REQUIRED AUDIO READINGS (Lecturas de Audio Obligadas)

julio 4, 2013 10 comentarios

Everyone must read:

hometheaterhifi.com Mark Levinson: For the Love of Music, Part 1 by Scott Wilkinson, 25 June 2013

bla, bla, bla and

• Audio Measurements

• High-Efficiency Speakers

• Tubes vs. Solid-State

hometheaterhifi.com Mark Levinson: For the Love of Music, Part 2 by Scott Wilkinson, 03 July 2013

• Analog vs. Digital Audio

• The Great Cable Debate

• 2-Channel vs. Multichannel Music

• Audio for Movies

• Shopping Advice

Archivado en audio, música Tagged with , , , , , , , , ,

Acerca de maty
Nauscopio Scipiorum

10 Responses to REQUIRED AUDIO READINGS (Lecturas de Audio Obligadas)

  2. maty says:
    julio 19, 2013 a las 5:23 pm

    audioholics.com AV Receiver and Amplifier Power Ratings and Trends: How and Why Wattage Ratings are Manipulated originally published: Nov 9th, 2004 by Patrick Hart

    A second, also fairly well understood way to be able to quote «more power» is by quoting the power at only 1kHz instead of the more traditional 20Hz to 20kHz figure. In some cases the difference can be 15% to 25% more power at 1kHz. This type of rating is sometimes seen with a manufacturer who has two separate levels of distribution with separate model numbers for each level, though the actual receiver itself may be essentially identical…

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  3. maty says:
    julio 22, 2013 a las 3:18 pm

    auriculares.org Variaciones en torno a la fase por rocoa

    Son frecuentes las disquisiciones en torno al tema de la fase y la polaridad entre los aficionados. Trataremos de aclarar una serie de conceptos básicos para entender la complejidad del asunto…

    En un sistema con un nivel de resolución alto es obvio que el prestar atención al problema de la polaridad absoluta redundará en unas mejores prestaciones. No obstante, muchos audiófilos se muestran insensibles a tal cuestión e incluso la desconocen. Sin embargo si percibimos que una grabación suena algo así como anémica, con una pobre definición del grave, sin profundidad, el agudo enfatizado y “arisco”, poco aire y sensación de espacio entre instrumentos e insuficiente dimensión de la escena sonora, entonces es recomendable que invirtamos la polaridad del sistema para ver si mejora la escucha. ¡Quizás nos llevemos una sorpresa! Lo he vivido con muchos aficionados que, teniendo esta función en el preamplificador o en el DAC, no conocían su utilidad.

    Tristemente algunas grabaciones tienen la polaridad mezclada debido a la falta de atención en este aspecto durante la grabación o la mezcla por no haber colocado todos los micros “en fase absoluta”. Esas grabaciones nunca podrán sonar adecuadamente…

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    • maty says:
      septiembre 9, 2013 a las 7:32 pm

      auriculares.org La importancia de la polaridad de los equipos Bec, Septiembre 07 2013

      ¿El resultado…?

      Los graves ahora los tengo perfectamente controlados y he ganado detalle y modulación en todas las frecuencias (casi nada…). Antes tenía que tener los altavoces con el puerto reflex de detrás tapado con el foam (lo que me hacia perder detalle), ahora los tengo a 15cm de la pared (se me oyen mejor que mas separados a 50cm) y la escena stereo ha ganado muchísimo (altavoces B&W 684 en sala de 18 m2).

      Antes había notado una mejora pequeña al pasar del Marantz PM7003 al Leben con altavoces, y ahora la mejora es grande, en línea con lo que habia leído del Leben y oído en casa de patorrents a principios de agosto.

      Con auriculares no he notado una diferencia tan grande de inmediato, pero al oir mas música lo vas notando todo mucho mejor…

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  4. maty says:
    septiembre 5, 2013 a las 6:43 pm

    audiophilereview.com Supervinyl! by Roger Skoff

    One alternative that’s not actually new, but does offer a real possibility of improvement is «half speed mastering.» In practice, this is really simple: To make the «master» recording, an original recording is played at half-speed (7 ½ ips [inches per second] if it was originally recorded on analog tape at 15 ips or 15 ips if it was recorded at 30) into a disc-cutting lathe which is also operating at half-speed (16 2/3 rpm instead of 33 1/3 rpm). Doing this reduces all of the frequencies to be recorded by half ― 20 kHz becomes 10 kHz, 1 kHz becomes 500 Hz, etc. ― and makes the job of the disc cutting head a whole lot easier. Because disc cutting heads, regardless of manufacturer, were limited in high frequency capability, and were typically rolled-off by 3dB or more at 15 kHz, half-speed mastering effectively doubles the high frequency response of the cutting head and allows for a new -3dB point well above 20 kHz, which is all there when the record is played-back at the normal speed of 33 1/3 rpm. Yummy!

    Another option which increases available high frequency recording capability (at the cost of less recording time per disc) is cutting an LP at 45 rpm instead of the customary 33 1/3. Doing that increases the number of inches of groove that are cut every second by 35%, which doesn’t help the cutting head’s performance at all, but makes it easier for the playback cartridge to track the higher frequencies (and also explains the lowered maximum recording time). The one possible negative sonic side-effect may be somewhat higher «groove noise» as the stylus drags along 35% more groove for every second of playback. Dust in the groove may also be slightly more noticeable for the same reason, but if the discs are kept clean (and who doesn’t clean their vinyl before every play) it should be no problem…

    Another vinyl alternative that may or may not be worthwhile to you is the 180 gram disc. Ordinary LPs are standardized at 130 grams of vinyl, so the 180 gram format is a bit more than 38% heavier (although still less than the 200 gram UHQR recordings offered at one time by Mobile Fidelity Sound Labs)…

    Making discs heavier means, of course, making them thicker: When LPs are all 12 inches in diameter, if they’re all made out of the same stuff, about the only place the extra 50 grams of vinyl CAN go is into making them thicker. That can be an advantage because greater thickness makes them more resistant to both macro and micro warpage, which can affect the sound. It can also be a disadvantage because the extra thickness will change the effective vertical tracking angle (VTA) of your cartridge and even a small amount of VTA error can make your records sounds quite noticeably WORSE. If you are planning to use 180 gram discs, my best suggestions are to either use ONLY 180 gram discs and optimize your arm’s VTA setting just for them; OR buy a tonearm that features easy VTA adjustment and get really good at resetting it every time you change from standard to 180 gram records and back; OR, if you can afford it/them, get a turntable setup with two arms and two cartridges (and two phono cables) and a preamp with two phono inputs; set one arm up for 130 gram standard LPs and set-up the other for 180 gram discs and simply switch back and forth at your preamp. Mmmm, Good! Mmmm…

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  5. maty says:
    septiembre 6, 2013 a las 9:15 am

    Somewhere over the rainbow

    j….

    As someone involved in audio production, recording and mastering, I have to say that in reality it is very difficult and quite rare to be able to do your job in such a way that you KNOW from your own experience of audio is correct.

    So very few people understand all the intricacies, knowledge and subtle adjustments that go towards even just creating something that sounds ’normal’ never mind something that sounds great! and, that it is very difficult to help other parties fully appreciate your skills.

    Often your bosses will say things like “make it brighter, louder etc etc” after listening on their apple Mac’s speakers! or their $20 Sennheisser cans.

    Occasionally you can demonstrate on a good system or headphones the difference between a mix and the final mastered audio. THEN they understand…sort of!

    Most of the sound engineers I know tend to be very humble hard working people who soon learn that they have to just keep quiet to keep being employed!

    …

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  6. maty says:
    octubre 27, 2013 a las 11:03 am

    reddit.com Mastering engineer Bob Katz declares the loudness war as "won" (digido.com)

    -> Digital Domain [Forum] THE LAST BATTLE OF THE LOUDNESS WAR HAS BEEN WON

    “I have just completed loudness measurements of iTunes Radio using iTunes version 11.1.1. Tunes Radio’s audio levels are fully-regulated, using Apple’s Sound Check™ algorithm. This is a very important development,” Katz said.

    During several hours’ testing, Katz measured the output level of several stations, and concluded that each song’s loudness averages -16.5 LUFS, within better than 2 dB, usually plus or minus 1.5 dB. The Apple release notes state that version 11.1.1 “improves stability”, which he interprets as having solved some loudness regulation issues which were present in the previous iTunes release.

    It is clear that music producers want their music to sound as good as possible on the nascent but already popular iTunes Radio platform, given the many listeners instantly available. This immediately opens an opportunity to curtail the loudness race within the next few months. Added Katz, “The way to turn the loudness race around right now, is for every producer and mastering engineer to ask their clients if they have heard iTunes Radio. When they respond in the affirmative, the engineer/producer tells them they need to turn down the level of their song(s) to the standard level or iTunes Radio will do it for them—and not always in a pleasing way. iTunes radio will not just ‘turn down the volume,’ but may peak-limit the important transient peaks of the material and make the song sound ‘smaller’ and less clear than its competition.”

    Katz suggests, “The engineer/producer should also tell their clients to turn on Sound Check in iTunes to hear their music exactly the way they will be broadcast on iTunes Radio. This makes all music played in iTunes, whether it be on IOS devices played while jogging, connected in the car, or on the desktop computer, perform consistently. It’s a revolution in the making, with instant positive results.“

    Katz’s discoveries show that current squashed and smashed pop releases are being attenuated more than 7 dB in order to make their loudness equal to that of more-conservatively mastered releases. In other words, true peak levels of current pop songs are as low as -7.8 dB below full scale! “There is so much available peak headroom now in iTunes Radio that anyone who wants to master their songs with more conservative levels and prefers higher peak-to-loudness ratios will produce music with immediate loudness and sound quality advantages, compared to what’s being played out there now. The cream will soon rise to the top. The music will sound better, even a bit louder, and will attract more listeners. iTunes Radio is already so popular that it will end the loudness race by force majeure. This development is a great opportunity for producers to explain and demonstrate to their clients how to make their songs sound better on iTunes Radio and everywhere else.”…

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  7. maty says:
    diciembre 15, 2013 a las 10:53 am

    About DSD.

    audiocircle.com A visit to a Friend, Tape Project, DSD, Vision MC preamp, electrostats, & more by avahifi

    …Finally DSD playback using the Schitt DAC. Well, this sounded very nice indeed, certainly something worth exploring further. My friend helped me set up J River playback software on my Mac, loaded me up with a bunch of source material, and sent me home with his DSD DAC. I am not positive why DSD playback is so nice. I suspect that much of it is because the source material has had less mixing and cadiddling done to it. Simply better production values than with stuff normally stuffed on a CD. I do know that a lot of old great music will soon be available in DSD format at rational prices and terabyte hard drives are cheap now. I am enjoying playing DSD stuff here right now.

    dB Cooper -> realhd-audio.com John Siau: Benchmark Audio Guru by Mark Waldrep

    I actually had a SONY engineer say to me one time and this is quite few years ago…he said, ‘we realized after we got a ways down the road that DSD was kind of a mistake but we had too much invested in it’.

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    • maty says:
      diciembre 15, 2013 a las 10:54 am

      First comment is of John Siau:

      Where does Benchmark stand on DSD vs. PCM, and why?

      1. Benchmark recognizes that DSD (64x and higher) has significant advantages over 44.1/16 PCM.

      2. Benchmark recognizes that high-resolution PCM (96/24 and higher) has significant advantages over 44.1/16 PCM.

      3. Benchmark’s measurements and calculations show that the performance of 64x DSD is almost identical to the performance of 20-bit 96 kHz PCM (the in-band SNR of 64x DSD is about 120 dB). 64x DSD does not have any time-domain, frequency domain, or linearity advantage over 96 kHz PCM. DSD marketing materials have been very misleading.

      4. 24-bit 96 kHz PCM has a 24 dB noise advantage over 64x DSD (144 dB vs. 120 dB), but this 24 dB noise difference is completely masked by the noise produced by other components in our recording and playback systems, and by the noise limitations of our recording and listening spaces.

      5. Benchmark recognizes that 64x DSD and 96/24 PCM formats outperform most of the recording and playback chain. Bandwidth of either digital transmission system meets or exceeds the bandwidth of our microphones, amplifiers, and speakers. Likewise, the SNR of either digital transmission system meets or exceeds the noise performance of microphones, microphone preamplifiers, and power amplifiers. In addition, these digital transmission systems both exceed the performance of most A/D and D/A converters. 64x DSD and 96/24 PCM are not the factors limiting the performance of our audio systems. Focusing on DSD vs. PCM will distract us from much bigger issues in the recording and playback chain. Any sonic advantage of one digital system over the other will be very small when compared to improvements that can be made in other parts of the signal chain.

      6. 64x DSD and 96/24 PCM both offer excellent sonic performance as distribution formats. PCM is more compact, but DSD provides better copy protection (a frustration to those of us who use music servers, but an important consideration for copyright holders).

      7. Every A/D and D/A converter that Benchmark has produced uses Sigma-Delta conversion with equally-weighted 1-bit conversion elements. Benchmark never used multi-level conversion because of the THD issues caused by the linearity errors that are common to all multi-level systems. Benchmark has always placed high priorities on THD and linearity, at the expense of SNR. Sigma-delta 1-bit DACs tend to produce more noise than multi-level systems (such as ladder DACs), but the 1-bit systems achieve near-perfect linearity, which in our opinion is much more important than SNR. Benchmark has overcome the noise limitations of 1-bit conversion through the use of parallel 1-bit conversion systems. Our DAC2 sums the outputs of four balanced converters. Each of these four converters has sixteen equally-weighted balanced 1-bit converters (for a total of 64) that are summed together to improve the SNR of the system. These 64 1-bit converters can be driven from a 32-bit PCM signal, or from a 1-bit DSD signal. Either way, the performance is nearly identical, and none of the multi-bit THD issues exist. In this sigma-delta configuration there is almost no difference between the in-band performance of PCM vs. DSD. The only measurable difference at the output of the DAC2 is that 64x DSD signals produce about 8 dB more noise in-band than 96/24 PCM (due to the SNR limitations of DSD). Ultrasonic noise is not an issue at the output of the DAC2 because we are careful to remove the ultrasonic noise produced by DSD noise shaping. These same filters also remove the ultrasonic images that are always produced by D/A conversion (DSD or PCM).

      8. The ultrasonic noise produced by DSD noise shaping must be removed after D/A conversion. It cannot be removed from the DSD signal before D/A conversion. This noise is due to the 6-dB SNR of the 1-bit DSD transmission system. Aggressive noise-shaping must be used in the DSD A/D, and at least once more in the mastering process. This noise-shaping is used to achieve an excellent SNR in the audible band by moving most of the 1-bit quantization noise to ultrasonic frequencies. Each time this process is applied, the quality of the DSD audio degrades (noise and distortion both increase). For this reason, the quality of DSD degrades very quickly in the mixing and mastering process. DSD has produced impressive results when the mixing and mastering processes have been omitted from the signal chain. To date, most of the DSD vs. PCM listening tests have omitted these processing steps. Unfortunately very few recordings can be produced without some mixing, editing, and mastering. Cascaded DSD noise-shaping processes should be avoided. For this reason, Benchmark does not recommend recording and mixing in DSD.

      9. The 24-dB noise advantage that 24/96 PCM has over 64x DSD begins to become significant in the mixing and mastering processes. In terms of in-band noise, each DSD noise-shaping process is equivalent to at least 16 cascaded 24-bit dither processes. In terms of distortion, there is no comparison; the DSD noise-shaping process adds distortion while the PCM dithering process is distortion-free.

      10. If the ultrasonic noise of DSD is not removed after D/A conversion, it will usually cause distortion in the playback system. The slew-rate limitations of most power amplifiers will fold the ultrasonic noise into the audible band causing distortion that is not harmonically related to the music. If the power amplifier has sufficient slew rates to pass the ultrasonic frequencies, similar problems will occur in the speakers. For these reasons, the ultrasonic noise must be removed from a DSD source after D/A conversion or before amplification.

      11. Benchmark introduced 64X DSD on the new Benchmark DAC2 converter family. This gives our customers the ability to play DSD recordings in native format. Existing DSD recordings should not need to be converted to PCM to be enjoyed on a Benchmark converter.

      12. Currently there is no practical way to play SACD disks through a high-quality outboard converter. SACD copy protection holds most existing DSD recordings captive to the limited quality of the low-cost conversion systems built into SACD players. It is our hope that many of the fine recordings that exist on SACD disks will be released for purchase as DSD downloads.

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