Noisy system
January 29, 2007
I recently bought a Bose Acoustimass 16 Series II speaker
system and at the same time a Yamaha RX-V1600 amp. To protect it all I bought a Monster
Power HTS 3600 Mk II. The DVD player is a Sony DVP-NS975V connected with a digital optical
audio cord and the cable box (HD) is connected by coaxial.
When I first turn on the DVD player or cable TV, it sounds
great. But then after a while a weird hissing or power-surge noise (not loud but annoying)
can be heard. It comes and goes, and if I change the settings to play only two-channel
stereo the noise is eliminated. But when I turn on the 6.1 sound or any of the DSP modes,
the noise comes back. You can only really hear the noise when the movie gets quiet or if
there is no action or sometimes not at all. If I disconnect one of the speakers (any of
them) the noise also goes away. There are speaker A and speaker B buttons on the front of
the amp. When I hear the noise start, if push the speaker A button with the speaker B
button on, the noise stops, but then will return when I turn the speaker A button off
again. Is this common?
LV
It could be several things: I’d first check all of
your wiring, particularly that going into and out of the Yamaha unit. A wiring mistake --
and believe me, we all make them -- could easily be at fault. Make sure none of the
speaker wires are touching any of the others as they come out of the Yamaha amplifier.
Second, make sure all of the speakers are connected to the right speaker outputs. You
might be overloading the Yamaha’s amplifiers in some way, perhaps by having the wrong
speakers hooked to the wrong outputs. If all of the wiring seems to check out, you could
be getting some interference from a nearby appliance. You may need to experiment with
which outlets you have the system plugged into. There could be some interference coming
through the power line, despite of the Monster unit. Lastly, it could be an issue with the
Yamaha itself. If you have return privileges where you bought it, swapping it out for a
new one might be wise.
Atom review coming?
January 26, 2007
Is the review of the Paradigm Atom Monitor v.5 still
scheduled for February? Will it be February 1? I am interested in this speaker and read your feature "The Birth of an
Atom." I am looking forward to the review.
Paul Buckman
The Atom review is scheduled for February 1. If you
think you want to hear the Atom now, just wait until you read the review. It sounds like a
boatload of speaker for the money.
Speaker impedance
January 22, 2007
I have a question on speaker impedance. I have two sets of
front speakers: one is 6 ohms and the other 8 ohms. The manual for my Yamaha RXV450 tells
me that if I want to use two sets simultaneously, the impedance of each speaker needs to
be 8 ohms or higher. A few times I have realized that, unintentionally, both sets were on.
It sounded fine. Can that lead to problems?
Sergio
Your Yamaha receiver is rated at 6 ohms or higher, and
by running both sets of speakers simultaneously, you’re showing it a 4-ohm load. It
may be OK with that load, but it wouldn’t surprise me if it overheated and shut down
on occasion, especially if you played it loud. My advice would be to avoid it so as to not
harm your receiver. If you do play both sets of speakers, however, it would be a good idea
to make sure the receiver is well ventilated so as to keep it cool while it is pushing a
tough load.
More cabinet bracing?
January 19, 2007
I own an older pair of Yamaha floorstanding loudspeakers
and have been thinking of doing some tweaking to them. Specifically, adding more bracing
to the cabinet to make them vibrate less. What is your opinion of this?
Kent
First, I am no loudspeaker designer, so you may wish to
ask someone with a bit more expertise in that area. With that caveat, my thoughts are
these: Your loudspeakers were designed to have a specific internal air volume. When you
add internal bracing you will reduce that air volume and thereby slightly change the
parameters in which the drivers are working. So the result you hear will be a combination
of the added stiffness to the cabinet (likely a good thing), with the reduced air volume
within the cabinet (likely a bad thing). How will that affect the final sound? That’s
anyone’s guess, but I don’t think I would take the chance, as you may end up not
liking what you hear. An alternative to that might be adding some mass, in the form of a
sheet of heavy stone, to the top of the loudspeaker. I have heard of audiophiles doing
this to increase mass and damp the cabinet itself. It’s also easy to reverse if you
don’t like the results!
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