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Q My receiver is a Yamaha RXV992 and I'm using B&W 602 for the front and CC6 for the centre. My friend told me that I should get an extra amp like the Carver AV-705. My question is what is the difference if I added an extra amp? Is it just for the extra power? The AV-705 is 125/channel, and my 602s are only 120watts. Would they match?
A The
advantage of the outboard amplifier is not just simply more power.
It is greater dynamics. Even though many receivers are rated at
quite a bit of power, they really don't have the power supplies
to deliver the kind of punch that we need with new digital surround
sound. We damand so many features in receivers, and also want
them at a great price, something has to give, and it is the power
supply (the most expensive part of the receiver). Also, continued
clipping of the amp can eventually damage your speakers if you
are like most home theater buffs and crank the system once in
awhile, especially with action films. Lastly, the quality of amplification
is better with outboard amplifiers, so it is not just a comparison
of watts. The 602s will mate beautifully with the AV-705, so your
friend gave you good advice.
Q As
part of moving to a better room for theater (and the house that
comes with it), I plan to upgrade my system. I currently have
NHT 2.5i speakers and a Nakamichi AV-1 receiver. I would like
to increase and balance power all around, and I like the Sunfire
Cinema Grand. However, the rural area I am moving to has softer
power than I currently enjoy. Will the Sunfire's unique approach
be compromised by power at 116-118 volts, with some dips? Would
a conventional amp fare any better?
A All
AC supplies fluctuate. I have seen ours go from 115 volts to 120
volts with or without power amplifiers on in the lab. When I first
turn a big amplifier on, the voltage drops from 118 volts to 115
volts for half a second or so as the power supply capacitors draw
high current and charge up. Then, when I turn the volume up and
there is a large transient, like a kettle drum thud, I can see
the voltage drop as well. But even during quiet passages, I can
see the voltage flickering up and down a couple of volts. It does
not cause any problems, although I think it would be best if the
voltage were stable. The Sunfire's efficient way of handling power
will probably make it perform better rather than worse under conditions
of fluctuating voltage since the tracking downconverter maintains
a certain voltage above the signal. If you really want to keep
it under control, then get a voltage regulator. CinePro makes
one designed for audio (get the 20 ampere model). Voltage regulators
are expensive, but if I were moving to a rural area with unstable
line voltage, I would certainly make the investment.
Q One
thing that comes up often in your publication, it seems, is the
damage that clipping can to do speakers - particularly for those
of us who use mass-market receivers that might not deliver top
power at low distortion rates. I have my speakers fused, using
in-line fuse holders available at most electronics stores, but
I've forgotten the formula to use to figure out the wattage needed
for the fuses. And I've changed my receiver! Do you know the method
we need to use to figure out what fuse rating we need to protect
our speakers?
A It
is the power formula: Power = Current2 x Resistance.
So, if your amplifier is rated at 80 watts per channel into 8
Ohms, and you are using 8 Ohm speakers, it would be 80 = current2
x 8, or current2 = 80/8, or current2 = 10.
Taking the square root of 10, the current is 3.16 Amperes. In
that case, use a 3 Amp fuse (250 Volts). The same amplifier might
have a rating of 120 watts into 4 Ohm loads. So, it would be 120
= current2 x 4, or current2 = 120 x 4, or
current2 = 30. Taking the square root of 30, we have
5.48 Amperes. Use a 5 Amp fuse (250 Volts) for this case. Get
regular fuses instead of the "Slo Blo" type. You want
a quick reaction to overload. Put the fuse in the "hot"
(+) side of the speaker wire pair.
Q I
noticed that you rate movies on whether they contain the F word
or S word. Isn't this a little old fashioned?
A Although
I don't consider myself prudish, and I am just as vulgar as the
next guy from time to time, I don't care for graphic language
and explicit sex in movies when I am with my wife and daughter.
It's OK for poker night with the fellows and a couple of beers,
but not appropriate for family. The standards for movies have
changed significantly from when I was in college. What is now
an R movie, such as "Boogie Nights", would not have
even made it into an X rated movie theater a couple of decades
ago. Does this mean our American culture has just grown up? I
don't think so. Humans have not really changed in the last few
thousand years. In ancient civilizations, there were certain types
of behavior that were considered acceptable, and then they became
unacceptable. Now we are getting to the point that some of those
behaviors are acceptable again. We have more ways now of communicating
those behaviors, and the most powerful are the movies and TV.
Because sex, violence, and profane language are so common in the
movies, we have become desensitized to them. They don't shock
us anymore, and they should shock us. It is not a big deal to
see someone killed in the movies or on television, because we
see so many violent deaths in films and programs. So why should
it be a big deal to see someone killed in reality? Or why not
have sex on the driveway in front of other people, just like in
the movies? I really don't like going to a film or renting one
that has a thumbs up rating, only to find that it embarrasses
me or my family. I decided to put the specifics about these items
in our reviews that are missing from other published reviews,
and let the readership make up their mind as to whether they want
to see and hear such things for themselves. For the average person,
it might not make any difference at all, but for many of our readers,
it is the only place to get that information before they rent
the movie.
About 20 years ago, I lectured at the University
of Berlin Medical School, and it was my first visit to Europe.
One thing that really impressed me was how clean the streets were.
No beer cans bouncing in alleys, no constant police sirens. Jewelry
cases adorned the outside edge of the curb on a major street in
front of the jewelry stores that owned the merchandise. When I
flew back to the US, there were some German tourists on the plane,
and as we landed in New York City, I was ashamed of how dirty
our city streets were by comparison. Instead of jewelry cases
on the streets, there were sacks of garbage. Police sirens every
30 seconds. I think we take our freedom a bit too literal. It
doesn't mean freedom to be irresponsible. When we are constantly
hit with terrible things in movies, television, and the media,
it promotes acceptance of the worst in human nature instead of
making us focus on improving the way we live.
Q Like
you guys, I bought some Audio Alchemy components way back when.
Now I need some repair work, and they are out of business. Where
should I take the units?
A Contact
Dusty Vawter, who used to be with Audio Alchemy. He can do the
repairs for you.
Dusty Vawter
Channel Islands Audio
567 W. Channel Islands Blvd.
Suite #300
Port Hueneme, California 93041
Phone 805-382-9398.
Q I
have a Yamaha RX-V992 receiver, B&W 602 speakers and Sony
DVP-S3000 DVD player. I have tried everything but the bass is
still not deep. I listen to music most of the time. The sound
is too bright for me. Please let me know what I have to do? Something
like setting up the system correctly, adding a subwoofer (or a
power amplifier), or replace my current speakers?
A There
are two causes of the brightness. One is the receiver. Most receivers
use lots of negative feedback and this can result in the sound
being a little too bright (edgy or harsh). I have one of the Yamaha
990 series too, and I just turn the treble tone control down a
bit. That will soften those hard edges for you. Secondly, DVD
players are not very good at playing CDs. They all sound bright.
Again, the treble tone control can help. A good outboard amplifier
is always a plus with a receiver, and will also knock a little
of the edginess off. Lastly, you do need a subwoofer. The 602s,
like other mini-monitors, will not handle the lowest octave (20
Hz - 40 Hz). Since you listen mostly to music, I would suggest
a servo-feedback subwoofer like the Velodyne HGS-10.
Q I
have been looking for a long time for information about the 12"
bass-element in the bass speaker to Bose´s 802-series. I
have one of these elements and want to use it as a subwoofer to
my home stereo. I wonder how I shall build a box that will fitt
the 12"-bass. Do you know how, or do you no where to look?
A In
order to build an enclosure for a driver, you need to know the
Thiele-Small parameters of the driver, which include the fs (free air
resonance), Qts (total Q), Xmax (voice coil overhang), and others. Unless you have
these numbers, it would be very difficult to design the enclosure.
I would suggest going with one of our DIY projects or one posted
on other DIY websites which matches the driver to the enclosure.
Q I
currently have a Lexicon DC-1, Rogue Audio 2 channel tube amp,
Rotel 150 watt x 3 channel amp for home theatre, Vandersteen 2CE
Signatures, Vandersteen Sub/Center/Rears, and Kimber Kable wire/interconnects.
I will probably buy a Sony 7000 for DVD, and then have another
$800 to $1000 left over. Should I (a) Use the extra money for
a separate CD Transport (maybe the Theta Pearl?), or (b) Use the
extra money for a separate CD Player (maybe the Rega Planet or
Arcam 8?) or (c) Pocket the money and just use the Sony 7000 as
a transport?
A DTS
DVDs are finally about to hit the market, so I would suggest getting
a DVD player that is DTS compatible. I published a press release
on the new Yamaha DVD S-700 this week. You will need a DTS decoder
or DTS mod/upgrade for your Lexicon. Secondly, 96 kHz 24 bit Digital
Audio Discs (DADs) will be here pretty soon. They are played on
DVD players though, not CD players. So, you want to make sure
that whatever DVD player you buy will handle 96 kHz and 24 bits.
In any case, I would suggest getting a separate CD player rather
than using the DVD player to play CDs. None of the current DVD
players do a very good job of playing CDs.