Q&A # 157 - January 20, 2000

Staff

Q I own a Sony KP-61V25 (Color Rear Video Projector). The unit is about 4 years old. It has been nothing but one big convergence problem after another. Luckily, it was under warranty for 3 years. I have had a tube replaced, the board soldered, and four convergences done to it. The past few months it has been stable, but as of today the convergence is going again. Usually a technician comes over, hooks a box up to the back of the television, and places it in test mode and does a 64 point convergence to it. After that it is beautiful. Then six to nine months it's out again, as I am another $150 for the service. What I would like to do is converge the unit myself. I called Sony for the Test Mode instructions and all I received from them was the basic setup instructions (the four point convergence). They informed that I was not allowed to place the television in service mode. It's my television! Anyway, how do I get the KP-61V25 in setup / test mode so I can converge it properly? Also, do I need the little video box the technician had? (Who, by the way, would not show me the test mode either.) Please help me on this matter. I am going crazy with the red lines shifting on top and not anywhere else, as the blue shifts to the right, but only in the middle.

A You can obtain the service manual for your TV from Sony Accessories/Parts/Manuals 1-800-488-7669. I am not sure about the box you mentioned. The service manual is designed for factory trained personnel. I touch up the convergence on my RP set once a month.

Q I am interested in upgrading the components of my home theater system. Currently, I am using the Parasound HCA-1206 amp, the Fosgate Audionics Model Four, and the Philips LDP-CDV600. While I have no problem with the present system it does not allow me the opportunity to enjoy AC-3 Dolby Digital sounds. I would like to know if any of the components have the ability to be upgraded or do I need to start rebuilding my system from the beginning? I am awaiting any information that you can provide.

A I don't know about the Fosgate, but it is time for a DVD player. You can get your LD (laserdisc) player upgraded to output AC-3 RF, but then you would need an AC-3 RF demodulator in your receiver. LD is just about dead. The only reason to have an LD player now is if you have access to the huge library of LDs out there, but most rental stores I have encountered have sold their LD library in favor of stocking DVDs for rental.

Q I'm trying to put together a home theater, and I would like to know which is the best performing A/V Receiver out there. I read the Marantz SR-18 got some awards this year. What about the Denon AVR-97 or something else maybe? Or would I be better off putting separate components together for the money? I was thinking of using the Paradigm StudioSeries Speakers Studio/60 or /80s with the CC & 2 ADP speakers.  If you could help me stop this feeling of going around in circles, that would be GREAT!!!

A The receivers you mentioned are all good. Most of your sound differences would be affected by your speaker choice, so if you have decided on the Paradigm (also good choice), then choose your receiver based on the features, including how easy the remote is to use. Check for pre-outs and pre-ins for all channels and good speaker binding posts.

Q I am a novice when it comes to home theater equipment. I have seen demos of the Bose Lifestyle systems and am considering buying the Lifestyle 25. The rep was not able to answer this question to my satisfaction: does it provide true surround sound? I noticed that it has only two audio connectors per video source. How is it able to provide surround sound with only a right and left channel?

A Dolby Pro Logic is true surround sound, but the new formats (Dolby Digital - DD, and DTS) require a digital input on the receiver in order to have true DD or DTS. Otherwise, you use the two analog outputs from your DVD player to the two analog inputs on your receiver, and the receiver performs Pro Logic decoding. That is still true surround sound, but it is not true Dolby Digital or DTS. Whatever system you buy, be sure to check that the receiver portion can decode DD and DTS through digital inputs on the receiver.

Q During the course of watching television in various DSP modes, 4 out of 5 of my speakers periodically stop playing. After shutting down the receiver for a couple of minutes and then turning it back on, everything returns to normal. I have checked physical connections as well as settings on my Yamaha. I am looking for hints as to what can be causing this problem.

A I suspect your TV stereo audio signal is momentarily going to a mono signal, which would end up being decoded into just the center channel. This could be caused by weak TV signal reception, and sometimes this actually happens on satellite and cable TV too. The satellite and cable companies take the signals they receive from the various TV producers, assemble them into various channels, and then rebroadcast them on to you. A lot can happen between the TV station and your home. If this is happening with other sources such as DVD, then it might be a defective receiver, but if it is just the TV, I am reasonably sure it is the stereo/mono problem I described.

Q I currently have an 'old' Dolby Pro Logic System consisting of a Denon 2030 Amp, Mission 753 front speakers, a Jamo 100 center, and Mission 160s for the rears. I'm setting out on the perilous upgrade path, and I haven't got a clue where to begin! My current system sources are just the standard VHS, CD, and TV. I shall be purchasing a DVD player, but for the moment, since I have access to four different models for loan, I want to concentrate on the rest of the system. I shall need Dolby Digital and DTS plus some element of future-proofing. My immediate requirement is therefore a suitable amplifier, but my speaker setup is a bit of a disaster. The 753s are excellent, but I don't care for the others. I would appreciate advice on either a set of speakers (center/surround) to suit the Mission 753s or an alternative to the 753s. I've heard countless comments that the 753s, while excellent for audio applications, are not suitable for cinema sound. I've listened to other manufacturers' systems and have yet to find speakers as good. However, I may not have been listening to a comparable type. Can you also recommend speakers regarded as being good with both audio and movie sound? With regards to the amplifier, I'd prefer to have the sound processors integrated with the amp. I've been very happy with the sound from the Denon. Also, do I really need a subwoofer with good quality floor standers? The room is rectangular in shape, and I (luckily) have use of the full room. The rear speakers, however, will have to be wall mounted at the upper corners at the back of the room. My upgrade budget is around $3,000. I know I'm asking a lot, but I'd appreciate any advice. I'm in Ireland and there are very few quality HiFi stores here (none near my exact location), and it's difficult for me to audition any top-end equipment.

A The Mission 753s are very nice speakers, and the old criticism of a particular speaker not being good for music and movies just does not hold up in general, especially when you like the speakers at hand. Get yourself another pair of 753s for the rear. For the center, if you cannot find a Mission speaker that suits you, try the B&W CC6. For a receiver, perhaps the Yamaha RX-V995, and a Velodyne CT-150 subwoofer. Yes, a good subwoofer will help, even with nice floorstanders (except for the AR1s that we just reviewed, but they have powered subs built-in). The above-mentioned items should be within your budget.

Q I have an Optimus 125 Watt Powered Subwoofer that has both spring clips (left and right) and RCA jacks (left and right) for the inputs. The receiver is a Pioneer Elite VSX-24tx, with a single RCA jack subwoofer output. Since the subwoofer has left and right jacks, should I connect them to a 'Y' cable to combine the left/right signals to feed into the single receiver output?

A No, because the single subwoofer output jack on your receiver is a mono (combined from the various channels) signal. You can connect it to either the right or left channel RCA jack on your subwoofer.

Q If I can equate the output of an amp to an engine for a moment, if power = power can I think of current in terms of torque? If so, is it possible to purchase a "high current" 25W/ch amp? Sure, some amps will deliver more current/watt, but to designate it high current is that fair Can you explain for me please exactly what characteristics a "high current" amp should exhibit?

A A high-current amplifier is one that is designed to handle low impedance speakers. The reason is that, when the impedance goes from 8 Ohms to 4 Ohms, the current demand doubles for any given output voltage. This stresses many amplifiers, particularly those in mass market receivers. A 25 w/ch amplifier could be called "high current" if it delivered 25 watts into 8 Ohms and 50 watts into 4 Ohms, and especially if it could deliver 100 watts into 2 Ohms. Most amplifiers don't double their output when the impedance is halved though. They might be 25 into 8 Ohms and 40 into 4 Ohms. So, instead of looking to see if the marketing term "high current" is associated with the product, just look to see the various impedances it is rated into, and how close to doubling its power it has between 8 Ohms and 4 Ohms.

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