Hans Fifth gear | Join Date: Mar 2005 Location: Tampa Bay, FL Posts: 3,290 |
Hans
Fifth gear
Join Date: Mar 2005
Location: Tampa Bay, FL
Posts: 3,290
Quote:
Originally Posted by wrusprod
...I believe Kenwood is the only one who sells HD radios, so Im waiting to see more in the marketplace.
Incorrect. Just look on Crutchfield; there's several models from different manufacturers. The other one I was looking at is a Clarion, but it's $450. The Kenwood unit is MUCH cheaper.
Quote:
Originally Posted by GeaugaFletcher
I think the bitrate of HD broadcasts is something like 96kps at the MAX.
Actually, it's 96kbps/second *constant*, not "max". Adding the "max" implies that it usually transmits at a lesser freq, which HD Radio does not. Unlike Sirius or XM...read on:
Quote:
Originally Posted by GeaugaFletcher
Think about how your 128kps MP3s sound compared to a real CD or even just a regular analog FM broadcast. Now think about 96kps...
Actually, 128kbps is fine. Sounds better than FM stereo. But that's a marketing blurb spread by the satellite radio people as "we're better, here's why". 
Want to know the truth?
Sirius Satellite radio uses mp3PRO to encode and transmit their audio. They also keep the constant bitrate a *secret*, and refuse to publicly announce exactly what it is, claiming it's a trade secret. mp3PRO is an audio compression algorithm (or codec) that combines the MP3 audio format with spectral band replication compression methods. It claims to achieve transparency at lower bitrates than MP3, resulting in a file nearly half the size of standard MP3. mp3PRO typically starts at 40 to 96kbps and will peak at 128kbps as required, but rarely goes above 80kbps. (That number is important, and you'll see why in a second.)
XM satellite radio uses aacPlus compression, with Neural Audio broadcast audio processors in front of them. My understanding is that most of their music channels are 40kb average bitrate. aacPlus is optimized for sounding CD-quality at 64kb and there is no reason to use aacPlus at over 64kb (you would just use normal AAC-LC) XM uses constant bitrate, 80kb for the most important music channels, 40kb for the music channels and 32kb for the talk channels.
Notice how both Sirius and XM use 80kbps for music? (That's why I said it was important.) It's also why Sirius and XM sound virtually the same...they're both transmitting at roughly the same kbps/sec.
HD Radio, however, has both AM and FM flavors. The AM version can carry 36 kilobits per second of data for the main audio channel, while FM stations can carry information at 96 kbit/s. The Federal Communications Commission selected HD Radio as the standard for local area broadcast of signals within the United States. It offers multiple programs on one channel and works on the same frequencies allocated to analog (FM and AM) radio stations. Supporters claim CD quality sound and reduced interference.
In a car with two speakers (typical Miata with no headrest speakers), all you're getting is stereo L/R anyway. I regulalry listen to MP3s at 96kbps (they're on my iPod phone, or on my iRiver H120 DAP), and they still sound great.
Have you listened to HD Radio? Or are you just repeating what you've read about
free High Def Radio, as opposed to pay-per-month satellite radio, as told to you by supports of satellite radio? 
I've listened to both, side by side - at best, I can't tell the difference. At worst, HD Radio sounded better. But that's my opinion of how it sounds.
Quote:
Originally Posted by GeaugaFletcher
Also, I'm heard that 96kps can not reproduce high frequencies without some kind of voodoo kludge.
Neither can 128kbps. But again, more hoopla from XM and Sirius about why HD Radio is inferior. But then again, Sirius and XM are only 80kbps constant for music? And last time I checked, 96kbps is higher than 80kbps, right?
Quote:
Originally Posted by GeaugaFletcher
Every radio station and every radio manufacturer that uses HD radio must pay a chunk of money for the original equipment and license, then renew that license annually. HD radio is a cash cow for the originator of the technology and provides lower sound quality than analog (with a decent antenna). YMMV, but you know my opinion now! 
And this is different from Sirius and XM how? It's not. Except with satellite radio, you, the consumer, have to pay $12.95/month for the "privilege" to listen to their content. Or get an HD Radio receiver, and pay nothing more.
Which would the average person chose? Well, we know your answer. But at the time that Sirius and XM came out, HD Radio wasn't an option. It is now. And as more and more HD Radio receivers hit the market, you'll see Sirius and XM's market share continue to decrease. People just won't pay $12.95 a month when they can listen for free.
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