XM vs Sirius

Posted on by Ian C.

Background:
I tried Sirius a couple of years ago on my Kenwood, but it cut out predictably often under trees – there are lots of trees on my commute!

Recently, with receiver prices so low, I bought an XM receiver – using it was a revelation for the first week (just one quick cutout under a big tree on the rotary near my house). Of course, as soon as I signed up, XM had a major outage but now they’re working again and perfect.
However, I wanted to know if Sirius had improved – I remember their channel line-up being better than the XM offering (of course memory makes things seem better!), so I also bought a low price Sirius receiver.

The Sirius receiver looks much nicer than the XM – it’s amber backlight and black case works well with a stock MINI, and the receiver needs no stand so it’s small; the XM requires a stand and is a dull gray with off-white backlight. The Sirius channel select is easier for me too – up/down buttons – while the XM has a tuning knob (which is OK) but requires an extra click-to-select once you’ve got the channel you want. Mostly though, both are easy to use.
However, the Sirius antenna is a bit more bulky than the XM …

 

For trials before you subscribe, the XM is better – preview channel 1 continuously plays “sound bites” from other channels, giving a good flavor of the type of music and quality available. Also, I found that a collection of channels (including 7, 20, 54, 121) were active to try! I don’t know if that was a bug in my receiver, but if it’s normal then it’s a great way to let users try out the system.
Sirius on the other hand offers just one channel, which spends most of the time playing the Weather Channel – not a good demonstration of quality, and no real indicator of what’s available on other channels. Adverts regularly push Howard Stern / Martha Stewart, but no examples of sound on other channels.

Of course in the end, it’s down to reception – if I can’t hear it, it doesn’t matter how good it is! XM, apart from the outage, has been 99.9% perfect. On my commute, it drops out for less than 1s, as I pass under / by heavy foliage at the rotary near my house.
All along tree lined routes 133 and 22, it receives perfectly. One other cute feature (maybe just for this receiver, when the dropout occurs you get a mimic “FM static” instead of just silence).
Sirius on the other hand, is no better than it used to be 😦
At the rotary, Sirius drops out for a total of about 5s, spread over my drive through the rotary – repeated on/off dropouts seem more annoying than a continuous cut to me! Driving routes 133 and 22, Sirius has a habit of cutting out if the trees get too heavy. It doesn’t seem to have to be directly above the road, but certain angles present problems.
When Sirius does cut out, as I said it cuts on/off repeatedly – it also seems to “skip” slightly so on a short cutout, you’ll notice the speech/music is discontinuous. My old Sirius used to do that and I assumed it was early buggy hardware, but this brand new receiver does it too so it must be a “feature” of Sirius!

I thought I might activate the Sirius for a month anyway, to compare its programming with XM (and with my memory!) … first problem, you have to specify your car and it doesn’t list “MINI” as an option. I selected BMW and entered “MINI Cooper S JCW GP – not BMW” for model name, but it rejected that 😦 so I just used “MINI Cooper S JCW GP” …
Next problem, there’s no way apparently to select the “month-by-month” subscription that’s listed on the plans page! Quarterly is the lowest cost, and paying almost $40 to experiment is a no-no (turns out you can get the month-by-month plan, but only by phoning them!)

On the way home tonight, I took Apple Street in Essex – it’s a twisty but VERY residential road, about 1.3 miles long (3 minute drive) and very heavily foliaged!

Apple Street in Essex, MA

I drove it twice, first listening to XM and timing the outages, then listening to Sirius … I was a bit surprised by the results:
XM outage totalled 20s … Sirius outage totalled 9s!

What was interesting too was how the outages occurred.
Sirius repeatedly dropped out for short periods of time, or had momentary distorted sound. The longest single outage was maybe 3s.
XM on the other hand was perfect for most of the drive, but cut out completely over one long section, where the road wraps around some large rocky outcrops (small hill!)
It seems that XM can penetrate foliage much better than Sirius, but because XM is low in the sky compared to Sirius, it’s more likely to be affected by pure bulk like hills and buildings. Of course if there’s a terrestrial repeater, everything is fine, but out on Apple St there isn’t …

So I’m still undecided. I think I’ll have to try a month of Sirius and compare the actual music choices – but given that I almost never drive Apple St, and XM is much better than Sirius for my normal drive, I might still choose XM in the end … I’ll be able to trial both during The Great Ice Cream Run next month!

16 thoughts on “XM vs Sirius”

  1. Sirius has BBC Radio 1 so that makes it a winner in my book.

    But since my XM is hooked up to my head unit via the CD changer port, its too much of a pain for me to make the switch. It is nice not having an extra unit in the front though.

  2. I’m not young enough to listen to Radio 1 any more! When I go “back home”, it’s radio 2 for me … I’m a Steve Wright kind of guy 😉

  3. Could the choices of units affect your reception? Maybe one XM unit is worse than another XM unit, viceversa with Sirius.

    I have Sirius for the car, I have the Replay unit and the antenna is about the size of the XM antenna you pictured (not the disc). I just stuck it to my dash, and for the most part the signal during my (no trees, etc) commute is fine except for the same underpasses when it cuts out briefly. I’m in California.

    Also, I stream XM via WinAmp, it’s free, you don’t get many channels but at least it’s something different for when I don’t want to listen to streaming Sirius.

  5. Hello Ian,

    Foliage, especially dense wet foliage is a problem for both services, but I suggest taking the Sirius down “Apple Street” at different times of the day and comparing results. Since the Sirius systems uses low earth orbit sats, you might find that the results are different each time. If you stick with the XM, and the merger goes through, you may find that the best channels of both systems end up on the XM system and you are out in front!

    Also – sorry we didn’t get a chance to speak at the MOP event. I didn’t want to disturb your phone call, then we left right after the prizes were pulled. I wanted to see the ICE in the GP but the rain would not let up. I’ll hook up to take a peek at MOT.

    Cheers Mate!
    Dave N

  6. The signals are in the same frequency range so they should have the same ability to penetrate leaves etc. The major difference is XM’s satellites are geostationary and always drop out in the same places, while Sirius’s satellites move in the sky (and spend much of their path further north than XM) so dropout spots change with time.

    Also, terrestrial repeaters play a big part in reception around cities. I do wish they put more effort into adding more repeaters to cover the suburbs like your area.
    You can find websites that show the satellite positions and the repeater positions.

  8. Interesting write up Ian, and something that’s made me continue in my ambivalence towards sat radio.
    One thing that did strike me… do you know (or does Josh) if the two systems use different buffering schemes? If Sirius is playing what it recieves in real time and XM is buffering, it may explain why Sirius’ drop outs are short and frequent whereas XM’s are longer – once the buffer is empty, it has to refill once the signal is re-established.
    Like I say, your write up does nothing to make me want to buy into either system. If that tree on the rotary can block the signal, and what I get when it works is Howard Stern and Martha Stewart, you can keep it..! 😉
    If you want Steve Wright (and other BBC radio people like Simon Mayo), podcasts are the way to go and they’re free. 🙂

  9. My understanding Gavin is that both systems transmit two streams – one being “now” as it were, and the second being “soon” (ie: a few seconds ahead).
    So if there’s a drop out now, the radio can fill it in from the earlier “soon” data.
    If the drop out is longer than the gap between “now” and “soon” (I think 3s) then you’ll get loss of sound.

    XM transmits both streams from each satellite position – so you get both or neither.
    Sirius transmits “now” from one and “soon” from the other, so you can be in a situation where you get audio, but all bridges/etc give you a drop out always … more confusing, the drop out can happen after you’ve passed under the bridge, if the data you’re receiving is “soon”!

  10. Again today, I drove down a heavily tree lined road (Bond St in Gloucester) – XM didn’t drop out at all, while Sirius dropped out regularly.
    It’s clear to me that XMs transmissions are “stronger” and can penetrate leaves, while Sirius cannot.

  11. Ian,

    Don’t you have an Alpine CDA-9857 in the GP? If so, it appears that it is XM or Sirius ready (per the manual on the Alpine website). You can do away with the seperate display unit and use an XM Direct Reciever ($35 at myradiostore.com). Your Alpine head unit becomes the interface. I use an XM direct with the stock MINI HU and a Blitzsafe adapter and it work flawlessly.

    The only downside is that the receiver is not truly portable although you could move the unit from vehicle to vehicle if you placed it in an accessible location.

    Phil

  12. It looks like you would also need an XM direct to AI-Net interface which is another $40 at myradiostore although the site indicates out of stock right now. Still, it might be something to consider.

    Phil

  13. Correct Phil – but it was less expensive and quicker to get a couple of $30 units to try both services.
    The comments about look / color / etc were for other readers rather than for my own concern.

  14. I prefer my XM to Sirius.
    I have their Inno unit which is smaller than an iPod and has storage for MP3s. It also allows you to record and play back songs on the go. It also allows listening on the go to Live Satellite
    plus, Red Sox games in any state with the local feed (when playing at home) is nice.

    I hated the toy-like nature of the Sirius units. Plus the abundance of terrestrial repeaters for XM makes reception better in most places.
    I hate the constant cutout of the Sirius units… I prefer to just LOSE my connection for a few seconds then the aggravating staccato cut out.

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