bradykp

XM claims it used proprietary compressions. from googling it, i found various "opinions" on what the bit rate is. but nothing fact. some said 128, some said 96, some said 64. who knows! lol

Karl O.

Only on the magic internet, where the laws of physics (and reality) are routinely ignored on a regular bases.

Sometimes reading the internet makes me stupider.

gmfreed

I would ask you to read the article in the link i posted at the top of page 2 of this thread. Now I am no computer guru, but it clearly states in that article than XM uses a compression of MPEG Layer II at 384 kilobits per second. That seems far better than your stated 96kbps. If I am wrong about this please show me or atleast explain why I am reading this wrong.

stewie20068

I have the monster icable. I think it was supposed to be for the ipod(which I have) but I got it off ebay for $20. Usually it goes for about $35.

stewie20068

I found my xm and fm info off of google. The other stuff I have just noticed when using itunes/musicmatch/etc.

The xm stuff I found said:
"XM uses constant bitrate, 80kb for the most important music channels, 40kb for the music channels and 32kb for the talk channels."

"Sirius and XM each have around 9MHz of downstream bandwidth at 2.3GHz. Both services dedicate about 128kbps per music channel, and an estimated 64kbps is used for each talk station."

I found another site that said 96kbps (that I can't find now) and I've heard that before so that's what I put down.

bradykp

the one that is the car charger, with the aux out on it?

jakesdad

I find some XM stations better than others, and almost all of them are better than what we get as FM stations around this town. Most of our FM stations are all own by Clearchannel and they limit/compress the hell out of the music. And, I'm talking about audio dynamics compression - limiting the strong peaks and boosting the average volume so that there is no difference between the loud passages and the soft passages. It's very noticable in a lot of 70's music and in the hard driving beat of most dance music. You get that "air-pumping" sound between the beat as everything is artificially boosted until the next beat comes in cutting everything else back down again.

Pretty much the same smashed sound you get from today's over-limited, over-maximized commercial CDs whether new releases or remastered older stuff.

And then when those over-compressed FM stations play music sourced from those over-compressed CDs, then... small children begin to cry.

If you can't tell, such stuff is the bane of my existence.

On top of that, FM is frequency band limited to no higher than 16KHz. About the same as 192k mp3 or a cheap cassette deck. 128k mp3 cuts out at 14kHz. Below that in bitrate and the top end lowers more, or at least cuts it out when those higher frequencies drop below a certain amplitude threshold and you end up with that swishy, swirly sound typical of low bitrate digital compression.

I have not recorded XM to see where it's frequecy range really falls, but it sounds like it depends on the channel.

I did find that XM's 70's station was noticably lacking in that limited/compressed sound. I actually heard Boston's "Don't Look Back" in pretty much it's original full dynamic quality. A song that typically sounds really bad on FM (as does anything by Pink Floyd). But, there are other XM stations that hit the limiters real early and it's noticeable. The talk radio and news stations sounds like cell-phone conversations with it's constant swishy distortion sound of ultra-low bitrate digital compression.

I actually find the factory stereo in the TSX to be quite nice sounding. I'd like to eventually get the Avincar replacement speakers, and replace the amp. But it pretty much works for me as it is now, except for the "auto-loudness" that progressively cuts the bass and highs relative to the midrange once you go above 20. Really annoying on some of my older CDs where I can't get them to sound good at 21 or higher because of the rather abrupt auto bass/treble cut. However, if I rip the CD, increase the volume by about 4 or so decibels (having to resort to a small amount of limiting of these transient peaks - don't like doing that, but this is for the car, not critical home listening), and re-burn the wave to a cd-r, I can play them up to 19 or 20 and still retain the bass before it get's artificially cut by the amp.

stewie20068

no I have this icable



I have the my ipod plugged into a (griffin??) carcharger that has a lineout. It plugs in through the dock connector. Then I have the icable running from the lineout on the charger to the rca plugs in my console.

sccpu3d

ROFL I'd be so pissed for that haha because I've been listening to XM on AIM Triton for a while haha its free!!! =) But as you'd expect, crap quality sound. Then again, while im playing CS, who the heck cares? ^__^

For the cable connection to my car, I jacked the cable off my computer speakers, and its pretty dang good. The speakers are THX certified Dolby Digital, so it only uses the SPDIF connection. Efficiently, I took those analog cables for the rear speakers and front speakers (both are unused because 1 SPDIF can power the whole setup) and I plugged them into the car. The ipod sounds great as well.

I still gotta try lossless though, but im too lazy to rerip all my cd's when I can barely tell the difference between CD and AAC 192

themayor

I believe what you are misinterpreting is that they ripped the tracks from CD and STORED them using MPEG Layer II at 384 kilobits per second. From there they are compressing the bijesus out of them using aacPlus and then processing it through Neural Audio Edge ( ) for broadcast. Coding Technologies Article

The result is a heavily compressed and proccessed sound. A bummer if you're someone who's interested in hearing what the original recording sounded like. But, not a big deal if you're someone who thinks Bose makes good stereos/speakers.

Obviously a lot of this detail and discussion is moot when listening at 65mph in our TSX's. But interesting stuff if you have XM hooked up at home.

bradykp

ahahahaha. i love the knock on Bose. not many people out their believe that Bose sucks. glad i'm not alone!

bradykp

ohhh.....right.

i'm thinking of this....

http://www.monstercable.com/compute...er.asp?pin=2132

i have the 2006 with aux in.

WDP-Acura TL

XM is far more superior than FM and CD's. This is the future of radio. Since I got XM radio a yr ago I couldn't get enough of it. That is mainly what I listen to when I get in my car. I get to listen to music that hasn't been released on FM yet. It's like cable television so many more choices to choose from than attenna TV which is to 1980's.

stewie20068

We are saying that the quality of XM sucks! Maybe you can get a wide selection of advertisement free music on XM, but I can do that with my ipod which has vastly superior quality. If you want to talk about CD's I say mixed CD's are better than XM because they are much better quality and I can load six 20 song mixed cd's in my changer and have 120 high quality songs of my choice.

I'm not viewing XM as the future until they work on the quality issue.

cusetsx

XM is great...especially when driving under overpasses, in parking garages, and tunnels. It's the clearest sweetest sound of silence I've ever heard. If you can't tell that XM sounds compressed then you obviously don't have as tuned of an ear as some people. Once digital FM and AM come out there won't be much of a "quality" difference. In fact I think I've heard that digital FM will sound better than XM.

As far as iPods are concerned if you have a large hard drive version you don't have to compress at all if you don't want to or don't have to compress as much.

Either way I can't see spending money on XM for the car for something that:
A) I can't listen to no matter where the hell I am in my car.
B) Though it's digital it sounds like something being streamed over the internet.
C) Even though it has no ads I can do the same with a Mp3 CD/iPod etc.
D) During the trial membership I only listened to a handful of the channels available, and you can't pay for a limited set of stations... like I only want these channels.

However, once XM ( or maybe it's the other company) starts streaming Video into my car I might be more interested. I've heard they are looking at starting that with some kids channels first.

Oh yah and don't forget Mini Discs....though ATRAC is not Mac friendly it's still a option out there for music storage. A lot of radio stations use MiniDisc for their music.


I'll give you this.... XM is great for sports stations. Some areas can't get certain shows like ESPN radio etc on FM/AM.

bradykp

i love the sports radio and news radio....but the talk shows are the worst sounding out of anything XM.

as far as the songs, i really don't think it's a big issue of quality in the car right now.

yeah, so you can achieve the same quality or better with your mp3 player....but you have to have all those songs. some people like listening to new songs....and i don't scour the internet anymore and download songs. i think XM is a nice offer....especially if you score it at a discounted price. 5-7 bucks a month....no biggie. especially in the summer with all the baseball!

would i have bought XM if it didnt come with the car? definitely not.

cusetsx

True you do have to download all the songs that you don't have. True you won't hear "new" songs on your Ipod. But any "new" song that I like that I hear for free on the normal radio I can download and have the next time I'm out driving.
And for 5-7 bucks a month I can download (legally) those 5-7 songs that I've heard on the radio that I don't have. Wash and repeat.

It's really a to each their own situation. I'm not one for baseball or to listening to sports on radio. I'm more of a visual person when it comes to sports. Either I have to be there in the stands or watching it on my big screen at home in surround sound.

frescagod

i can tell the difference between those two, but a CD vs. something ripped -alt preset standard (VBR) is pretty transparent to me, even on my reference bookshelf speakers. in the car, i probably can't tell the difference between those two either, but i'd say the majority of people have 128kbps mp3s (and crappy ones at that) on their iPods.

cusetsx

Yah like Mmmmm Bop!

jakesdad

Bose is great...


...at marketing.


But, that's all they are good at.

bradykp

true..... i'm just not a big fan of the mp3 craze. and i should be right in the middle of it as a 23 year old.

but i do like www.allofmp3.com to download music.... much better than apple.

i enjoy xm over fm for sure. could i use my ipod and get the same effect....probably. it would take effort for me to keep up on new songs, and then go out and download them. and i like being introduced to new songs.

if you're the type of person that listens to the same 20-50 songs for a period of time....xm is probably a waste of $$$$

sccpu3d

Well, theyre good enough to kick our TSX's sound system, and toss it around a couple times to boot Although, in all serousness, I think theyre getting lazy. Havent been seein their commercials in a very very long time.

bradykp

if you gave me bose speakers, i'd consider taking them. then selling them on ebay to some poor sap, and buying b&0 speakers.

bose are worthless to me, and this was confirmed by a friend of mine who owns a home entertainment store. said they sound good, hard to argue that, but the quality and durability is crap. i won't buy em

vidgamer

Wow, they're lossy-encoding them twice? No wonder it sounds horrible. Don't they realize that if they at least started with an uncompressed file their overly-compressed signal at least would sound a BIT better?

(Answer: they probably don't care....)

Not really moot, IMHO. The TSX seems quiet enough that I can hear the flaws of XM.

From what I can tell, just listening by ear, I would believe that some of the more popular channels are compressed less, and all of the variety is compressed more. I suffer though it because I like the variety, but I can supplement my playing with CDs & FM. I hope to soon add an AUX (which I may end up listening to podcasts more than anything else!).

As for FM, lately, I've been noticing some distortion, and I keep trying to decide if I've damaged my tweets or something, but I only seem to hear the problem on the radio, so I wonder if it's related to them overboosting the signals? CDs still sound good.... XM still sounds like XM...

themayor

Yeah I can definitely hear the difference between XM and CD no matter what the conditions. But, I was thinking I'm not sure it would be significant enough if XM upped their signal to say 192kbps from current compression unless I was in a very quiet environment.

FM normalizes their sound level, that's why it sounds distorted/overboosted at times. So, no matter what the dynamic the sound level is always the same...lone acoustic guitar - level 10, Smashing Pumpkins' 12 guitars, bass, drums, vocals - level 10.

jakesdad

I don't know... stick in Pink Floyd's The Dark Side of the Moon and play "Money" (I know it's overplayed on "classic rock" stations, but bear with me...).

During the saxophone solo, there is major 30Hz continuous tone (in the range of something you feel more than hear) in the right channel that runs under the solo and stops just before the drum run into the first guitar solo. I use that track as a check of the low-end response in a system. In the TSX, it's got the rumble.

The thing is, I think Bose outsources their car stuff. Who knows who really makes the speaker components. Their home audio stuff (like the Acousti-mess, as it's known in audiophile/videophile circles) all emphasizes the 100Hz and above tones and ignores anything lower. I think they even top out at about 14-16kHz. Ever wonder why none of their stuff ever lists the frequency response? It bites, that's why.

They were something back in the 70's when they actually spent more money on R&D instead of dumping it all to advertising as they do today.

They still advertise... check out any Good Housekeeping magazine or Parade section of the Sunday paper... ...where all great audio companies advertise

peter_bigblock

I consider myself able to discern quality speakers and a quality recording -- I spent enough time in my brother's recording studio and listening to music, although I'm no audiophile. I consider XM to be what it is -- a great way to listen to a variety of music and other programming, anywhere on the road (practically), for $12/mo. The sound quality is a little over-compressed but not so much as it bothers me.

As for Bose, man I can't stand listening to anything Bose makes. My home system is Audio Research tube and Vandersteen speakers and DVD-A. I'd love to have a 24/96 player in my TSX (that's 4608 kbps). Doesn't have to be 5.1, just love the clarity and presence, even in a car (in the TL, it's amazing).

That said, I love my XM -- I can catch any ballgame I want during the summer, and I hear a lot of songs I never thought of or knew about. Eventually, my guess is the sound quality will improve. It always does.

I wonder if the quality depends much on the equipment -- I use a Roady2 in my '04. Maybe the DA converters are better in some than in others. Probably marginal at those relatively low bit rates.

J.A.S.

I agree with the above. To me, XM is about variety of programming and being able to listen to what you want, when you want it. Most of the programming is stuff that I'd never hear on my local FM stations and guess what, I hardly ever listen to FM anymore.

The sound quality of XM isn't as good as playing a CD but I'm happy with XM's programming.