drm audio programs

IBOC, HD Radio, FM eXtra, DRM, Importers, Exporters, Exgines...digital radio spoken here!
hocine
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drm audio programs

Post by hocine » Thu May 03, 2012 8:54 am

Hello

I want ot understand why drm brodcasting radio is limited only for 04 audio programs ?
is it possibile to broadcast stereo programs in drm mode ?

thanks

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Re: drm audio programs

Post by w9wi » Fri May 04, 2012 7:28 am

I'm sure the limitation is bandwidth.

According to the DRM website, stereo, and even 5.1 surround sound, are possible, even on MF frequencies.

The available datarate seems to be about 20% greater than offered by the U.S. "HD Radio" system. "HD Radio" offers 2.0 stereo on MF and as many as four 2.0 stereo programs on VHF. (albeit, some of them at rather low datarates)
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Re: drm audio programs

Post by RFWarrior » Sat May 05, 2012 9:57 am

Doug is right - but remember that DRM is a digital only system and doesn't have to make compromises to allow for the existing analog signal, as does IBOC.

I'm going to embark on a rant here (off topic, so I won't be offended of one of our illustrious mods edits, deletes or moves it :lol:).

I read so much whining on the lists about the problems with IBOC and how DRM is such a better system. How it's cheaper, because it's open source and doesn't have the licensing fees, blah, blah, blah. There's no question that both systems have pros and cons. HD Radio technology is proprietary and has a licensing fee, true - but DRM is much more expensive to implement in general, although it doesn't have the ongoing licensing fees down the road. HD Radio tech has had some situations where it has resulted in interference to adjacent channel analog stations. DRM doesn't have that, true, but only because in a DRM system, there ARE NO ANALOG CHANNELS TO INTERFERE WITH or, because it doesn't have to accommodate hybrid operation, it can more easily be run in an SSB mode when it's operated in an area where there are a mix of DRM only and analog only stations. Also keep in mind that, to date, most of the on-air work has been done in areas that don't have nearly the band congestion that the US has, so the perception is skewed by circumstances that have nothing to do with the tech itself.

To put it in perspective, basic hardware for a DRM system runs about 40,000.00 more than for a system using HD Radio technology. That is enough to cover the license fee at full price (which has never been charged - right now iBiquity is selling licenses for 11,500.00 if paid in cash up front) and almost 30 years of licensing for an additional channel. Note that this is based on list prices for Nautel equipment, as seen in my database (and the DRM equipment is third party, so it's based on our last purchase price for same) - there will obviously be significantly variation for other brands.

I'm not for or against either system - as I said, both have advantages and disadvantages when compared to each other and when compared to analog only broadcasting - but people who go online and rave about how "THIS is all wrong and total garbage, while THAT is so much better" really drive me crazy. Not pointing the finger at Doug (sorry for hijacking your response!), as he didn't do that at all - I came here from an "anti-IBOC/pro-DRM" rant on another list I follow and this was a friendlier venue to get it out of my system. Now go spread the word - there's no, "this system is the best, bar none" answer here - each system has definite benefits and drawbacks as does analog only broadcasting and, ultimately, unless the end users (those folks who actually pay the bills for all of us - the listeners) find content compelling enough to get them to go out and buy new technology, it won't matter if you're looking at DRM, HD Radio or a tin can on a string.

</rant> Okay, I'm going back to playing shoot-em-up games with the 11 year old :P

Jeff
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Re: drm audio programs

Post by Deep Thought » Sat May 05, 2012 11:37 am

"HD Radio tech has had some situations where it has resulted in interference to adjacent channel analog stations"

Some? Try all situations on the US AM band. If you consider obliterating third adjacent stations (and most second-adjacent) OK then I guess I'll have to call you out on it. Why do you consider it acceptable to cause interference inside the 2 mv/m contour of a third adjacent station? Please answer that.
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Re: drm audio programs

Post by RFWarrior » Sat May 05, 2012 2:41 pm

Deep Thought wrote:"HD Radio tech has had some situations where it has resulted in interference to adjacent channel analog stations"

Some? Try all situations on the US AM band. If you consider obliterating third adjacent stations (and most second-adjacent) OK then I guess I'll have to call you out on it. Why do you consider it acceptable to cause interference inside the 2 mv/m contour of a third adjacent station? Please answer that.
I never said that. Never even hinted at it. Whether a station is IBOC or analog makes very little difference to me - it's only one (or two) more piece(s) of equipment on the purchase order. Ultimately, I was referring primarily to FM IBOC in my previous comment, as there aren't a whole lot of AM IBOC stations relative to FM ones and I haven't had an AM IBOC inquiry in so long I'd pretty much forgotten it existed :P

As I've said before, I'm neither pro nor con with respect to IBOC - the technology exists and, within the constraints that broadcasters put on it, can work in most cases - IF the effort is put into making it work. Ultimately, physics governs. Plain and simple, many of the AM stations I've encountered should not be permitted to run IBOC because their antenna systems aren't capable of it and the cost to make them so would be prohibitive. An example would be a station with electrically short towers... you can do magic in the phasor/ATU's, I've seen it firsthand and that will make the transmitter happy, but if the impedance at the base of the radiator isn't phase linear across the whole 30+kHz of the transmitted band, it's going to have the potential to step on the neighbours. Too many stations that do run AM IBOC rely on the measurements at the transmitter sample point for all transmitter setup, not on far field measurements of the actual radiated signal... and that can lead to improperly adjusted transmitting equipment and antenna systems that aren't totally corrected for bandwidth and linearity limitations.

The other issue is more political than physical - and this is probably not the proper arena for it - too many AMs have been stuffed into spaces that were already close to saturated and probably shouldn't exist at all... but they do, so that does need to be taken into consideration. Given that AM IBOC has supported asymmetry from day one, in many cases 3rd adjacent interference can be made acceptable (i.e., removed from the primary contour) by turning down the HD carriers on that side - they can be adjusted down to -50dBc. This would resolve many of the issues - but probably not all. Short spaced second and third adjacencies would be another area where IBOC would probably best be left out of the picture, because with LED traffic lights, switching power supplies and so many other interference causing devices already in existence, the noise floor is already so high as to make AM fairly challenged.

Again, I don't tend to agree with blanket statements that say anything sucks all the time - that would be like me saying all Michelin tires are crap because I once had two simultaneous blowouts when I got forced into a curb by a merging car. I can point to several of my customers, some in fairly RF congested areas, who are having good success with IBOC - coverage rivaling their analog, better sound quality and no interference complaints. I can point to others where they have had interference issues, or receivers not being able to acquire the HD signal, and were able to successfully resolve them, sometimes by adjustments to the antenna system, or by turning down the HD carriers on one side or the other, or by other adjustments to the IBOC settings. But if you're convinced that it's all bad, all the time, I'm just beating my head against the wall - I try to avoid that, since it doesn't do either of us any good or do anything to advance the discussion.

Best,

Jeff
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Re: drm audio programs

Post by Deep Thought » Sat May 05, 2012 6:43 pm

Jeff, my comment is backed by field experience and was directed at AM, not FM. FM IBOC actually has some intrinsic benefit...the additional HD subchannels...while AM IBOC is nothing more than a high power interference generator.

In one particular case the 3rd adjacent station generating the interference is a well-known nondirectional 50 KW class-A owned by one of the Ibiquity backers. If their engineering dept can't get it right (and not take out 70 KHz of the band while doing it) then it needs to be retired, now. My client suffers actual documented economic loss due to this fiasco and neither the interference-generating owner nor the FCC gives a crap that this interference is happening inside the 2 mv/m service contour. It is a disgrace.
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Re: drm audio programs

Post by RFWarrior » Sat May 05, 2012 7:31 pm

To that, I can do nothing but agree - ultimately, interference issues should, in most cases, be something that can be overcome. However, there are going to be situations where they can't easily or affordably be overcome, for various reasons (physics does have a say in things, no matter how much we try to legislate it). In those cases, we're in agreement, the IBOC carriers should be shut off, at least until such time as an all digital option becomes available - and I suspect we'll both be long retired before that day.

I'd agree about the limited benefit of AM IBOC - it does make a very noticable improvement in sound quality, when heard on an HD receiver listening to a <b>properly processed and set up</b> station. At least it did on the 2-3 I've heard that fit into that category out of the 30-50 that I've installed or monitored. A case in point would be Radio Disney in north Houston - their HD coverage at install time was superior to their analog coverage in the main lobe, on both day and night patterns. Sound quality, with their bubble gum pop format, was extremely good. Unfortunately, they're the rare exception, not the rule.

Then again, FM stations running unique, compelling formats on their multicasts are also pretty rare - which is probably why nobody is rushing to buy receivers. There are exceptions here, too - Entercom's delta blues format on HD2 makes me dig the Insignia out of the laptop case and plug it into the car radio whenever I'm in a market that plays it (Doc, don't ever let them kill that format, please!). University of Utah is running long form "classic classical" on their HD3 and it's very popular - even at a bit rate of 24kbps. There are several others that come to mind. The funny thing is that those stations actually have an audience to their secondary channels - because they're providing something that people want to hear, and those people will actually go out and buy a receiver to do that. Hopefully, some day, all stations running multicasts will realize this and learn to capitalize on it. Of course, that would cost money - producing that unique, compelling format, instead of jamming another channel of "more of the same" into the ether.

I think we mostly agree, except I'm perhaps overly optimistic that someday folks will do what needs to be done (and probably should be done in the interest of better coverage overall) to improve the situation on AM and FM, whereas you're coming from a more cynical (some might rightfully say "realistic") vantage point.

Best,

Jeff
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Re: drm audio programs

Post by w9wi » Sat May 05, 2012 7:40 pm

RFWarrior wrote:Doug is right - but remember that DRM is a digital only system and doesn't have to make compromises to allow for the existing analog signal, as does IBOC.

I'm going to embark on a rant here (off topic, so I won't be offended of one of our illustrious mods edits, deletes or moves it :lol:).

I read so much whining on the lists about the problems with IBOC and how DRM is such a better system. How it's cheaper, because it's open source and doesn't have the licensing fees, blah, blah, blah. There's no question that both systems have pros and cons. HD Radio technology is proprietary and has a licensing fee, true - but DRM is much more expensive to implement in general, although it doesn't have the ongoing licensing fees down the road. HD Radio tech has had some situations where it has resulted in interference to adjacent channel analog stations. DRM doesn't have that, true, but only because in a DRM system, there ARE NO ANALOG CHANNELS TO INTERFERE WITH or, because it doesn't have to accommodate hybrid operation, it can more easily be run in an SSB mode when it's operated in an area where there are a mix of DRM only and analog only stations. Also keep in mind that, to date, most of the on-air work has been done in areas that don't have nearly the band congestion that the US has, so the perception is skewed by circumstances that have nothing to do with the tech itself.

To put it in perspective, basic hardware for a DRM system runs about 40,000.00 more than for a system using HD Radio technology. That is enough to cover the license fee at full price (which has never been charged - right now iBiquity is selling licenses for 11,500.00 if paid in cash up front) and almost 30 years of licensing for an additional channel. Note that this is based on list prices for Nautel equipment, as seen in my database (and the DRM equipment is third party, so it's based on our last purchase price for same) - there will obviously be significantly variation for other brands.

I'm not for or against either system - as I said, both have advantages and disadvantages when compared to each other and when compared to analog only broadcasting - but people who go online and rave about how "THIS is all wrong and total garbage, while THAT is so much better" really drive me crazy. Not pointing the finger at Doug (sorry for hijacking your response!), as he didn't do that at all - I came here from an "anti-IBOC/pro-DRM" rant on another list I follow and this was a friendlier venue to get it out of my system. Now go spread the word - there's no, "this system is the best, bar none" answer here - each system has definite benefits and drawbacks as does analog only broadcasting and, ultimately, unless the end users (those folks who actually pay the bills for all of us - the listeners) find content compelling enough to get them to go out and buy new technology, it won't matter if you're looking at DRM, HD Radio or a tin can on a string.

</rant> Okay, I'm going back to playing shoot-em-up games with the 11 year old :P

Jeff
Don't worry, no offense taken :)

Yes, I simply mentioned IBOC as a point of comparison, to show how many programs can be transmitted by a system with data rates on the same order of magnitude as what DRM offers.

At this point I'm regretting doing so :)

And yes, I just came from a "DRM will save the AM band" discussion on another site...
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Re: drm audio programs

Post by RFWarrior » Sat May 05, 2012 7:44 pm

Hehe, don't have any regrets, Doug... Mark and I have known each other too long to get upset over the fact that we've each got opinions - I think we usually agree, we just tend to do it rather forcefully and from opposite directions :lol:

J
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Re: drm audio programs

Post by Dale H. Cook » Sun May 06, 2012 6:26 am

RFWarrior wrote:Then again, FM stations running unique, compelling formats on their multicasts are also pretty rare
Jeff -

I have listened to all of the multicasts in my market. None of the commercial stations are running "unique, compelling formats" on their multicasts. The only station that does is WVTF, the NPR station, and theirs are the only HD2 and HD3 signals that I listen to. They run "Radio IQ" (24/7 news and news features from NPR and the BBC) on their HD2, and "XPoNential Radio" (AAA format from WXPN, Philadelphia) on their HD3. Note that there is a local AAA station in our market, but XPoNential Radio is far better programmed than the local station.
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Re: drm audio programs

Post by Trip » Sun May 06, 2012 9:43 am

Dale,

I could not agree more. Radio IQ is the only reason I had an IBOC radio (outside of the "because it's there" argument) when I lived in Virginia.

And, of course, they have gone to great lengths to get Radio IQ out there. http://173.255.226.66/wvtw-201103172300.mp3

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Re: drm audio programs

Post by Deep Thought » Sun May 06, 2012 1:25 pm

"The funny thing is that those stations actually have an audience to their secondary channels - because they're providing something that people want to hear, and those people will actually go out and buy a receiver to do that."

The even funnier thing is this same process happened almost 50 years ago with FM. It was dead in the water until new compelling programming was put up there, often just to have something to run. Sadly, with the industry mostly controlled by hedge funds and bankers there are precious few owners willing to even think about it.

And for the record, Jeff and I are cool with it. We both want what's best for radio in the long run.
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Re:We both want what's best for radio in the long run.

Post by RGORJANCE » Sun May 06, 2012 1:32 pm

Where's Captain Midnight, Captain Marvel, Tom Mix, Batman and Robin, The Green Hornet and Jack Benny when you need them? :roll: :roll:

Fossil

Oooops - almost forgot Sky King

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Re: drm audio programs

Post by KPJL FM » Mon May 07, 2012 3:14 pm

RGORJANCE wrote:Where's Captain Midnight, Captain Marvel, Tom Mix, Batman and Robin, The Green Hornet and Jack Benny when you need them? :roll: :roll:

Fossil

Oooops - almost forgot Sky King
I was almost gonna :evil: you for not mentioning Sky King!
But you forgot one of the highest rated radio programs, The Arthur Godfrey program (Mom always listened) and don't forget the radio quiz/game shows. Radio quiz /game shows, hmmm, not a bad idea for HD2 or HD3.
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Re: I was almost gonna :evil: you for not mentioning Sky Kin

Post by RGORJANCE » Mon May 07, 2012 5:08 pm

Whew! Dodged a bullet on that one.

Godfrey was a variety show - I was referring to the thrillers.

"Who knows what evil lurks in the heart of man?????"The Shadow Knows - L A V A- L A V-A "The FBI in peace and war" - "Treasury Men" - These are all i remember of the mystery type shows. Now, the soaps and variety shows are another list altogether. I remember a ton of them.

Best line I ever heard was from Phil Harris on the Jack Benny show. "I feel sorry for the man who doesn't drink because when he wakes up in the morning, he knows that's as good as he is going to feel alllllll daaaayyy lonnnngggg"!

Boy did he get that right!

Fossil

Sorry for hijacking the thread

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