So, I wore out another car and it was time to get a new one. Unexpectedly, the new car came with one of these fancy gizmos:
This is not the first HD radio I have owned, the Jeep Cherokee had one that I install myself. This is the first time it came with the car and I didn’t even mention it to the sales guy.
A few observations:
- Many stations’ HD1 channels don’t sound very good, they are either shrill and tinny, or not synced with their analog counterpart.
- There still aren’t very many stations transmitting HD Radio; FM stations are either NPR affiliates or belong to a few larger corporate owners. The AM stations are few and far between.
- AM HD Radio still has numerous problems in the mobile listening environment.
- Many of the HD 2/3 don’t sound very good; low audio levels, muffled modulation, low bit rate audio, etc. The only exception that I have found so far is Vermont Public Radio’s classical format, transmitted on the HD2 of WVPS, Burlington.
- HD2/3 channels mainly serve as “translator loophole” stations, AKA “Metro Stations”
As far as the new ownership by DTS goes; I will reserve judgment until they do something with it.
Wouldn’t it be a lot more fun and potentially useful if cars came with an APCO25 receiver to listen to public service communications?
If you ever make it down to Louisville Kentucky, check out my three public stations here. WFPL, WUOL & WFPK. I just installed three new Nautels for them, complete with HD. I think they sound pretty good, but of course I would. 😉
I think you may be listening to stations using their exporter to create both the analog and AES feed to the exciter. In this setup, the analog usually sounds muddy or muffled, no high freqs and lot’s of bass. When your radio switched to HD you hear lot’s of high freqs…sounds kind of like normal FM.
You may be stuck with this setup if you have a single AES audio feed showing up at the transmitter.
I feed the exciter multiplex directly (delayed) and route the processor’s AES output (setup for HD) to the exporter. I use a Justin to sync analog to HD and the switchover is transparent except for a noticeable drop in the noise floor.
MY HD 2 & 3 are processed by Orban cards included in the Nautel importer.For 32 kbps audio they sound pretty good!
Part of the blame for low quality HD stations is the PPM encoders. I don’t know if you’re listening to encoded stations, but here in Portland I thought they sounded bad before the code density update… Now they’re even worse!
Tom/Scott, there are a few stations that actually sound good. I think that for most engineers and technical types, HD is still a secondary concern, to be looked at after all the more important stuff is taken care of. The audio quality issues on at least two of the HD subchannels are simply GIGO as far as I can tell.
Chris, that is a good point. Some of the stations are indeed PPM encoded. Now that you have mentioned it, I’ll pay closer attention in the PPM markets.
I agree with what Tom said. If a station is gonna invest in HD, invest a little more and get a processor that can get your the audio feeds you need to do it right. In the grand scheme of things, a good processor won’t cost that much more.
What I’ve done with these three is use the loop thru that Nautel has for the AES audio. I feed all three stations with the AES output of the Optimod. I loop that through the Nautel exporter into the exciter. WFPL is the highest powered station we have so I then put UOL on it’s HD2 and FPK on it’s HD3 using the AES output #2 of the respective Optimods. I did it primarily to see of three HDs would show any degradation on the main HD.
Something else to consider, check the delay on a regular basis. It drifts. I check the delay on all three of these every week when I’m up there and adjust it in the exporter as needed to keep it as close to 0 as possible. Normally the delay hangs around .022ms which I’m ok with. I have found the difference as high as 2ms before.
@Paul-You wore out the Subaru already? I know you liked how easy it was to change the oil. What vehicle came with this radio? I’m getting ready to launch a HD3 channel and need to make the leap from MP1 mode to MP3 to have meaningful audio quality. At least my Nautel gear is relatively new, and audio alignment is assured by using Cat6 as the E2X; the exporter is at the transmitter site.
Eric, yes, I traded it in a few weeks ago, it had 75K miles on it. The new car is the same model as the old one, just slightly updated electronics.
” it had 75K miles on it.”
Funny how that “get rid of it” threshold changes over time. In the past I’ve driven my vehicles 200-250K miles before replacing them. These days the wife’s car gets traded before it hits 80K. Something about a warranty something-something.
Paul, Was the car CVT or the 6-speed manual? I have been thinking about the model for some time, wondered how you wore it out and how you found it getting to those sites.
It has a CVT, which takes a little getting used to. I wore out the old car by driving 75K miles in 18 months. I found the Crosstrek to be fairly good at getting to most sites, but it is not really an off road vehicle. It does okay in the snow on paved roads, but my old jeep was much better. I do like the 34 MPG, it has a comfortable ride and lots of room if the rear seats are folded down
Shrill/Tinny HD-1’s are probably using a split off the analog processor and have pre-emphasis enabled….
Reminds me I need to put a processor on my HD-2, Audio is a bit low….but it is mostly just used for feeding translators…..;)