Q&A # 292 - June 9, 2002

Staff

Q Does the Pioneer DV-47 DVD player have the "CHROMA BUG"?

A Yes, it is identical to the DV-37 and 48A.

Q How important is 3:2 pulldown detection when shopping for a DVD player?

A 3-2 pulldown detection is important if you want a progressive scan DVD player. 3-2 pulldown detection results in almost a 50% increase in vertical resolution on 24 fps (film) sources.
 

Q I am currently experiencing a problem with DTS-encoded movies with my Panasonic RP56 DVD player. During play, usually around the middle of the movie, there seems to be a stutter in the audio and picture. Almost as if the movie was paused and then restarted again right away. Again, this always happens with just DTS for some reason.

A DTS does not have just one standard unfortunately, and this has caused some problems ever since DTS started showing up on DVDs. Player manufacturers use a variety of chips, and not all the flavors are on every chip. I see the Audio/Video glitches on DVDs from time to time, and just move on to the next chapter if I can't get past the glitch by using the fast forward button. It is not just DTS either. I see glitches on all types of DVDs. Also, modern DVDs have layer changes that occur midway through the movie, and this usually causes a short pause, but it should be happening with DD as well as DTS.

Q I have an old pair of Bose 901 speakers (with active equalizer). I plan on buying a surround receiver. I wrote a letter to Bose Corporation, questioning the use of the Bose active EQ with a surround receiver. They sent me a list of receivers available that have (Pre-Out/Main-In) jacks. They said by hooking up the EQ to these jacks, the EQ would be isolated, and would not interfere with the surround processors in the receiver or the other speakers. I found a receiver in my price range (Yamaha RX-V1000), but I have one minor problem. This receiver is a 5.1 unit with the Pre-Out for the new DD Matrix 6.1 and DTS ES (rear center). Is it possible to hook up my old receiver to power the 6th channel and at the same time keep the EQ isolated?

A The only time you would have to worry about EQ messing up the surround is if you used EQ with a two-channel stereo signal and input it to the receiver for Dolby Pro Logic decoding. For 5.1 analog inputs, the signal is already decoded for surround sound, and EQ will not affect it. If you use the Pre-Out/Main-In loop, again the signal is already decoded, so EQ won't affect it. The reason EQ can alter Pro Logic is that this format depends on the phase of the signal between the left and right channels. EQ changes the phase. For the matrix rear center channel, if you are taking the rear right/left pre-outs and feeding them to an old Pro Logic processor to get the 6.1, yes, EQ will mess that up, but if the 6.1 channel is already decoded when it comes out of the pre-out, then no, EQ won't cause a problem. Set your EQ to 0 when you are first firing up the system. Then adjust the EQ and see if it affects any of the channels as to where the sound ends up.

Q I have always been used to dealing with strictly 8 ohm speakers. However, I recently made a series of online purchases that may cause me problems.  I have an AIWA AV-d98 with 600 watts. I just purchased a set of KLH 82TA 250 watt speakers (4) as a front and rear pair but found out they are 6 ohm!!! The center channel is an 8 ohm BIC and the powered subwoofer is also 8 ohm (AR108).

Will I have trouble with the 6 ohm speakers? Should I set the receiver for 4 ohm or 8? And that only counts for the front. Rear says I should use 8 ohm. I guess what I am trying to find out is will they work just fine as long as the unit 'breathes" and is not overdriven?

Thanks in advance. I searched the net on this and you have given the clearest answers. By the way, the 6 ohm KLH's are Audio 82TA Virtuoso BLK 250 watts Tower Speaker with dual 7 inch woofers,1 inch cone tweeter.

A You will be fine with these speakers at either setting, but just don't crank the system up too loud. All the 4 Ohm setting does is limit the voltage on the volume control so you don't draw a lot of current.

Q I am currently in the market for a home theater system. I just purchased the speakers to go in the wall to appease the wife (Paradigm Reference front and rear). I am looking for advice on whether to go with a receiver and DVD player (such as the Denon AVR-4802 with DVD-3800 or perhaps the new AVR-5803 and DVD-9000) or should I go to separate components? I want to be under $10,000 for these components and want the best sound possible for movies and music. If you suggest components, what do I need (preamp, amp, tuner, DVD player, CD player) and what do you suggest? Help, I'm confused!

A The mass market receivers these days are really nice quality. Just pick out one that has a comfortable remote control and easy to read panel display. It should have at least 100 watts x 5 or x 7. Plan on getting the upper mid-level in the line, which should cost around $2,000 US. Some have AM/FM and others don't so if that is important, be sure to check that the model you choose has a tuner. As to DVD players, the Denon DVD-1600 that we just reviewed is a superb choice for video, CDs, and the new DVD-As. Don't forget a good subwoofer if you don't have one yet. Plan on about $1,000 -  $2,000 for one that will rattle your timbers.

Q I just purchased a Panasonic DVD RA60K DVD-Audio player that I have connected to my Denon AVR4802 A/V Receiver with the optical output. The DVD player claims to be capable of passing a 24bit/96kHz signal through the optical output, but my receiver is only reporting 48 kHz being input to it. Is this because of some copy protection written into the DVD-A software? If it is, are there any discs available without this copy protection? If not, what's the point of the player being capable of passing a 96 kHz signal?

A Yes, unfortunately some discs have a copy protection flag on them (CSS) that prevents the digital signal being output at high resolution. They are down-converted to 48 kHz before being output. The problem is that the disc packaging is not necessarily going to tell you it is protected. That might cause you to put the disc back on the rack and not buy it, which is a marketing no-no. The way around this is to just use the analog output jacks of the DVD player in these cases, and you will get the full resolution since the players have 24/96 or 24/192 DACs in them.

Secondly, the optical and coaxial digital output on DVD players today do not have the bandwidth to pass six-channels of 96/24. They can only pass two-channels of 24/96 or one-channel of 24/192. If there is a two-channel mix on the disc, there is a good chance you will get the 24/96 on the output as long as CSS is not enabled.

Q I  have a Runco 5801C rear projection TV with the VHD deinterlacer controller. Is there any advantage to using one of the newer players with higher bit rate and word length video processors? I am now using a Sony DVP S7000 DVD player. Would these newer players (Pioneer A47, for example) be any better in the interlace mode than the older 10 bit 27 MHz units or does the more powerful processor only benefit the progressive output?


A Going from 8-bit video DACs to 10-bit made a big difference, and now 12-bit DACs are starting to show up, but I am not sure how much visible difference these will make. The new 54 MHz DACs are using this bandwidth for "Over-Sampling", which might have an advantage for reducing video noise, but we have not tested this yet.

DVDs use 8-bit video. The reason to go beyond 8-bit DACs is that you want to ensure you get true 8-bit linearity. Most 10-bit DACs do just fine here. Higher bit DACs may also offer a lower noise floor. The Meridian 800 has 10-bit / 27 MHz DACs, and it has a lower noise floor than all but one DVD player on the market.

2x over-sampling is important. 27 MHz is 2x for interlaced video. For progressive video you need 54 MHz for 2x oversampling. There are new DACs with even more oversampling, but we have yet to see it make any difference. The reconstruction filters after the DAC are more important.

The Sony DVP S7000 is a fine DVD player. The Panasonic RP56 or Denon 1600 would both offer a nice improvement for low cost. The Kenwood 5700/5900 also produce great video, and they are carousel changers.

 

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