Q&A # 196 - August 28, 2000

Staff

Q I heard Lucas is shooting the next Star Wars with a high definition video camera set for 1080 x 1920. Won't there be a problem converting the 30 video frames per second to 24 film frames per second in theaters that don't have video projectors and have to use regular film projectors?

A Lucas will be using the new Sony HDW-F900 video camera, which can shoot at 24 video frames per second as opposed to the conventional 30 video frames per second. It will also be 1080p instead of 1080i. Panavision has developed the anamorphic lens for the camera that allows 2.35:1 aspect ratios on the video tape. Assuming that the theaters' video projectors will be formatted to handle 24 frames per second, there should be no problems regardless of whether it is shown in video form or film form. High definition video cameras have come down in price from several hundred thousand dollars each, several years ago, to about $60,000 now. So, I suspect we are going to see more HD programming on TV, as studios can now afford the cameras. Also, I suspect, we will see more theater movies shot with video. It saves a fortune in film costs. But, if I were producing a movie, I would use 16:9 rather than 2.35:1. This would mean no black bars in home theater 16:9 TVs when it was released on DVD. On the other hand, ABC has just announced they are shutting down HDTV programming except for the SuperBowl until there are more HDTV sets out there. Gee, that ought to really spur sales of TVs!

One additional thing about 24 video frames per second is that it looks more like film than 30 frames per second. In using my Canon DV camera in the progressive scan mode, I noticed that it looked less "real" or "live" than when I use the interlaced mode. That is because, with interlacing, there are really 60 pictures per second on the screen, even though each one of them is only half picture (a "field"). In experiments, the movie industry found that using film at 60 frames per second made it look too "real", sort of like live TV. So, in order to keep having the movie at the theater looking like film, 24 video frames per second is used when shooting the movie.

Q What does PMPO stand for? How is it measured? What does RMS stand for? How is it measured? Is there a link between the two . . . can one be figured out if the other is known? Are there any other ways of measuring sound power?

A PMPO means Peak Music Power Output, and is a term used in the mass market receiver industry. RMS stands for Root Mean Square, and it is the most basic term for representing power output. The RMS specification is the one to look for, but even it can be stretched a bit if the measurement is taken only at 1 kHz, which is something you see, again, with mass market products. Also, it can be specified at 4 Ohms, 6 Ohms, or 8 Ohms. The standard reference is RMS at 8 Ohms and 20 Hz - 20 kHz.

Q I am in the market for Klipsch RF-3 speakers and an Onkyo 696 AV receiver. However, I came across the Yamaha RX-V995 receiver, and it seems to have more features and functions than the Onkyo. I am lost. Which AV receivers would you recommend ?

A Yamaha receivers tend to have the most features, while Denon and Onkyo tend to have larger power amplifiers. All of them do a pretty good job of dealing with surround sound. It is a matter of what you prefer and whether or not you plan to add outboard power amplifiers later. If you like a lot of features and will get an outboard power amplifier, then get the Yamaha. Otherwise, get either the Denon or Onkyo.

Q I finally bought a DVD player and A/V receiver to add to my VCR and CD player, replacing the old stereo receiver. My TV has an S-Video input, so I connected the DVD and receiver that way, and it's great. The VCR, however, is connected via composite video, so it won't output to the TV through the S-Video connection. Is there a converter available that will allow me to connect the VCR to an S-Video input on the receiver?

A Yes, Monster Cable makes one. It's called the CSVA-1, and MSRP is $99.95.

Q I have this rather primitive TV, that has mono sound. On the back of the unit, there is only an outlet for the cable TV, thats it! Is there any way to add a mediocre surround system to it because the sound is just horrible! Can I do it through a VCR?

A Yes, your VCR is the key. They all have TV tuners in them, and as long as it is a stereo VCR (most of them are), all you need to do is connect your TV cable to the VCR, with the video output of the VCR to your TV, and the audio output of the VCR to a surround sound receiver. And, by the way, it does not have to be a mediocre one. It can be just as wonderful as your checkbook will allow. If your TV is really old, you may have to use the antenna output of the VCR to your TV. In that case, turn the volume control of your TV down when using it for surround sound. The antenna input carries both video and audio.

Q I've just bought a pair of tube monoblocks that put out 70w and 120w in triode and ultralinear mode respectively. What are the pros and cons of these modes and which mode is better for a pair of speakers that have an 85dB sensitivity and 50-120w power requirement?

A You did not mention the brand or model, but I suspect they have pentode tubes. Pentodes have three grids rather than the one grid in a triode. With the amplifier set in ultralinear mode, the three grids are wired separately, and the output is more linear than with a triode, along with a higher power output. However, there is a price for this, and it is in terms of distortion. With the amplifier set in triode mode, the three grids are connected together, so it effectively has one grid, making it a triode. The response is not quite as linear, there is less output, but the distortion spectrum is less irritating. If you had sensitive speakers, I would say use the triode setting, but since your speakers are not very sensitive, you will just have to try both modes out and see which one you like. If you don't listen to music very loud, the triode setting may still be fine.

Q I have a pair of Acoustic Research AR312HOs for my front, AR308HOs for my rears, ARS10 (sub), and a ARC25 for my center, with a Sony STRDA777ES receiver with 5 channel pre-outs for an external power amp. I would like to use the pre-outs to bi-amp my fronts and my rears to give the best sound. How would I do this?

A The HO series is so sensitive, I don't think you will need to bi-amp, but if you want to go ahead with it, you will need to use the built-in power amplifiers of the Sony, along with the outboard power amplifier. Remove the bus bars that connect the two sets of binding posts on the speakers first, as it is extremely important that you not connect the outputs of two amplifiers to the same speakers. Leave the speaker outputs from the receiver connected to one set of the binding posts (either the mid/tweeter posts or the woofer posts). Connect the pre-outs to your outboard power amplifier, and the speaker outputs from the outboard power amplifier to the other set of binding posts on your speakers. Be sure to have the correct channel pre-outs going to the outboard amplifier channels that are driving the same speaker channels as the speaker outputs of the receiver. In other words, use the right front pre-out to drive the outboard amplifier channel that goes to the right front speaker. You could also consider using the outboard amplifier to bi-amp just the front left and front right speakers, and let the receiver drive the rear speakers. This would mean using a Y adapter to connect the front left and right pre-outs to two (each) inputs of the outboard amplifier. Then, the outputs of the outboard amplifier would drive both sections of each speaker. The remaining channel of the outboard amplifier could be used for the center channel. This would free up some power reserves in the receiver to handle the rear speakers.

Q What's the scoop on Minidisc? It's never mentioned in any magazines, online or not. I'm interested in the technology, but am worried about being stuck with the Betamax of digital recording. I hear conflicting stories of how they outsell CDRs in Asia and parts of Europe. Yet, I see that Sony only has 3 models this year when they had close to a dozen last year. Are they exiting the market they created or are they coming with new stuff this fall? I live in New York where the stores rarely stock more than one really old model Minidisc component, yet I see over a dozen portables. I don't get it? Why are they never mentioned in magazines? I was led to believe that most if not all people can't tell the difference sonically? In general, when is the year's model released - in the fall?

A Minidisc uses a compression algorithm that was touted as being as good as CD, but it is not. The differences are audible. However, it is a clever technology that is nice for portables, where it is not so important that it sound absolutely as good as a CD. The problem as I see it is the cost of the media. They didn't want to make the discs so cheap that it would be economical for you to just copy your friends' CDs instead of buying the CDs themselves. Their copyright paranoia killed the format. Now that MP3 is so popular, with lots of portable MP3 players available, and with CD-R being able to handle MP3s, Minidisc is headed for the dumpster.

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