Audio Quality

Depends on which channel.

It also depends on the program material or song. All the satellite broadcasters, radio and TV use what's known as Statistical Multiplexing, where the bitrate of any individual program has a bit rate range which varies depending on the density or the audio type. For example, talk formats have a very tight and limited range of available bits due to a limited frequency response and program density, whereas a rock station with less dynamic range will be allowed more bits to play with. When the next song for the rock station comes along, let's say Stairway to Heaven by Led Zeppelin, with the single solo guitar in the beginning, less bits are allocated to that particular channel during the quiet part of the song, with more bits made available to another channel with more program density as required. Then when the vocals start and things rev-up in the song with the dynamic range decrease, more bits become available for use on that channel. The idea is overall management of a finite total bandwidth available on the particular satellite transponder.

ai4i said:

Depends on which channel.

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Also depends on which service is being used to listen. The Sirius tuners and corresponding service are using an old, fairly inefficient codec and if the listening is being done on a Sirius branded tuner, the channels will be heard in low fidelity. When I listen to my favorite music channels (which include the Decades channels) on my Onyx Plus, they sound good due to the superior HE-AAC codec being used in the SiriusXM branded tuners and on their corresponding service.

When the Sirius Backseat TV service is discontinued on New Year's Eve would this contribute to improved audio on the old Sirius branded tuners? (I'm thinkin' that it won't be so simple as that, though)......

It depends as to whether they decide to make those bits available for use in the MUX pool. If they choose to keep those bits for future channels, then no.

I was driving along listening to the crappy audio quality on Sirius and thinking about their encoding scheme. ADS Satellite TV organizations like (DirecTV and Dish) go through significant 'forklift' upgrades to their encoding systems about every two years. The idea is to squeeze more services into the same transponder channel without the viewer noticing a decrease in video or audio quality. Now I don't know this for a fact, but it seems like Sirius-XM are several encoding evolutions behind the times. Granted, replacing/upgrading all your encoding and MUX systems every other year is expensive and onerous, but like satellite TV, that expectation and capital cost should be planned-for and baked into the budget. Using antiquated encoding schemes to save money or defer maintenance will eventually hurt your growth and existing subscriber base when renewal time rolls around.

Perhaps they would address the encoding scheme on Sirius radios first since it is the furthest behind the times when it comes to updating the codecs however subscribed radios are in the minority against xm/siriusxm units. They need to realize that those receivers are still being installed in some 2016 models, and that they would possibly need to continue the corresponding service well beyond the 2020 decade for the sizable installed base. There are intervals where the music (high end frequencies) sound as if it were Shortwave from a sizable distance at that.......wonder if they have the $$$$$ at all to pull that off........

I'd say between 24-32kbps audio Sports and talk channels much lower... I have Sirius trail on my radio in my car right now, I can say HD radio sounds much better then Sirius does.

landtuna said:

Although my old ears are not capable of finite measurement.

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Well, if your ears are not capable of finite measurement, does this mean that they are capable of INfinite measurement or no measurement?

I just posted this to another board and thought it would be appropriate to share here.
Don't mind my sarcasm, they tolerate it.