Q&A # 236 - July 10, 2001

Staff

Q I understand that IEEE 1394 Firewire may become a standard for interconnecting components (Receiver, DVD, TV etc.) in the future. It seems that that the standard is for interconnecting components with less than approximately 25 feet of cable. Is this true? Will it be possible to use IEEE 1394 as an A/V distribution technology throughout a house with cable runs longer than 25 feet say, up to say 200 feet or more? Will there eventually be a IEEE 1394 Hub or Router like that used for a 10BaseT physical layer? If I were to try to future proof my Home Theater, what cabling should I put behind the sheetrock now to allow the use of IEEE 1394 in the future? Any guidance would be appreciated.

A Firewire has a problem with cable lengths more than 12 feet. That is one of the obstacles, but I am sure it can be solved, perhaps with repeaters every so many feet. The connectors are probably more important than the wire in the cables themselves, so I would suggest putting in a couple of runs of 200 MHz or greater Cat5 cable into your walls.

Q I am about to consider the purchase of a LCD projector and this model looks like a good bet. http://www.mitsubishi-ryoden.com.hk/Multi-mediaLCDProjector_LVP-SA51U.htm 

According to the manual and brochure, it can do HDTV at 720P or 1080i, but it doesn't mention the DVD format 480P even though it says it has DVD (component) inputs. I actually checked out the unit in a local dealer, and he didn't have a DVD player available, so we were not able to check out that feature. Plus, the component inputs (also progressive I hope) are d-sub 15 pin standard VGA video type. In Hong Kong we don't have any HDTV yet, so I can't check those capabilities.

I have just purchased a Skyworth Progressive Scan DVD player and it works fine in progressive mode when connected to my 15" (1024x768) LCD monitor via the VGA input. The Skyworth has both RCA type and 15 pin VGA connectors for progressive. I presume since this is a data projector also, I ought to be able to connect a DVD player which is outputting a 480P signal?

Have you had any experience with this projector and if so, would it be a good recommendation for a basic HT system?

A LCD projectors scale take whatever signal that is coming in and scale it to one specific resolution. Assuming the LCD panels are 4:3, It might be 800 x 600 (SVGA) or 1024 x 768 (XGA). The really expensive ones will do 1280 x 1024 (SXGA). I am sure it will handle 480p coming out of your DVD player too, but it will be scaled up to one of the above resolutions. However, if this projector is made for computer data presentations, it will not be optimized for home theater images like you get from a DVD player. The contrast and color are likely to be far from satisfactory. I would suggest taking your DVD player to the dealer and just trying the projector out using some DVD movies you are familiar with. The Sony 10HT projector uses 16:9 LCD panels so that all the pixels are active with a 16:9 movie. New 16:9 LCD panel projectors are being introduced this summer, including the Sony 11HT. They will all be priced in the $7,000 range, and having used the Sony10HT here in our lab, I would suggest you wait for one of these, as they are true home theater projectors and have wonderful image quality for movies.

Q I've recently had most of my home systems upgraded, including a new Faroudja pre-processor. My existing Runco IDP 980 projector creates an adequate picture, but it's just too noisy. If one is screening something with dialogue rather than car chases, the fan noise is the aural equivalent of the olfactory sensation of a steaming (expletive deleted).

So what to do ? The goal here is to get as close to perfection as technology allows and humans can discern - sans fan noise. I'm not averse to spending whatever is necessary to that end.

I have seen only one projector vendor, DWIN, make a feature out of quiet operation. Is this a reasonable replacement for the old Runco unit?

The Runco projector currently is ceiling mounted and has a throw on the order of 12-14 feet.

A Runco makes very good projectors, so I would hate to see you spend so much money for a new projector just because of the fan noise. I would suggest calling Runco to see if they have an upgrade fan configuration. Secondly, try putting some acoustic tile in between the projector and the ceiling. This will absorb the fan noise that is otherwise reflecting from the ceiling down to your listening position. You could even encase the projector, allowing openings for the lens projection paths and exhaust, with acoustic tile. Third, and this would be a bit more tricky, you could disconnect the fan in the Runco and replace it with a computer fan (120 volt) that is mounted outside the exhaust port, drawing air through the projector. You might also put one inside the projector to blow air across the CRTs. Be sure to consult Runco before doing this, however. If you want to just replace the projector, the Dwin is certainly one that is quiet. You might also consider one of the new three panel LCD projectors. The Sony 10HT, for example, just sits on our coffee table and is whisper quiet.

Q I really need your help here, as I am about to make a somewhat major investment on upgrading my speakers, and I don�t have the luxury of trying any of the two that I have selected (I currently live overseas where there are no dealers). I narrowed my choices to the Revel Ultima Salon ($17K retail) or the new Genesis 450XS ($20K retail). I have not heard either one but read some reviews for the Revel, but not for the Genesis. However, the people who heard the Genesis in shows said that they are very good. What do you think? My electronics are all Sonic Frontiers flagship starting with the Transport 3, Processor 3, Line 3, Power 3. My current speakers are Martin Logan Request.

A This is such a major investment, I would suggest two possibilities. One is to go onto some of the audio newsgroups and post a message stating which city you live in or near, and asking if anyone has a pair of the Genesis speakers and if you can come by and give them a listen. The other possibility is to find a dealer in the nearest country and fly there for a demo (vacation at the same time of course). Just about every speaker in that price category sounds good, but there are subtle nuances that some people will prefer over others. You are likely to find someone not only with the Genesis, but Sonic Frontiers components driving them as well.

Q My recent experience at the Prairie State Audio Construction Society taught me a little bit about A/B/X testing that I found interesting to say the least.

A/B/X is not about subjective impressions. It's about whether you can correctly discern between A and B when presented with X by whatever mechanism you're using. If you can reliably detect A (and therefore B) then you can go to town on the differences you perceive.

If you can't, then you perceive no difference under the test conditions only.  This means nothing under different conditions.

BTW, I had the highest "score" with A/B/X when comparing an op-amp padded down to unity gain vs. a straight wire, and that was only 5/11. 

The thing that I feel is missed with A/B/X - and I have no scientific basis for this - is that I'm not sure or brains do well with this type of rapid switching. You know a bit about neuroscience, so how much of our cognition under these conditions is reliable to begin with?

A Scientific testing is very important, but perhaps the main problem with audio equipment A/B or A/B/X testing is that not enough test subjects (people) are used. This is the only way to get statistically significant results when the differences are subtle, which they are in most cases. To test whether cable A is different from cable B, we should probably have 100 people as subjects. Secondly, the tests may be organized in more casual ways than are appropriate. There are lots of books on setting up proper scientific tests for various types of research, and the procedures are rigorous. They are just not rigorous enough in audio testing in most circumstances. The stress of being in a test lab itself is not even considered, and it can have profound effects.

Q Wow, what an excellent job of DVD player reviews! The professionalism and detailed results blew me away. Wish I had not read it though, as it has me lusting even more for a Meridian 800 - after the upcoming upgrade of course!

A Thanks for the compliments. We are evaluating the data from our most recent Benchmark Event, and will publish them shortly.

Q I have a Sony STR-DE925 receiver. When I try to use the digital optical input, I get a message that reads "UNLOCK" and I get no sound from the source. Reset doesn't help. What can I do to remedy this situation?

A Have you verified on any other piece of equipment that the optical cable is actually delivering a digital signal? Some components, such as DSS receivers, need to have their digital output configured to go live.

Q I am putting together my first home theater which will consist of the following:

Mitsubishi WS-65807 65" rear-projection widescreen TV
Denon AVR-3801 receiver
Adcom 545 amp (for powering 3As)
Vandersteen 3As (for fronts)
Vandersteen VCC-1 (center)
Vandersteen 2W sub (no LFE capability; will be hooked in line with fronts)
Paradigm ADP-170 dipoles (2 pair for DTS ES surround)
JVC Progressive Scan DVD player

My questions are: would a separate subwoofer hooked to the LFE output provide much better effects than the Vandersteen sub & 3As set to "large"? Would another sub on the LFE integrate well with the Vandy's sub and 3A woofers? Do you think I will have a big problem with speaker voice differences using the Paradigm surrounds with the Vandy fronts? Lastly, any suggestions for improving the system?

A Vandersteen and Paradigm are excellent speakers with neutral voicing, so I doubt if you will have problems mixing brands between front and rear. The Vandersteen 2W subwoofer is a top of the line model, so you probably won't need anything more. I am not familiar with that particular Mitsubishi TV, but I would suggest making sure it has progressive component video inputs to maximize your DVD player's capabilities. Progressive component makes a huge difference in image quality.

� Copyright 2001 Secrets of Home Theater & High Fidelity
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