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Do you by chance remember Lee Knight? "LOCATION: (I'm in parentheses -- that's why you can't hear me.)" Coincidentally (or not) I was thinking of Lee when I posted, a moment ago to my own thread (where you kindly left a "Thank-You" this day). The subject was "My Mom, Mitch Albom and The Very Thought of You" and it was a re-capitulation of an entry made on my previous thread -- that was 'this close' to 500,000 "views" before the platform here had a little glitch that made it all disappear! You and Lee, I see, joined the world's biggest website for musicians at the very same time -- July 2005. I always loved Mr. Knight's postings. Say hi to him for me, would you. Thanks, blue2blue.
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Mark Blackburn started following blue2blue
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Good overview. Thanks, Craig!
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Don't laugh...anyone have a CARLOS acoustic?
blue2blue replied to centuryhouse's topic in Acoustic Guitars
I dunno. Doesn't seem like it would give a troll much satsfaction. If it's not a troll, there certainly a lot of these guitars turning up. I guess it's no surprise. As a cheap Pac-Rim import there's probably thousands in closets and in basements. After 30-40 years it's time Johnny's old guitar goes to the yard sale. People get a guitar from an unfamiliar maker and Google for info on it. The first article up (just now) in Google is a Wikipedia article, then two mentions from vintaxe.com and then there's Harmony Central at return 4... -
Don't laugh...anyone have a CARLOS acoustic?
blue2blue replied to centuryhouse's topic in Acoustic Guitars
Don't laugh - not an expensive or reputable brand. As a matter of fact there are NO CARLOS guitars on ebay OR listed at Harmony Central in the reivew database - not one. Now bear in mind I have owned nearly 150 guitars (maybe more) in the last 15 years, including many Gibsons, Taylor, Ibanez, Washburn, etc. I know my guitars pretty well. That said, I bought a CARLOS II model 240K acoustic 6 string at lunch today from a pawnshop for $50. It's Korean made, probably late 70s I'm guessing. It has what appears to be *original* brass nut, brass bridge/saddle and instead of pearloid dot inlays it has actual brass studs inlayed. Despite needing some serious work on the action and a truss rod adjustment, and the strings being ancient, the guitar actually had a good sound and feel. I'll be working on it tonight when I get off work and then can give a real assesment. But initially, I think it's going to be a great guitar. A web search revealed that several recording studios have CARLOS acoustics on hand for recording, but other than that I found nothing online. Can anyone tell me anything? If you have one how old is it, and does it suck? Is it just oK? Is is good? Thanks, Daniel I bought a Carlos 12 string dread from a pal for $75. It's not a bad sounding guitar but the nut really, really needs to be replaced, since the string spacing is wack, per my thinking. The individual strings of the pairs are way too far apart and the sets of pairs too close together. As a consequence, fretting accruately is difficult. Makes a decent 12 string slide, though. Finger picking accurately is a bit of a pain because of the string spacing (better than the fretting though, as the bridge spacing is ok.) Tone is really pretty OK. -
Does hanging carpet on walls to dampen room really work?
blue2blue replied to 44caliberKid's topic in Recording Forum
It's not nearly as effective as proper treatment, which will work to combat early (side) reflections as well as to minimize standing waves resulting from room resonance (which often result in booming resonance in the bass range in some spots while other spots cancel out in the same range -- making the room potentially a mine field for mixing in). Carpet will tend to absorb some frequencies while bouncing others while proper anti-reflection materials will be more effective across a wider range. -
Just Wondering...How Did You Start Writing?
blue2blue replied to Writer's topic in Songwriting Workshop
While discussing lyrics in another thread, I remembered how it was that I started writing and I was wondering if anyone had a similar story. I think it would be interesting to know how other writers caught the 'writing bug' if any of you wouldn't mind sharing your story. Here's mine: During my teen years, writing became a way for me to say what I was feeling when I didn't think I could just come out and say it or didn't know exactly how to express my feelings. I had a very strict upbringing and would have been in a world of trouble if I said what I sometimes thought. However, for example, if I disguised my longing to spread my own wings as a song about a bird, I could say whatever I wanted...pretty sneaky, huh? tee, hee... So...who's game? Anyone? I think it was a rainy day in 7th grade English, when the teacher said, Well, we're all going to try out hand at writing short stories today. Being a big fan of spy stories and sci-fi, I wrote a terse and schematic story about a NATO like alliance attacking an international terrorist conspiracy. If that sounds like the plot of a James Bond/Man from UNCLE type scenario, well, art imitates art. If it sounds like current events... I hear ya. When I first read about Osama bin Laden almost two decades ago, I thought he and al Qaeda sounded just like a James Bond plot... Anyhow, the rest of the stories must have been really, really bad... because me and one or two others were singled out for praise. I went out and bought a copy of the then current issue of Writer's Digest, realized there were some markets where a guy could pull some serious bank, and plunged into my new career. I was so serious about it that my folks bought me a typewriter for my 14th birthday. Later I discovered blank verse and drifted into poetry as well. In college, I was part of the poetry scene, did a number of readings, edited a poetry anthology (that got its funding pulled at the last moment due to budget cutbacks) but soon enough realized that the guys playing guitars under the trees in the quad were getting all the cute girls -- including some of the poet girls. It was clear I would have to extend my horizons... PS... Actually, come to think of it, my real start was a year or two earlier when I scripted and performed a couple of radio-style parody skits into my ultra-primitive battery powered tape recorder. (No capstan. That's how primitive.) I did my own 'mic 'n' mouth' sound FX, too, a la (the coincidentally named) Tom Keith on Prairie Home Companion. -
Very nice, sir. I do science for living, and know a little bit about it, but I try not to comment on the field I don't know deep. But one thing I can tell for sure (or at least in a general sense) is, it is much harder to prove something "doesn't exist" than to prove something "do exist" by experiemnts in science. So, yeah, who knows what happens in the next 100 years in science. Somebody may show synaptic ends releases molecules called "xxx" in response to 20MHz ultrasound wave, which has an impact on music perception....things like that. And, also thanks for Android suggestion. Yeah, I've been looking at that too. Particularly, I'm interested in Skype mobile which allows me to show my backyard here to my mom 5000 miles away, who survived WWII in her teens. Unfortunately my dad passed away few years back, without seeing these tech stuff developed by former enemies (that's what he always told me) and benefit of seeing talking with his son over the screen. I might buy Droid for my son when he goes to college, so that I can "police watch" what he's doing?? No, just to see his face, you know. College kids can get in trouble -- no question -- but they also have to learn how to make their own mistakes. It's a big, dangerous world and it can, no doubt, scare the heck out of parents... but if you try to protect them too much, you just hobble or cripple their own ability to think and act sensibly for themselves. (I'm very good at giving advice to parents, since I've been able to concentrate on it without the distraction of having my own children. ) Sounds like we're roughly from the same generation. My mom was a teenager during WWII, as well. My dad in the Army Air Corps, attached to a squadron of B-25 "Mitchell" light, two engined, split-tail bombers. (Sort of like a scaled down B-24, actually.) My first GF was, coincidentally, a sansei Japanese-American. Her parents both nisei; her father spent some time during WWII in an internment camp for Japanese-Americans -- an institution that was a shameful overreaction to wartime threats, real and imagined, it's always seemed to me -- and then, like many Japanese-Americans, he volunteered to fight the Third Reich in Europe.
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Yeah... it was interesting at the sort of open house, there were a number of young Vietnamese guys there and I was thinking, man, didn't they fly B-24's in Vietnam jungle bombing support? It was tough, 65 years later, on a sunny tarmac in Long Beach, talking to a B-24 pilot who was there for a couple of days -- a guy who must have been pushing 90 -- to imagine the hell that the guys in the planes went through -- a lot of planes got shot down in those days and even when they didn't, the crew often got shot up pretty bad. Losing a couple members of a close knit team was not uncommon. But they were soldiers. It's even more painful to imagine the horror of innocent civilians caught up in the war. War. It's not a good use of human energy. I'm convinced. It may be unavoidable at times but... there's nothing good about it, except ending it. Anyhow... some amazing old planes. ___________ Sounds like your common sense approach to your son's phone situation is a good one. I think maybe you have to make some of your own mistakes -- not, mind you, that an iPhone is a mistake, but it might not be worth it to him in the long run or he might decide in 6 months that he wants an Android so he can participate in the whole web. (Or he might just kick himself that he bought when he did and wish he'd waited for the latest, greatest iPhone. I'm told that's a common situation. Part of learning how and when to spend, I'm thinking.) With regard to his discomfort with the ultrasonic Doppler, I'm positive he's not hearing that but he could well be hearing or discomforted by very high frequencies in or around the range of audibility that are generated by electronic components in the hardware -- much like old fashioned TV hardware (particularly the cheap stuff) often produced acoustic noise around ~16kHz by such pats as the "horizontal flyback transformer, deflection yoke, other transformers, [or] even ferrite beads in the horizontal deflection circuits." (High pitched whine or squeal from TV with no other symptoms) Here's the thing, your son might be near the top range of human hearing -- but more than a half century of extremely rigorous scientific testing has failed to reveal any humans capable of hearing any higher than around 25 kHz -- and most perceive a lot less, particularly with age. The problem with one-off, somewhat informal tests is that there are so many variables (like mechanical component noise, for instance), as well as the familiar problems of cognitive bias/distortion. That's the reason that even extremely rigorous scientific testing is expected to be revisited and replicated in order to make sure that there were experimental mistakes or other anomalies, and then the data from those tests is frequently analyzed and reanalyzed both in order to see if other conclusions may be drawn from those of the experimenters. Human perceptual testing is a minefield of potential gotchyas and perceptual scientists actually spend much of their formal education simply learning how to set up meaningful testing of perception. This latter is exemplified by the informal findings of those working from data from the Oohashi study (which had noted some unexpected results relating to subjects wearing actual blindfolds [blindfolds are almost never used in conventional 'double blind' testing as they are generally deemed unnecessary with proper experimental design and conditions]) who noted that the apparent ability of one of their subjects to perceive extremely high frequencies disappeared when they put heavy goggles on her. (I think I noted above that they supposed that it might be related to physical excitation of the subjects forebrain through the soft tissue of the eyes.) Fascinating stuff, no question.
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absolute statements are a lot harder for me to swallow than all this gibberish about your so-called new-fangled flying machines. My great grandmother was already in her 60s when these were a common sight in the skies over southern California during World War II -- they were made in Long Beach, in fact. She didn't have any good answers for me when I would ask her what all those planes in the sky were. There were still plenty flying out of the old El Toro Air Station in the 50s and early 60s... She passed away a few months before John Kennedy was assasinated -- and then the planers really got thick as the Vietnam war effort accelerated. Believe it or not, they were still flying WWII vintage bombers during the Vietnam war, B-24s, B-29s, others. Of course, we're still using B-52's (designed not long after the end of WWII) today because the 'modern' bombers simply can't carry the payloads and are woefully expensive to fly and maintain, with cost of manufacture and maintenance making them thousands of times more expensive (per pound of payload). A B-17 "Flying Fortress" cockpit: I got to crawl around in this one and in a B-24 "Liberator" last week. I also got to film them right after takeoff... part of the Collings Foundation's WWII Warbirds tour. More pix: http://picasaweb.google.com/tkmajor/WWIIWarbirds#
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Well... we always have to be careful about using absolutes like all, none, never, and... always.... In the past, before oversampling, when there was a much greater reliance on conventional anti-alias filtering, it was possible to see a cheaper unit that could sound better at a higher SR than at 44.1 because there was greater headroom, and, hence, more likelihood that the anti-alias filter could be effective. So, while a more expensive converter might sound just fine across the nominal range at any rate from 44.1 up, the cheaper unit might sound better at the high rate than the low one -- even though it might not even have any extra high end -- but it might be cleaner. And, while modern converters should be as I described, who know what's going to cause some anomalous behavior in a given converter? Stuff happens. That's why I try to talk about principles rather than particulars. Because the particular so often diverges from the principle. PS... Using qualifiers like many, most, usually, and the like is pretty well second nature to me now (after arguing about everything from audio to politics online for a couple decades [dial up BBs before the www]... well, actually, mostly about audio and politics) but after writing all that... I had to go back above and check to see I hadn't made any rash, all-inclusive, absolutist statements... You know... stuff happens.
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Well, I think the world is flat. I see it that way so it must be so. I don't care that it's been proven otherwise. My great-grandmother, born in the decade after the US Civil War (that would be the 1870's, for those hazy on their US history), insisted that she firmly believed the earth was flat. (Not only that, she said she didn't believe airplanes actually flew.) It used to drive me crazy. There were no accepted facts or conventional logic that could persuade her. My great-grandmother, of course, was a product of a very limited education in backwoods, one-room school houses and didn't get past grammar school. She could probably be forgiven for her obstinacy and intransigence. But what are we to think of people today who have (theoretically) had the benefit of 9-12 years of mandated public or private education -- and have access to the most amazing information ever created, the internet -- yet who willfully remain as intransigent in their lack of knowledge and unwillingness or inability to use logic and common sense as my great-grandmother?
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There are some decidedly incautious -- and therefore likely inaccurate -- statements above. Whenever one finds oneself using words like all, always, never, 100%... it should ring alarms. Almost nothing in this world is absolute. Lavry's extremely informal 'optimal' sample rate suggestion was simply one that would have afforded ample 'headroom' for gradual anti-alias filtration above even the highest frequencies reported as audible by humans. While most adults hearing trails off between 10kHz and 18kHz, some youngsters and young adults have been tested as hearing as high as 22 kHz or a trifle more. But, as he points out, advances in oversampling and filtration have obviated the need for these exaggerated frequency head rooms in large part. He does allow that there's probably 'little harm' in using so-called double rates (88.2 and 96 and that some FX and other DSP processes may deliver preferable results at such rates, but he adds that one can track at 44.1 or 48, upsample for processing, and then downsample for output). However, he is quite pointed in his dismissal of so-called 'quad' rates like 192kz, pointing out that there is a trade-off that exists between the number of samples taken and the accuracy of their measurement. (One may recall that sample measurement is accomplished by comparing the signal voltage very rapidly against a series of known voltage values; the more time devoted to this process, the more accurate the result.) With regard to sound transmitted through air (as opposed to bone conduction), there is virtually no accepted science that suggests humans can tell the difference between two otherwise identical signals, one with ultra high frequency componts intact and one with them removed. In other words, if you can't hear a given frequency of sound in the first place, its presence or absence in a full range signal is not going to make a noticeable difference to your perception. Or, if you can't hear it, you can't perceive it.* Guys, I've had enough of this. You are not getting an accurate reproduction of waveforms at the upper limit of human hearing when sampling at 44.1 or 48kHz and it DOES make a difference to the quality of the audio. This is backed up by Lavry's paper above and is the one point that I've consistently made that none of you have been able to successfully rebut. Lavry himself says that the optimum sample rate for audio is around 62-63kHz taking into account that the only reason that sample rates higher than this are not optimal is due to machine speeds not yet being fast enough so clearly there is a benefit from recording with a higher sample rate. That's all I've been saying for the last 2 days. I've read the math and it backs up what I'm saying so take it or leave it people, higher sample rates = better quality audio Not exactly. Higher sample rate means higher Nyquist frequency (the uppermost frequency limit of sound which can caputred and reconstructed). And, as noted earlier, before advances in sampling technology made oversampling and advanced filtration the rule, a higher Nyquist frequency meant more headroom for gradual filtering. But those concerns are eased by such advances. And there is NO science or theory that suggests a higher sample rate improves sample accuracy within the sub-filter frequency bandwidth. A properly designed, modern AD running at 44.1 should be able to deliver just as great accuracy in the nominal hearing range [20-20kHz] as one operating at 88.2 or 96. (And, as noted, increasing the SR to a quad rate may well degrade accuracy.) And with regard to frequencies above the nominal range or the discredited notion of 'High Frequency Transients,' Lavry himself wrote in his old PSW forum: Listning to transients: It is a well accepted fact that even a very good ear does not hear much above 20KHz, that most mics do not pick up energy much above 20KHz, and that most speakers will not generate sound much above 20KHz. It is also well known that most of the energy generated by musical instruments is at frequencies not much higher then 20KHz. For some reason, many ear types seem to have bought into the notion that all that I have stated above is true for some of the music, and there is also another part of the signal which they refer to as “high frequency transients”. The concept of transient energy is well accepted by all EE’s (not just in audio) to differentiate between signals made of repetitive cycles and signals that have little or no repetition. EE's and math types make the distinction between steady state and transients (non steady state) because the math and analysis of steady state signals is simpler and easier. Non steady state analysis (transient analysis) requires much more complicated tools. However, the non repetitive audio signal behaviour (transients) does NOT contain frequencies higher than audio. Non-repetitive behaviour DOES NOT require, imply or call for high frequencies. The fast attack of sound, be it drum, bell or a muted trumpet may have some low energy at frequencies above human hearing. But if your system could pick 100KHz transient energy, it would certainly be able to pick up and react to 100KHz sine wave! Why bother with 100KHz energy? If you can not hear 30Khz sine wave, you can not hear 30khz transients. The whole concept of “high frequency transient” has been repeated over and over numerous times in the audio industry, in audio magazines, in marketing material and by people intend on finding "some sort of an explanation" for various fallacies they are trying to explain or promote. After so much repetition of that faulty concept, I would not be surprised if many ear types will simply refuse to hear what I am saying but I am stating the FACTS! Example – “multiple choice test question”: Which case yields the fastest voltage change you can archive with say a 22KHz bandwidth system (such as a 22KHz mic, ear or speaker)? I am talking about the steepest slop, thus the fastest changing signal. A. 100Hz 1V peak square wave B. 1KHz 1V peak square wave C. 5KHz 1V peak square wave D. 10KHz 1V peak square wave E. 22KHz 1V peak sine wave The 5 waves are plotted below: A. 100Hz 1V peak square wave is the red trace B. 1KHz 1V peak square wave is the blue trace C. 5KHz 1V peak square wave is the green trace D. 10KHz 1V peak square wave is the purple trace E. 22KHz 1V peak sine wave is the black trace The fastest signal slope you can ever get in a 22KHz bandwidth system is not a transient. It is the slope of a steady state tone sine wave at the edge of the bandwidth - it is a 22KHz sine wave. The fastest signal in a 30Khz bandwidth system is a 30KHz sine wave, and so on. It is faster then the fastest transient you can create within the given bandwidth! I know that many in audio “became attached” to that MISCONCEPTION about high frequency transients. Sorry to burst the bubble, but it is long overdue to have that nonsense cleared up. It is time to refocus on the activity to what happens WITHIN the audio band, and put an end to that fantasy about things that do not matter and things that do not exist. If you want to test your system or your ear for "the fastest signal it can handle", go for the highest sine wave frequency within the available bandwidth. That is true for ears as well as speakers, amps and everything else. There is no such a thing as high frequency transients extending beyond the audio bandwidth. A mic that can not capture a steady state signal above say 20KHz, can not capture transients above 20KHz. The same is true for the ear, speaker or anything else in the system. We can argue about how high an ear hears, and be sure it never gets higher then 30KHz. For most people it is well below 20KHz, be it steady state or transient energy. Regards Dan Lavry www.lavryengineering.com http://recforums.prosoundweb.com/index.php/t/4097/0/ * The Oohashi study is often cited by those holding out for the possibility that sounds above the hearing threshold may somehow still affect perception. The conclusions of that study, initiated by a commercial interested vested in HF technology, is held in a certain amount of skepticism and it has not been replicated, as far as I know. One highly informal follow-up test from a tech- and testing-oriented audiophile group did turn up some interesting results in the case of one individual, who appeared to be able to differentiate between two otherwise identical signals, where one contained ultra HF components but the other did not. Interestingly, the subject's ability to differentiate disappeared entirely when she was wearing goggles, whether opaque or translucent. From that tidbit it was speculated informally that the highly directional UHF sound components may well have been physically stimulating her forebrain through the soft tissue of the eyeballs. With her eyes sheilded by the goggles, she was unable to differentiate between the test sounds.
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Two crucial things seem to be absent in this entire thread; oversampling and reconstruction filters. Modern converters do not employ the old AD method of successive approximation as suggested in one of the posts on this page. That method required rigorously matched resistors and was spotty at best, compared to the more modern methods where you sample at (for example) 256x baserate as in a digidesign 192 interface. Working with very high sample rates and very low bit depth, the resulting signal (which shares a lot of traits with DSD) is then mathematically winded down to baserate (32, 44.1 or 48 kHz, or any of the multiples thereof). This enables us to construct better anti-aliasing filters. In other words, the selection of 44.1 or 88.2 or even 176,4 kHz sample rate is simply an instruction to the A/D converter telling it what we want out of it. It's still, to the best of my humble knowledge, working at the same speeds more or less internally. Also, at least the first four pages of discussion could have in great parts have benefitted from the mention of the reconstrucion (D/A) filter used. These are the golden item making sure that the reconstructed analog signal is close to a perfect representation of the audible frequencies going into the digitalization. I'll gladly defer to those with greater/deeper knowledge. I was basically just trying to paraphrase what Lavry had written at some points, but I believe you are certainly correct in that new oversampling strategies have changed how we approach AD and DA (and Lavry has written at length about them, as well; if there's a failure to keep up, here, I'm positive it's mine. )
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PPS... I'm sure this has also come up: problems with very high sample rates. At first blush, it sounds quite reasonable to say, well, even if it's overkill, why not use very high sample rates? The problem becomes apparent when we look at how a sampler works. A sampler's clock circuit 'gives' it a certain amount of time to take a measurement of the signal voltage at the AD, approximately .000023 seconds at 44.1 kHz sampling rate or .000010 sec at 96, and .000005 seconds (5 µs) at 192. The way that measure is taken is by comparing the incoming voltage against a series of known voltages until you run out of time and have to move on to the next sample. If you are trying to take so many samples that you do not give your circuit enough time to do its work accurately, you could actually have a significantly less accurate signal -- all for the ostensible purpose of being able to reproduce frequencies that the overwhelming preponderance of solid evidence suggests are not perceivable. EDIT: My take on it is that 96 kHz is probably a pretty good compromise, if you've got the resources to support it. The aforementioned Dan Lavry has suggested that a standard sample rate in the 60-70 Hz range would have been optimal, giving plenty of headroom for the critical anti-alias filter (which, at 44.1 kHz, must do the herculean job of being wide open at 20 kHz and completely closed at 22.05 kHz -- a very steep filter under normal design considerations). However, various oversampling and filter advances have greatly improved the ability of lower sampling rates to cover the nominal range well. BTW: I also suspect the subject of DSD, which Sony originally developed as the core technology of their failed SACD push has arisen. Lavry (and others) have some very pointed comments on DSD that suggest that it's actually not much improvement at all and is probably a step backwards from conventional digital audio with higher sampling rates. http://recforums.prosoundweb.com/index.php/m/3002/0/?srch=dsd#msg_3002 http://recforums.prosoundweb.com/index.php/t/18762/974/ http://recforums.prosoundweb.com/index.php/m/42652/0/