HOme Audio - Old School vs What ever the hell they think that STULL is...

Factual Questions
21

You made a nice case for doing the best with what you got but that can only be the sum of all parts. You cannot equalize a mediocre speaker to the clarity of a high end speaker or amplifier. It does sound like it gives the user the best bang for the buck.

sound equipment has always been a monetary french curve of quality received. The new systems that can electronically correct for shortcomings and room acoustics is pretty cool. Not the end-all for the music purist but better than what we had to work with in the 70’s and 80’s.

22

Depends upon what you mean by spherical. Also depends upon what you mean by ultimate.

A pure omnidirectional speaker has pros and cons. When you put a speaker in a domestic room your biggest problem is the effect of reflections off the walls. Managing these to create a satisfactory illusion of sound isn’t trivial (and is why so often careless placement of speakers ends up with poor results.) Humans hear over the range 20Hz to 20kHz. That means wavelengths from 17metres down to 1.7cm. That is a huge range, and a range which encompasses just about every wretched effect possible with sound. Low frequencies are already so long that any radiator is omnidirectional. This is why you can place a subwoofer almost anywhere in a room (so long as it is well designed and doesn’t create higher harmonics that you can localise). At the other end of the range you get directional emission and all sorts of nasty interference and diffraction effects that make any semblance of even frequency response fanciful.

However the human ear has a few tricks up its sleeve, and splitting consideration of the direct (unreflected) sound from the diffuse (reflected around the room) sound makes sense - as the ear actually does this. Making both the direct and diffuse sound fields flat is important, but the most critical is the direct.

To cut a long story short, there is value in an omnidirectional radiator, but the room needs to be sympathetic to it. In the enthusiast community Sigfreid Linkwitz’s Pluto is a very affordable and well regarded approximation to an omnidirection speaker. But you might note that it isn’t a sphere. Because of the wavelengths involved it gets away with this for the most part.

There have been speakers designed that are nothing more than a sphere covered with small drivers. However you spend a lot of drivers, and you always have to ask the question whether this was a cost effective way spending your money, versus perhaps fewer and higher quality (lower distortion, better frequency response etc) drivers.

At the very expensive end of town you have drivers That do attempt to aproximate omni sources. The MBL is probably the closest. You will need to sell the house and children. Cabasse make an interesting and very expensive driver that tries to work as a point source.

23

Speaker, yes. Amplifier, no.

I’ve heard far too many expensive, high-end speakers that sounded mediocre, and a shocking number of cheap speakers that sounded great. Radio Shack Minimus 7 is a wonderful example of the latter. A dark secret of the audio industry is how few actual raw speaker driver makers there are, and the engineering behind putting a speaker system together is really not that complex. It makes for a product that is well suited for the tinkerer type of company.

As for amps, I’m in the camp that assuming that all specs are equal, there is no audible difference between two amplifiers. I doubt that anyone could reliably distinguish between two amplifiers, one costing several as much as the other when tested through an A/B/X comparator. Again, this is assuming the specs were the same, and levels were perfectly matched.

I don’t know of any tests at the amplifier level, but I’m very fond of this article from Mix where they took SuperAudio CDs and ran the high bit-rate audio through one side of the A/B/X comparator, and processed the high bit-rate audio through a CD recorder, limiting it to 16-bit, 44.1k. The listener would hit a button that would randomly either switch from one to the other or not switch. They could do this as many times as they wished. Neither the listener or the tester knew what had happened until the end of the test.

From the article:

[QUOTE=Mix magazine]
The number of times out of 554 that the listeners correctly identified which system was which was 276, or 49.82 percent — exactly the same thing that would have happened if they had based their responses on flipping a coin. Audiophiles and working engineers did slightly better, or 52.7-percent correct, while those who could hear above 15 kHz actually did worse, or 45.3 percent. Women, who were involved in less than 10 percent of the trials, did relatively poorly, getting just 37.5-percent right.
[/QUOTE]

One of my other favorite articles is this one by Ethan Weiner. What’s so enjoyable about it is that it shows how someone could hear a difference between two cables. They hear a difference, but not for the reason they believe.

His point is that you should spend the money on room acoustics, rather than upgrading your amplifier. He may be accused of bias because he sells room acoustic products, but it was the research that led him into making acoustic products.

24

There is a long history about amplifier comparisons. One of the standing challenges was from Bob Carver who threw down the challenge that no-one could tell any amplifier from another once he had been allowed to compensate out any intrinsic frequency response anomalies.

The Boston Audio Society’s SACD test is interesting, and caused a lot of controversy. (Note that getting 37% wrong is potentially a significant result - for something.) Personally I agree that it mostly proved what we already knew, that the ear can’t hear better than 20kHz and that 96db of dynamic range is fine. What is also true however is that the CD format is right at the edge, and you need some room around this when recording and mixing. But the last step - creating the CD master, with appropriate dither, yields a result that betters any ear. What actually caused a lot of anguish in the test was the apparent quality of the device used for the conversion - which wasn’t highly regarded at all, and many expect to sonically colour the result - possibly in a manner that made any positive test result null. But getting a negative result showed that the mediocre quality converter was transparent as well. (However there are technical reasons as to why the converter was working with the best of all possible circumstances in its favour.)

Ethan is an interesting guy. His “believe” essay is a favourite with many. His selling room treatments, does leave him a little bit tainted by commercial self interest, however I happen to agree with him about the importance, and generally think he is a sincere and honourable guy. He does however get a little strident about his beliefs in the lack of importance of high end recording gear, some of which is evidenced by a lack of technical appreciation of why a lot of gear is intrinsically complex and has to operate in less than ideal circumstances. He does like the stir the pot.

25

Bob fan here. My main speakers at home in Chicago are his “The Amazing” (first generation). In my defense, I was working at the AV store at the time, and bought them used for $300 for the pair.

And if it was such a shitty converter, it should have been glaringly obvious.

I agree. Give me more bits and a higher sampling frequency on my multitrack - why not, as media is cheap.

As I said, he shows how people of good intention can fool themselves. And I’m in agreement that the basic level of quality available to us is amazingly high. Of course I’m possibly tainted by my lack of money to buy the more expensive stuff.

26

I’m not sure I get the 16 bit 44.k. Are you saying someone couldn’t tell a 44 kbps bit rate from the original CD? That would be hard to believe. I rip cd’s at 128 kbps for car use and willingly give up any loss but I can hear it clearly. The inaccuracies are (IMO) added noise and not loss of signal.

It’s been 20 years since I went shopping for home equipment. All I had to go on were my ears and a handful of carefully chosen CD’s. Money didn’t seem to be the qualifier unless massive amounts were involved. I really focused on instruments I could relate to unamplified (guitar, piano, drums, wind instruments etc…). I also focused on the size of the “sweet spot”. It’s hard to find a speaker I really like. Wasn’t too impressed with the brand I ended up buying but I liked this one particular speaker.

so what do you get in sound quality between the different priced Yamaha’s now if they all have ability to adjust for room acoustics

27

Sorry for not making it clear. The format of an audio CD is 16-bit PCM encoding at a 44.1 kHz sampling rate. That is the original CD. The MPEG encoding standards for MP3 are entirely different, and the numbers are not directly comparable.

Which is exactly as it should be. I’m not saying all speakers are equal, but that mediocre speakers today are better than mediocre speakers of the 90s, and much better than the mediocre speakers of the 80s. There were good designs back then, but finding one was much more difficult.

The receiver compensates for variations in distance and level, and matching the level of the subwoofer to the main speakers. Nothing is done about compensating for a bad room, only for poor placement and adjustment. The main purpose is to improve the surround-sound experience. Too many people would set their rear speaker levels too high because they didn’t hear them during dialog scenes of movies. It’s the same ignorance that lead them to stretch 4:3 material on their 16:9 TV because they wanted to “fill the screen”.

The difference is that speaker designers of today have acoustic modeling software on their computers to design cabinets optimally, have measurement equipment that will enable them to ensure that the prototypes perform as expected and more tools to figure out why not.

And they have to. Few stores have good demo rooms any more, and honestly, few consumers or sales people have the knowledge to benefit from one. The set of speakers and a well-matched receiver and sub-woofer in a decent Home Theater in a Box will give a more reliable and consistent result than any number of hours spent with a sales person in a demo room. The best you can expect is that they will have come up with some combinations that seem to work well together, without the test gear the engineers used in assembling the HTIAB package.

28

This was comparing a SACD - which is sampled at 2.8MHz (albeit only one bit wide) and has a bandwidth of 50kHz, with CD, which is sampled at 44.1kHz (and thus about 20khz wide) and 16 bits wide. The test compared the original SACD music stream with a real time converted stream that was sampled at 44.1/16 and converted straight back - thus yielding CD quality. ieother are compressed formats, so there isn’t a mp3 bitrate equivalent.

Those audiophiles that claimed that SACD was intrinsically audibly better than CD were not happy.

Compensating for room acoustics is actually a bit of a problem at the best of times. You can prove trivially that it isn’t actually possible. You can however ameliorate some issues, and make things better than they were. There are a number of competing room correction systems, and they come in various levels of ability, partly depending upon how much DSP horespower you have to throw at the problem, but also as a way of getting more money for better systems. With home receivers you get better amplification, which can mean more powerful, and better other specs, more complex room correction systems, and nowadays, more image processing capability, with better upscaling, motion artefact, and jaggy artefact processing capability as you go up the price scale.

Ninga’d by gaffa but I do add a few additonal bits.

29

To add about room correction. I mentioned earlier that problem with the diffuse field. Within a restricted, but useful frequency range it is possible to perform some correction for room acoustics. The biggest benefit is in the bass, where it is possible to correct for room loading effects on the subwoofer, and remove wild peaks and troughs in the room’s response. As the frequency rises it becomes less and less useful. To really get the bass right requires more than one subwoofer and careful placement of them, with appropriate delay and phase tweaks. Some very high end receivers provide this capability for two subwoofers, bespoke correction systems can handle many subwoofers, and provide almost perfect bass throughout a room. Once the wavelength of sound becomes small relative to the room size, any sort of compensation for the room’s effects is intrinsically impossible. So you can do useful things up to a few hundred Hz, but no more. After that you are back to speaker placement and room acoustics.

As gaffa notes, compensation for the distance a speaker is from the listener is important. Typically a delay is added to the rear speakers sound so that the sound arriving at the listener is aligned with the sound from the front speakers (which are typically further away.) This is crucial to maintain an illusion of immersion in the sound. The ear brain will always latch onto the first heard component of a sound (within 10ms) and if it hears the rear channel first it will wreak the sound localisation illusion.

30

Holy cow, I’ve never even heard of SACD. Man I’m getting old. Sure wouldn’t take any challenge against a CD.

31

SACD and DVD-Audio were the last effort to produce an improved disc standard. They both essentially died for several reasons:

[ol]
[li]There were two competing systems. Beta vs. VHS all over again.[/li][li]As the test showed, the difference was not audible to the public.[/li][li]The one area where both were truly superior never caught on.[/li][/ol]

#3 was surround sound. It’s amazing, and with a well set-up system a compelling reason to upgrade. But too few albums ever came out to develop a good head of steam. Artists waited to see if it would catch on. That, and the public was moving in the opposite direction towards compressed formats that you could listen to on headphones.

I love surround sound, and have a small collection of titles. But the way we used to listen to music seems to be a thing of the past. Teens don’t believe me, but we actually used to invite friends over to listen to albums, instead of everyone listening to the same album on their own headphones at their own home.

It’s official. I’m an old fart.

32

The idea of everyone listening to an album together is strange to me. Unless you’re dancing, you’re just…sitting there, I don’t get to see my friends enough so we’re either talking or playing games or watching a fight or something. I’m not knocking it, just a different way of looking at music. Also, none of my friends like my music.

When you would listen to albums were you talking over it or just sitting there stoned?

33

If you had a reasonable home theatre setup, would you invite friends over to watch a movie? Music was similar, but more important. This was when much music was really new. It wasn’t background, it was life. Also disposable incomes were much more restricted. A new LP cost a significant amount of money relative to income. This was the birth of home taping. There was no internet, but there was FM radio and friends.

Nowadays I subscribe to the local symphony orchestra, you can’t get better sound than the real thing, and they have a very intelligent programme of music that always includes new works as well as the cream of the old. Sadly most people really don’t care much for innovative or really good music. But enough do to keep the art alive.

34

…still using the Harmon/Kardon PM640 amp I bought for $230 (which I earned at my $3.45/hr fast-food job thankyouverymuch) in 1982…

35

hell, I have several different OE car door speakers which sell for ~ $3/ea that are objectively better in the areas that matter than aftermarket component sets costing 10x that much. Shiny cones and cast baskets are irrelevant if the speaker is non-linear and has unusuably high distortion within its stated operating range.

36

I’d still be using my Heinz 57 system (Denon, NHT, Klipsch, etc.) if we hadn’t downsized from a big place to a crackerbox. That was for the music. I also had a Yamaha amp coupled with B&W speakers for the surround AV system. All gone. Now it’s an iPod sitting in a docking station with piss-poor sound. :frowning:

37

What about the local small firms that design and install “home theater” systems? They seem to be hanging on. Although, in an era where compressed audio is acceptable, what’s the point?

38

theater systems for watching movies is a bit different, since generally you do sit there and watch/listen.

39

Still listening to a pair of KEF Concertos I built from a kit in about 1977, and also a 100 Watt MOSFET amp I built in 1980 (and rebuilt in about 2005.) Neither are state of the art in any way, but both are still pretty reasonable.

40

Isn’t it wild how things expand and contract? I remember going and listening to speakers, for fun! To compare the quality. And daydreaming about buying $400 speakers someday :slight_smile:

In other news - my older cell phones, long before “smart”, included nice features that now cost extra - like, fun ringtones! Now those are add-ons.

Meanwhile, on the rare occasion when I happen to watch a minute of my Mom’s highfalutin digital TV (on which she watches the whole array of death and mayhem reruns, NCISUVWTF?) the audio and visual aren’t lined up! It’s like old karate movies! And during football games, the images pixilate!

New solutions = new problems :slight_smile: