Sirius XM

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    Jeffrey Kopp

    I never activated the satellite radio in my car when I got it a year ago, and the trial period did not happen. Well, today I got another note from Sirius in the mail, but this time they are offering a year at $4.99 a month, so I decided to give it a try.

    First of all, they add $1.07 a month for copyright fees. All right.

    The fidelity is better than FM.

    I read on-line that when the deal expires in a year, I can call and plead for a cheaper rate (like one does with the cable companies).

    I am partial to 80s music and they have a channel.



    “The fidelity is better than FM”

    Not in my experience. It varies from ok to terrible. The digital artifacting due to limited bandwidth is horrible at times. Talk stations get the least b/w. Classical seems to get the most b/w.

    See what happens when you drive under a bridge or into a parking garage or on a street with a heavy overhead tree canopy.

    Having said that, if I did a lot of long-distance driving, I’d subscribe.



    Jeffrey, I have no idea what stereo you have but, I have never experienced ‘better fidelity’ with Sirius XM. My experience is a very compressed sound comparable to lower-end internet streams. I listen to Sirius when I have nothing to listen to on the terrestrial side. (I am one of those whom drive a lot.)


    Jeffrey Kopp

    It must have been a difference in processing levels.


    Jeffrey Kopp

    Well, I enjoy the 80s channel so much I upgraded from Select to All Access so I could listen on the Web at home. They quoted me $25 a month, but I said it was too much, so they offered me a promotion at $10.99 plus $2.35 royalty fee for a year, and I went for it. I wonder if they had a better deal yet because he sounded delighted to sign me up for $10.99. To my surprise they invited me to call back in a year to try for another promotion.



    Sirius/XM has a definite bent towards overpacking audio streams, so much that all channels (music, talk, news) give me a headache after about 30 minutes of tortured listening. The corporate minds believe more channels are better. Fix the audio and I may come back.


    Jeffrey Kopp

    Sorry, but I find the sound of SiriusXM preferable to FM, due to the lighter processing. FM sounds noisy to me because it is overcompressed.



    It may have lower dynamic range compression (audio companding; what you’re referring to), yes, but the pathetic-ass bitrates they use (data compression; what everybody else is referring to) in order to overpack and overcrowd their service defeat the entire purpose.

    I’m with cheesyduck. I find the synthetic high-frequency component generated at the receiver to make up for loss of it in the data stream, and all the general artifacting, migraine-inducing after about that long. Remember, I’m “that guy” who will listen to the mono 32 kHz 64 Kb Muzak MP2 streams off SES-3, on headphones for hours at a time sometimes, with little complaint.


    Andy Brown

    It’s a shame that a “new” service would choose to self destruct like sat radio has. They had no backwards compatibility issues like analog FM did when it went stereo or HD FM had when IBOC was decided. The slate was clean and they fucked it up, but it is not the first time that technology capability has been hammered when the marketing and sales departments have such heavy sway with the string pullers. Chessyduck and no signal understand. Jeffrey, better check your ears. There is little on the internet I could find to support your side of the analysis.

    FM HD will only improve when analog is retired whether or not they go with the same architecture in the full mode or develop another method.

    When I started doing C Band uplinks at KATU in the mid 80’s, the standard methodology for modulating was fm. Video was fm’d around center with over 5 MHz bandwidth (more then the 4.2 in NTSC) and audio was fm’d on subcarriers at (generally) 6.2 and 6.8 MHz from center. Sat channel bandwidth was 10 MHz. Other subcarrier frequencies were used sometimes (5.7 and 7.5 being the next two most popular). There was plenty of bandwidth around each subcarrier center so the audio sounded fantastic. Unfortunately, the most popular use of C Band at that time was news backhauls, syndicated programming and network distribution (unsecured in the beginning if you want to believe that). The only distinction is that C Band service involved fixed antennae. Sat radio involves a somewhat unique problem in the consumer world, the receiving antenna is a moving target. To the untrained, this may not sound like a big issue but in fact it is. Solving those challenges should have been front and center, but they aren’t. In fact, the low bit rates and narrow bandwidth only exacerbate those issues. Those satellites up in the sky are not stationary, they are geo stationary. Satellites move in a small figure 8 and even with giant 9 or 10 meter dishes that are attached to the earth (what you need at this latitude, in Seattle they need even wider dishes to uplink) constantly have to be adjusted to get the best quality uplink. Downlinks aren’t as sensitive depending on your equipment, but if the uplink is off even a little, everyone downlinking it suffers. The 6 GHz uplink is like target shooting. You need a spectrum analyzer (or a readout of ss that it can provide) to really know that you’re inside the center box of the tic tac toe game board each satellite presents to the uplink station. Ku Band (14 GHz uplink) may have smaller dishes but securing the dish from motion is even more important). Now with that in mind, enter sat radio technology whereby not only this uplink tweaking should be ongoing (it’s probably not, and reception suffers) until one day it’s so far off the alarms go off and someone has to re-aim the uplink dish. Add to this the fact that the receiving antenna is moving down the highway at 65 mph. RF S/N suffers as the rx antenna keeps moving through the sat footprint which is not of equal strength one minute to the next due to atmospheric conditions, terrestrial factors and the like. As if that wasn’t a challenge enough to engineer around, the marketing and sales departments decided that more narrower channels with lower bit rates would be easier to attract new customers looking for program options. Fewer wider more robust channels would have been possible. That would have gone a long way to overcoming the moving receiving antenna issues. My point is twofold: 1. Satellite uplink technology allows for better audio if they wanted it and 2. Mobile satellite receiving technology is a much bigger challenge than it appears to be on the surface.

    Also, be reminded that “compression” exists in digital technology by definition. Reed Solomon removes some redundant data. So even so called uncompressed digital audio is technically slightly compressed. In addition to that, analog AM radio, analog FM radio and analog TV audio use or used compression both by implementing pre-emphasis at the transmitter and de-emphasis at the receiver and that’s before the program directors started twiddling with the knobs on the Orban.

    It’s all about the money.



    To start, I am not an advocate or a shill for SiriusXM. Most of my radio listening happens on a band centered around 300 meters, which has generally been maligned and considered socially obsolescent since at least the late 1980s.

    Nevertheless, I am surprised that satellite radio works at all. Keep in mind that the typical receiver setup consists of a low gain dielectric patch antenna hidden inside a “shark fin” radome on a car roof. That antenna is receiving a high UHF signal (approximately 2340 MHz) broadcast from a satellite thousands of miles away. I vividly remember straining to watch snowy UHF television pictures while growing up. In that era, UHF television was approximately 470 – 800 MHz (the only station I ever saw above channel 70 was CITY TV 79 in Toronto). The UHF stations typically had effective radiated powers on the order of a million watts. Direct broadcast satellites, on the other hand, don’t have the luxury of being able to emit such strong signals. The UHF TV stations were being received with low gain loop or bowtie antennas. Unfortunately, rotary UHF tuner designs on older TVs were often very insensitive, leading to lousy pictures.

    When quality comparisons are made of very disparate media, I think that those comparisons can be quite subjective. Satellite radio has an extremely high signal to noise ratio that, in practice, is limited only by the program material. Some listeners find typical analog radio interference sounds to be extremely strident, so they would prefer satellite radio, even if they could hear some amount of artifacts due to the perceptual coding (lossy codecs) used by that medium.

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