Q&A # 99 - January 19, 1999

Staff

Q There was a question on the Q&A section that got my attention regarding the Yamaha RX-V990. Since there are only 5 inputs on the RX-V990, in order for a person to maximze the output without robbing power from the receiver or sending LFE to the mains in a sub equipped system, I would suggest that the person use an 80 Hz high pass filter with a subout at 12 dB per octave and set the DD DVD player to speakers "large" and bass to "mains only". This has been an annoying problem, and at good volume levels, an improper crossover will cause certain problems. An example is the Sony SDPEP9 decoder that sports a mere 6 dB per octave high pass. My question to you is this. DTS is not a standard for anyone in the consumer electronics arena. Do you feel it will always be a niche market or will it die out as we achieve higher and higher resolutions on DD?

A Since DTS is now a standard feature on all new receivers and processors, at least those in the $799 and up range, the DD vs. DTS format on DVDs will probably become transparent to the user. That is, we will just rent or buy the movie and not worry about which format it has. For the future, DD has the more difficult task, since it is the one that cannot accommodate 24/96 in mulltichannel (5.1) sound. DTS can accommodate this in their current spec, and DVD audio can as well. The fact that there are several formats available gives movie producers more flexibility in giving the consumer the best picture and sound for any particular situation, such as special editions of successful films. We are becoming too obsessed (I'm guilty too) with the technology being absolutely perfect, and have stopped enjoying the movies. A visible one second pause, when the DVD changes from layer 1 to layer 2, upsets us. If we see five pixels in the corner for an instant, our evening is ruined. Do you remember when it was just VHS at the video store? Remember how lousy the picture and sound were by comparison? Every movie had glitches here and there. But that did not keep us from enjoying the movie. We need to get back to that enjoyment. From what I saw at the CES a couple of weeks ago, I am resigned to the fact that home entertainment technology will never again be at a resting stage. It will always be in flux, now that the signals are digital. So, let's be happy with what we have in the here and now, and take each day as it comes.

 

Q I am contemplating my first step into Home Theater. My question is very simple. Will using a Home Theatre Amp (I am looking at the Yamaha A592 or at a push the new A792) compromise listening to normal stereo Compact Discs? My current hi-fi amp (Yamaha AX550 ) has a "pure direct" switch which bypasses the tone controls. The sound difference is very significant. So will playing CDs through an AV amp with the signals going through various DSP chips, etc. affect the sound quality?

A Every circuit component that the signal passes through degrades signal quality.The goal is to get the job done with the minimum amount of circuits in the path. So, if your receiver has a direct mode that sends the source signal (CD player) direct through to the power amplifier (usually called a bypass), the sound will likely be better than if it has passed through all those DSP chips. Tone bypass switches still have the signal passing through those switch contacts, but not through the tone control circuits. Plus, you don't have phase shift when tone controls are not in the path. Thus, the sound is better here too. Therefore, the answer to your question is "yes", and you should use the simplest path possible for the purest sound.

Q When watching videos on cable TV, when the background turns white as the scene changes, there is a distortion in the audio. Is there a way to filter the signal or are there too many splits in the house (4)?

A I have seen this problem before. When there is an appearance of a large amount of white in the background, the picture will flicker and there is a lot of static in the audio. It only happens on cable, not satellite, and I would suggest this may be due to a weak cable signal. I see it in the upper channels where the signal is not very strong to begin with. Too many signal splitters can reduce the signal strength. You might be able to solve this problem with a signal amplifier placed at the spot where the cable comes into the house. If you put it at the TV, you will be amplifying noise in the system too, so put it where the signal is strongest.

Q I was wondering if there would be a problem for me to bring my receiver (Yamaha) and DVD player (Pioneer) to a country which uses the PAL system. I know that I would have to get a multi-system TV, but is there anything else that I need to be aware of?

A As far as I know, it should all work properly, even at 50 Hz, but you will also need a 240 to 120 voltage downconverter. However, if any of our readers have taken US video equipment (VCRs, laserdisc players, DVD players) to the UK (which uses 50 Hz rather than 60 Hz here in the US), or equipment from the UK to the US, please let us know if you experienced any problems and how you solved them, so we can post the info.

Q Of the improvements to Marantz's new RC2000 MkII, I'm confused about its ability to handle ultra-high-frequency IR codes. Are new product developers moving in this direction? How significant is it for a learning remote to do this?

A Both Philips and Harman Kardon offer new remotes that can handle higher IR codes. Both are programmable like the Marantz but are a lot more flexible.

 

Q I read a review by Stacey Spears on an Audio Alchemy time base corrector and was interested to see a mention of ghost cancellation. I that an available option? Are there any other devices that provide ghost cancellation?

In Chicago, several over-the-air signals are plagued with ghosts due to the placement of the skyscrapers around the transmission sites (signals transmitted from the Hancock building have major mulitpath reflections from the Sears tower, and vise versa).

I'm interested to know what methods are available to remove the ghosts and how effective they are.

A I received the ghost chip, but I never had it activated while I was in the Los Angeles area. This was a hot topic a couple of years ago, but has since vanished. I guess the introduction of DSS and the promise of HDTV have changed things. Meanwhile, we all live with ghosts. I would suggest going to a dish if you have a clear view of the satellites. The picture is much better, and no ghosts.

Q I have noticed on my TV a tendency for light areas across a middle gray to cause what resembles a streak. The streak is always to the right of the source of light, and it makes the area to the right of it darker (which gives the appearence of a streak). I have noticed this on several other sets as well. The streaking doesn't seem to be as bad from DVD sources as it is from broadcast and VHS. It is becoming very annoying.

A This is often caused by having the contrast set too high, something we all tend to do. Try turning the contrast and/or sharpness down. You may have to compensate by adjusting the brightness or amount of color.

Q I have a Sony SAT-A2 satellite receiver with digital audio output via Toslink. Would placing a jitter reduction device between the satellite receiver and the preamp improve performance?

A Yes it could improve the sound, but this is a new area, so you should try before you buy. Remember, the digital output of DSS is not the same bitrate (even though it is 48 kHz - 20 bit) as the digital output from a CD player, where jitter reduction components have been available for some time.

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