Q&A # 26 - August 28, 1997
Staff
Q Why buy multiple speakers for home theatre, when possibly a couple of good front speakers, and an SRS processor, would produce a very realistic surround sound effect? The money saved on the extra speakers can be spent on
better front speakers. In this way music appreciation will be maximised.
Why buy big speakers, when a couple of good bookshelf speakers, coupled
with a subwoofer, can reproduce the full frequency range for music and home
theatre?
A The two channel "surround sound" idea is a good one, but it uses electronic processing to fool your ears into thinking that the sound is coming from behind you. It can work to a certain degree, but it is not a substitute for sound actually originating from the rear. This is especially true for digital surround (AC-3 and DTS), where the rear surround is discrete left and right. Where I see SRS and other such technologies coming in handy is for consumers who don't have the room for a complete surround sound system, or don't want to clutter the room with a lot of speakers. As to bookshelf speakers and a subwoofer, again, this works well for a situation of not having the room for big speakers, but what we have found is that using bookshelf speakers all the way around results in a loss of some of the "you are there" sensation due to having the frequencies around 60 Hz - 70 Hz going to the one subwoofer. As our reference system, we now use full range speakers (floorstanding) for the front left/right and for the rear left/right, with all four of them being exactly the same. We then crossover the subwoofer (low pass) at 40 Hz - 50 Hz. For Pro Logic, small rear speakers are OK, but for AC-3 and DTS, having the full range speakers in the rear, identical to the front left/right speakers, really makes a difference.
Q I plan to build my own speakers for my home theater system. Right now I would like to know how to turn
my passive subwoofer into a powered sub and get more volume out of my rear channel.
A To turn your passive sub into a self powered one, you just need to
put in a good single channel power amplifier. It would be best not to
use a stereo amp in the bridged mode if your subwoofer driver is low
impedance (4 Ohms), which a lot of them are. Unfortunately, it would probably
cost more for the power amp than it would for a powered subwoofer.
As to the rear channel, if you are going for AC-3 or DTS, get big
speakers for the rear (the same size as your front speakers), since digital surround uses full range sound in all channels except the LFE. What we generally recommend is
getting a receiver with pre-in jacks and pre-out jacks, so that you
can add outboard processors and bigger power amplifiers anytime you
choose. This will give you the added volume you want for the rear
channel as well.
Q I keep noticing more and more articles regarding outboard DACs and improved sound. I have what I would consider a modest system which
includes the Onkyo 919THX receiver/ED901 DD processor combo, a Pioneer
CLD704 and B&W 600 series speakers (the largest, 604 I think). If I add a
DAC, such as the Theta Chroma to my system, will I notice a remarkable
improvement with CDs and LDs? Or, am I just wasting my money?
A A good DAC will definitely make an improvement when using it with a mass consumer LD/CD player. We tried this, using an inexpensive CD player and a DAC costing about 10 times as much as the player. The improvement was very audible. In particular, LD players have very modest DACs, although they seem to have improved over the past couple of years. What you will notice is increased detail. However, it is not as simple as just getting any good DAC. Each has a different sound character to it. So, you might want to experiment a little. Take your LD/CD player into a couple of dealers and have them connect it to the DAC you are interested in (your player will likely have a Toslink optical digital output for the connection). Have them connect the analog stereo outputs of the player and the analog stereo outputs of the DAC to the same preamp at the same time, and switch back and forth between preamp inputs, keeping in mind that the volume might be different and has to be taken into account.
Q Are the Tandy gold patch interconnects you have referred to in several reviews the gold plated interconnects sold at Radio Shack? Are these any good?
A Yes, they are Radio Shack products and they are pretty good. We use them quite a bit in our home theater lab, because we have so many components connected together for test purposes. It would be very expensive to use high end interconnects in this case, and the gold patch cables are as good a compromise as we can find. They are also available just about everywhere, so our readers can easily get them. What you DON'T want to use are the cheesy little cables that manufacturers seem to pack with most receivers and CD players.
Q I am just starting a home theater system. I currently have a GE 32" TV (I am going to wait for HDTV to upgrade the
TV).
1. I am considering the Yamaha RX-V992 for a receiver:
a. This would be a good choice, right?
b. Will this receiver be "HDTV-ready" (is there a such thing as
"HDTV-ready"?)
2. What speakers would sound great with the Yamaha RX-V992 (or whatever
your recommendation is)?
3. What subwoofer (preferably one that looks like a piece of furniture)?
4. Should I go for a DVD player, or just a good S-VHS recorder? Which brands/models do you
recommend?
A The Yamaha line is very good. I liked the RX-V990 so much, I bought three of them. The 992 is the 990 with AC-3 built-in (but no set of 5.1 inputs for another outboard processor, such as DTS). HDTV will likely have AC-3 sound and a digital output for AC-3 processors, so any AC-3 decoder should work. However, current receivers are designed to throughput analog video signals rather than the digital video of HDTV. For speakers, get something with high efficiency (> 88 dB/w/m) and 8 Ohms nominal impedance. This goes for pretty much any mass market receiver, since the power supplies are not really designed for 4 Ohm speakers played at high SPL. Most subwoofers come in black vinyl covering and are big. Only a few have a wood veneer option, but they are also large. The M&K MX-5000 comes in light oak and is beautiful. If you want something inconspicuous but has great bass, try the Sunfire. Skip the S-VHS and go for DVD. (That does not mean you shouldn't own a VCR, but DVD has copy protection, so you can't copy them on any VCR, S-VHS included.) Sony's 7000 is the best mass consumer DVD player at about $1,000, with the Toshiba 3006 in second place, at around $600 (MSRP $699, but I have seen them on sale at several locations).
Q I am thinking of buying two Paradigm PS1000 subs. My room is 19x24. Is this overkill? Any thoughs on this sub, i.e., is it a good choice? Also, should my speakers all match, meaning all one manufacturer? Is the Paradigm good for
music? Also I am going to Definitive Technology BP-10s C1 center & BP2-X surrounds. Should I stick with bipolars for front and rear to get uniform coverage?
A Paradigm makes very good products. You should stick with one brand for the front left/center/right and rears, but certainly for at least the front left/center/right. The subwoofer does not need to be the same brand, because the low frequencies don't have noticeable tonality. Having two good subs is not overkill at all. Place them in non-symmetrical positions. By turning each one down a bit from where it might be if using only one sub, you will get cleaner bass because each sub is not working so hard. Bipolar rear speakers have been recommended for use with Pro Logic because it adds an element of diffuse sound quality. But with AC-3 and DTS, the rear is just as discrete as the front. So, if you are planning to have digital surround, you probably will be better off having all the speakers either bipolar or non-bipolar.
Q I plan on purchasing a 55
inch Toshiba rear projection in the next couple of weeks. I have read a
lot about professional monitor calibration. It would cost about
$350.00. Do think it is worth the money? The work would be done by an ISF
approved technician. He said the picture would be optimized for viewing
in a dark room and that watching the TV with ambient light would wash out
the picture. I would be watching the set with and without ambient light.
Is there some sort of compromise where you can view an accurate picture
under both lighting conditions? I have a laserdisc player, so what kind
of results would I get using a calibration laserdisc such as Video
Essentials?
A I believe ISF calibration is a must! I have attended the ISF training
in the past, and what they are doing is making your TV follow the rules that
were created back in the 50s. These rules are practiced (at least they are supposed to be) by the people who are transferring the film to video. In order for you to see what they saw, and what the director intended, you must follow the basic rules.
What they should do is remove the screen, clean the mirror and lenses,
focus the lenses, converge the TV, set the front panel controls, and
properly adjust the gray scale. Most, if not all, Mitsubishis are VERY blue
(have a high gray scale above 10,000 Kelvins) out of the box. The higher
the gray scale the brighter the picture "appears" to be. When you have the
TV properly set up, it will be a little dimmer, but you will get the optimum
picture in an ambient light controlled room. You can still watch TV during
daytime, but it will just not be as bright. There is not a SINGLE TV ON THE
PLANET that can give you an optimum picture while competing with ambient
light in the room!
Video Essentials will allow you to set the front panel controls and also
educate you on the importance of setting up a TV and Audio system. Highly
Recommended! Gray scale will require the use of a color analyzer or a Photo Research spectrum analyzer. These devices start at $5,000. Something most consumers do not have, but ISF techs are equipped with.
Q I read the TW40F80 review, and am wondering how does it compare to, say, the Toshiba TW56F80 or the new Pioneer 57" 16:9 TV?
I'm tempted to buy Toshiba's 16:9 RPTV since it has component
inputs, but can't decide which way to go, 40" or 56"? The price
difference is $2,000 vs. $2,700. If they are based on the same technology, I
probably would spend $700 extra for double the screen area. If
TW40F80 is somewhat more advanced technology, then ...
Comparing the TW56F80 and the new line-doubled TP61G90, will the line
doubled image of a letterbox movie on TP61G90 still be worse than the
"unsqueezed" 16:9 image from a DVD to a TW56F80?
A The TW40F80 and TW56F80 contain the same electronics inside.
The distance you sit from the TV should be the deciding factor as to which TV to purchase. You should sit between 5-8 times the screen
height back. With my 40" TV, I am sitting about 12 feet back, and with the 56" you
will need to sit AT LEAST 15 feet back, probably more in order not to see the scan
lines. When you use the zoom feature to blow up the letterbox (non
anamorphic) material, you would probably want to sit even further back
because those scan lines become apparent.
The zoom will probably appear better on the line doubled version
because the blown up scan lines will not look as bad (but I have not
seen the 65" in action.) With the 65" you will still need to be somewhat back, depending on the quality of the internal line doubler. With a line
doubled image you can sit closer because the scan lines are smaller or non
existent.
� Copyright 1997
Secrets of Home Theater & High Fidelity
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