I have been lurking around here for maybe five years and see a major change in the subject matter and input of new ideas. Have we lost the gurus and unique thinkers to some other medium? I have not witnessed a major heated exchange of ideas on a given subject in over a year and a half. The bickering and name calling, though at times unnecessary, released many a good thought. It got numerous unique points of view involved. A plethora of facts, charts and graphs could, at times, be displayed and saved by the bystanders for future reference.
Where has all of this gone? Any thoughts? I have much to learn and a few miles left on these old tired legs. Technology and its progress have always been great interests of mine.
Tad
Where has all of this gone? Any thoughts? I have much to learn and a few miles left on these old tired legs. Technology and its progress have always been great interests of mine.
Tad
Technology means digital, more and more precise thanks to MACC formats like 32x32+64=64, running at 168 MHz like with the newest STM32 F4 single-core microcontroller, or running in the GHz range like with any PC.
Power supplies are switched mode, operating close to the MHz range, and regulated.
Amplifiers are direct-digital, fed by a I2S digital stream.
Audio is now multichannel 5.1 or 7.1, delivered by HDMI. But wait a minute. Is there a HDMI decoder available, delivering four I2S streams to be exploited by DIY enthusiasts ?
Audio is now multiformat like 44.1 kHz, 48 kHz, 96 kHz and 192 kHz. But wait a minute, how can you guarantee a "bit exact" quality when you apply an Asynchronous Sample Rate Converter (ASRC) on every input, converting all those formats to a common 96 kHz digital audio ? Should ASRCs be banned ? Should the whole audio reproduction hardware follow the sampling frequency ? But wait a minute, what to do when cross-fading two audio files having different sampling frequencies ?
Audio is said to be 20 Hz to 20 kHz. Most of the time you need a multiway system to reproduce such bandwidth. But wait a minute, how can you guarantee a "bit exact" quality when there are so many different crossover topologies like Linkwitz-Riley, Lipshitz-Vanderkooy phase compensated, Liphitz-Vanderkooy delay compensated, and Baekgaard ? How to take into account the Bode plot of the naked transducer ? Is a perfect sound wave reconstruction (linear phase) possible without introducing relative phase shifts in the transition bands ? What is the optimum compromize ?
The DIY market may be downhill because all those questions do fly too high above the heads of most DIY people.
The best DIY things I have tasted those last five years are some extraordinary 2496 vinyle rips (24 bit ADC running at 192 kHz) encoded in a lossless digital format. The Dave Brubeck "Time Out" album, the Keith Jarrett "Koeln Concert" and so on, if you see what I mean.
The new DIY wave will only show when there will be new 5.1 and 7.1 recordings available, from new artists, same quality as those famous stereo recordings dating back from the sixtie and the seventies.
But wait a minute, as sound engineer, how can you be "minimal and accurate" in a 5.1 or 7.1 context ?
Actually, I'm not sure that "minimal and accurate" is the right paradigm. The story about the Keith Jarrett "Koln Concert" is here : http://en.wikipedia.org/wiki/The_Köln_Concert. Apparently, Manfred Eicher (producer) and Martin Wieland (sound engineer) needed to tweak the sound using post-production.
In DIY audio, the more you dig, the less it becomes innocent.
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Sadly, no. We still have people who proclaim their guru status, and their fanboys who do it for them. We still have unique thinkers, who appear to live in a different universe with different laws of physics (or no physics at all!).tryonziess said:
Far too many discussions get bogged down when it appears that people don't actually understand the basics, so have no basis from which to argue a case. That doesn't stop them arguing, of course. It merely means they feel free to reject counter-arguments which they simply do not understand. Going to the other extreme, we have newbies who either expect to be spoon-fed the most basic information (do they not know what the Y stands for in DIY? Have they never heard of google?) or think that after a few weeks discussion (starting from total ignorance) they can design a 'high-end' item by bolting together a few boutique components whose function and correct value seems to have escaped them.
Fortunately we still have some people who can argue a coherent case for their understanding or point of view, so the rest of us can learn from them. We still have newbies who ask sensible questions and then take the trouble to understand the answers. DIY Audio is still a good place to hang out.
In the sixties and in the seventies, the vinyle was containing more information than a normal HiFi setup could reproduce. The microphones, the mike preamps and the vinyle cutting head delivered together a 30 Hz to 17 kHz bandwidth in a 3dB corridor.
In the sixties and in the seventies, at home, if you were lucky, the magnetic cartridge, RIAA preamp, preamp, power amp and loudspeaker delivered together something like a 60 Hz to 12 kHz bandwidth in a 6dB corridor, for a ideally placed listener facing the loudspeakers, same height as the ears.
The use of cone tweeters combined with baffle edge diffractions caused a pathologic high frequency dispersion, hence the need for tone controls in the highs for restoring a decent tone balance in a semi reverberant room like your living room.
Unoptimized closed boxes or unoptimized bass-reflex boxes caused an amplitude peak in the bass near the cutoff frequency, masking the deep bass range below 50Hz. For this reason you also needed a tone control in the lows, but such tone control was not selective enough, not able to damp the amplitude peak at the cutoff frequency, say 60Hz.
Knowing this, in the sixties and in the seventies, using simple means and scarce money, you could improve your audio setup, making it more linear, extending the bandwidth, uncovering the essential information from the vinyle. All you needed was to dismantle your existing two-way speakers, reuse the existing drivers as medium and tweeter, time-align them, avoid baffle diffraction, use a trivial 1st-order passive crossover, and add one or two RLC networks in the medium for suppressing the high-frequency cone aberrations. For the bass, you needed an active subwoofer, electronically equalized, for delivering the 30 Hz to 120 Hz spectrum in a corridor of 3dB. So simple ! So cost-effective !
Very few people did this, actually. Why ?
During the sixties and the seventies, the whole DIY communauty went focusing on solid-state, more output power, less harmonic distorsion, less crossover distorsion, more slew-rate and direct-coupling (capacitorless). For this reason, during more than 20 years, vinyles continued to have more info inside, than most HiFi setups could deliver in your listening room. Things could have radically changed in 1961 when Thiele published his work in Australia about optimizing the closed-box speakers and optimizing the bass-reflex speakers, but his work remained ignored during one decade, untill published in the Journal of the Audio Engineering Society in 1971. But again, even after 1971, just like there was a conspiracy about not delivering the deep bass range, most audio reviewers went focusing on loudspeaker sensitivity, writing that anything below 90dB/Watt was pathologic. A company like Cabasse managed to get a good reputation, consistently producing speakers exhibiting a sensitivity of 92dB/Watt, but lacking bass, delivering "dry bass" as some said. Like the Yamaha NS-10 as near field monitors. Companies like IMF, B&W and KEF were initially disregarded, when they introduced wide bandwidth loudspeakers having a sensitivity of only 86dB/Watt, even if for the first time those loudspeakers were delivering the actual vinyle bandwidth to your home. Jacques Mahul (Focal, JM Labs) came shortly after and showed to people how to deliver more bass thanks to a dual coil speaker. Jacques Mahul came back showing to people how to deliver more bass using the 4th-order passband dual chamber subwoofer. Bose was there since the beginning (with their 904), with the idea of electronically equalizing the woofer, but Bose never gained the DIY communauty acceptance. Philips was also there since the beginning (with their 22RH532 Motional Feedback), putting a sensor in the woofer cone and applying electronic feedback. Linkwitz, like Bose, came with the idea of electronically equalizing the woofer (the Linkwitz Transform), but again there was no wide acceptance, no adoption from HiFi manufacturers apart KLH and Yamaha (if I remember). Bose came back in the eighties armed with their patent about the 8th-order passband triple chamber subwoofer, that nobody dares to copy, even today.
We are now in 2011. The vinyle is still there, especially in the 24-bit 96 kHz ripped form, lossless format. Now we know that all first generation CDs need to be dumped, especially the ones that were remixed for promoting the "CD sound quality" like adding heavy bass and adding multiband compression for making the sound more "juicy". Now we know that sound gets recorded using 24-bit 96 kHz, so why continuing buying CDs delivering 16-bit 44.1 kHz ? What are the alternatives ?
As a starting point, the DIY audio concept should encompass a global market offering audio tracks recorded, mixed and mastered in a genuine format like 24-bit 96 kHz, without any sample rate conversion inbetween.
As a bonus, the DIY audio concept should propose 5.1 and 7.1 recordings, as experimental path. There should be sound engineers, artists and composers, affiliated to such concept.
In a digital world, something very reassuring would be to expose the algorithms and the source code for all sorts of sound processing like equalizers, dynamics compression, enhancements, crossovers. Also expose the algorithms running in digital power amplifiers, and in switched-mode power supplies.
In the sixties and in the seventies, at home, if you were lucky, the magnetic cartridge, RIAA preamp, preamp, power amp and loudspeaker delivered together something like a 60 Hz to 12 kHz bandwidth in a 6dB corridor, for a ideally placed listener facing the loudspeakers, same height as the ears.
The use of cone tweeters combined with baffle edge diffractions caused a pathologic high frequency dispersion, hence the need for tone controls in the highs for restoring a decent tone balance in a semi reverberant room like your living room.
Unoptimized closed boxes or unoptimized bass-reflex boxes caused an amplitude peak in the bass near the cutoff frequency, masking the deep bass range below 50Hz. For this reason you also needed a tone control in the lows, but such tone control was not selective enough, not able to damp the amplitude peak at the cutoff frequency, say 60Hz.
Knowing this, in the sixties and in the seventies, using simple means and scarce money, you could improve your audio setup, making it more linear, extending the bandwidth, uncovering the essential information from the vinyle. All you needed was to dismantle your existing two-way speakers, reuse the existing drivers as medium and tweeter, time-align them, avoid baffle diffraction, use a trivial 1st-order passive crossover, and add one or two RLC networks in the medium for suppressing the high-frequency cone aberrations. For the bass, you needed an active subwoofer, electronically equalized, for delivering the 30 Hz to 120 Hz spectrum in a corridor of 3dB. So simple ! So cost-effective !
Very few people did this, actually. Why ?
During the sixties and the seventies, the whole DIY communauty went focusing on solid-state, more output power, less harmonic distorsion, less crossover distorsion, more slew-rate and direct-coupling (capacitorless). For this reason, during more than 20 years, vinyles continued to have more info inside, than most HiFi setups could deliver in your listening room. Things could have radically changed in 1961 when Thiele published his work in Australia about optimizing the closed-box speakers and optimizing the bass-reflex speakers, but his work remained ignored during one decade, untill published in the Journal of the Audio Engineering Society in 1971. But again, even after 1971, just like there was a conspiracy about not delivering the deep bass range, most audio reviewers went focusing on loudspeaker sensitivity, writing that anything below 90dB/Watt was pathologic. A company like Cabasse managed to get a good reputation, consistently producing speakers exhibiting a sensitivity of 92dB/Watt, but lacking bass, delivering "dry bass" as some said. Like the Yamaha NS-10 as near field monitors. Companies like IMF, B&W and KEF were initially disregarded, when they introduced wide bandwidth loudspeakers having a sensitivity of only 86dB/Watt, even if for the first time those loudspeakers were delivering the actual vinyle bandwidth to your home. Jacques Mahul (Focal, JM Labs) came shortly after and showed to people how to deliver more bass thanks to a dual coil speaker. Jacques Mahul came back showing to people how to deliver more bass using the 4th-order passband dual chamber subwoofer. Bose was there since the beginning (with their 904), with the idea of electronically equalizing the woofer, but Bose never gained the DIY communauty acceptance. Philips was also there since the beginning (with their 22RH532 Motional Feedback), putting a sensor in the woofer cone and applying electronic feedback. Linkwitz, like Bose, came with the idea of electronically equalizing the woofer (the Linkwitz Transform), but again there was no wide acceptance, no adoption from HiFi manufacturers apart KLH and Yamaha (if I remember). Bose came back in the eighties armed with their patent about the 8th-order passband triple chamber subwoofer, that nobody dares to copy, even today.
We are now in 2011. The vinyle is still there, especially in the 24-bit 96 kHz ripped form, lossless format. Now we know that all first generation CDs need to be dumped, especially the ones that were remixed for promoting the "CD sound quality" like adding heavy bass and adding multiband compression for making the sound more "juicy". Now we know that sound gets recorded using 24-bit 96 kHz, so why continuing buying CDs delivering 16-bit 44.1 kHz ? What are the alternatives ?
As a starting point, the DIY audio concept should encompass a global market offering audio tracks recorded, mixed and mastered in a genuine format like 24-bit 96 kHz, without any sample rate conversion inbetween.
As a bonus, the DIY audio concept should propose 5.1 and 7.1 recordings, as experimental path. There should be sound engineers, artists and composers, affiliated to such concept.
In a digital world, something very reassuring would be to expose the algorithms and the source code for all sorts of sound processing like equalizers, dynamics compression, enhancements, crossovers. Also expose the algorithms running in digital power amplifiers, and in switched-mode power supplies.
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if only you had written DIY audio, instead of DIY Audio 
if you mean this forum, I think its healthy, and more active than ever
one problem I see is some resistance to changes
some like it to stay the same forever
or that it was better last year
but its an illusion
everything goes up and down, back and forth
and so it should
shows its a dynamic forum
but maybe its simply the increased activity that at times causes some issues
but it will never become 100% trouble free
and I don't think it should
maybe it would even be worrying if it was
if you mean this forum, I think its healthy, and more active than ever
one problem I see is some resistance to changes
some like it to stay the same forever
or that it was better last year
but its an illusion
everything goes up and down, back and forth
and so it should
shows its a dynamic forum
but maybe its simply the increased activity that at times causes some issues
but it will never become 100% trouble free
and I don't think it should
maybe it would even be worrying if it was
In the late sixties and throughout the seventies there were many great individuals who contributed vastly to the solid state design. These same people went forth and began there own companies. We all know who they are and I for one thank many of them for contributing to this forum.
In the more modern era the good monolithic designers and contributors to todays discrete products are still, unless layout off, having there contributions absorbed by the conglomerate that they work for. It would be nice to know just which individuals are responsible for all of the fun we have had and are having with the vast chipamp builds. These are the things many begin this hobby with today.
Much more could be said about the tube amp genre which has its foundations as far back as the late twentys and thirtys. I like to know what is going on in my hobby today and this place plus Elector seem to provide much of it.
Tad
In the more modern era the good monolithic designers and contributors to todays discrete products are still, unless layout off, having there contributions absorbed by the conglomerate that they work for. It would be nice to know just which individuals are responsible for all of the fun we have had and are having with the vast chipamp builds. These are the things many begin this hobby with today.
Much more could be said about the tube amp genre which has its foundations as far back as the late twentys and thirtys. I like to know what is going on in my hobby today and this place plus Elector seem to provide much of it.
Tad
I'm now realizing that the main reason why most of the DIY effort went into wrong directions (see post #10 above) in the sixties and in the seventies, is the lack of proper DIY measurement gear, at the time. In the sixties and in the seventies, for measuring loudspeakers, you needed the expensive Bruel & Kjaer generator, condenser microphone, mike amplifier, selective amplifier, logarithmic detector, plotter ... and paper rolls. It was not realtime like any nowadays PC-based FFT analyzer, thus even if you could afford the B&K gear, any interactive measurement session would have been extremely long.
The only measurement gear you could afford in the sixties and in the seventies was a low distorsion sinus generator (the HP oscillator), a second-hand 2 x 20Mhz oscilloscope, a T-bridge rejector filter and a 100 watt 8 ohm resistor. Hence the "stupid" output power battles, THD battles and crossover distorsion battles.
Later on in the early eighties, you could afford an audio generator outputting a square wave having fast clean edges, so you could join on the "stupid" slew-rate battles.
This is a lesson we can learn from.
So, in 2011, what measurement gear do we miss in the diyAudio communauty ?
Can somebody help me finding articles dating back from the sixties, seventies and eighties, aiming at equipping amateur DIY people with decent measurement gear, enabling them to measure their loudspeakers, possibly in real time ? Was there an analog 20Hz-20KHz 1/3 octave analyzer outputting on a LED matrix maybe ?
Is some equivalent available today for a few dollars, like a iPhone or androPhone application ?
The only measurement gear you could afford in the sixties and in the seventies was a low distorsion sinus generator (the HP oscillator), a second-hand 2 x 20Mhz oscilloscope, a T-bridge rejector filter and a 100 watt 8 ohm resistor. Hence the "stupid" output power battles, THD battles and crossover distorsion battles.
Later on in the early eighties, you could afford an audio generator outputting a square wave having fast clean edges, so you could join on the "stupid" slew-rate battles.
This is a lesson we can learn from.
So, in 2011, what measurement gear do we miss in the diyAudio communauty ?
Can somebody help me finding articles dating back from the sixties, seventies and eighties, aiming at equipping amateur DIY people with decent measurement gear, enabling them to measure their loudspeakers, possibly in real time ? Was there an analog 20Hz-20KHz 1/3 octave analyzer outputting on a LED matrix maybe ?
Is some equivalent available today for a few dollars, like a iPhone or androPhone application ?
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Objection...
DF96
DIY is a wide thing, with some wanting to redesign and rebuild everything from the ground up - that is, doing it for it's own sake, and others who want to utilize "boutique components" correctly and achieve results beyond their budgets and capabilities.
There are plenty of guys who use pre-built Hypex or MiniDSP components (for example) who also understand the formalism. Just because you don't build everything from the ground-up doesn't mean that you don't know what you are doing. If the pre-built is better than you can do then why not use it?
People come here, learn what they need to know, and move on to build the best gear they can - the more they know, the better the gear. It really doesn't matter if they re-invent the wheel or not.
Peace,
Tom
DF96
DIY is a wide thing, with some wanting to redesign and rebuild everything from the ground up - that is, doing it for it's own sake, and others who want to utilize "boutique components" correctly and achieve results beyond their budgets and capabilities.
There are plenty of guys who use pre-built Hypex or MiniDSP components (for example) who also understand the formalism. Just because you don't build everything from the ground-up doesn't mean that you don't know what you are doing. If the pre-built is better than you can do then why not use it?
People come here, learn what they need to know, and move on to build the best gear they can - the more they know, the better the gear. It really doesn't matter if they re-invent the wheel or not.
Peace,
Tom
I think you may have misunderstood me. My concern was people who expect to be able to design decent gear after only few weeks discussion, most of which will have gone way over their head. The people who ask "should I use Brand X or Brand Y capacitors" when it turns out they don't even know what that particular capacitor does in that particular circuit. People who think the brand is more important than the value. People who 'know' that cathode followers destroy sound.
People do DIY at various levels. Nothing wrong with that. Few people construct their own electronic components, like people did in the olden days. The problem can be that some people expect to be able to design circuits without actually learning anything. I suspect this is a side-effect of modern education, which emphasises learning the answers instead of understanding the questions.
People do DIY at various levels. Nothing wrong with that. Few people construct their own electronic components, like people did in the olden days. The problem can be that some people expect to be able to design circuits without actually learning anything. I suspect this is a side-effect of modern education, which emphasises learning the answers instead of understanding the questions.
They learn by listening. No good? Another circuit coming in.
I think it's more fun for people who know a little but not too much. Surprises get bigger at that stage. Look at the joy of children playing with their toys. Some people take audio too seriously - it's no rocket science. Well, now that I think of it, sometimes stuff blows up and you could also get killed... not astronaut style but playing with electronics can be dangerous too.DF96 : I agree
Agreed that there are some who don't want to learn what's necessary and it is a shame that they are sometimes aggressive about that. Worse yet is that they will probably never achieve what they have set out to do - which must be awfully disappointing.
My motto is:
Knowing what you don't know is often more valuable than knowing what you do know.
Regards,
Tom
Agreed that there are some who don't want to learn what's necessary and it is a shame that they are sometimes aggressive about that. Worse yet is that they will probably never achieve what they have set out to do - which must be awfully disappointing.
My motto is:
Knowing what you don't know is often more valuable than knowing what you do know.
Regards,
Tom
Trying to create a material machine that is supposed reproduce the most immaterial of arts (music) is a great challenge of our time. The amateur has now a lot of incredible tools, for simulating, measuring or making. The communication by internet is outstanding, the novices can learn from the old farts.
The forum where we are now is from far the most active, the most complete, the most accurate.
Where do you see a problem ?
The forum where we are now is from far the most active, the most complete, the most accurate.
Where do you see a problem ?
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