September 16, 2001
I finally bought my system: a Pioneer DV-444
DVD player and VSX-D710S receiver along with these speakers: Magnat Vector 77, Vector 22
and Vector Center 13.
Now my question: what are biwiring and
biamping? Both the front and rear speakers that I'm using have two terminal pairs. It
mentions biwiring and biamping in the speakers' user manuals, but it doesn't explain in
detail how to do it and what the benefits are.
Thanks again for your help!
Paolo
By removing the jumpers (metal straps)
between your dual pairs of binding posts, you can access the crossover for the connected
drivers independently. In a three-way speaker, the tweeter and midrange usually are
connected to the upper binding posts, and the woofer/s to the lower ones. In a biwire
setup, two pairs of speaker cable are connected to the speaker, one per pair of binding
posts. On the amplifier/receiver end, the two hot and the two ground runs are tied
together to connect to the single binding post pair there.
In a biamp scenario, identical stereo
amplifiers are used. Two possibilities exist: one amp can become the dedicated
"upper" power source (connected to each speaker's upper terminals to drive the
tweeter/midrange grouping) and the other becomes the bass amp (driving each speaker's
woofers). Or, one amp can drive the left speaker and one the right, in which case one
channel drives the upper terminals and one the lower ones.
Biwiring electrically separates the larger
motor structure (magnet and voice coil) of the woofer/s from the smaller midrange and
tweeter. This routes electromotive force generated by the woofer to the amp instead of
interfering with the other drivers. Claimed benefits include enhanced transparency and
clarity for the tweeter and midrange. Experiments are in order to ascertain whether the
added expense of a second run of speaker cable does indeed create audible improvements.
One thing to keep in mind is that the factory-supplied straps or jumpers (that connect
both terminals for single-wire connection) usually sound lousy. For a fair A/B between
single- and biwire hook-up, replace those jumpers with any garden-variety 12-gauge copper
wire.
Biamping (especially when one amp each
drives one speaker) separates amplifier power supplies into two discrete channels, which
may benefit soundstage precision and depth.
September 14, 2001
I have three totally unrelated but probably
useful questions. First, I was struck by your review of the nOhr speakers, and I now want
a pair very badly. I've heard nothing but good things about the speakers, but I'm worried
about the waiting list. I've heard that potential buyers sometimes must wait MONTHS to get
the speakers. Can you confirm or deny this? How do you think these speakers would compare
to a $2000 speaker like the B&W Nautilus 805 (which I currently own)?
On the subject of the Nautilus, what do you
think the minimum wattage needed to power the Nautilus 805 to reasonable (NEVER loud)
listening levels would be? Could 15Wpc do the trick?
As you might be able to glean from these
questions, I'm "downsizing" my system and getting back to basics in order to try
and recapture my excitement for audio. All of the components I'm considering are about
one-third or one-half the retail price of the ones I have currently. Any ideas where I
might be able to get fair prices for my (very gently used and lovingly cared for) current
gear? I'd like to be able to sell everything for about half of what I paid for it new so
I'll have a little money to play with.
Rob
Considering how labor-intensive
manufacture of the nOrh speakers is, I wouldn't be surprised about a waiting list. All I
can say is that the performance makes any possible delays seem well worth it. I would
contact nOrh directly and get an estimate about the current back-order status.
The B&W 805 is rated at 88dB
sensitivity; 15Wpc might be sufficient, but remember that "loud" is a relative
term and also dependent on room size and how far away you sit from the speakers. My room
is 13' x 19' x 10'. I drive 93dB sensitive speakers with a 6Wpc amp, no preamp. I'm not
even close to maxing out the amp. My average listening levels are probably around 2 watts.
An 87dB-sensitive speaker would require 8 watts for equivalent output levels. You can see
that, especially with preamp gain, your proposed 15 watts might well be all that's needed.
It's best to try first just to be sure.
www.audiogon.com and www.audioshopper.com
are two reputable used-audio sites that I've used in the past to sell personal gear. Fifty
cents on the dollar is a very common and fair selling price. I sold my stuff in less than
a week, so if what you have is desirable, you should have no problem.
September 13, 2001
I have inherited an NAD 541 CD player and a
NAD 370 integrated amplifier. I have an old pair of really poor-quality speakers. Can you
recommend some speakers that I should look at to have a well-matched system?
Robert
I'd look into the $275 per pair Axiom
M3Ti. They're available factory-direct from Canada but carry a comprehensive satisfaction
guarantee. Look up our review in the archives. Quite a few reviewers of sister publication
SoundStage! use these
speakers in their second systems and report excellent results as well.
September 12, 2001
I've been kicking around the idea of upgrading
my system. I have a ten-year-old NAD 7240 PE receiver that works fine and B&W 602
speakers. I don't know if I'm better off adding an amplifier and using my receiver as a
preamp or adding a subwoofer. Do you have any comments about which would be better?
Rick
Add a good subwoofer like the Hsu VTF-2 we
recently reviewed ($499). At a lower price point, the smaller Axiom subwoofers look very
promising and we currently have one in for a forthcoming review.
September 11, 2001
My system has a Sony ES receiver running
center, surround, and subwoofer channels. It's connected via its front-right and -left
pre-outs to a Rotel RB-1070 amp, which is connected to my Klipsch Reference towers. My
music source is a Rotel RCD-971 CD player, connected to the CD inputs on my ES receiver. I
listen to all, but am much more interested in music than home theater and broadcast TV.
The music sounds clean, punchy, and dynamic. There's no spurious noise other than the
receiver's noise floor, which you hear if you put your ear next to the tweeter. I cannot
identify any noticeable distortion. Keep in mind my receiver has an Analog Direct mode,
which shuts off all digital processing and even takes the balance and tone controls out of
the signal path. This is how I listen to my CD player.
Would a preamp in the path necessarily be
cleaner than this Analog Direct feature of the receiver? Will a two-channel preamp, either
passive or active, inserted between the receiver and the amp, with my CD player connected
to it and bypassing the receiver altogether for CD listening, make it sound even better?
Paul Elliott
In your proposed setup, the preamp can
connect to the receiver via its tape output, a second pre-out or a Y-connector on a single
set of pre-outs. The CD player connects to the preamp that drives the Rotel stereo amp.
Your movie sources (TV, DVD, VCR) connect to the preamp. When one of those is selected,
the tape out/pre-out feeds this signal to one of the receiver's inputs to drive the
surround channels via the receiver's on-board processor. Using a pre-out is, of course,
preferable as you'll only have one volume control to contend with.
Whether a dedicated preamp would give
better results than the ES receiver in processor-bypass mode, I don't know. The only way
to find out is to request a weekend loan from a local dealer and try. That you don't
report any misgivings about your current sound might mean things are just fine the way
they are. It used to be a given that two-channel preamps outperformed surround processors
in two-channel mode. That seems to no longer be the case, but it depends on the intrinsic
quality of the processor -- one would certainly hope that a $500 standalone preamp
outperformed a $800 home-theater receiver's preamp section.
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