Newsgroups: ba.broadcast
Subject: Sangean HDT-1 HD tuner (long)
Organization: 1.94 meters
[written February 20, 2007]
I ordered a Sangean HDT-1 from Amazon on Sunday and, even with "Super Saver" shipping at no charge, it arrived this morning, much earlier than I expected. I was at home today and had the chance to do quite a bit of listening with it.
This is going to be a somewhat impressionistic post because I don't have test equipment. As it is, I'm going to have to explain the appearance of yet another tuner in the TV room, but I'll figure that out.
Before saying some more things about the unit itself, I'll note some observations about HD:
1) Household static does not seem to have much effect on whether an HD signal on AM can be decoded. That said, the only HD AM station that consistently could be decoded was KGO. KNEW and KQKE could sometimes be decoded. The presence or absence of static didn't seem to make a difference.
2) There is a brittle, metallic edge to almost all spoken voices on AM HD. It is especially notable, and downright obnoxious, on women's voices. AM HD may set back the cause of women's equal opportunity in radio by 50 years as a result.
3) There is also something else odd, more notable on AM HD, but somewhat noticeable on FM HD as well. I may fumble around in describing it, but here goes: when people speak, the sound when they take a breath, or separate words, or stop speaking decays quickly but smoothly. On HD, that decay is cut off below a certain audio level, giving the spoken word an odd sound, as if it were being squelched unnaturally in an overstuffed room. It sounds unnatural.
4) The quality of FM HD seems to be variable, even among stations using (or not using) multicasts. KMAX's main channel sounds overcompressed, for example, with noticeable swishing 'n' swooshing artifacts. Yet it's only multicasting one other channel. Other stations -- KOIT, KDFC, KFOG, and so on -- did not have nearly the degree of artifacts that KMAX evidenced. On AM, KNEW sounded uniformly awful in HD; KQKE a little better; KGO, probably as good as could be done given the circumstances. (KCBS is currently not in HD.)
5) Stations generally seemed to be doing a good job of matching their analog processing and their digital processing. Most got the timing down OK. Only KFOG had about a 1/2 second delay when HD kicked in. The unit has to read the signal for 1-4 seconds before locking into HD. (HD also can't be turned off.) On AM, KGO also had a slight delay when HD kicked in; KNEW and KQKE didn't.
6) Upon extended listening to several stations, I found that the stereo image was somewhat altered compared to analog reception. I can't describe exactly *how* it's altered, other than that stereo separation seems a bit lower than for analog. I should note that this comparison was made with an NAD 4300 tuner, usually in wide bandwidth mode, that I've had for 17 years and was realigned last year. Whether a box that cost $450 in 1989 is a fair comparison to one that costs $200 today is an issue I'll have to beg off on. That said, I know the NAD well. I've always felt that it could have a bit more "warmth", but in this case, it sounded more natural and less tiring than the HD unit.
7) Artifacts are slightly more noticeable on the multicast channels than the main channel. They are not overtly obnoxious to me, but, as I mentioned in #6, I think they contribute to cumulative fatigue when listening. It should also be said that, on FM HD, all channels sounded better than XM does. This is not an especially high hurdle to jump, though.
8) The other noticeable characteristic is an overly bright, "forward" sound that, on FM HD, becomes apparent over time as one listens for a while. Whether this is the tuner or HD is hard to say. I don't have golden ears or even silver ears any more. But there is a brightness, sounding like some sort of boost in the 4-6 kHz range, that is obnoxious. (I didn't notice it on KNGY, which tells me it's probably not the tuner.) It's reminiscent of the harsh sounds some early CDs had, combined with kind of a "ringing" sound. The NAD was much, much smoother and easier to listen to.
9) On the other hand, HD provides absolute freedom from multipath, which is a problem up here in the hills.
10) The only FM HD station that couldn't decode was KUFX. This is no doubt because of distance and location.
11) Programming on HD sucks. It's mostly more of the same. CBS is probably the most forward-thinking in this regard, putting country on the 99.7-2 multicast and KCBS on 106.9-2. Otherwise, it's mostly just another channel of the same old stuff, with at most slight variations, just without commercials. KFOG is even brazen enough to use a service called "The Matrix", which appears to be intended for HD multicast channels, and which is nothing more than a watered-down "alternative" rock format. (This may be replaced soon by the "10 at 10" channel.) If HD is going to help fight off the incursion of other choices, this isn't the way to go about it. Ultimately, I think HD will sink or swim based on programming. So far, Bay Area stations running HD are mostly swimming with a leaden necklace.
As for the unit itself, it seems to adopt a "car radio" approach to a home tuner, by which I mean to say it has lots of presets (20 FM, 20 AM) and relatively few options. AM bandpass filtering is adaptive. This was most noticeable on KTRB, where I could alter frequency response significantly by reorienting the supplied (and flimsy) loop antenna. There must also be a high-pass filter with a relatively high cutoff. There seemed to be no bass below 150-200 Hz or so (again, compared to the NAD tuner, which is flat 100 Hz-8 kHz on AM).
Reportedly, the tuner can decode C-QUAM stereo but I had no way of testing that out. It doesn't appear that KDIA is running stereo any more, for example.
On FM, there is no "mono" option and no option for shutting off HD decoding. There also appears to be some adaptive filtering and there is definitely a blend circuit. It could actually suck some stations out of the noise -- for example, it can give a readable signal on KKIQ, which the NAD can't do, at the cost of reduced separation and high-frequency audio performance. But it couldn't pluck out KKDV, which the NAD *can* do when in narrow-band mode. The unit came with a folded dipole terminated in a balun; I just used a 30" wire connected to one terminal of a balun, which is enough for many stations up here. I previously mentioned the AM loop antenna, which is supposed to be used at least 20 cm away from the tuner to keep the tuner from interfering with itself. The AM section also appears to be prone to overload, with several images encountered across the band.
The HDT-1 can display RDS information. Well, OK, that's a nice party trick. It also comes with a clock. Why it needs a clock, I don't know, but the clock displays when the unit is on standby.
Instead of a clock, I would rather have had an output level control. There is just a fixed output at a rather high level. That made comparisons more difficult, but in the end I think I was able to give the unit a fair hearing. In my copious free time, I will need to do something about that output level.
It also has a small remote control. All functions can also be done on the front panel. The unit generally seems well-made though one wonders if it couldn't have been made a bit shorter in height. The width and depth match well with other stereo components.
For $200 - not the best, not the worst. I find myself wishing it had cost a bit less to satisfy my curiosity, but I knew that going into the purchase. I don't think I'd buy another HD Radio-enabled device, though, not until the programming would become more diverse and less like more of the same stuff you could get without it.
Update: Subsequently, I obtained the Sangean HDT-1X, which does allow shutting off digital reception and makes other relatively minor improvements. While good, sensitive tuners, the Sangean tuners still lack the warmth of my NAD 4300 tuner from the late 1980s.