HD Radio goes, I don’t see anything happening with that.  Medium wave broadcast channels do not offer enough bandwidth to facilitate reliable digital transmission.

In any case, for better or for worse, change is coming to terrestrial radio.

Norway says “Goodbye, FM”

Norway will switch off its national FM networks in 2017, according to the Ministry of Culture announcement.  In the place of analog FM will be DAB.  The aim is to have the migration to DAB completed by December of 2017.  According to the article, approximately 54 percent of households and 20 percent of automobiles have DAB radios.  What is left unsaid is the 46 percent of households and 80 percent of automobiles that do not have DAB capable receivers.

I am sure that in the ensuing year and a half to two years, those numbers will change somewhat.  It still seems to me that there will be many people who will likely not have a DAB radio in their car before the analog switch off.

Judging by the comments on the Slash dot story, many are not happy with this decision.  Perhaps the most telling comment is this:

This is just Norway going off on its own crusade urged on by commercial interests of 10+ new channels, fuck whether it makes sense to throw out millions of radios… I expect this to lead to a massive interest in building out 3G/4G coverage as ex-FMers give DAB the middle finger.

Yup, that sounds about right.

I don’t know much about radio in Norway, but it if is anything like radio here, good programming trumps technical do-dads and and fancy gimmickry.

HD Radio development Stasis

I have been working on an HD Radio installation these last few days.  This particular installation was manufactured by Broadcast Electronics.  Some 13 years into the HD Radio development cycle and the implementation still seems like a kluge to me.  To get some idea; to transmit a digital HD Radio with added sub-channels, the following equipment is needed:

  • HD Data importer, off the shelf computer with a sound card and specific software from iBquity.  This is used to import the audio for the HD-2 and HD-3/4 channels.  Runs on Windows (Win 7), Linked to the exporter via IP ethernet
  • HD Radio exporter, another specialized computer with a sound card.  Frames the HD Radio data and adds PID, etc.  Runs on Mandrake Linux, communicates with the exciter via data connection.
  • HD Radio exciter; like other exciters, generates RF and modulates it.
  • HD Radio transmitter; essentially an FM transmitter designed to run as a linear amplifier.

The HD Transmitter part can come in several configurations, including low level combining, high level combining or using a separate antenna for digital and analog signals.

Broadcast Electronics HD Radio transmission system

Broadcast Electronics HD Radio transmission system

None of this is news, of course.  My point is, after ten years, there does not seem to be any further development in HD Radio technology.  In the mean time, competitors are not standing still.  The mobile wireless industry has evolved several times during the same time period; 3G, 4G and LTE have been successfully deployed and widely adopted by mobile phone users.  Truly, mobile data is the real competition to terrestrial broadcasting.

The HD Radio transmission process is an overly complicated patchwork of hardware and software.  The importer in particular seems substandard.  It’s function is to run a bunch of small programs, each doing some small part of the importing process.  The web-admin used Internet Explorer, who uses Internet Explorer anymore?

Since the HD Radio inception, little or no further development seems to have taken place.  There are features, such as album art, program data, traffic data, etc but the system interface is weak, the hardware clunky, the data paths fragile, the operating system outdated, the typical installation is a compromise between cost and available floor space at the transmitter site.

HD Radio is also expensive to deploy and proprietary.  There is little compelling reason to listen to HD-1 channels because the programming is identical to the main analog channel.  HD-2, 3 and 4 channels seem to be mostly used to generate translator feeds, which again, are available with an analog radio.  This use of HD Radio actually damages uptake because, If all the HD Radio sub channels are available on FM analog frequencies, then why even bother with an HD Radio receiver?

Thus the forces at work in the development of HD Radio seem to have reached equilibrium:

Consumer apathy + expensive deployment = 16% uptake on FM and 6% uptake on AM1

The digital radio roll out has been stuck at those levels for many years.  Unless something changes, FM HD Radio will be limited to translator program origination and distribution.  AM HD Radio will go the way of AM Stereo.

1: FCC data on HD Radio deployment; 1,803 of 10,727 FM stations and 299 of 4,708 AM stations have installed HD Radio as of December 31, 2014.

Brother, can you spare a theorem?

A theorem is not, indeed, a fact.  It is rather, an idea which is deduced and supported by other proven facts.  Thus, a theorem is generally believed a truth.  It should be of interest to the “All Digital” AM (AKA Medium Wave) proponents that noise on the digital channel will reduce data throughput as a function of channel bandwidth and Signal to Noise Ratio.  This is known as the Shannon-Hartley theorem:

 C =  B \log_2 \left( 1+\frac{S}{N} \right)

Where:
C is the channel capacity in bits per second;
B is the bandwidth of the channel in hertz (passband bandwidth in case of a modulated signal);
S is the average received signal power over the bandwidth (in case of a modulated signal, often denoted C, i.e. modulated carrier), measured in watts (or volts squared);
N is the average noise or interference power over the bandwidth, measured in watts (or volts squared); and
S/N is the signal-to-noise ratio (SNR) or the carrier-to-noise ratio (CNR) of the communication signal to the Gaussian noise interference expressed as a linear power ratio (not as logarithmic decibels).

With this equation, one can discern a fundamental flaw in the all digital logic.  One of the main issues with AM Medium Wave broadcasting is the ever increasing noise floor.  Our society has changed drastically in the last one hundred years or so since AM was invented.  Electrical noise generators; computers, plasma screen monitors, mobile phones, appliances, energy efficient lighting, data over power line, street lights, poor utility line maintenance, even electric cars, it seems, generate a cacophony of noise in the Medium Wave frequency band. A digital modulation scheme, be it HD Radio or DRM, will mask the noise to a certain extent, that is true.  However, once the SNR exceeds the ability of the receiver to decode the necessary bits, the receiver will mute.  While it is true, the listener will not hear noise, they may not hear anything at all.

I will also note; none of the current “AM improvement” schemes under consideration by the FCC addresses the noise issue on the AM band.  Without addressing the noise issue, any digital modulation scheme will be a temporary fix at the very best.  The noise floor will continue to rise and after it gets high enough, the all digital modulation will simply not work.

It will be interesting to see the data from the all digital HD Radio testing that is being done in various locations.  That is, if the NAB, et al. does not decide to treat that data like some kind of state secret; they have become reticent of late.  When somebody acts like they have something to hide, it makes me think they have something to hide…

AM Stereo Renaissance?

At least in some quarters, there appears to be interest in reviving AM Stereo.  Perhaps as an unintended consequence of AM HD Radio, it seems.  Some people have discovered, quite accidentally, that some AM HD Radios will detect the presence of AM stereo pilot and open up with IF bandwidth automatically, making the analog signal sound much better. AM Stereo being received on an AM HD Radio receiver:

That particular brand of AM HD Receiver only allows 5 KHz audio, which still sounds much better than the typical 2.5 to 3 KHz.

A short video comparing AM HD Radio and AM C-QUAM:

As IBOC and C-QUAM are incompatible, it is an either/or situation.  Being that C-QUAM is open source and many new solid state transmitters come with AM stereo cards installed, the financial leap from AM mono to AM stereo is not nearly as steep as it would be to install AM HD Radio.  The other nifty thing;  C-QUAM is it is completely backwards compatible with existing AM mono receivers, the all digital version of IBOC is not.

It bears repeating; AM is not inherently inferior to FM sound.  Wide band AM can sound really, really good.   Something that we seemed to have forgotten over the years of listening to crappy receivers.  This has caught the attention of Tom King, owner of Kintronics, who penned the following letter to the FCC and all AM broadcasters:

Subject: Meeting with FCC Commissioner Ajit Pai and Mr. Peter Doyle,
Chief of the Audio Division of the FCC Media Bureau
at the offices of the FCC in Washington, DC on Tuesday, September 23, 2014.

To All AM Broadcasters in the USA:

Kintronic Labs is concerned about the declining position of the AM radio service in the United States, which we reflected in our Reply Comments to the FCC NPRM Docket No. 13-249 on the subject of “AM Revitalization,” issued on October 31, 2013. In the interest of preserving this great national resource for local public media, we have scheduled a meeting with FCC Commissioner Ajit Pai and Audio Media Chief, Mr. Peter Doyle, to address what we believe are the critical steps toward putting AM radio on a more competitive basis with FM as follows:

(1) FCC enforcement of regulations relative to the power distribution industry and the consumer electronics industry that are not currently being enforced, resulting in a constantly worsening electromagnetic environment for AM radio service.

(2) The need for parity between AM and FM receivers through the establishment of minimum technical standards for AM receivers that would become effective as soon as January 2016. We plan to demonstrate a comparison of full-bandwidth C-QuAM AM stereo reception with a local FM station and with a typical AM receiver in a popular consumer multi-band receiver. The effects of adjusting the AM bandwidth from 2.5 to 10 kHz in 2.5-kHz steps will also be demonstrated.

(3) The need for FCC authorization of AM synchronous boosters. Unlike FM translators, such on-channel boosters would serve to increase the AM stations’ audiences while concurrently maintaining the future viability of the band. The related technique of wide-area AM synchronization for coverage improvement will also be addressed.

Referring to Step #2, it is absolutely essential that very close to full parity be established for new AM radio receivers versus their FM radio counterparts. This includes all key AM receiver performance attributes, including:

Low internal noise floor, well below the average AM-band atmospheric noise level. This includes all internal synthesizer and DSP circuitry within the receiver (and in the immediate environment for integrated automotive applications).
High overall RF sensitivity, selectivity, and dynamic range, to provide adequate amplification of weak signals, even in the presence of significant adjacent- and/or alternate-channel signals, especially in strong-signal environments. This would incorporate typical advanced, multi-stage AGC action, with appropriate interaction between the RF and IF AGC control mechanisms to maximize overall receiver dynamic range, including adaptive front-end attenuation for signal-overload protection in very strong-signal areas. Useful typical specs include: sensitivity – 1 mV for 10-dB SNR; selectivity (adjacent-channel) – 25-50 dB (adaptive).
Highly effective noise (EMI) rejection, including staged RF and IF noise blanking, accompanied by appropriate audio blanking and/or expansion when required. Such features were developed and included in Motorola chip sets in the 1990’s in the AMAX program, and are easily integrated into modern, high-density AM/FM receiver chips.
Full 10-kHz audio bandwidth capability with low detector distortion. This would obviously incorporate dynamic, signal-controlled bandwidth control (including AMAX-style adaptive 10-kHz notch filtering) as dictated by noise and adjacent-channel interference.
Stereo capability. If the receiver has FM stereo capability, it must have corresponding C-QuAM decoding for AM.

Without fulfillment of the first three requirements (this also includes the associated AM antennas both for vehicles and for home use), basic AM reception will suffer significantly compared with FM. Without the last two, the output sound quality cannot be closely competitive with FM (i.e., 10-kHz full bandwidth on AM versus 15-kHz nominal for FM).

We therefore petition the FCC to mandate the following minimum allowable performance specifications for all AM receivers that will be manufactured and installed in new automobiles as of January 1, 2016:

Audio Bandwidth: 10 kHz typical, adaptive, with a minimum nominal bandwidth of 7.5 kHz
Signal-to-Noise Ratio: minimum 55 dB, preferably 60 dB
Sensitivity: -120 dBm for a signal-to-noise ratio (SNR) of 10 dB
Selectivity: 25-50 dB (adaptive filtering, using co-, adjacent-, and alternate-channel detection)
Dynamic Range: 100 dB
Noise Figure: 1 – 3 dB
Image Rejection: -50 dB
Intermod: IP2 , IP3 intercepts +10 to +40 dBm
IF: low with image-rejecting down-conversion, or double-conversion
Stereo Separation: minimum 25 dB

Respectfully Submitted,
Tom F. King
President

All of those technical specifications are doable with modifications to the current receiver chipset.  Currently there are very few if any AM Stereo receivers being manufactured.  One might ask, how can a typical AM mono receiver be modified to receive AM Stereo.  A great question.  For a small sum, an outboard circuit board can be purchased and installed in a typical AM mono receiver.  For most non-car radios, this modification would be fairly easy.  Car radios, on the other hand, will be very difficult to modify since most new radios will be bricked if tampered with (thanks a lot, crackhead radio thieves of New York).

And for those interested, there are also lists of radio stations broadcasting in AM stereo:

According to the Wikipedia source, there are 90 some odd station using C-QUAM AM stereo.  Using iBquity math, that is nearly the same number as are broadcasting AM HD Radio.

If you are an AM station owner, you can start by transmitting good programming.

CES 2014 and the Digital Radio question

I have been busy of late, however, still keeping abreast of the news of the day.  Along with that, CES 2014 wrapped up recently.  No huge developments, especially when it comes to Broadcasting.  However, there was one item of interest; the updated technical specifications of IEEE 802.11ac.

It is of interest here because of the implications of the mobile/portable data developments and their impact on traditional AM and FM broadcasting. The new specification calls for 1.2 Gbp/s per device in the initial release, increasing that throughput to 6 Gbp/s in later releases.  These data rates are for overall transmission, including the WiFi overhead.  Actual usable application data (layer 5-7) would be about 20 to 30 percent less.  Even so, 900 Mbp/s is a phenomenal data rate.  Truely I say to you; this is the future of digital broadcasting.  HD Radio™; it may well prove that the “HD” stood for “Huge Distraction.”

The new 802.11ac specification uses MU-MIMO, high density modulation, larger channel bandwidths, and beamforming technology in the 5 GHz WiFi spectrum.  Of course, the question is, at what distances will this system work?  If it is like conventional WiFi, then 100-200 feet is about all that can be expected.  However, there are also many people interested in wireless broadband (WiMAX) service as an alternative to traditional wired ISPs. For that application, having many outdoor 802.11ac nodes connected by a backbone could potentially blanket a city or campus with free high speed wireless data.

Example of cjdns network

Example of cjdns network

Along the same lines, there are many people involved in creating mesh networks of various types; be they ad-hoc mobile networks, darknets, bitclouds, etc. Mesh networking is a very interesting topic, for me at least.  The network protocols are getting better and more secure.  WiFi hardware is becoming less expensive and more reliable.  As more and more people put effort into developing protocols like cjdns, local mesh networks will become wide spread, unless they are outlawed.  You know; because of teh terrorism!!1!!

As it stands today, I can drive for two hours in mostly rural upstate NY and CT streaming my favorite radio programs and have nearly seamless hand offs and very few dropouts.  This is on my three year old, beat up 3G HTC android phone sitting in the passenger seat of my car.

Digital Radio is here, it is simply not the In Band On Channel system that legacy broadcaster’s have chosen.

Happy New Year

I wish everyone a Happy New Year and hopefully, a prosperous 2014.

Another year has gone by, and there were few things remarkable about it. Among those are:

From the digital radio front; HD Radio continues to be a non-factor in the bigger broadcasting picture.  FM HD Radio continues to make very small inroads, especially with public radio groups who’s HD Radio expenditures are mostly tax payer subsidized.  AM HD Radio continues to backslide slowly from it’s high water mark of 310 stations in 2007.  It is difficult to nail down the exact numbers of AM HD Radio broadcasters, however, Barry McLarnon notes that 177 stations are currently transmitting AM HD Radio.  No official numbers are available from either the FCC or iBiquity itself.

The great 2003 translator log jam (Auction 83) was finally fixed so that the FCC could move ahead with the LPFM application window in October.  In the end, some 1,240 translators were granted, with more conflicting applications still in the works.

The LPFM filing window opened in October amid the government shutdown.  Many groups were predicting 10,000 new applications for 100 watt LPFM licenses.  The actual number is closer to 2,800.  The final number of Construction Permits issued with likely be somewhat lower as defective and competing applications are dismissed.  This number seems low to some LPFM proponents.  When I approached a local interest group about launching a low power radio station, I was basically met with indifference.  With a very complex set of application guidelines and operating rules, plus very low power levels, it is not surprising at all.

The NAB and the FCC have been working diligently on revitalizing the AM broadcasting band.  Results of these efforts are yet undetermined as the proposal works it’s way through the regulatory process.  The so called “analog sunset” still lurks in the background somewhere, waiting to be trotted out at the most opportune moment.  I remain skeptical of the current proposal.

Cumulus Broadcasting purchases Dial Global and renames it West Wood One.  Some people lose their jobs.

Nielson buys Arbitron rating service and renames it Nielson Audio.  Some people lose their jobs.

Clear Channel tries to fly under the radar with “staff reductions.”  Some people lose their jobs.

Long time online radio forum “Radiodiscussions.com” ceased existence.  Starting out as Radio-info.com in the mid 1990’s, radio discussions was largest, longest running radio forum in the country.  It held tens of thousands of posts on almost every radio topic under the sun.  Unfortunately, it was bought and sold a few times over the last few years and the new owners could not figure out how to monetize it.  The end.

Bernie Wise passed away on December 13th.  This is truly unfortunate as Bernie was a character perfectly suited to the radio business.  He started working for RCA and is responsible for UHF television broadcasting in the US.

On the blog front, we continue to grow in page views and readers.  As of this date, Engineering Radio gets approximately 540 page views per day and has 227 RSS subscribers.  The split is 60/40 percent domestic/international readers.  The top five international traffic sources are; Canada, UK, India, Germany and Brazil.

2013 stat counter image

2013 stat counter image

There are some 634 articles with 2,640 legitimate comments and 429,600 spam comments.

Regarding site outages, there were 343 minutes of server down time.  Two DDOS attacks lasting six and three hours respectively and one incident of a corrupted .htaccess file rendered and error 500 message for six hours.  Total down time 1,243 minutes or 20:43 hours which gives a 99.87% availability for the website.  Not bad, but we can do better as the uptime goal is 99.99%.

On a personal note, my college studies are progressing well.  I have three more classes or 10 credit hours left until I am done.  My GPA is 3.90 which is not terrible considering I am working full time and going to school almost full time.  Truth be told, I cannot wait until it is finished.

What bitrate is needed to sound like analog FM?

As it turns out, 300 kbp/s or greater.  At least in critical listening environments according to the paper titled Perceived Audio Quality of Realistic FM and DAB+ Radio Broadcasting Systems (.pdf) published by the Journal of the Audio Engineering Society. This work was done by group in Sweden and made various observations with different program material and listening subjects. Each person was given a sample of analog FM audio to listen to, then they listened to various audio selections which were using bit reduction algorithms (AKA CODEC or Compression) and graded each one.  The methodology is very thorough and there is little left for subjective interpretation.

In less critical listening environments, bit rates of 160-192 kbp/s will work.

I made a chart and added HD Radio’s proprietary CODEC HDC, which is similar to, but not compatible with AAC:

System Codec Bit Rate (kbp/s)
HD Radio FM; HD1 channel* HDC (similar to AAC) 96 – 144
HD Radio FM; HD2 channel* HDC 24-48
HD Radio FM; HD3 channel* HDC 24-48
HD Radio AM* HDC 20-60
DRM30 (MF-HF) AAC/HE-AAC 34-72
DRM+ (VHF) AAC/HE-AAC 700
DAB+ AAC/HE-AAC 32 – 128
DAB MPEG II, Dolby digital 192 – 256
Blu-ray PCM** ≥6 Mbp/s
DVD PCM, DTS, Dolby digital >800
CD-A PCM 1,411
Web Streaming MPEG I,II,III, WMA, AAC, etc 32-320, 128 typical
iTunes AAC 128 – 256
Spotify Ogg Vorbis 96 – 320
Wimp AAC/HE-AAC 64 – 256

*Hydbrid mode
**PCM: uncompressed data

This is the composite Mean Basic Audio Quality and 95% confidence intervals for system across all excerpts:

digital-analog-audio-compar

Over the years, we have simply become accustomed to and now accept low quality audio from mp3 files being played over cheap computer speakers or through cheap ear buds.  Does this make it right?  In our drive to take something good and make it better, perhaps it should be, you know: Better.

Special thanks to Trevor from Surrey Electronics Limited.

A few updates

UPDATE: I notice that Radio World has a little star rating system on their articles. According to the rating, twenty one people think I suck… That is okay, but when I started looking around at all of the other articles on the website, I noticed most have but one or two votes.  It seems odd to me that my little opinion piece would have so many negative votes, especially in light of the e-mails, phone calls and personal interactions I have received supporting my position. 

Perhaps a few of you could run over there, read the article then objectively decide what you think… Here is the link: AM Efforts Should Include Tech Solutions

I am deeply immersed in all things networking, yet again. I regret the sparse posts, but there are a few things of note:

  1. It appears the the WYFR shortwave site in Okeechobee has been sold to the operators of WRMI (Radio Miami International).  This is a good turn of events for shortwave broadcasting.  WRMI programmed mostly to the Caribbean and were difficult to hear in these parts.
  2. Nielsen Radio, formerly Arbitron, says it will increase the sample size for the PPM program.  This is good, larger sample size means better accuracy and fewer extrapolation related errors and strange rating spikes.
  3. I published an commentary in Radio World Commentary: AM Efforts Should Include Tech Solutions. What do you think? Should the industry be looking at something other than HD Radio?
  4. Then, from across the pond there is this:

    Which is a digital radio promotion from the BBC. It seems Great Brittan is trying to force an all digital transition. A glimpse of things to come?

  5. In spite of the lack of posts, the blog continues to grow, averaging 550 to 600 page views per day with about 180 RSS subscribers.  As far as content goes, I can assume more of the same will suffice.

As time becomes available, I will post more.

Axiom


A pessimist sees the glass as half empty. An optimist sees the glass as half full. The engineer sees the glass as twice the size it needs to be.

Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
~1st amendment to the United States Constitution

Any society that would give up a little liberty to gain a little security will deserve neither and lose both.
~Benjamin Franklin

The individual has always had to struggle to keep from being overwhelmed by the tribe. To be your own man is hard business. If you try it, you will be lonely often, and sometimes frightened. But no price is too high to pay for the privilege of owning yourself.
~Rudyard Kipling

Everyone has the right to freedom of opinion and expression; this right includes the freedom to hold opinions without interference and to seek, receive and impart information and ideas through any media and regardless of frontiers
~Universal Declaration Of Human Rights, Article 19

...radio was discovered, and not invented, and that these frequencies and principles were always in existence long before man was aware of them. Therefore, no one owns them. They are there as free as sunlight, which is a higher frequency form of the same energy.
~Alan Weiner

Free counters!