Q&A # 123 - July 6, 1999

Staff

Q I saw an old Cinerama movie a few days ago, on DVD. Why didn't they just use one wide angle lens instead of three regular lenses? Wouldn't this have achieved the same thing?

A The lenses used in Cinerama were 28mm focal length onto 35mm film. This is already slightly wide angle. Secondly, for many of the shots, there is no wide angle lens that could have recorded the same field of view that the three lenses did. It would take something around a 9mm lens to do it, and such a lens would have unacceptable distortion when trying to record an image onto 35mm film. Three-camera Cinerama was too expensive though, so they went to single lens photography and just showed them in the Cinerama theaters. "The Greatest Story Ever Told", "Ice Station Zebra", and "It's a Mad, Mad, Mad, World" were shown there, but they were really not that much different than regular widescreen movies shown in conventional theaters. "Cleopatra" (the one with Elizabeth Taylor) and "The Greatest Story Ever Told" started out as three-camera Cinerama, but the studios canceled that plan and completed them with one camera, redoing the initial three-camera shots. It would be very interesting to see what is in their vaults with respect to leftovers from the three-camera scenes that were shot.

Q Help!!!!! So far, my wife has been very patient with me as I have indulged my growing fascination with home audio equipment purchasing. But, although she is genuinely as pleased with our purchases as I am, I do see a day on the horizon when her sound fiscal policies will say enough is enough. Therefore, I need you all to tell me what piece in my system to upgrade that will give me the greatest bang for my buck. Current system is Sony DA 30 ES receiver, Rotel six-channel amp, Yamaha 760 CD player, Pioneer DV05 DVD player, B&W 600 series mains, B&W CC6 center, Velodyne 12" sub, Nordost cables (awesome!!), and B&W 302 surrounds. I use the system 60% for music and 40% TV and DVD. My budget is $1,000 or less. Thanks. We both love your Q&A!!

A Frankly, I think you are in pretty good shape, so there is no reason to spend your $1,000 right now. However, you will probably want HDTV towards the end of 2000, so put your money in the bank and add a little to it now and then. By that time, HDTVs will be available for about $5,000.

Q Several months ago I got a pair of B&W DM-603 speakers and I am running them through a Technics DX-6 receiver. My problem is, the bass is boomy, even if the speakers are placed 2-3 feet away from the back wall. When I bought the speakers, the guy at the store said that my receiver is not good enough for the speakers I am getting. The thing is, this Technics receiver has lots of features for the price, and I just don't have enough money to buy better receiver/amplifier. Please give me some tips on how to get better performance out of my system. Is the boomy bass due to not-so-good receiver, or is it because the passive radiator scheme the speakers use?

A Just about any speaker can sound boomy under certain conditions, in particular, with the placement, size and shape of the room, and surrounding objects. However, it is not your receiver. The 603s have 90 dB sensitivity and are 8 Ohms nominal. That is a relatively easy load for your receiver. The 603s have a port along with the passive radiator, so I would suggest putting foam plugs into the port (plugs should have been in the boxes with the speakers). That will reduce the bass output and make them less boomy. If you can't find the plugs, you can get some soft foam at hobby shops or stores that sell material (cloth).

Q I  just wanted to make a comment regarding the availability of the Multi-System Audio/Video appliances in US. I beg to differ regarding your suggestion of these items being "high priced". Considering the supply and demand economics, yes such appliances will cost higher. However, the prices found at some places (usually Electronics stores found in and  around Pakistani or Indian communities in North America) are not all that much higher. For example http://www.kumud.com/ has Panasonic and Sony multi-system VCRs for as low as $224.

A I stand corrected. I see that such products can be had for low prices indeed. Apparently, these VCRs will record and play in NTSC and PAL. Depending on your specific needs, however, it might be wise to get the best model available, rather than the cheapest one, if high-quality recording and playback (as well as long-term reliability) are major concerns.

Q I recently purchased a DVD player for my Home Theater System and was hoping to find an answer to the question regarding Optical or Coax for the digital output. My DVD player and receiver have both, but I want to get the best sound without spending as much on the cable as I did on the player. Any help you could offer would be appreciated. For your reference, I am running an Onkyo TX-DS838 receiver with an Onkyo DV-S717 DVD player.

A The use of optical vs. coax for digital signals is controversial, and some people feel coax is better. However, I don't know of any scientific studies that show one is superior over the other. I have not heard any differences, so I use optical most of the time. Optical cables are inexpensive, and they eliminate impedance issues as well as result in one less possible source of ground loop hum.

Q I just upgraded my home theater to 5.1 Dolby Digital and discovered that my receiver is also equipped with 5.1 inputs besides the Optical inputs for my DVD player. I thought of using the 5.1 inputs for DTS signals. My question is, why can't we find any DVD players that have two optical outputs for DD and DTS, and also two sets of 5.1 outputs? Then we could eliminate the need for outboard DTS decoders.

A If DTS decoding were built-into DVD players, you would still only need one set of 5.1 ouputs, since the DVD player would be able to route the decoded DD or DTS through the same set of outputs. You only need one digital output as well. The DVD player automatically switches the proper signal to that single output. However, the use of DTS decoding to 5.1 outputs in DVD players is slow to catch on with manufacturers, because it adds expense. Competition is tough, and there are not many DTS DVDs out there (perhaps 20, compared to several thousand DD DVDs). You are absolutely correct though. DD and DTS decoding to 5.1 coax outputs would make life much simpler for those consumers with receivers that don't have decoding built-in.

Q I have a question on the delay time for center channels on Dolby Digital Processors. Mine is the Pioneer SPD07 which has DD and DPL decoding. Basically, the manual says to set the delay to short (0ms) if the distance between the center and front is short and to set it to long (5ms) if the distance between the center and front is far apart. The settings provided are from 0ms to 5ms.  My center channel is about 2 ft to 2 ft 11inches apart from both the left and right front speakers. As such, which would be a suitable setting for the center channel?

A This would actually depend on how far away you are sitting from the speakers. Measure the distance from your sitting position to the center speaker and from your sitting position to the left/right front speakers. Because of geometry, you will be sitting slightly closer to the center speaker. For every foot closer to the center that you are sitting, add 1ms of center channel delay.

Q Great magazine! I was wondering, have you ever done any evaluations of Dolby Digital or DTS systems with and without center channel speakers (in Dolby Pro logic, referred to as "Phantom Mode")? I don't yet have any digital sources or even a processor, but for Pro Logic soundtracks, I don't like the sound of a center channel. I understand that with DD, all channels are discrete (not derived). Does having a center channel speaker make a big difference in DD or DTS?

A The reason you probably don't like the center channel in Pro Logic is that the center channel speaker is, in most cases, much different in its design than the front left and right speakers. It is usually smaller, and is laying on its side. As a result, the tonality is different in the center than the other speakers, and this is annoying. It does not sound "right". Instead of a smooth soundstage across the front, the center sounds out of place. I don't think this problem will go away just because the front left/center/right are discrete with DD and DTS, compared to Pro Logic. Also, in my experiences so far, the improvement going from Pro Logic to DD and DTS has been (1) less decoding artifacts such as noise and pumping (where the center voices move back and forth between the center speaker and the sides, due to phase misalignment between the two original stereo channels from which the center is derived); (2) superior sound in the rear, due to having full range of frequencies and being stereo; and (3) deeper, more powerful bass. The center, with DD and DTS, does not sound (to me) significantly more discrete than with Pro Logic (because Pro Logic is very good at steering). Whether you listen to Pro Logic or digital surround (DD and DTS), you will be more satisfied with having a center channel speaker if you get one that is neutral in tonality, and have the center speaker as much like the front left/right speakers as possible.

� Copyright 1999 Secrets of Home Theater & High Fidelity
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