No more analog FM in Norway?

[Osvaldo de Banfield]

But it can, I've demonstrated myself this.

 

[nigel pearson]

AM was never 'almost hi-fi', although it was better than it is today.

Maybe LP also is not really hi fi if the cumulative specification is looked at, nor a Revox tape deck as typically used. I think AM at it's best as reported to me was about 2% THD and 50 dB signal to noise ratio. This would not be the standard AM. I was told this service was to be used in the USA and Austrailia to cover large areas. If I understood correctly 0 to 30 Hz on each sideband was to provide a centre location for the system to lock onto.

Some very good radios on AM could sound more like real music than a typical DAB. What I mean is a feeling something live is happening. Even my awful bathroom FM radio can do this now that small improvements have been made.

My feeling it given limited bit rate could something more modest in bandwidth and dymanic range sound more like live music? 78 do so why not DAB.

 

[DF96]

AM is not really comparable to LP or tape.

I am not saying that AM as a modulation method is not capable of reasonably high sound quality, but that AM as usually implemented in broadcast transmitters and receivers never approached hi-fi levels of quality. DAB, of course, can sound worse than AM because the distortions introduced by DAB can be aurally more annoying than the weaknesses of AM.

 

[scottjoplin]

I seem to recall reading somewhere that some of the UK lower bit rate stations have little output above around 11-12kHz.

Sadly not a big issue for me these days

 

[nigel pearson]

Sometimes when not perfect it's best to debate what can be done. Curry poweder added if you like. My simple observaton is both good AM and FM radios can sound live. Often our Radio 4 on Womans Hour ( the radio is on all day so Womans Hour it is ) will have a live music performance which can often sound better than something they spent money doing. Although hard to define this if a form of " high fidelity " which mysteriously most DAB doesn't have. If I was controller of the BBC I would have a DAB in my room and monitor all broadcasts. I would insist my technical people contrive a good sound with what we have as a system. I would buy them a valve AM/FM radio ( Seimens ) and say get it to sound as good as that.

My friend Neil broke his girlfriends wartime radio. He found an indentical one in a junk shop. Turns out it wasn't identical and also broken. So we built a special out of the two. At first it had problems so we redesigned the output stage and removed what seemed like too much bass filtering. It boomed so we damped the insides. Suddenly it sounded very real. Best of all was a 78 being played on Radio 3 of a lady cellist with Nightingale singing in a garden whilst she played. Rushing to the FM radio it wasn't quite as good. As my friend said it was a complete system, exactly as it would have been in 1942. The speaker cone was repaired with PVA wood glue and Rizla paper. It seems this repair is better than the original. My bathroom radio has these two mods. If sounded like a singing yoghurt pot before.

Maybe what we got wrong when calling things hi fi is we balanced two equally wrong concepts and picked the easy one as our touch stone ( THD this, Wow and flutter that, we rejected music as being too abstract ). Can you imagine if hi fi was only judged by musicains and what we talk of here was of no use except to a technician to make a repair. As daft as defining petrol quality when filling the tank to the garage man.

 

[scottjoplin]

will have a live music performance which can often sound better than something they spent money doing.

Because it hasn't been processed within an inch of it's life. I love 50's jazz recordings for this very reason. They had the technology for high quality recording and hadn't yet learned how to muck up the sound properly

 

[mckaymckaymckay]

Remember now days the radio stations need to cater for all possibilities of reproduction (namely car radios and such). The processing involved makes sure its sounds reasonable on even the most crappy equipment. This is similar i believe to the loudness wars of late.

 

[DF96]

Maybe what we got wrong when calling things hi fi is we balanced two equally wrong concepts and picked the easy one as our touch stone ( THD this, Wow and flutter that, we rejected music as being too abstract ).

The only meaningful test for hi-fi is "does it sound like the real thing?" This test is best performed by having the real thing handy so people can do a comparison between the real thing and the reproduced thing, without having to remember for more than a few minutes what the real thing sounded like. Rather surprisingly (to some people) it was the boring engineering parameters which determined whether the reproduction sounded like the real thing.

For DAB it is known that only 256kb/s sounds like the real thing. 192kb/s sounds somewhat degraded. 128kb/s sounds annoying (IIRC). These are the results found in the original tests for MP2 coding when DAB was being developed. So we know have a radio system with most music stations having a bit rate which is known to be subjectively annoying. Note that MP2 sounds as good as MP3 (or perhaps slightly better?) at the highest bit rates, but at lower bit rates MP2 sound quality collapses quicker than MP3.

 

[jgazal]

The only meaningful test for hi-fi is "does it sound like the real thing?" This test is best performed by having the real thing handy so people can do a comparison between the real thing and the reproduced thing, without having to remember for more than a few minutes what the real thing sounded like. Rather surprisingly (to some people) it was the boring engineering parameters which determined whether the reproduction sounded like the real thing.

Off topic, but IMHO, lossy codecs are a tiny part of the chain accuracy. I hope lossy codecs in digital radio can preserve ILD and ITD cues.

Originally Posted by castleofargh

of course then the only valid reference would be something like the sound recorded from mics in your own ears at the studio while the band was playing.

something that doesn't exist so it begs the question, is it even worth considering such a reference?

while many audiophiles somehow dream of a playback system that would output the reference you're talking about, it's a fact that recording professionals in their vast majority do not care about that and prioritize other matters.

for example most will record instruments in mono, and when using several mics, it's usually to be able to mix them in a pleasant way.

not to reproduce a 3D position.

aside from binaural stuff and a few specific methods that are a niche market, the "soundstage" is made up in post processing.

(...)

as the headphone bypasses part of the acoustic impact of my body that is included in 100% of my real life experience of sounds, I wish to have that impact added back to the headphone's sound. (and it's easier said than done, which is why I can't wait to fool around with the Smyth realiser for that exact purpose).

Does not exist, but can we listen to something that was recorded with cues close enough to achieve a fair horizontal spatial effect?

13 Is the 3D realism of BACCH™ 3D Sound the same with all types of stereo recordings?

The stereophonic recording technique that is most accurate at spatially representing an acoustic sound field is, incontestably, the so-called “binaural” recording method 15, which uses a dummy head with high-quality microphone in its ears 16. Until the recent advent of BACCH™ 3D Sound, the only way for an audiophile to experience the spectacular 3D realism of binaural audio was through headphones. Many such recordings exist commercially, and more have recently been made thanks to the iPod revolution.

BACCH™ 3D Sound shines at reproducing binaural recordings through two loudspeakers and gives an uncannily accurate 3D reproduction that is far more stable and realistic than that obtained by playing binaural recordings through headphones 17.

All other stereophonic recordings fall on a spectrum ranging from recordings that highly preserve natural ILD and ITD cues (these include most well-made recordings of “acoustic music” such as most classical and jazz music recordings) to recordings that contain artificially constructed sounds with extreme and unnatural ILD and ITD cues (such as the pan-potted sounds on recordings from the early days of stereo).

For stereo recordings that are at or near the first end of this spectrum, BACCH™ 3D Sound offers the same uncanny 3D realism as for binaural recordings 18.

At the other end of the spectrum, the sound image would be an artificial one and the presence of extreme ILD and ITD values would, not surprisingly, lead to often spectacular sound images perceived to be located in extreme right or left stage, very near the ears of the listener or even sometimes inside of his head (whereas with standard stereo the same extreme recording would yield a mostly flat image restricted to a portion of the vertical plane between the two loudspeakers).

Many of well-made popular music recordings over the past two decades have been recorded and mastered by engineers who understand natural sound localization and construct mostly natural-like stereo images, albeit artificially, using realistic ILD and ITD values. Such recordings would give a rich and highly enjoyable 3D soundstage when reproduced through BACCH™ 3D Sound.

________

15 The accuracy is due to the fact that binaural audio preserves not only the correct ILD and ITD cues discussed in Q&A10, but also contains so-called “spectral cues,” which are the effects the torso, head and ears have on the frequency response and which the brain uses, in addition to ILD and ITD cues, to locate sound, especially at higher frequencies.

16 The spatial accuracy of dummy head recording is only surpassed by recordings made with microphones placed in the listener’s own ears - alas, a rare commodity that would have benefits upon playback for only that listener.

17 This is because binaural playback through headphones or earphones is very prone to head internalization of sound (which means that the sound is perceived to be inside the head) and requires, in order to avoid this problem, an excellent match between the geometric features of the head of the listener and those of the dummy head with which the recording was made (this problem has been recently surmounted by the Smyth headphones technology smyth Realiser A16). Pure Stereo does not suffer from this problem as the sound is played back though loudspeakers far from the listener’s ears.

18 The 3D realism is the same although the ability of reproducing a sound source at a location that accurately corresponds to the original location is relatively decreased due to the absence of spectral cues.

https://www.princeton.edu/3D3A/

Originally Posted by JimL11

Well, there's a number of things you have to understand before I give an answer.

First, I am used to hearing live sound as I played the violin and piano as a kid, played in a children's orchestra, and restarted the piano again about 4 years ago. Live sound in my experience varies - a lot. Further, I do not consider myself a critical listener, and I am not a connoisseur of small differences. Generally speaking when someone points out a difference to me I can hear it, but it's usually not a big deal to me. In other words, I probably tolerate (ignore?) small differences in sound more than many (most?) audiophiles, and don't really differentiate readily between pieces of equipment.

I am not a bass freak, a detail freak, and don't give a damn about sound staging. The ONLY time in over 35 years of listening to hi fi systems I have ever had a "way ahead in sound quality" experience was the first time I heard Quad electrostatics, which I have owned since the 1980s.

BTW my first headphones were Stax SR-5s, which I still have. I have heard TOTL speakers like the Infinity IRS, Apogees, Musicos and Avant Gardes, among others, and none of them impressed me over the Quads the way the Quads impressed me over anything I had heard before.

More bass, more highs, louder, yes. Better, as in, more like live music? Meh.

Frankly I think there is a lot of hype in high end audio (or as someone called it, hind end audio), and reviewers make a living exaggerating differences.

Here's the thing - Quads were introduced in 1955, cost around $1800/pair when they were discontinued, and when they are demonstrated at Hi Fi shows in the 2010s, they still make top ten best sounding room lists. That says a lot about diminishing returns.

In my experience, nobody has broken the law of diminishing returns in audio, and nobody has ever produced a system that sounds like the real thing.

Especially true for headphones, since nobody has heard a real live orchestra in their head, or even around their head - no, sitting in an orchestra is NOTHING like listening to one on headphones. My definition of, "way ahead in sound quality" means that I can notice a difference in the first minute, without straining to hear a difference or stopping to analyze it, and that has only happened to me once, so you probably see where this is going.

One weird effect of the HE-1s was that for whatever reason the soloist on one piece of music I tried was located toward the back of my head, which I have not heard with any other headphone. Since nobody else has noticed this presumably it was unique to me or the way I was wearing the headphones.

That seems binaural recording with a microphone that does not match your HRTF and playback transducers angled in a way in which the externalisation is perceived at the back of the listener head.

Before my question, please consider these quotes about a dsp engine:

Originally Posted by arnaud

In regards to prirs for ceiling channels, I have something in mind.

What I realized is that, once back home, the only set I liked was the AIX one, because all the others sounded like weird echo / the reverb was intrusive.

So for me at least, even though the standards are such that you should have some reverb / avoid direct field from the surround channels in regular setup, I actually seem to prefer PRIRs taken in rather dry room (so I need the personalized xfeed but not so much the acoustic imprint of the room).

So to my idea: am wondering if it would make sense to get my own "PRIRs" (more like hrtfs) with the speaker rather close and stuffing the room walls to attenuate reflections as much as possible so that direct field dominates.

Then, I'd "simply" rotate the head to get the various headings, including elevation channels. The angle might not be accurate but, as long as the head is steady during the recording, it would be fine perhaps.

Cheers,
Arnaud

Originally Posted by Erik Garci

It's already possible to make a PRIR without crosstalk. You don't have to use Ambiophonics or BACCH. The quotes below explain how I did it. Since then I have added an A/B switch for the microphones.

Originally Posted by Erik Garci

I recently created a PRIR for stereo sources that simulates perfect crosstalk cancelation. To create it, I measured just the center speaker, and fed both the left and right channel to that speaker, but the left ear only hears the left channel because I muted the mic for the right ear when it played the sweep tones for the left channel, and the right ear only hears the right channel because I muted the mic for the left ear when it played the sweep tones for the right channel. The result is a 180-degree sound field (...).

Binaural recordings sound amazing with this PRIR and head tracking.

Originally Posted by Erik Garci

To mute it I unplug the left or right microphone from the Y-junction between sweeps. I set the "post silence" to 8 seconds beforehand to give me enough time. To make it easier I plan to hook up an A/B switch.

I actually got the idea from a comment by Timothy Link in this Stereophile article about Dr. Choueiri's BACCH.
The Bacch-SP 3D Sound Experience | Stereophile.com

(...)
The group of five faders on the bottom right are a new feature to the Realiser.

These sliders allow the listener to alter the reverberation characteristics of the virtual room in the frequency domain, much like a 5 band graphic equalizer except it is decay time that is altered rather than gain.

This feature has the ability to dramatically improve the quality of any mediocre sound room particularly in the low frequency regions.

(...)

We have added a second HPEQ filter option that uses a causal filter structure that has the potential to generate a cleaner headphone impulse response than our traditional symmetrical FIR approach.

http://smyth-research.com/downloads/additional_KS_info.pdf

@arnaud, @castleofargh, @JimL11 and @rrod: do you believe that such dsp engine (with convolution of a PRIR measured in a more and less dead room, no added acoustic - or virtual - crosstalk, decay room equalisation - in time domain -, causal headphone equalisation and tactile transducers, as described in the quotes above) can minimise the filtering effects that we are used to hear from the rest of the chain (mainly from playback room, playback amplifiers and playback transducers) compared to the current standard?

Please consider the spatial accuracy only in the horizontal plane (disregard then spectral cues). I did asked about the comparison between binaural and a third order ambisonics using such DSP engine, but apparently no one in head-fi except the creator has listened both.

head-fi - accuracy is subjective - post 14

Now not so offtopic, I also found a more down to earth HD radio, the Sangean HDT-20.

But I do not know if it used the same NXP TEF6730/SAF7730, which seems to have the same performance of the Accuphase method (see Sony XDR-F1HD).

Does anyone know what is the Sangean front end chipsets?

Anyway, since this is diyaudio, anyone would like to desing a bareboard with NXP front end, digital output and options to force analog radio and avoid blend of stereo?