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Q I am running an Onkyo TX-SV444 receiver (60watts across the front and 20 to each rear) with a Yamaha DDP-1 for Dolby Digital. Yesterday, while watching "Starship Troopers" on DVD, I heard what sounded like static electricity in the front speakers during some of the louder scenes and sometimes when people were yelling I could hear it in the center speaker alone (sort of a snapping or clicking sound). I am using the Energy Take 5 system and thought it should be easy to drive. Am I hearing amplifier clipping? The volume was only a quarter of the way up and I wouldn't say that I was listening all that loud; just loud enough to understand the dialogue. I was planning on replacing the DDP-1 this summer with a DTS/DD dual decoder, but now I'm thinking I need to replace the receiver too (it doesn't have pre-outs). I can't afford separates yet. Do you think I should look for a receiver with higher power AND pre-outs so that I can upgrade later? Could the static sound be something else? In two channel stereo I can listen much louder than the movie was playing without a problem, and the rear speakers never sounded problematic despite having only 1/3 the power of the fronts. What's going on?
A That snapping cracking static sound is definitely clipping. The power supply in your receiver can't deliver what's needed during those high energy movie scenes. The reason you don't have such a problem with two channel stereo, is that the power supply only has to deal with two channels instead of five. I would suggest getting one of the mid-level receivers that have about 80 watts to all five channels, a set of 5.1 input jacks, and a set of pre-out jacks. Since you already have a DD decoder, you don't need to waste money getting a receiver with DD built-in. Also, since you are already thinking about an outboard amplifier, and you like action films, there is no sense in getting a receiver with high power built-in amplifiers. However, if you have a receiver with 80 watts to each of the rear channels, then you may be able to get by with a three channel outboard power amplifier (125 - 200 watts/channel), to drive the front left/center/right, instead of having to buy a five channel amplifier.
There is a second possibility that the output
of the DDP-1 is too high for the inputs of your Onkyo. You can
test this by turning the volume down very low. If you still hear
the snapping sound, then the DDP-1 outputs are overloading the
preamplifier section of your Onkyo. In this case, turn the "high
level cut" feature down using the menu on your DDP-1. This
will compress the dynamic range, leaving the low level and mid
level volume alone, but reducing the level during high output
movie sequences.
Q I
don't understand about dual mono amplifiers. What is the difference
between a stereo amplifier and two mono amplifiers? Will the mono
setup make the sound quality better with just listening to music?
Can they also be used to drive the two front speakers in home
theater?
A A
stereo amplifier has two amplifiers, but the power supply may
be common to both channels. A dual mono amplifier still has both
amplifiers in one chassis, but has two separate power supplies,
and sometimes, two separate power cords. A dual mono amplifier
is still a stereo amplifier. A mono amplifier, often called a
monoblock or monobloc, is a single channel amplifier in a chassis.
It has its own power cord and power supply. Having two monoblocks
will offer better channel separation, but as to better sound than
a stereo amplifier, it depends on the quality of the two products,
not simply that one is a stereo amp and the other two monoblocks.
Home theaters can incorporate any type of amplifier, including
monoblocks, stereo, three channel, four channel, five channel,
and six channel. One nice thing about monoblocks is that you can
put the amplifier very close to the speaker, using a long interconnect
rather than a long speaker cable.
Q I
have a new receiver, and I am a bit confused to say the least,
about the Bass Management feature. I have five full range speakers
with no separate sub. How do I set this feature or defeat it?
The owner's manual is of little help in this problem. Currently
I have it set using the on screen menu as "5 full range no
sub". It sounds pretty good, but I feel it could be better.
I know you will say I should have a separate sub, and I will as
soon as I can afford a good Velodyne (HGS10, or FSR18).
A You
may actually improve the sound by setting the bass management
to be full range WITH subwoofer, since the setting you have now
is routing all bass from the various channels, plus the signal
from the LFE (assuming you have Dolby Digital) through your main
speakers. This might be sending too much bass into them. And,
yes, get a good sub when you can. All systems benefit from one,
including those with full range speakers, since "full range"
usually means down to about 35 Hz. The last octave (20 Hz - 40
Hz) needs a dedicated subwoofer.
Q I'm soon going to purchase a HT system. The processor will be the Meridian 565 Z3 with the 562v Control Center. The speakers will probably be the Paradigm Studio 100s for the left and right, the Paradigm CC-450 for the center, and the Paradigm ADP-450s for the surrounds. I am also thinking of adding a Velodyne FSR-18 subwoofer to the list, however the Studio 100s supposedly produce a whole heap of bass by themselves (all the way down to 25 Hz). Will adding the subwoofer cause muffled or so much bass that the dialogue and higher frequencies won't be heard clearly?
Also, how much power do you recommend I
give the speakers? My room is 14' X 20'. The Studio 100s can handle
much more power than the other speakers, so should I give them
a separate more powerful amp?
A The
Studio 100s have a modest sensitivity and are 8 Ohms nominal.
The 25 Hz rating is a 3 dB down measurement, meaning that this
frequency is 3 dB lower than the volume at higher frequencies.
A good subwoofer will improve your setup considerably, but you
should set the low pass crossover at about 50 Hz so that the system
won't sound boomy. Although the 100s can handle more power, you
should not turn the front speakers up to much higher volume than
the surrounds, or else the surround sound will be unbalanced.
I would suggest about 125 watts per channel to power this system.
Q I
am confused about all the talk on 96kHz/24 bits D/A Converters
found in the newest generation DVD players. I have the Marantz
DP-870 AC-3 decoder. If I connect a DVD player to the AC-3 decoder
via the digital output, will it bypass the DVD player's 96kHz/24
bits DAC and I am down to 16 bits? How does it actually work?
How do I make the best out of these new DVD players?
A Although
standard CDs and Dolby Digital (AC-3) both use PCM (Pulse Code
Modulation), they don't use the same DAC. That's why you need
a DD decoder (which is a DAC designed for DD). Your DP-870 will
decode DD from the DVD player without loss. As to 96/24, that
is the bitstream from DADs (Digital Audio Discs). It is PCM too,
and your DVD player, whether it is an older unit or the newest
generation, will play them. The new ones are supposed to be able
to handle all 24 bits, but such high resolution is very controversial
right now. DTS on DVD is not going to use PCM, but something completely
different. A separate decoder (which is a DAC) is required, and
older version DVD players will not play them.
Q I
have one of those "timbre adjustable" center channel
speakers (Atlantic Tech 253c). How does one go about using the
adjustment nobs to match the mains? Is trying to match (by ear)
the sound of a test tone sufficient? It seems that would be distorted
by the additional bass presence of the mains. Or are these adjustments
just a sales gimmick?
A Center
channel speakers have the problem of bass loading caused by the
front of the TV screen, when the speaker is on top of the TV.
That's why speaker stands have very little flat surface in parallel
with the front of the speaker. The timbre adjustments on center
channel speakers reduce the output in the 80 Hz - 160 Hz region
(this is where the bass loading occurs) with a notch filter. Forget
about the test tones. Just play a movie with some dialogue and
adjust the center channel timbre control knobs by ear. The bass
loading from a TV makes the speaker sound chesty (voices too deep,
like they smoke three packs a day). The particular peaks caused
by your TV might be in between the test tone frequencies.
Q DTS
has changed again. More specifically, the DTS flag in the soon
to be released DVDs are different than the LD DTS flag. This means
that all the processors and DVD players out there today will not
be able to decode a DTS signal from DVD. Additionally, Motorola
has been given exclusivity in the DVD DTS realm and will incorporate
the new algorithm in their next chip which is due later this year.
Only two companies, Madrigal and Meridian, have been grandfathered
and can provide software updates to their DVD players/DTS processors.
Everyone else has to wait until the new chips from Motorola come
out. I imagine that this is very bad news for the Acurus ACT III
which uses the Cirrius chip (if I remember right). I guess that
unless Mondial (Acurus) switches chips, the ACT III may not be
able to play DTS DVDs. On the other hand, until the new Motorola
chips come out, no one else can either!!
A Yes,
DTS DVDs use a flag. DTS LDs have no such flag, and the decoder
has to listen for DTS, then switch to that mode. DTS DVDs will
use a flag, and DD DVDs also use a flag. The flag is used by the
player to detect the type of signal that has to be sent out (DD
or DTS). DD is PCM, but DTS is not, so that is one of the reasons
a flag is required.
Will existing DTS decoders be compatible?
DTS has stated that yes, they will work. But until actual software
is in hand no one really knows. Some high end DTS decoders like
Meridian, Lexicon, and the Millennium are software upgradable.
There are several processors already available that use different
decoding chips than Motorola. Currently there are about 8 different
LD versions of DTS out there. I have had a couple software upgrades
from Meridian to be compatible with all of the different versions.
Q I
currently use a Pioneer DVL-909 for playback of DVDs. The playback
quality is great but I have noticed that the brightness of the
picture
seems to be erratic with some scenes going from dark to light
and vice-versa. I've switched monitors from my projector to a
conventional TV but the problem seems to be still there. This
is no such problem when I play LDs. I have narrowed it down to
the copy protection inherent in some DVDs. I managed to source
a DVD - Michael Jackson's History which does not have copy protection
and it works fine with no switching of brightness/contrast. I'm
just wondering whether this is defect of my player and do other
people experience it too? Can it be remedied? Is it some software
problem?
A It
does sound like Macrovision Copy Protection, as I have seen that
when trying to dupe a movie. My first suggestion would have been
to try a different monitor because some monitors are tripped up
by macrovision, while others work fine. Since you have already
done that, the next is to go to the store where you bought the
player and try one of your movies in one of their players (the
same model you bought) and see if the problem is still visible
there. If not, get a replacement player from them. If it is still
there, try a different player.