Sangean HDT-1 Tuner - Page 8

Great, thanks!

Well, I must say I am pleasantly surprised at the support I am getting for being here on behalf of my company. I came here to help you and find you are helping me more than I am you.

In regards to the HDT-1 and future renditions of it. . . There is one key factor that will determine the speed of new models, sales!! If sales for the HDT-1 1st gen drops we will see a slow down in the speed of new development.

If we keep up with current sales (moving somewhere near 200 a week) we should see something by end of summer. It will be more costly at a whopping target retail of $225.

But what shal ye faithful persons get for the additional $25? I can't answer fully right now, but I know with certainty that we will add SPDIF and coaxal digital outputs.

All other changes are really software related and will be considered, but I have not gotten a response from the factory on exactly what changes they are willing to make. I have positioned them with these vital changes. . . LCD brightness controll, the ability to turn off HD Radio function to use analog only, and discrete on/off commands, and that you do not have to press the preset button to access the memory, and a memory scan function.

I have reccomended a new remote, but am certain that is a no-go.

There are no other changes I am aware of. These seemed to be the ones that cover most all of the requests. For the HDT-2, we have no release date for that, and are looking again to add more functions and features for a target price of $299. But will likely be USB firmware upgradeable, rear-port IR sensor, recording function, and the other obvious requests for the HDT-1 2nd Gen.

I would ask all of you, provided it is affordable to continue to support sales of the HDT-1 so that we can make the HDT-1 2nd gen a fact instead of a possibility.

And thank you all for your continued support.

Master Theseus, a question about the audio spectrum display mode: There are ten bands on the histogram; are those octave bands? What are the center frequencies of the bands? How is the y-axis scaled? I.e., if logarithmic, how many dB per segment?

Hm, good points. I think you are right, I should probably just buy an HDT-1 and enjoy it now, rather than wait for something that may never come, or may come later than I'd like. If/when the HDT-2 comes out I can evaluate whether I want to sell my HDT-1 to get the new model. OK I'm sold (I guess it doesn't take much to convince me to buy new electronics equipment; just gotta clear it with the wife ).

So far so good.It pulls in analog better than my old Luxman tuner. Getting drift on the station I bought it to listen to, WBGO 88.3, NPR Jazz out of Newark, but I could not even pick it up at all on the Luxman. The station does broadcast in HD as well. I purchased the Winegard PR-6010 antenna based on suggestions in this forum, and should receive Monday . Plan on putting it in my garage which has a 1 1/2 story high ceiling. I know I will lose some signal (abt 50 miles from station) by not putting it on roof, but no way I'm climbing up there. Got a price for a roof antenna with installation of $289. That's more than the tuner cost, so in the garage it goes, directly on the other side of the wall the tuner is on. I hope to get at least a clear analog signal to listen to, good HD would be even better.
What we JAZZ fans won't do to listen to our music. Unfortunately all the real good classic jazz stations are gone except for WBGO. 89.9, that broadcast jazz and classical music from Columbia University in New York, is another choice but it is weaker than WBGO and not in HD.
Off Topic, Dianna Krall was on WBGO last night on Marion McPartland's Piano Jazz program and they were a pure delight. Just got to get a clear signal now. Great music on this station.

Huh? I have no idea what you just asked and am not even slightly able to answer the question. I am a sales person after all. But I will send the question to factory and see if I can get a response.

Just ordered my HDT-1 today Unfortunately, the $25 rebate is gone. But newegg has a "combo" buy (at least, they do as of this posting) that gives you a choice of free audio cables or a surge protector for $5 extra. I opted for for the 2-meter cables (they are from "Best Deal Cables", which I've never heard of).

The tuner should be here at the end of next week, looking forward to it!

[/quote]Originally Posted by Picspop
Master Theseus, a question about the audio spectrum display mode: There are ten bands on the histogram; are those octave bands? What are the center frequencies of the bands? How is the y-axis scaled? I.e., if logarithmic, how many dB per segment?


Huh? I have no idea what you just asked and am not even slightly able to answer the question. I am a sales person after all. But I will send the question to factory and see if I can get a response.

Sorry for being obtuse. I'm referring to the display depicted in figure E on p. 14 of the user manual. That's what you get when you click the INFO button six times. The dancing bars indicate the sound level in each of ten frequency bands, I suppose, but the axes on the graph are not labelled. It would be interesting to know whether there is program content in an HD signal beyond the range (frequency or dynamic) of that same music played by that same station on the analog broadcast.

Listening to a violin concerto recently, I noted that the far right bar did not move when the violin played solo, even in the upper register. But when the full orchestra entered there was a jump in the far righthand bar. I was not aware of activity in the piccolo section, but at my age that might be my ears and not the technology. The display might also be used to indicate whether a station is feeding a less compressed audio signal to its HD channel, which would be a welcome reversal of conventional broadcast practice.

Not bad for an extra $25. Now, what about the upgrade program that lets us early adopters trade in our old, tired units for a brand spank'n new unit? (no harm in asking, right?)

Seriously, I am very impressed with the HDT-1. Today I picked up an $8 pair of rabbit hears from a Lowes Home Improvement store and tripled the number of HD stations! I live about 25 miles west of Boston, MA but can now pull in WGBH, WBOS, and several others in HD, even though the antenna is in the southwest corner of my house. Very impressive!

-- Dave

The HDT-1 sounds like a great product. I own several Sangean products and can attest to their excellent quality and engineering. My ATS-909 is a workhorse that gets daily use. Now if only Sangean would put HD-Radio into one of their portables! That is what I'm really waiting for.

I've had my HDT-1 for a little over a day now, and it is terrific. I receive 14 stations with the supplied FM dipole antenna, 13 of which have a multicast feed (I haven't heard a commercial on one of these extra stations yet). I live about 15 miles from Philly. One, 104.5 has a great nostaligia multicast feed. Plus, I can now listen to classical music 24 hours a day on 90.1. I don't find the display too bright (in home office, not bedroom), and I like the credit card sized remote on my desk. Though the feed is crystal clear, I'm not sure the digital quality quite matches analog - not the fault of the tuner but, perhaps, the nature of the digital feed (the same discussion when LP records were replaced by CD's). The bottom line is that this is a great product at a great price - something I've been waiting to buy for more than a year. There's no need to wait anymore.

TheOx

I picked one of these up and I'm mostly happy with it and it sounds good. My biggest complaint would be having to push the preset button before you can push the number. The buttons don't do anything otherwise so its seems pointless.

What would I need to go with the HDT? Both an amplifier and a preamplifier?

Dead of night wonders if he would need "both an amplifier and a preamplifier".

Don't forget the post-amplifier! (KIDDING!)

Okay, but what equipment would I need to set the HDT up?

Any old receiver with an open set of RCA analog inputs will work fine....

I'll be starting from scratch, my current home receiver is all tied up. So when I get the HDT, I'll either need an integrated amp, or an amp and preamp? I guess what I'm wondering is if the preamp is built into the tuner. Thanks. For $200, the HDT is the steal of the century.

You can go with: 1. A receiver, 2. An integrated Amp (have both pre+amp),
3. Pre-amp+Amp (seperates). Lets be nice here guys.

Thanks, red knight.

Your response was correct and to the point. The HDT-1 has no preamp. To be more specific, the receiver has a preamp, amp and tuner, the integraded amp has a preamp and amp and the separates have a preamp and power amp.
Richard

If you ran out of spare RCA jacks on your receiver or standalone amplifier and you do not want
purchase a second receiver or amplifier you could always purchase a simple A/V switch from a big box store. You could also plug it directly into amplified computer speakers. You do not want to plug it into any phono jacks. Phono jacks usually include equalization to match recordsand will hose up tuner freq response.

Thanks for the advice. I guess my main problem is that my stereo system components are literally stacked on top of each other right now. I'd hate to load one more component on there.

I'm thinking that maybe an Arcam integrated amp and the HDT would be pretty good.

After reviewing this thread, I ordered an HDT-1 on 1/6/7 from NewEgg - at that time, it was $180 delivered, so after the $25 rebate, I am in at $155. I figure my cost of being an early adapter and selling to upgrade to an HDT-2 will be relatively low. Now that I've used it a couple of weeks, I have delurked.

I have been using a Sumo Charlie tuner that was rebuilt by its designer about four years ago, and I also stream Internet stations via a Roku m500. These feed into a B&K Ref 30 preamp (the Roku via a digital connection), and I have a Parasound amp.

Overall, I am impressed. Selectivity is excellent, sensitivity is very good, sound quality is good to very good (and would be better if I could lock a conventional signal). HD is interesting; although it appears that a couple of Austin, TX stations listed on the HDradio website are not yet broadcasting HD signals. Unfortunately, two local stations have beautiful conventional signals but sound flat once the HD signal locks. From this forum, I understand that is more of a station issue, but it is annoying that I cannot lock the preset on the conventional signal.

I have the standard wish list for a future version, namely the ability to step the LCD backlight settings (I think the THX standard requires an ability to turn off such lights), the ability to lock a conventional signal, and one-step recall of a station memory (programming and direct frequency access would then require an initial key). It appears Master Theseus has me covered there. Those are the items I would expect for $225.

I would be willing to pay up to $349 for an HDT-2 if, in addition to the HDT-1+ features, it had a digital output (happy to see that will likely be on the HDT-1+), could stream Internet stations, and could be programmed, addressed and updated via its network IP address. The model here would be the RokuLabs method of streaming Internet radio (an m500 originally listed for $149, and a refurb at the RokuLabs website is currently $99, so an HDT-2 with the Internet radio features shoud be able to meet or beat the $349 pricepoint). I would not want it to require any computer software (beyond the browser -- special software is a dealkiller for me) or stream media from my computer (that is the Roku's primary job). Rather, I would want the HDT-2 to stream directly from my network (without a PC powered), and have a simple interface like the Roku to set and rearrange presets (including conventional radio presets) and program Internet stations that use the top three or four codecs. It would preferably have a way to send a username and password for stations that require it, which would enable satellite radio subscribers to stream those stations from the 'Net (optionally, the tuner could also periodically sync to a time server to avoid clock error issues). A standard network connection would be fine - if I did not have a convenient wired network connection, I could set up a bridge (that would need to be referenced in the user manual). Alternatively, a PCMCIA slot with an included conventional network card and the ability to substitute a separately-sold wireless card or a satellite-specific interface card could be employed, but that would probably drive up the cost beyond what I would be willing to pay, and the optional cards would probably not have enough sales volume to permit a reasonable price. The other upgrade on the HDT-2 would be additional memory - three banks of ten for the NET, three for FM and two for AM. I am not that interested in a recording function (unless it can be done in a manner that does not add much cost, such as writing an MP3 to a user-supplied memory, such as a thumbdrive, via a USB port), but the ability to program a few on time/preset/off time-sequences might be an interesting method to record to another component (my minidisc will trigger on input), and would have other uses as well.

Given that the included hardware can decode network codecs and that many radio stations stream both conventional and HD programming (and many shortwave stations also stream), including Internet streaming would result in a universal tuner (streaming, is, in a way, a spiritual successor to shortwave, so including it would be consistent with the Sangean brandname) that would give the HDT-2 a selling point beyond a conventional tuner to appeal to consumers outside of HDradio markets, and give the tuner a longer shelf life and wider appeal should HDradio not continue to penetrate the broadcasting market.

fastforward, congratulations on your delurkment! I live in Austin also and am interested in your comments and experience with the local stations. Which ones sound flat with the HD signals and which HD broadcasts have you noticed sound very good?
thanks,
Murray

[I've been e-mailing friends about the HDT-1 that arrived today and it occurred to me that I should be posting here. Below is the e-mail I sent a few hours ago. I will be doing a full technical review of the HDT-1 and posting it at my web site in a few days. All measurements mentioned here are preliminary and subject to further checking.]


My HDT-1 arrived a couple hours ago and I thought I'd pass along preliminary
impressions and measurements. I spent an hour and a half tuning around and
listening before I measured anything. I'm glad I did things in that order as
you'll see below.

I listened with a Stax SR-40 electret headset to eliminate room funnies, to put
my head in the exact stereo center, and to try to discern nuances, which I can
always hear better with headphones. I did a live A/B test with a level-matched
Sony ST-S555ES tuner, my standard. I fed both tuners through a 75-ohm power
splitter from by rotary HD6065P Yagi mostly pointed at L.A. and a fixed
vertically polarized FM-4G Yagi pointed at San Diego. All of the two or three
dozen FM tuners I've restored have sounded identical to me, despite much
searching for differences in sound, so the 555 is as good a standard as any.

I'm very impressed with the HDT-1 audio quality on both analog and digital. I
did not run many A/B analog comparisons with the 555, but I don't recall any
great differences. I do believe I heard some small ones and I'll return to
listen more. But the overall tonal balance sounded the same, remarkably so. From
reading the HDT-1 specs I wasn't expecting this.

In most cases I liked the HD Radio quality better than the analog. It usually
was brighter and it sometimes seemed crisper. It often had more separation,
sometimes so much that I thought it might be artifically enhanced. These kind of
differences could easily be due to the processing at the station. I heard no
digital artifacts on full-bandwidth digital signals. I did hear some artifacts
on a couple of multicast channels, but I didn't listen to these long. The
primary channel of multicast stations was surprisingly good. I don't think I
heard an artifact in that case, but I'll be listening more. I tried to listen
mostly to full 96 kbps single-channel nonmulticast digital signals to see what
the digital algorithm was capable of at its best.

There were sometimes level differences between analog and digital when the HDT-1
switched over. I had inserted a 50k pot in the line out to equalize levels with
the Sony ST-S555ES and this came in handy. Different stations required different
audio levels to match the Sony. I thought this was curious.

Sensitivity seemed fine, although I have few weak stations here, and the
selectivity was better than the Sony, which uses a pair of 250 GDTs in wide and
cascades a pair of 110s with them in narrow.

I did not like the sound of HD Radio on AM. The artifacts were immediately
obvious and funny. I would not listen to that kind of audio given a choice and
it is hard to believe anyone else would. I did not experiment much after hearing
what it sounded like, but I'll go back and listen more. This was a great
disappointment. The background noise did go away on digital. I can't remember if
the frequency response widened out, as it should have. I presume it did, but I
was so focused on the funny sound of the voices that I didn't pay attention. I
don't think I heard any music being transmitted on HD AM.

FM measurements. The 1-kHz mono distortion is around 0.08%. In stereo there are
many harmonics that extend well beyond what I see in an ordinary tuner. The
second was the largest and is around -50 dB. The third was at -60 dB. The rest
are lower and won't contribute much to THD, so I think it is about 0.33%, which
is what -50 and -60 yield. This is much higher than a good analog tuner in wide
IF mode. It is typical of an analog tuner in narrow mode, or maybe somewhat
lower (I often see 0.7% with a pair of 110s). I was completely unaware of any
distortion when listening to analog signals. This is why I'm glad I listened
first and didn't bias myself with measurements.

Now the really odd thing. The 1-kHz stereo separation measured 45 dB at high
signal levels. As I dropped the signal from the 73-dBf level where I normally
measure distortion, the channels started blending at 53 dBf. By 49 dBf there was
only 10 dB of separation left. This is a very high level for blend to occur.
Most tuners still have 50 dB of stereo quieting around 36-40 dBf. The S/N when
blend began was somewhere in the mid-60s, unnecessarily high I think.

So I couldn't really measure stereo sensitivity in the normal way because the
tuner had blended stereo away by the time 50 dB S/N was approached.

Now for mono. At low levels the tuner starts dropping the audio level. The
literal 50-dB mono quieting point is at 13.6 dBf. This would make it the most
sensitive tuner I've ever measured. But a 1-kHz tone is down 10 dB at that RF
level. The tone is down 3 dB at 17.6 dBf and down 5 dB at 16.6 dBf. The level
drops in steps, not continuously. The software is deciding that things are
getting bad and is doing a stepped mute. I don't think it ever cuts off the
audio completely.

So I'm not sure what to consider the 50-dB quieting sensitivity. If you're
willing to turn up the audio gain 10 dB then it is 13.6 dBf, a spectacular
figure. On the other hand, if you limit yourself to a 3-dB drop in signal level,
then the sensitivity is 17.6 dBf (not a bad figure in itself). At the 5-dB drop
point, 16.6 dBf, the S/N was 56 dB, not that far from the 50-dB standard. I'll
be going back and doing this again to see what else I can find. There may be
other things going on.

The adjacent channel selectivity is as spectacular as Bob reported. I got 63.5
dB and the upper and lower numbers differed only by 1 dB. Unlike anything I've
ever experienced, the interference once it began was not 1 kHz and a raft of
harmonics. It was all noise. I presume this means that the selectivity is
limited by phase noise, not a leaking signal, although it's not clear to me how
this occurs.

OK. I'm so fascinated by this device that I can't stand not playing with it
more, so back on the antenna it goes for more tuning around.


[Here is the second e-mail I just sent.]


Here are the deemphasis errors I measured on the HDT-1. Input was a 73-dBf mono
signal through the aux connector of the ST-1000A (very flat). I used a constant
audio level and my deemphasis utility to record the HDT-1 response and calculate
the errors.

Freq Error dB
1000 +0.0
2000 -0.2
3000 +0.9
4000 +1.4
5000 +1.6
6000 +1.7
7000 +1.9
8000 +2.1
9000 +1.9
10000 +1.4
11000 +1.0
12000 +0.6
13000 +0.4
14000 +0.2
15000 -0.5


The rise from 4000-10000 is quite large, the worst I've ever seen. I made this
test after thinking I was hearing a difference at high frequencies when
comparing the analog signal with my reference tuner.

I'm going to report this to Sangean as there's really no excuse for such a large
error, especially since the deemphasis is done in software.

I finally heard coding artifacts at 96 kbps on a female speaker. I was busy with
something else and didn't linger, but there were definitely some funnies.
Nothing like those on AM though.

I also heard some gross transcoding errors. I noticed telltale digital
artifacts, checked my preamp, and I was listening to the Sony tuner! It was the
digitally encoded voice of a foreign correspondent. When I switched to the
HDT-1, it was much worse. Don't transcode if you can help it is the rule.


Brian

I have the same Stax earspeakers (headphones), purchased in 1978, replaced the elements in the mid 1980's due to distortion issues, perhaps brought on by cranking up the volume too high. Thanks for the detailed observations Brian, nice work.

I took an inexpensive way out of streaming mp3 collections and internet radio sites to my sound system, using a Linex USB connected FM transmitter, designed by a Canadian company, seems to use Onkyo drivers. I've been comparing the output of this device as heard on the HDT-1, the Sangean ATS-803A stereo FM/AW/SW, a pair of Boston Acoustics Receptor clock radios, and whatever else I have around the house. The jury is still out on these tests with the ATS-803A providing the best results, the HDT-1 having alot of high background hiss on quiet passages, and the Receptors in mono only mode attached to the same outdoor antenna as the HDT-1 completely silent during quiet passages. The LineX unit seems to provide a 150 foot radius signal. Still trying to figure out why the HDT-1 has so much white noise in the background with this toy.

Steve
73 de N2UBP

Here are several more observations about the HDT-1.

HD mode is not always brighter than analog mode as I first thought. This varies considerably with the station. I suspect it depends on the transmit processing.

One station, KPBS in San Diego, had considerably less dynamic range in HD than analog. Weak classical passages were really boosted in level on HD. It really should be the other way around.

I did a brief check of the spectral bars. They are centered very approximately at 57, 77, 122, 263, 528, 1055, 2070, 4180, 8370, and 15450 Hz. Each bar is 4 or 5 dB, but I didn't check closely.

The bit error rate is always somewhere around 0.1. This can't be the actual error rate (1 bit bad in 10). It doesn't vary once HD is running. This display needs work.

The carrier to noise ratio display varies continuously and is very useful for antenna aiming.

Once you hit HD seek, all buttons are locked out until an HD signal is found. This is really annoying.

I ran several tests involving co-channel interference. It completely disappears in HD mode as you would expect. This can really silence a noisy background and so far, is the biggest benefit of HD for me. It should work the same for multipath although I haven't run into any today.

In one test the HDT-1 seemed to suppress co-channel interference for an analog station better than my Sony ST-S555ES, trying both wide and narrow filters in the 555. I don't know why this should occur.

If you unplug the unit, the clock resets but the station memories are retained. For how long I don't know.

After several hours of listening I finally tried speakers. No surprises, same results as headphones.

I tried listening for AM stereo stations but couldn't find any. I wonder if that feature has been removed. I have version 1.2F.

Brian

Thanks Murray. I am in the West Lake Hills area of Austin, so I should get good reception for Austin. For those not familiar with the area, my house is about 3-1/2 miles west of, and 160' higher in elevation than, downtown Austin. Several radio towers are within 2.75 miles NNW at a point that is about 180' higher in elevation. From the NE corner of the house, I can see both the Texas State Capitol and radio aerials.

The Emmis stations (KGSR, KROX) are not sending HD signals yet (or at least I am not receiving HD from those stations). I've always had problems with the reception of KGSR 107.1, and have resorted to streaming it at times, but the Sangean picks it up without much effort (albeit the SSI is a few points lower than other stations). Most of the HD signals in the area are good. KUT (which also streams) has one of the best sounding HDradio broadcasts in the area, and primarily broadcasts the BBC on its second band (on Friday, I left my stereo powered while I ran a few errands; when I walked into the house later, I was a bit disconcerted by a clock chime, and could not figure out where it was sourced, as I don't have a clock that chimes -- then I realized it was Big Ben via the BBC). The worst HDradio signal at this time, at least at my location, is KVET 98.1 -- the broadcast signal sounds great, and when HD kicks in its muddled, like someone put boxes over my speakers. Frustrating, given that the conventional broadcast sounds great, even though I hardly ever listen to that station.

I made some measurements of the HDT-1 AM performance this morning. I thought the results were quite interesting.

First of all, when tuning around before sunrise on weak skywave signals I noticed that a tone would appear and then drop in frequency as the audio unmuted. This never occurred for strong signals but was quite common on weak ones. It sounded like the HDT-1 was phase-locking to the AM carrier and doing synchronous detection.

I checked 1-kHz AM distortion. I got 0.6% at 90% modulation (signal generator distortion 0.3%) and 0.4% at 30% modulation (signal generator 0.1%). These numbers aren't bad for an AM detector. I never heard anything that I thought was waveform distortion.

The frequency response was more interesting. The bass does have a rather high cutoff as Bob reported. I measured -3 dB at 215 Hz using the 1-kHz response as a reference. It was down 6 dB at 130 Hz, 10 dB at 72 Hz, and 12 dB at 55 Hz. Seems like a single-pole rolloff.

Listening to several analog AM signals, I wasn't aware of the bass rolloff, which surprised me. There is an old rule from the vacuum tube days that the product of the bass and treble cutoffs in Hz for a radio should be around 500,000. Supposedly this preserves tonal balance. The idea is that if you don't have extended treble response you should roll of the low end so the audio doesn't sound bassy. The HDT-1 seems to do this. Its cutoff product is 564,375.

The treble response is down 3 dB at 2625 Hz, but what's interesting is the rolloff. The tuner pretty accurately follows the suggested NRSC AM deemphasis curve, which is a 75-us pole and a zero at 8700 Hz (so-called modified 75 us). Here are the errors I measured from NRSC AM deemphasis:

Freq Error dB
1000 +0.0
2000 +0.1
3000 -0.5
4000 -2.1
5000 -3.7
6000 -6.0

This is the closest NRSC response I've ever measured. Ordinary tuners and radios typically start to cave in below 3000 Hz.

The tuner has an impressive brick-wall filter somewhere around 5800-6500 Hz. Response drops suddenly there. The edge of the filter moves around in little steps that you can see as you vary the modulation frequency. Apparently the tuner adaptively widens the passband somewhat if it thinks what's out there isn't interference from the adjacent channel. I will hook up two signal generators and check this out a bit more. When tuning around before dawn, I was very impressed with the selectivity. I could easily pick up weak skywave signals next to strong local ones without any sideband splatter.

After the sun rose and the local stations turned on their HD, I was able to find a few voices that didn't sound so funny when digitized. The algorithm seems to be quite sensitive to the particular voice. The frequency response noticeably widens, both on the bottom and top ends, when HD kicks in.

Brian

I forgot to mention that I scanned the AM band before dawn for AM stereo signals but found none. I checked out two strong Radio Disney stations, both of which I believe run AM stereo, but only mono appeared. I suspect this feature has been removed from my version 1.2F box.

Brian