Sirius and XM: Satellite and Repeater Technology.

[Three Hole Puncher]

Does Sirius use some sort of different broadcasting techmology(tm- Ali G.) than XM?

I saw a thread over at SFN where all the Hoo Hoo zombies were pissing and moaning about their Sirius units getting interference from "FM transmitters" and they were saying something about how there aren't enough "repeaters"?

Fhat the wuck?

I thought "satellite radio" meant that the signal was coming down from a satellite, hence the term "satellite radio". What the hell is this shit about FM transmitters and repeaters? I have a factory XM in my honda and once in a blue moon it'll drop out for a few seconds if it's pissing down rain or if I'm in a neighborhood with heavy tree cover, but it's amazing how well it works. It even works when my car is in the garage... I still haven't figured out that can even be possible. I once took my car on the car ferry from Long Island to Connecticut and the XM worked the whole way, and this was inside the steel deck of a ship:idontknow How the hell is that possible? Must be some sort of slanty-eyed jap electronic magic.

[mcipoletti]

Yeah I hardly ever have problems..actually the only problem I have is occasionaly I get interference from another car with XM in it. I have listened to an hour of Ron and Fez with just having my radio tuned to 107.7 or whatever the station is, and having my xm unit turned off.

[Pete from CT]

Does it matter how it works? All that matters is that Sirius subscribers are unhappy. ;-)

[deadfruitvirus]

I guess they're all using FM modulators on the road, and other sat radio modulators are cutting in?

[DonTheTrucker]

This is a picture of the inside of a doggie brick

http://www.digischool.nl/kleioscoop/abacus.jpg

[chauncegardener]

I saw a thread over at SFN where all the Hoo Hoo zombies were pissing and moaning about their Sirius units getting interference from "FM transmitters" and they were saying something about how there aren't enough "repeaters"?



Why read anything at SFN?

[Three Hole Puncher]

I guess they're all using FM modulators on the road, and other sat radio modulators are cutting in?

Oh... is that how the non-hardwired units work? They transmit an FM signal that you tune to with your reg' lur FM radio? What an abortion. They should make all factory car stereos with input jacks.

[Three Hole Puncher]

Why read anything at SFN? For the same reason that I slow down at the scene of car wrecks.

[Amazingkaddycap]

What funny about this is, when Howie first went to sirius and was bashing Xm, he made fun of the fact that XM told him how many repeaters they had compared to Sirius. And Howard Said Whocares about repeaters. The King of all egos actually claimed he went to Sirius because of Content and Technology. Like Howie cares about any content beside himself. And we all know what kind of Tech Sirius has. I read on XM411 that Xm has almost 1000repeaters and Sirius has about 150.

[medium_rare]

Like the post above, more repeaters means that you can get a signal in heavy urban or wooded areas where buildings, trees, tunnels, etc. get in the way of the straight signal from the sky. I also read that the XM and Sirius satellites orbit differently. Basically XM's satellites orbit the earth at the same speed as the earth's rotation so the signal is always coming to you from the same direction. Sirius' are stationary in the sky so in the morning you may have to have your antenna facing the northeast but by the time you drive home the satellite may be southwest of you.

So all in all, Sirius stinks again!

[Three Hole Puncher]

The King of all egos actually claimed he went to Sirius because of Content and Technology.

Yeah... the Content of his bank account, and the Technology of electronic direct deposit.

[Baggity Bag]

I thought "satellite radio" meant that the signal was coming down from a satellite, hence the term "satellite radio". What the hell is this shit about FM transmitters and repeaters?

Dude, not to be a prick, have you ever cracked open a physcis book in your life? You know how some cities outside of Whsitle Stop, KS have those big big buildings? Well, with the satellite's angle in the southern sky (being in geostationary orbit and all), sometimes, the signal gets blocked. You know, you're in the shadow of the signal.

The satillite is not directly over your car.......

Does Sirius use some sort of different broadcasting techmology(tm- Ali G.) than XM?

Well, their satellites are NOT in geostationary orbit....

Edit: Oh, I see someone else covered it a few minuted before I did.

[BruceKellysJunk]

those sirius units broadcast the modulation for like 500 ft, so if you get near somebody who is listening to one on the same frequency as you are, you will start getting heavy interference.

Friday my car was in the shop so i had to take my airware in the truck i was driving to work and use the modulator. I pulled up next to another car who was listening to stern at a red light and it completely cut off my O&A feed. Luckily it was 6:30 am, so it was still thursday's show and stern was talking about them, so It was like i didnt miss anything at all. It was still annoying though. I could never use a modulator like that

[acomputernerd]

last I heard XM had 2x as much repeaters than shitirius. I listen via repeaters only. They allow for antennas to be located in the building. Using the 207-xm on the skifi you can see where you are getting the signal from and adjust the antenna as needed.

[westben2002]

i just did a presentation on XM the company for my class....and i bashed the technology sirius developed and i swear someone in the audience went "hoo hoo"

[nemohgod]

Ok just to clear it up in one post here it is.

I think in newer models of all XM and Sirius unit there is a FM transmitter installed. For those of you that use the AUX connection in your car sterio or home this is not important, but it is for people like me. I can tune into whatever station that the device can broadcast to and with the least interference from the real FM transmitters from live stations. I suspect that Sirius transmitters on thier units are pretty weak.

The whole thing about repeaters is basically repeating the transmission of the satelite signal. XM has invested in a bunch of these while Sirius did not. That's why the folks over at SFN are bitching about. You can't get satelite everywhere, especially if you have an XM2Go unit so repeaters are very helpful. You need to be available to the southern sky to get the transmition but at some points you will not be facing that direction. A building or a mountain can obstruct your view so repeaters have become very helpful. Ever wondered why you go under a bridge and you don't lose your signal? It's the repeaters.

[vegasbob]

last I heard XM had 2x as much repeaters than shitirius. I listen via repeaters only. They allow for antennas to be located in the building. Using the 207-xm on the skifi you can see where you are getting the signal from and adjust the antenna as needed.

XM might only have 2 satellite, but a lot more repeaters. i drive from Las Vegas to Los Angeles frequently & my XM signal is awesome. The Myfi has the antenna aiming mode so you can see how strong the signals are for either satellite or terestial i.e. the repeaters.
In Los Angeles I love the XM signal very strong compare to the woof woof signal. my buddy has a built in unit is his ford & it fucking sucks. i have a myfi & the hidden antenna & still i get a better signal.

[FreeTheCricket]

Well, people pretty much summed up the repeater thing. XM spent tons of $ (wisely, I might add) on repeater technology, because they could see the problems that might arise. Sirius bought... ummm... welll.... Howard Stern? A "portable" unit that needs to be docked? They were fucking morons over there, and XM was brilliant. I can walk around downtown Cleveland with my MyFi tucked in my backpack listening to O&A or whatever else I want with zero interruptions. I can even go deep into buildings before my signal fades. I think repeaters are why XM's portables work so well and Sirius hasn't been able to do shit. If XM tried portables with no repeaters, the signal would fade in and out constantly.

[Exanimate]

I wish like hell that they would put some repeaters in this shithole state. I lost signal quite often. Goddamn mountains.

I really want to buy a portable, but there are no repeaters here so I can't listen live while inside.

[bobimpact]

I was a car stereo installer for several years and I sell them now so please excuse any jargon.

Essentially both companies put wireless transmitters in their recievers with one major difference, Sirius units transmit ONLY from the reciever, so the FM signal must pass through the glass/metal of the car to reach the FM antenna. Usually they include a small wire in the packaging that acts as a small antenna to help out. The signal is weak enough that any strong signal near it will cause it to cut out. Two Sirius recievers parked next to one another will nearly cancel each other out.
XM uses the reciever to transmit as well but also makes the XM antenna an FM emitter. This is why XM always recommends installing the antenna on the outside of the car and as close to the FM antenna as function and esthetics allow. Esentially this allows XM to have acceptable FM transmission without having to use inboard 12v power supplies on their recievers, (all new XM units run on 5 or 6 volts, everything Sirius makes aside from the S50 runs on 12). Excluding those power supplies reduces heat, size and weight and dramatically increases lifespan when compared to Sirius units. An easy fix to any signal problems FM users have is to go to your local car audio store and have them install the Delphi FM direct adaptor (part number SA10112). This works for all XM recievers with Wireless modulators, and with most cars on the road (outside of SOME new Volvo, Subaru and Mercedes models) and should cost around 50-75 bucks installed. For a better sound quality option check into Auxilary input adaptors for your car. They can be pricy but are the best sounding option.

Repeaters have been covered, but another fun fact about Sirius is the S-Plex technology they use on their signal. Essentially this technology compresses the signal on the fly, removing bandwidth from the signal when it is not needed. Unfortunatly Sirius does not have enough bandwidth as it is, so they remove some from talk channels and less popular channels, which is what most Sirius subscribers complain about. It causes talk to sound like it's being broadcast from an gymnasium and it causes music to sound like a heavily compressed MP3. Awful.

Sorry to go so long, but hopefully I explained things well enough to help someone out.

[FreeTheCricket]

I was a car stereo installer for several years and I sell them now so please excuse any jargon.

Essentially both companies put wireless transmitters in their recievers with one major difference, Sirius units transmit ONLY from the reciever, so the FM signal must pass through the glass/metal of the car to reach the FM antenna. Usually they include a small wire in the packaging that acts as a small antenna to help out. The signal is weak enough that any strong signal near it will cause it to cut out. Two Sirius recievers parked next to one another will nearly cancel each other out.
XM uses the reciever to transmit as well but also makes the XM antenna an FM emitter. This is why XM always recommends installing the antenna on the outside of the car and as close to the FM antenna as function and esthetics allow. Esentially this allows XM to have acceptable FM transmission without having to use inboard 12v power supplies on their recievers, (all new XM units run on 5 or 6 volts, everything Sirius makes aside from the S50 runs on 12). Excluding those power supplies reduces heat, size and weight and dramatically increases lifespan when compared to Sirius units. An easy fix to any signal problems FM users have is to go to your local car audio store and have them install the Delphi FM direct adaptor (part number SA10112). This works for all XM recievers with Wireless modulators, and with most cars on the road (outside of SOME new Volvo, Subaru and Mercedes models) and should cost around 50-75 bucks installed. For a better sound quality option check into Auxilary input adaptors for your car. They can be pricy but are the best sounding option.

Repeaters have been covered, but another fun fact about Sirius is the S-Plex technology they use on their signal. Essentially this technology compresses the signal on the fly, removing bandwidth from the signal when it is not needed. Unfortunatly Sirius does not have enough bandwidth as it is, so they remove some from talk channels and less popular channels, which is what most Sirius subscribers complain about. It causes talk to sound like it's being broadcast from an gymnasium and it causes music to sound like a heavily compressed MP3. Awful.

Sorry to go so long, but hopefully I explained things well enough to help someone out.


Longest, most technical jargon-filled first post EVER!! :clap:

Welcome to posting on the 'bag, sir. Have you really been lurking since 2003?

[FreeTheCricket]

Yeck - double post.

[bobimpact]

Yeah, this is the one and only username I've ever had on this board, just never felt the need to post anything before.

[Toilet Boy]

Oh... is that how the non-hardwired units work? They transmit an FM signal that you tune to with your reg' lur FM radio? What an abortion. They should make all factory car stereos with input jacks.


That is how my XM Sky FI works too. I also have the Sirius Starmate. I never have a problem with either one.

[Pizdets]

both sirius and xm use fm re-transmitters or repeaters. this is the reason why you can get a signal anywhere in nyc no matter where you point your myfi, as opposed to, say, nj, where the unit has to be pointed south and have an unrestricted view of the sky.

as for technology differences, a friend of mine actually works for sirius, and i asked him about the difference between xm and sirius transmissions. apparently the biggest difference is the way the satellites are positioned.

xm satellites use geo-stationary orbits, meaning they are ALWAYS in the same part of the sky. they never move. this means that you always know where to point your system, but there are areas where the view may be obstructed.

sirius uses non geo-stationary orbits, meaning their satellites are never in the same place and always moving. at any given time a sirius unit can recieve transmissions from 3 different satellites that are in different parts of the sky. in theory, this creates a system with less chance of the satellite signal being obstructed. unfortunetaly, it also has the unfortunate side effect of making a portable unit extremely hard to develop (hence xm's beating sirius in the mobility department).

he also told me that xm has more fm re-broadcasters than sirius (about 800 to 200, but that gap is probably less since this info is several months old and sirius was in the process of putting in more re-broadcasters). this is due to the fact that sirius is the younger company.

as for the ability to recieve those re-broadcasts via fm, that one i havent asked. if sirius users are having difficulty with the repeated signals its probably not sirius's fault, but that of another radio station close to whatever band sirius is transmitting on, which is different with every city you go to.

they may also have been talking about interference from radio stations with a car adapter kit. i get this one every once in a while with my myfi, but not often. if anyone else has a similar problem, then here's a link for you:

http://www.fmfind.info/index.php

haven't played with it myself, but it looks like it does a good job of finding an empty fm band that you can use for any fm car adapter kit, xm, sirius, or other.

[Schwapp]

Does Sirius use some sort of different broadcasting techmology(tm- Ali G.) than XM?

I saw a thread over at SFN where all the Hoo Hoo zombies were pissing and moaning about their Sirius units getting interference from "FM transmitters" and they were saying something about how there aren't enough "repeaters"?

Fhat the wuck?

I thought "satellite radio" meant that the signal was coming down from a satellite, hence the term "satellite radio". What the hell is this shit about FM transmitters and repeaters? I have a factory XM in my honda and once in a blue moon it'll drop out for a few seconds if it's pissing down rain or if I'm in a neighborhood with heavy tree cover, but it's amazing how well it works. It even works when my car is in the garage... I still haven't figured out that can even be possible. I once took my car on the car ferry from Long Island to Connecticut and the XM worked the whole way, and this was inside the steel deck of a ship:idontknow How the hell is that possible? Must be some sort of slanty-eyed jap electronic magic.

Repeaters are used in major cities to pump the signal up. My Roady demonstrates terrestrial AND satellite signal.

[TEXAS TRUCKER]

a Repeater is a ground based antenna that XM has in most major cities that sends out an exact duplicate digital signal that is picked up by your units "terr" antenna. The "terr" antenna is built into the regular satellite antenna. My old Sony pnp unit actually had seperate inputs for the two antenna leads. Most newer units have only one lead. Without this system you would have major problems in large cities around buildings and overpasses. With a repeater you can listen almost all the way through the Baltimore tunnel on 95. without it. 5 seconds in and your dead.

[Deebomber]

Doggie company is the older company pal. Look it up they started first. They also made the decision to have more satellites than repeaters. XM chose to have fewer birds and more repeaters. That's why you get a beter signal with XM.

[NullNVoid]

Ok just to clear it up in one post here it is.

I think in newer models of all XM and Sirius unit there is a FM transmitter installed. For those of you that use the AUX connection in your car sterio or home this is not important, but it is for people like me. I can tune into whatever station that the device can broadcast to and with the least interference from the real FM transmitters from live stations. I suspect that Sirius transmitters on thier units are pretty weak.

The whole thing about repeaters is basically repeating the transmission of the satelite signal. XM has invested in a bunch of these while Sirius did not. That's why the folks over at SFN are bitching about. You can't get satelite everywhere, especially if you have an XM2Go unit so repeaters are very helpful. You need to be available to the southern sky to get the transmition but at some points you will not be facing that direction. A building or a mountain can obstruct your view so repeaters have become very helpful. Ever wondered why you go under a bridge and you don't lose your signal? It's the repeaters.

Due to the different orbit configurations, Sirius has a direct-above satellite footprint, so they don't need as many repeaters as XM. XM's sats are stationary over the equator, so the footprint is at an angle. Doggie's do a figure 8 over North and South America.

The interference has nothing to do with repeaters, it is likely from other Sat radios on the road. Using the default frequency of 88.1, I've listened to both HooHoo and the bboys without having a Sat radio unit even turned on.

You can get a thing that attaches to the head unit of your FM radio and a FM Out of the Sat radio to get rid of the interference.

[NullNVoid]

Doggie company is the older company pal. Look it up they started first. They also made the decision to have more satellites than repeaters. XM chose to have fewer birds and more repeaters. That's why you get a beter signal with XM.

I have both. MiFi in my car and factory installed Sirius in my work truck. I've never noticed a difference in signals.

[Angelfuck]

the new portable sirius unit, added features, make coffee too!

http://i83.photobucket.com/albums/j281/angelfcksalbum/sirius.jpg

....someone had to do it

[mcstark]

I too have both and honestly the sirius unit was better for recieption, but XM has lots more that is worth listening to!

MCS out!

[NoSurviivors]

the wireless fm tranmiters in sirius units stink. (this was covered in other posts) if you have any trouble when fm'ing signal with either, use a wired FM mod direct to the antenna.
any system can pick up the repeater signal or pure satellite. my old pioneer 903 I had years ago had the doube antenna lines... worked ok in NYC. nowadays it's the same or better with the terk to deck kit i have in my car. or the xpress I have in my girl's car.

[Iron Duke]

For the same reason that I slow down at the scene of car wrecks.

And watch my sister get undressed for her shower.

Nothing?

[Moonwick]

Just to set everyone straight... the repeaters that both XM and Sirius use are nowhere near the FM band. FM sits at 88-108MHz, while satellite radio is in the 2.3GHz range. XM and Sirius have equal slices of frequency allocation, and their slices are right next to each other.

Both the satellites and the repeaters on the ground use this same frequency allocation; I'm not entirely sure how Sirius does it, but XM divides their allocation into three equal segments: one segment for Rock/Roll, one segment for Rhythm, and another segment that's used by the repeaters.

[NoSurviivors]

there's going to be a quiz at the end of this thread.

If you miss it, you have to write a report.. and buy an S50.

[BigBuffaloFan]

both sirius and xm use fm re-transmitters or repeaters. this is the reason why you can get a signal anywhere in nyc no matter where you point your myfi, as opposed to, say, nj, where the unit has to be pointed south and have an unrestricted view of the sky.

as for technology differences, a friend of mine actually works for sirius, and i asked him about the difference between xm and sirius transmissions. apparently the biggest difference is the way the satellites are positioned.

xm satellites use geo-stationary orbits, meaning they are ALWAYS in the same part of the sky. they never move. this means that you always know where to point your system, but there are areas where the view may be obstructed.

sirius uses non geo-stationary orbits, meaning their satellites are never in the same place and always moving. at any given time a sirius unit can recieve transmissions from 3 different satellites that are in different parts of the sky. in theory, this creates a system with less chance of the satellite signal being obstructed. unfortunetaly, it also has the unfortunate side effect of making a portable unit extremely hard to develop (hence xm's beating sirius in the mobility department).

he also told me that xm has more fm re-broadcasters than sirius (about 800 to 200, but that gap is probably less since this info is several months old and sirius was in the process of putting in more re-broadcasters). this is due to the fact that sirius is the younger company.

as for the ability to recieve those re-broadcasts via fm, that one i havent asked. if sirius users are having difficulty with the repeated signals its probably not sirius's fault, but that of another radio station close to whatever band sirius is transmitting on, which is different with every city you go to.

they may also have been talking about interference from radio stations with a car adapter kit. i get this one every once in a while with my myfi, but not often. if anyone else has a similar problem, then here's a link for you:

http://www.fmfind.info/index.php

haven't played with it myself, but it looks like it does a good job of finding an empty fm band that you can use for any fm car adapter kit, xm, sirius, or other.

What? FM re-broadcasters? The FM transmitter is built in to the radio unit. I think all the models have it besides the Roady I. Sirius also has less repeaters because it has a lot less money. Also Sirius has been around since 1990 and XM 1992. I bet you don't even have a friend thats works for Siruis.

[BigBuffaloFan]

the new portable sirius unit, added features, make coffee too!

http://i83.photobucket.com/albums/j281/angelfcksalbum/sirius.jpg

....someone had to do it

This is exactly what sirius needs. Something to keep the listeners awake.

[R.BuddDwyer]

Sirius may not as many repeaters, but they have a crack team of technicians doing their best at maintaining them.

http://histoire.info.online.fr/images/eniac4.jpeg

[cknight725]

I too have both and honestly the sirius unit was better for recieption, but XM has lots more that is worth listening to!

MCS out!

Then you have the only sirius unit in the world that was better for reception. I have never been so infuriated in my life as I was last year in a cross country trip being stuck with my dad's XACT Sirius piece of crap. Every damn overpass caused the signal to "boooiiingggg .. silence ... resume". Crap hardware, Crap receivers, and CRAP programming -- what was good about sirius now???

Incidentally, something that has kinda been glossed over is that ClearChannel has been involved with XM from the very beginning. They are and have been a large shareholder and have had a representative on the XM Board of Directors since the beginning. The repeaters that XM uses are essentially tied in with ClearChannel's terrestrial presence. The whole ClearChannel XM suit was really just an odd disagreement between two partners.

[cknight725]

Sirius may not as many repeaters, but they have a crack team of technicians doing their best at maintaining them.

http://histoire.info.online.fr/images/eniac4.jpeg

Yeah, you gotta lick those bad boys and stuff 'em back in the cabinet ...

[Baggity Bag]

Ever wondered why you go under a bridge and you don't lose your signal?

You say it's the repeater....BULLSHIT. There's a buffer built in to the units....it can handle a car going under a bridge (even out in the middle of Bumble Fuck, IA where no repeaters are needed) easily.

Now, some cities may have repeaters in larger cities near bridges (by mere coincidence)....

Wow, how much would it cost to have a repeater under every bridge in the US?

[supertool]

I have a XM unit in my truck, but any more I throw the MYFI in the cup holder to listen to the show pre-recorded. I was doing just that yesterday when I pulled into a Home Depot . As I pulled in the sound fuzzed out and Howard Stern began to bleed in. I turned the MYFI off and Howard's show came in perfect. I guess someone in the parking lot had their Sirius unit on. I listened for a few minutes hoping to catch his reaction to the boy's announcement. Unfortunately he was tooling on that fucking retart high pitch Eric. I suddenly realized that shopping for paint would be more entertaining, so I shut the radio off, and went inside.

Below is the new portable Sirius unit which also checks your vitals to make sure Howard's incessant whinning and pontificating hasn't bored you to death.

http://i63.photobucket.com/albums/h128/supertool1/dce2.jpg

[MilitantRabbit]

The NY Metro's FM band is really crowded. Thankfully, my car's antenna broke, so it's stuck only able to receive local (like 5 feet from my Airware or a 50000 watt station). So it works great.

[Digital_Trauma]

I'm in different cities all the time, so I was having problems with the built in fm modulator on the roady2. I had to change to different stations a lot, or live with lots of interference. I ended up going to Best Buy and purchasing a new head unit with a cassette player, until it ended up dying from over-use. Next, I got a cd head unit with an aux input on the front. I never have problems now, but I've heard of Sirius units "overpowering" other signals, like the guy in the Home Depot parking lot. There was a thread about it on here a month or so ago. The signal strength issue is always strange to me. I can pick it up inside my warehouse, with all doors closed and no windows, near Louisville, KY. I doubt there are many extra repeaters in that city, if any.

[sshea]

If you are having problems finding a 'clean' frequency to use for your FM modulator in the radio, a real cheap solution is to unplug the antanae from your radio. It will still receive your signal, but cut out most outside signals (Only good if you never listen to regular radio anymore)

[jled41]

If you are having problems finding a 'clean' frequency to use for your FM modulator in the radio, a real cheap solution is to unplug the antanae from your radio. It will still receive your signal, but cut out most outside signals (Only good if you never listen to regular radio anymore)
That's a great idea, but I don't have xm andI want to see what all the fuss is about O&A is. So I have to listen on fm

[UCFGavin]

That's a great idea, but I don't have xm andI want to see what all the fuss is about O&A is. So I have to listen on fm

you wont regret it.

[jled41]

I don't think they have ever been on in Pittsburgh before, have they?

[DickStragin]

Yeah, this is the one and only username I've ever had on this board, just never felt the need to post anything before.

Agreed!

Oh shit I just fucked up again. How do I get post removed?

[Brezo]

i got an old SkyFi, allegedly a home/car unit. It tends to work good at home, but is mostly worthless in the car. POS, i could upgrade, by its not my fault the unit sucks, its xms'

[Angelfuck]

can a take a guess and say you had the "nerds" at best buy install it?

[NIPPLELUVER]

XM is so fucking superior. Sirius is crap.

[AngryFetus]

The thing about the sirius portable units is that they are so large that they are ALWAYS near a repeater...gimmee those ribs

[jmertzig]

XM has 3 satellites for the record. They launched #3 about a year ago, if I remember right it is farther north to help cover Canada better.

Also on a side note, I remember reading an article a few years back about Sirius letting their insurance policy expire on their satellites, to save money at the time. Meaning that if one failed they would have to eat the costs to repair or replace. Where XM said that the Satellites were most important to the company and would never consider not having insurance on them. Don't know if this has changed, I know I read it about a two years ago.

[5erdude]

I think sat #3 is named Rhythm and number 4 is supposed to be Blues.

[bobimpact]

Just a point of clarification:

XM has indeed launched a third satellite, and they are planning a fourth, but this will not be placed into active service concurrently with the existing satellites, they will be replacing sat 1 (Rock) and sat 2 (Roll). I belive sat 2 is getting phased out first and will reenter the atmosphere, buy a Sirius and go fuck it's mother.