Atmos Musings and Shelf Life (eng)

   A bit of an eclectic mix this time around with two topics, the first somewhat controversial, the second a useful (I hope) tip.

   Elsewhere on this site, and in our June Q&A column, we recommended using the same amplifier power for the front, surround and height speakers in an Atmos setup. I don’t entirely agree, though my personal experience with Atmos is limited so far to trade demos and theatrical presentations. Most Atmos-ready AVRs will, of course, have matched power—that’s just the nature of the beasts. But if you have a pre-pro and, say, 200Wpc amps driving the front speakers, do you really need 200Wpc on the other six (for 5.1.4 Atmos) “full range” surround and height channels?

   One consideration here is the sensitivity of the surround and height speakers. If they’re half as sensitive as the fronts (that is, 3dB lower in rated sensitivity) they’ll need twice the power—assuming they’re being driven to the same level. If they’re twice as sensitive (+3dB) they’ll need only half the power. The former is more likely; many (not all) smaller drivers of the sort used for the upward-firing element(s) of Atmos-enabled speakers tend to be quite low in sensitivity. I have yet to see the sensitivity of the upward facing drivers specified separately in such speakers, but if you own Atmos-enabled speakers you can check for this. When you calibrate the channel levels, simply note the difference in settings for the front and upward-facing speakers, assuming the level indicator on your AVR or pre-pro is in decibels rather than some generic number.

   But will you normally drive Atmos’ surround and height speakers as hard as the three fronts? Even if you’ve calibrated them to the same level, as you should, this is unlikely with most program material. Have you ever turned off the main speakers in your home theater and listened to the contribution of the surrounds alone? On films, at least, it’s astonishing how little they contribute, compared to their subjective impact with the entire system operating. Yes, occasionally they’ll speak out more aggressively, but that’s rare.

   It’s a safe bet that the same will apply to the Atmos height channels. Their contribution will be similar in level to the output of the main surround channels. One notable exception could be surround music, where the extra channels are used to put the listener in the middle of the performers, rather than merely providing ambience with the main music-making taking place in front as it would be in a live performance. But even then, if you’re considering Atmos-enabled speakers rather than discrete ceiling speakers, the small, upward firing drivers in these designs are generally bass managed very aggressively, sometimes rolling off as high as 180Hz. With so little bass to handle, this will further reduce the power needed to drive them effectively without clipping the amplifiers.

The power needed for other than the front channels will, therefore, depend on a number of factors. Do you plan on using Atmos-enabled speakers or discrete ceiling speakers? Do you have an AVR with its own amps or a pre-pro with separate amplifiers? And do you plan to listen to lot of surround music with the musicians placed all around you (though I don’t think many sound mixers will position a discrete musician or vocalist on the ceiling, unless the latter has god-complex!)?

   If you already have an Atmos-ready AVR with preamp outputs, and want to increase the power to the front channels, a 5- or 7-channel external amp might be just the ticket to drive the main speakers and surrounds. You could continue to use the AVRs internal amps to drive just the (typically, for home Atmos) four ceiling channels, whether Atmos-enabled or discrete. You could even go with a 3-channel external amp (though these are less common) for the fronts and use the AVR’s amps for both the conventional surrounds and the Atmos height speakers. If you already have a smaller external amp and a surround pre-pro rather than an AVR, you could move that amp to drive the Atmos channels and add a new, more powerful amplifier for the main speakers.

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New Use for a 2x4
   When I lived in California I was five minutes from the nearest IKEA and purchased five IKEA bookcases to hold not only books but also most of my collection of CDs and videos. I disassembled them for the move, and reassembled them in my new home. That’s not an exercise I’d recommend to anyone, but it did save a bundle on new bookcases, not to mention that the nearest IKEA is now hundreds of miles away. Now they’re filled mostly with videos, with only a few shelves dedicated to CDs and books. (More bookcases will be needed to house the rest of my collection!)

   The only issue with this is that video and CD cases are relatively shallow and the bookcases are 9-inches deep. This isn’t an issue at eye-level, but the deep setback makes searching the lower shelves a nuisance. My solution was to cut 2x4s to the width of the shelves. I bought ten such 2x4s; my friendly neighborhood Home Depot did the cutting. That gave me forty 22-inch wide 2x4s. So for an investment of just under $40 I can use them behind the videos, CDs, and books in a number of ways, moving the contents either 1.5-inches or 3.5-inches closer to the front of the shelf. By using two of the spacers, one flat, the other on its side, I can also move the contents almost flush to the front of the bookcase for a far better view of the titles on those low shelves.

If those measurements puzzle you, it's because modern 2x4s are actually 1.5 x 3.5-inches. I bought premium ones that cost an extra buck or so each; you can’t see them, but you’ll know they’re there and you can tell your audio friends that they sound better!!!

   An additional possible benefit to this arrangement is that varying the depth on different shelves might offer some useful diffusion on the wall behind the seating position where the bookshelves are located. I haven’t yet evaluated this, however, and an AB test will be impossible. (Listen, remove contents of shelves, change spacers, reload, listen again!)

sursa: soundandvision.com

YouTube's new 4K, 60fps videos are gorgeous — but probably won't run on your laptop (eng) and /si (ro)

   

   YouTube is now testing 4K videos at 60 frames per second. Last year, the video streaming company tested both 4K and 60fps videos separately, but this small batch of videos marks the first time both settings have been shown together.

   Most viewers won't be able to enjoy these videos to their full potential. You'll need both a 4K monitor along with a computer and internet connection powerful enough to stream the footage. I just upgraded to last year's Macbook Pro Retina, and even with a 300mbps connection, the video is stammering about like it's drunk and can't find its house keys.

   I thought today would be the day I watch K-pop in ultra-HD, but I guess not. Looks like today, just like every other day, I'm stuck watching Secret in junky old non-ultra HD. What do you think this is, YouTube, 2014?

   I've included a couple other videos that will torture your laptop:

   Correction: I originally described 60 fps as "a frame rate faster than the human eye can discern." That's incorrect, and obviously so. How else would we enjoy arguments over first-person shooter frame rates if not for people distinguishing 60 fps versus 30 fps?

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YouTube extinde suportul pentru redare video la 60 FPS şi la clipuri cu rezoluţie UHD

   După ce în urmă cu câteva luni a permis utilizatorilor să încarce clipuri video filmate la 60 de cadre pe secundă, îmbunătăţind dramatic cursivitatea mişcărilor redate în scenele rapide, YouTube testează extinderea acestei opţiuni şi la clipurile cu rezoluţie mai mare decât cea Full HD.

   

   Astfel, cei care deţin o conexiune bunicică la internet şi dispozitive de redare suficient de performante pot experimenta primele clipuri YouTube disponibile la rezoluţie 3840x2160 pixeli şi 60 cadre pe secundă. Din păcate, deocamdată va trebui să ne mulţumim cu selecţia de filmuleţe experimentale pusă la dispoziţie de administratorii YouTube, ceea ce nu este neapărat un impediment, din moment de dispozitivele capabile să filmeze la 60 cadre pe secunde folosind rezoluţie UHD sunt fie extrem de scumpe, sau cu prestanţă dezamăgitoare în ce priveşte calitatea imaginii.

   Pentru a ne putea bucura pe deplin de claritatea şi nivelul superior al detaliilor, YouTube recomandă folosirea unui monitor sau televizor capabil să redea în mod nativ rezoluţia 3840x2160 pixeli, folosind rată de actualizare a imaginii de 60Hz.

   Momentan, opţiunea pentru încărcarea filmuleţelor YouTube la rezoluţie 4K/60FPS este ascunsă publicului larg, însă putem consulta playlist-ul cu filmuleţe de test, comprimate folosind un codec experimental, optimizat pentru calitate crescută şi folosirea mai eficientă a lăţimii de bandă.

sursa: theverge.com  si   go4it.ro

Marantz AV8802 Surround Processor Review (eng)

PRICE $3,999

AT A GLANCE
Plus
11.1 channels with Audyssey MultEQ XT processing
Dolby Atmos, Auro-3D, and DTS:X surround
Full 4K video processing upgradable to HDCP 2.2
Minus
Limited range for remote sensor

THE VERDICT
Noticeably improved sound quality over its predecessor plus Atmos, Auro-3D, and DTS:X surround processing make the Marantz AV8802 a top-notch upgrade.

It’s been a little more than two years since I reviewed the Marantz AV8801 surround processor, and I liked that model so much, it never left my system. At the time, I thought it was the best-sounding pre/pro I had ever owned, and I had no real desire to upgrade anytime soon. That all changed last fall when Dolby announced that Atmos for the home was on its way. I started thinking how I could finagle four extra speakers into my room—because for some reason, I have this overwhelming desire to stay on the cutting edge of home theater technology, regardless of the personal expense.

Upping the Ante
The AV8801 was tricked out to the nines with virtually every bell and whistle that could be found at the time in a pre/pro, and the same is true of the AV8802. Networking goodies include Apple’s AirPlay, Pandora, SiriusXM, Internet Radio, Spotify Connect, and Flickr. In lieu of the four-port Ethernet hub that was on the AV8801, there’s a single Ethernet jack on the rear, but now you get Wi-Fi and Bluetooth, as well as DLNA 1.5 support for streaming audio files from your local computer network.

The upgrades don’t stop there. Marantz’s engineers dissected every critical component for the AV8802—including the transformer, the DACs, the HDAMs (the company’s proprietary amplifier modules), and the filter capacitors—and relied on trickle-down technology from the company’s Reference line, specifically the PM-11S3 integrated stereo amplifier. The 11.1-channel preamp section utilizes balanced outputs. Enhancements include brand-new, fully discrete current-feedback HDAM-SA2 modules, along with improved jitter-reduction circuitry for the optical, coaxial, and HDMI inputs. If that’s not enough, the engineers also included a lower-noise toroidal power transformer (derived directly from the PM-11S3), 768-kilohertz/32-bit DACs (AKM4490), and capacitors that have twice the reserve than what was in the vaunted AV8801.

As with its predecessor, the build quality of the AV8802 is outstanding. In addition to the upgrades listed above, the unit has a dual-layer copper chassis that’s carried over from the AV8801, which helps isolate the electronics from outside interference.

If you’ve liked the look of past Marantz AVRs and pre/pros, then you’ll be happy to know that the design philosophy hasn’t changed. The AV8802 has the same classy curved front panel and sparse layout, which includes a volume knob on the right, a source select knob on the left, a power on/standby button, and a simple porthole display showing the selected source and volume level. There’s a flip-down door beneath the porthole that reveals navigation and other controls along with a large traditional LCD. In addition to the plethora of discrete control buttons, there are connectors for HDMI, headphone, Audyssey mic, and auxiliary analog audio/video.

The rear panel is well laid out and accommodates 15 individual balanced and unbalanced output connections. This includes dual subwoofer outputs with XLR and RCA connections for each. These are on a single channel, but there are independent level settings for each subwoofer. Note that even with all these connections, a maximum of 11.1 independent channels may be playing at once. There are seven HDMI 2.0 inputs, three outputs (Monitor 1 with ARC, Monitor 2, and Zone 2), dual component inputs/outputs, and enough gold-plated analog inputs and outputs to satisfy most every audio need you could think of. Rounding out the features on the back panel are a moving-magnet phono input, dual antenna hookups for Wi-Fi and Bluetooth, HD Radio (AM/FM) connection, a single set of XLR balanced inputs, and a second USB input in case you want to permanently attach a storage device loaded with music and photos.

Video processing is handled by an Analog Devices ADV8003 chip, which performs admirably. Additionally, the AV8802 has 4K video processing with the ability to scale current sources to UHD (3840 x 2160), and while the initial units shipping into retail won’t comply with HDCP 2.2, Marantz says it will begin offering a free hardware upgrade at some undesignated point in the future in order to conform with the new copy-protection scheme (you’ll have to pay for one-way shipping). One thing I love about Marantz’s video implementation is the ability to customize the video output by source, so if you want the 1080p/24 signal from your Blu-ray player to be unprocessed but your cable/satellite signal to be upconverted to 1080p or 4K, you can make this choice in the setup menu.

The included remote is competent in its layout and fits nicely in your hand. Thankfully it’s backlit, so it’s easy to see in a darkened room. However, as with my reference Marantz AV8801, the remote sensor on the AV8802 is quite a bit less sensitive than those on my other components, and in my space, it only responds to commands if you are within 15 feet of the unit. While this may not be an issue for most folks, I sometimes watch or listen from an adjoining room, and these pre/pros have been the only pieces in my rack that won’t respond from 16 feet away to either the factory remote or my URC universal. Of course, if you use an RF remote or control system with a receiver hub, it won’t be a problem.

Setting Up
Marantz has the best user interface system I’ve come across (shared by sister company Denon). It’s extremely intuitive, and it looks pretty, too. When you fire up the AV8802 for the first time, a guided setup “assistant” will greet you and walk you through hooking up the various components to your new toy. The only downside of this setup is that I’ve never been a big fan of hooking up wires while the unit is powered up, but if you need it, it’s there. Regardless, once you have all your amplifiers hooked up—I used a total of 11 channels in order to take full advantage of the Atmos capabilities—you can then perform an Audyssey calibration by plugging the supplied mic into the front of the AV8802.

My first calibration didn’t go very well, with the unit setting my trims much too low, especially for my subwoofers. Perplexed, I ran through the process a second time, which worked perfectly. I may not have had the mic situated properly the first time.

Whether you’re a fan of Audyssey or not, I love how the company’s auto calibration simply nails the speaker distances down to a tenth of a foot, at least in my space. The AV8802 has the Platinum Suite of Audyssey technologies, including MultEQ XT32, Sub EQ HT, and LFC (Low Frequency Containment). Additionally, the unit is Audyssey Pro–ready for even more acoustical calibration accuracy when implemented by a qualified professional using Audyssey’s Pro Installation Kit. My colleague Kris Deering has opined that Audyssey should allow more flexibility (such as only equalizing the subs or telling the software to only measure below 200 hertz for further customization), which I agree with completely. That said, I think Audyssey and their implementation partners are trying to keep things as simple and automated as possible to make standard calibration a plug-and-play solution for their customers.

Another Format War?
Dolby isn’t the only company out there promoting new audio formats that make use of overhead height channels. Along with Atmos, Auro-3D was also well received at last September’s CEDIA Expo, and as I write this, DTS’s answer to the object-based Atmos system, DTS:X, is said to be nearing introduction. Marantz, in an unusually thorough commitment to future-proofness, has you covered on all three fronts. The AV8802 ships with Atmos capabilities, and an Auro-3D firmware upgrade costs $199. The company also told us that, before the end of 2015, a DTS:X update will be available (no decision has been made about whether this will be free or incur a nominal charge). What’s more, while Atmos and Auro-3D, at least, normally require you to commit in advance to different speaker locations for some of the surround channels, Marantz plans to mitigate this by allowing a unified speaker layout for all three formats, letting you switch easily among them to accommodate different software. Format war? Not with the AV8802.

Look Out Above!
My audio system consists of three M&K S150 speakers across the front, four SS150 surround speakers mounted approximately 6.5 feet from the floor (not conforming to Dolby’s recommendations for Atmos, but I own them and there’s no other way to place them in my living space), four Atlantic Technology IC-6-OBA in-ceiling speakers for Atmos height duties, and dual subwoofers—a Hsu Research VTF-15 MK2 and an SVS PC-Ultra. Amplification is provided by a Parasound Halo A 51 for the three front speakers and L/R surrounds, with a Parasound ZoneMaster 1250 bridged to six channels for the rear surrounds and four Atmos overhead speakers.

When I finally got to audition Atmos-enabled discs at home, I found that they really help draw you into the film much more than I had anticipated. In The Hunger Games: Mockingjay, Part 1, the Capitol has grown tired of District 13’s rebellious ways and decides to bomb its citizens into submission. We’re taken into the command center of the district as the explosions begin, and wowza!—your fight-or-flight instincts will have you ducking for cover as the roof seems ready to cave in. This is just one of many scenes that make great use of the additional channels.

Unfortunately, the number of Atmos-enabled titles on Blu-ray can still be counted on two hands—and the number of really high-caliber movies for the moment is limited to a couple of fingers. But thankfully, Dolby has a new derived-surround algorithm—Dolby Surround Upmixer (DSU)—which allows you to take full advantage of your Atmos-enabled system with traditional channel-based audio tracks. The additional speakers definitely add to the atmosphere of movies. For example, there’s a scene in Captain Phillips where pirates storm a container ship. The only way the ship can defend itself is with fire hoses (talk about taking a knife to a gun fight!), and when the camera switches to the perspective of the pirates, the Atmos overhead speakers come into play and add to that feeling of the water coming down on you—a fact I verified by manually turning off the amp supplying power to the overhead speakers to gauge the effect. My only gripe with the upmixing was that there was some occasional score bleed to the front ceiling speakers that could overpower the dialogue, but this might have been because the front overhead speakers were set a tad hot by Audyssey. (Dolby needs to release test tones on their demo discs.)

While I was wowed and amazed by Atmos and DSU on movies, the two-channel performance of the AV8802 is what really blew me away. The hardware upgrades done by the Marantz engineers revealed themselves in critical listening tests. The soundstage is deeper and wider, and voices are crisper and clearer when compared with my AV8801. I recently had a Krell Foundation pre/pro in my rack, which was head and shoulders better than the AV8801 on two-channel listening, but the AV8802 has closed the gap considerably in this regard (at only two-thirds the price of the $6,500 Krell).

This superb audio quality came to light on the song “Second Choice,” from the Marti Jones album Live at Spirit Square. It features a bass guitar, some bongo drums, and Jones’ fabulous voice. The bass is tight, and the layered track transports you directly to the live performance. The Marantz picked up the subtle aspects of the recording, such as the bassist’s fingers sliding along the strings. This has become one of the first audio recordings I use to test out new gear, and the AV8802 definitely made it shine.

Conclusion
I could wax poetic about the prowess of the AV8802 for several more paragraphs, but alas, the dreaded word count has caught up with me. After experiencing Atmos in my home, I have to admit: There’s no way I can ever go back to a conventional five- or seven-channel system. Furthermore, when the considerable improvement in two-channel performance is factored in, this is an easy upgrade to consider. In fact, the AV8802 would be my first choice for our Top Pick of the Year, and it will be tough to knock off its perch as the rest of 2015 plays out. Highly recommended.

sursa: soundandvision.com