Sirius Satellite Radio

Sirius has Sterns tapes for some years after he retires. I went to Sirius instead of XM (which I thought had better music channels) because of Howard. At some point I had subs for both, still have XM and Sirius home component receivers.

I will keep Sirius even after Stern retires, at least on my phone (no car satellite).

 

There will be losses on Sirius/xm but there is too much variety on for 33 million people to quit using it.
I'd say 1-3 million would leave once Stern is gone.....but what are they going back to? Terestrial radio? Spotfy? Keep in mind that Sirius/XM has comedy, all the major sports, golf, cnn and fox news.....all pandora and Spotif offer is music.

 

Yeah, I’ve noticed the weird balance issue too. No idea what that is. It also wreaks havoc with certain stereo Beatles songs where vocals are only on one channel.

 

I've noticed that too. There are times where it sounds mono, but then it will unfold itself back into stereo. It's very strange.

 

Sirius/XM is probably using a form of Parametric Stereo, which only encodes midrange frequencies in true stereo (below 3 kHz or so). The higher frequencies get summed to mono and then are reconstructed back to "stereo" by either steering the audio from left to right or adding an ambience effect (like "simulated stereo"). This works OK for modern recordings where the stereo difference is mostly just reverb, but not so much for 1960s-era recordings with the vocals in one channel and the instruments in the other channel.

 

They’ll just replace that loser with another loser to have to listen to. Can’t wait til he shuts up. As for Pandora Sirius/XM owns it. As for Spotify they have podcasts and are looking to buy Ringer which has something to do with sports which I also could care less about.

 

I haven't experienced any balance issues with SiriusXM; I've had it since late November in a new vehicle. I don't listen to the Beatles channel a lot; is that where this is happening? I've been listening to Volume and DeepTrks (All Rush All the Time until tomorrow?) mostly.

 

I haven't listened to the Beatles channel. I've heard it on the Garage Rock station and on the Bluesville station.

The Beatles channel should use the mono mixes!

 

It's more like Dictation Grade er, talk radio grade. I've heard better sounding Single Sideband on the ham bands. XM/Sirius audio quality blows chunks. Horrible too low bandwidth, too data compressed to be listenable for very long. The better the equipment you play it on, the worse it sounds. Equivalent to the worst quality MP3 file.

 

Sirius Internet Radio likely is better quality. Sirius/XM audio quality is bottom of the barrel. Nothing you can do about it. Not enough bandwidth to have very good audio quality. Too lossy compressed. Equivalent to the lowest quality MP3. The better the equipment, the worse it sounds.

 

IME Sirius internet (through the Apple TV app) is comparable to low-res MP3. It's a stark drop in quality when compared to streaming either Apple Music or Tidal through their Apple TV apps on the same system.

 

Here are some technical details on Sirius:

Studio:
Sirius uses Prophet studio automation software to assemble shows. I believe it's the largest single installation of Prophet in the world, something like 100 seats. The studios are in the McGraw-Hill building in midtown Manhattan, along with the broadcast digitizing equipment, encoders, and executive offices. The primary broadcast uplink dishes are in New Jersey, connected via a dedicated fiber optic link to the studios. There are backup transmitter dishes on the roof of the McGraw-Hill building, you can see them clearly on Google Earth. Sirius rotates music blocks in 8 hour loops, timed to coincide with east and west coast US drive times, so you don't get the same music block driving home as you do when going to work, more or less.

Satellites:
Sirius uses four satellites in a highly elliptical geosynchronous orbit, meaning they orbit in a lopsided figure-8 pattern, with the small 0 centered around Venezuela, and the big O centered around Montana. This gives decent coverage over northern Mexico, and good coverage over all of the US, and most of Canada. The satellites are moving too fast to work properly when over South America. The first three satellites were launched by Russia. The fourth, originally a ground spare, was launched later by Sea Launch.

Repeaters:
Sirius operates a large ground repeater network, though not as many as XM (XM has something like 10x more repeaters) This is due to the high orbit of the Sirius satellites, while XM uses geostationary satellites parked near the equator. XM needs more repeaters in urban environments, especially at higher latitudes, to deal with buildings blocking the relatively low broadcast angle of the satellites. The repeaters are strategically located along major highways to ensure coverage of roads that would likely be blocked by buildings or overpasses. They are usually in the same places as cell towers, for the same reasons. The repeater signal is also carried by the Sirius satellites, though re-broadcast on a different frequency to the repeater towers.

Radio:
Sirius broadcasts on three channels, two satellite channels surrounding the central channel left open for repeaters. As the satellites orbit, they switch on and off, exchanging frequencies instantaneously. It's a remarkable bit of engineering. Also the repeater channel and the two satellite channels are time-offset by something like two or three seconds. This is calibrated to be the average length of driving under a highway overpass - the idea being you'd loose the satellite signal and have a few seconds of buffer via the repeater channel in urban environments. The Sirius and XM bands are literally right next to each other, with XM being only a few MHz up the spectrum from Sirius.

Hardware:
The broadcast system and receivers were developed by Agere, an offshoot of Lucent, but now a division of LSI. It was based on military communication technology and it's conditional access system is pretty bullet-proof - IE hacking them for free radio is pretty much off the table. The audio codec is some weird proprietary system by Agere, selected because it could be used with some sort of statistical multiplexer scheme that they ended up never using. XM uses a tweaked AAC derivative.

Signal:
When stripped of error correction and auxiliary data channels, the Sirius stream is somewhere around 2-3MB/s. It was originally closer to 1.5MB/s, but they have since implemented an additional phase in the radio modulation, resulting in more bandwidth at the cost of slightly worse reception. This is why some old radios can't get certain channel groups.

 

I have my own perspective. However, the post is primarily intended to provide further, if somewhat different, information. Time has passed, things certainly have changed...

Strictly speaking, the Sirius constellation is not "geosynchronous", though a 24 hour orbital period is involved. I can't speak to the fourth satellite, launched after my time, but the initial three were put in an orbit we referred to as "supersynchronous". As you state, the orbits of the initial three were highly elliptical, and as you imply, the orbital plane was highly inclined with respect to the Earth's equatorial plane. The initial three were in the same orbital plane and path--and eight hours apart from each other--with, as mentioned, each having the identical 24 hour period.

Geosynchronous satellites have circular orbits and, barring some degree of orbit inclination, "hover" over an unchanging point on the equator. Small levels of orbital inclination lead to the satellite's primarily latitudinal oscillation over an equatorial ground point.

A single supersynchronous satellite would be over the same point once every 24 hours. And with the eight hour offset, eight hours later the following satellite would be at that identical position in the orbital plane. Since Sirius was intended for U.S. consumption, the satellites were never intended to be useful in the southern hemisphere (where, in my imagination, the Sirius satellites were each cutting a groove through the top of the Amazon rain forest, since--again in my imagination--that was the "low", and fast, point in their elliptical orbits). The maximum orbital "height" was over the continental United States--where, from the ground perspective, at maximum height a given satellite was doing a retrograde 'almost hover' for some duration. If I recall correctly, a bit of antenna shaping was done to provide Puerto Rico with service...but other than that, the service was intended, and beam stabilized and shaped, to be continental U.S. specific. Two of the three were supposed to be over the U.S. at any time, with the offset between the two that were over the U.S. providing signal "diversity"--intended to reduce the effect of ground structures interfering with the signal from a single satellite. This was some pretty tech stuff...it's a shame that the Sirius corporation doesn't in the slightest care about audio quality.

Given that end of life for any comm/weather satellite comes when orbital adjust propellant is exhausted, I'd expect the original three to be soon retired, if that has not happened already. Not that I know all the propellant has been used, but there are typical lifetimes.

As a consumer, I had very high hopes for Sirius (originally to be named "CD Radio"), but found out when I got it in my car that I could only listen to a channel for a short time before wanting to hear what was on a different channel. I now know that's due to the audio's extreme lossy compression. Yuck.

 

To my knowledge, geosynchronous orbits match the rotation of the earth but do not need to be stationary - hence geostationary. The space guys referred to the orbit as highly-perturbed elliptical geosynchronous.

I think the first three or four may already be retired. IIRC these particular birds had a lifespan of 20 years. That counts either on the ground or in the sky, as the propellant goes bad, batteries chemically degrade, etc... That's why they ended up launching the ground spare - it cost something like $20 million and was adding no value sitting in a warehouse, so might as well use it. I think the new satellites are probably going to be geostationary, matching XM's setup.

Yeah, the compression is bad to the point of distraction. It was much better when it first launched, but they kept cranking down the bitrate to squeeze in more channels, especially when they had to bring in a bunch of Canadian channels in order to sell the service in Canada.

 

My subscription was renewing tomorrow at $16.99/month

I knew I wanted to renew but call to cancel. Let them do their “let me see what we can do bit” and just did the year for $72 all in.

I could care less about the audio quality it’s not that bad, but more for convenience and talk radio, ESPN, etc. which I can also get on my phone.

 

I recall one of the receivers showing signal strength for both the satellite and the ground repeaters

 

Sirius announced today during their quarterly earnings that they will merge the XM Sirius spectrum within the next 5 years
He didn't elaborate on how Sirius would use the reclaimed spectrum, but its been planned for the last 5 years. I would say doubling the amount of stations is guaranteed from 200 to 400 channels

 

and they will still play the same songs over and over again.

sirius radio is much like spectrum cable to me.

they both need to have an ala carte menu, you pay for only the channels you want, each one priced individually, and then i believe they would have sales go through the roof.

if sirius charged 50 cents per channel, gave a deal, say 11 channels for $5 a month.

and spectrum charged $1 a channel, say 25 channels for $20 a month (not including premiums).

they both would kill it.

just thinking out loud

 

Sirius has over 33 million subscribers.

 

I remember in the early 2000’s when Sirius first landed, I added it to a Kenwood stereo I had in my Grand National. I had a pristine JL Audio system in there that the shop had to dismantle to add the stupid antenna box.
I’ll never forget how pissed I was when I first listened to it. I had it taken out after 6 months.
I have it free in my Grand Cherokee now, and if it’s on, it’s literally just background noise. Still sounds terrible 20 years later.

 

Thanks for the comment. This does sound like it could be happening here. Do you know if this is something that would be done during the encoding process or during the actual transmission? If it's during the encoding, I wonder how no one heard this and switched over to a mono mix for these odd-sounding songs?

Can any of the commentators on this thread who seem to have worked at Sirius/XM comment on the validity of this? I'm really just curious about the technical reasons. I have no interest in giving up Sirius/XM for my daily 2 hour commute.

 

Because even when a SiriusXM channel has a live DJ on the air, they can't listen to themselves truly "live on the air" due to all the encoding and transmission delays involved. On their headphones or monitor speakers they're probably hearing a direct in-studio feed coming directly off the board. The final encoding has to be done at the satellite uplink site due to the dynamic nature in which the total available bandwidth is allocated across all the active channels.

p.s. A few months ago I noticed one piece of music on the totally automated (no DJs) "Escape" channel was playing totally out-of-phase. I e-mailed them a description of the problem, and although the support staff member who responded to me clearly had no idea what I was talking about, I eventually got them to forward my message to the department responsible for managing the channel's music library.

 

I think when I renewed it for my father, I talked them down to 70% off the list price of $200 something. The guy said that was as low as they can go.

 

For my part, I worked at the company building the initial set of Sirius satellites...specifically, in the department that designed/developed/tested the onboard controls software. Some of my software was on those birds. May those that made it to space rest in peace.

At any rate I myself am in no position to know anything about the nature of the audio carrying signal, other than that I find the resulting audio, for music in particular, something I cannot really stand to listen to.

 

While Sirius/XM radio is not high-end audio, it's fine for me during my long commute. Let's put it simply - it's better than FM, which is filled with more talk & commercials than music. I used to listen to 105.7 WROR out of Boston for years but then the commercial breaks got longer & longer. One day, I timed it out at over 11 minutes of commercials - IN A ROW. Since I drive a little over an hour, I ended up hearing over 25 minutes of commercials. For that alone, I love Sirius/XM.

And FWIW, I listen to channels 93 & 95 a lot. These channels, Comedy Central Radio & Netflix Is A Joke Radio, sound fine for stand-up comedy.