Q&A # 71 - July 7, 1998

Staff

Q I'm collecting ideas so as to build respectable home theater systems for some of my family and myself. Roughly I'm thinking $hundreds perhaps a $thousand something per component (like a sub), then < $400 per speaker. I'd like to ask specifically about an idea for power amplification that I came across. A friend of mine is a musician and for his rocker needs he bought a Carvin HT1000 amplifier. I wasn't really able to determine the quality of  the sound this unit puts out because of my friend's terrible stage speakers. An up close look reveals that it seems to have all the right parts an amplifier should have for home use despite my assumption that it's just a roadie-rocker beast. I was checking out your review of the Niles SI-250 that seems positive for my application, and the Carvin seems similar, but the first two points as follows are eye catching. 225w/ch rms @ 8 Ohms, 500w/ch @ 2 Ohms, bridge to 500 @ 8 Ohms. My friend paid < $500. It has what looks like a hefty toroidal in the power supply, XLR & 1/4" phone plug inputs (no RCA), volume control for each channel, specified THD < 0.0 something%. So as I see it I have these choices: get the Sunfire Cinema Grand to have the nice 200w/ch; get a Carver or Adcom 5ch, upgrade speakers, and live with 100 - 130w/ch; use two Carvin HT1000s and a smaller Carvin (bridged), upgrade speakers, and have the power. To make the comparison less complicated I will ultimately use a set budget for each project. Then, any money saved in amplification I mean to put into the speakers. In your opinion is the Carvin option a potential winner for me considering my budgets for components?

A It all depends on the sound quality of the Carvin. Try it out with good speakers, and if is sounds great, with no hum or noise, it might very well be a nice deal for you. Other than that, you might also find a used Sunfire Cinema Grand too. 100 - 130 watts per channel are fine if you don't play the movies louder than about 85 dB, and especially if you have a good subwoofer. Setting the receiver or processor to small speakers will send all < 90 Hz to the sub and this will let your 100 watts/ch power amp perform much better. If you have to pay $500 though, I think the AudioSource Amp3 and Niles SI-250 are probably more suited for music and home theater. The power amplifiers built for industrial use often have massive power, but they are usually noisy (hum and hiss). That noise isn't really noticeable where the speakers are on a stage and the band is playing really loud. Also, you would have to use adapters for converting phone jacks to RCA and doing that always results in signal loss.

Q I am building a house. I want to run wires through the walls for a home theater system I will build slowly, as well as for speakers to the kitchen / sunroom / etc., simply for music. Do you have any suggestions on what kind / type / gauge wire to use?

A Get some bulk 13 gauge stranded copper zip cord for speaker cable, and bulk shielded interconnect cable for connecting the components (CD Player, VCR, Receiver, etc.) These items can be purchased at consumer electronics chain stores, such as Fry's Electronics. A somewhat more expensive alternative is the use of bulk Nordost 2-Flat speaker cable. You would end up paying about $2 a foot for this cable instead of about $0.25/foot for the bulk 13 gauge, but it is the cable I would prefer to use. In order to minimize signal loss, I would suggest running the cables out of the walls several feet rather than terminating them with sockets mounted in the walls. This way, you save the loss occurring at the extra connectors that would otherwise be necessary (your external interconnects and speaker cables would have to plug into the wall jacks).

Q In Q&A 66 & 68 you talk about progressive scan video output and an agreement with Hollywood. Where does the Philips DVX 8000 with its Direct Digital Video path fit in this discussion?

A The Philips does not have progressive scan video. It uses an internal line doubler that does not perform 3/2 pull down (detect if the source originated from film and compensate). The line doubled image is then output to your projector. I have seen the Phillips piece, and it has some great features with a very pleasing picture. The unit currently does not support Windows 98. It is also very temperamental.

Q I am looking for an inexpensive reverb unit I can hook up to my home stereo system and listen to music with reverb in it. I need to know if there are any units now that will hook up to a regular home stereo system. I had one 10 years ago from Radio Shack that was really nice (and small) that sold for just under a $100 but I lost it, and Tandy doesn’t make them anymore.

A When I played in a rock group a long, long time ago, reverb was produced mechanically by a spring in the guitar amplifiers. Now, it's all done with DSP to varying degrees in the receiver sound fields, such as "Stadium". A small number of DSP sound fields are also available in some Sony CD players. All sound fields are basically different combinations of early reflections (the first reflection from the wall near the speaker) and later reflections (reverberations) that are a result of the sound bouncing between two or more walls before they get to the listener. I don't think simple reverb units for home use are available anymore, now that we have DSP, so your best bet is an upgrade to a surround sound receiver or processor/amplifier that will add the reverb you like.

Q I have a Pioneer Pro Logic Surround receiver that has a sub pre-out on it. My question is, what frequencies are output from that? When I hooked an amp and speaker to that alone (with no crossovers), I seemed to get some of the high frequency as well as low from it. Right now I have the output going to an adjustable crossover with it set to cut out at about 60 Hz. From there to a 200 watt amp driving a bandpass/reflex encloser with two 10" drivers (20 - 110 Hz response). With the crossover I get very clean low sound but I was curious about the output being labled as a sub-out but hearing the higher stuff with no crossover connected.

A The latest receivers seem to have settled on a low pass frequency of 90 Hz for subwoofer line level output jacks. However, I have seen older receivers with mono out jacks that have full spectrum signals. The low pass for some sub outs may also be set to 120 Hz - 160 Hz, and you could have one of those.

Q 1. Should I wait for a second generation DVD player? (I have to stay with Onkyo for compatibility reasons.)  2. Does DVD do justice to music yet?  3. Are CD and DVD players compatible as one unit? (Onkyo's DVD player has CD "built-in".)  4. Should I wait for 96 kHz - 24 bit CDs, or will the DVD audio format take its place?  5. If my A/V receiver has DD decoding and the DVD player has DD decoding, what happens? (My receiver is the Onkyo DS-747, and the DVD player will probably be Onkyo.)  6. Are component video outputs a necessity, or will S-Video outputs suffice?

A The second generation players are here now, and we will get third generation this Fall (players with progressive scan capability). If you want to play DTS DVDs, then get the latest generation player (the ones that specify DTS digital output). If you are going to buy an HDTV right away, then wait until the third generation players become available. Some of the early DVD players had the ability to disable regional codes so that you could play discs from any country, and also, the ability to turn off the Macrovision copy protection. The new players don't have those capabilities, but they are the ones that will play DD, DTS, and any new MPEG software. All DVD players will play CDs. However, they don't do a very good job with CDs because the laser is set for reading the narrow tracks of DVDs rather than the wider tracks on CDs. For CDs, a dedicated CD player works best, followed by laserdisc players, and, in last place, DVD players. CDs will not, in the near future, be used for 96 kHz - 24 bit music, because there is not enough space on the discs. Meridian's new lossless packing would save about 30% of the bit space, but this would still make the CDs only have about 15 minutes of playing time. DVDs on the other hand, have plenty of space, and that is where the 96/24 music will be put. In fact, these Digital Audio Discs (DADs) are already becoming available, and current DVD players will output the two channel stereo analog signal from their built-in 96/24 DACs. Older DVD players truncate the bits so that you only get 96/20. The Meridian Lossless Packing (MLP) might be used on DVDs to allow less compression in the video image.

Q I have received conflicting reports from various equipment vendors regarding the need for an AC-3 equipped satellite receiver. I would like to be able to take advantage of Direct TV's new broadcasts in Dolby Digital and have an A/V receiver with AC-3 decoding. Do I need to have a satellite receiver with AC-3 built in to take advantage of this new feature?

A You need a DSS receiver that has an AC-3 output, like the new RCA model. Without this output you cannot listen to the AC-3 signals that are being broadcast with the programs. DSS is beginning broadcasts with AC-3 in July (now), and RCA is the first with a receiver that has AC-3 digital output.

Q I read with great interest your article on the CES in Las Vegas. I wonder if you could elaborate any further on the different projector setups you saw. Specifically, I'm looking to purchase the Dwin HDP-500/Transcanner or the Runco 991 unit with the TS. The DWIN is a WHOLE lot cheaper, but I've not had a chance to audition it. I've talked to people on the net, and they have said good things about it. My only problem is there is no local dealer to provide service should I need it. The Runco unit I know is great. Your observations would be most appreciated!

A The Runco 991 is a fantastic projector at a steep price. If you have the budget, go for it. The DWIN is a fantastic projector at $10,000. It is listed for more, but when you buy it with a TranScanner you get it much lower. The DWIN outperforms the Sonys in the same price range and makes zero noise. The Sony sounds like a wind tunnel with all the fans and does not track a gray scale as good as the DWIN does.

� Copyright 1998 Secrets of Home Theater & High Fidelity
Return to Q&A Index.