| Video Noise May 2006
A Rant on A/V Receivers and
Separate Amplifiers
Having just read an article purporting to
realistically delve into the differences between separate components and big A/V
receivers, I’m hopping mad. The author essentially dismissed the fact that the power
amplifiers in Japan, Inc.’s receivers, even the most expensive models, sound lame
compared to decent separate power amplifiers -- something that’s been my experience
with a ton of receivers.
While the article did mention that receivers essentially
won’t work acceptably with loudspeakers rated below 6 ohms, he failed to point out
that many of the best-sounding loudspeakers on the market are rated below 6 ohms --
or, at the very least, their impedances dip well below 6 ohms at one or more frequencies.
By selecting an A/V receiver rather than a separate surround processor and power
amplifier(s), you limit your choice of speakers to small models, or designs that may not
perform as well as similarly priced models of lower impedance. There are actually
technical explanations for why the best-sounding speakers money can buy tend to be rated
from 4 to 6 ohms, and why most of these dip to 3 ohms or below.
Back to the power-amp sections of A/V receivers: B&K
makes a good-sounding A/V receiver in the same $3000-$4000 USD range as top-of-the-line
Japan, Inc. receivers. McIntosh makes another strong performer that I’d call pretty
expensive (more than $5000), but you’d spend about that much or more on a good
surround processor and good separate amplifiers. NAD and Rotel make receivers with
better-than-average amplifier sound at lower prices (below $3000) than B&K and
McIntosh, but the amount of power available drops off, limiting your choice of speakers to
those that are usually physically smaller and easier to drive than the best available.
There may be a few other receivers whose amplifier sections are nearly as good as
separates, but there aren’t a lot of options.
When I compare the amplifier sections of A/V receivers from
any of the Japanese brands -- even their upscale mid-fi lines -- to a decent-sounding
separate power amp, I’m typically blown away by how bad the receiver sounds in
comparison. I always use the best power conditioning available and very good speakers
(Clement bookshelf models with 8" woofers and Vandersteen floorstanding models
capable of creating a very large soundfield with great width and depth and astonishing
clarity). The receivers make these speakers sound flat, gray, congested, dull, and
completely lacking the exciting transparency they can provide with good amplification.
However, when used as surround processors (by connecting
them to external amplifiers), these same A/V receivers sound just as good as
separate surround-sound processors. In fact, they sound so good that most A/V receivers
would be hard to fault if judged only as surround-sound processors -- especially if you
use AC power conditioning, good cables, and good source components. I can’t remember
an A/V receiver that I didn’t enjoy as a surround processor when it was used to feed
external amps through its preamp outputs. But when used alone, their own internal
amplifiers driving the same speakers, those very same A/V receivers sucked the life out of
the system. Every Japanese brand I’ve tried has had the same problems -- even the
brands people say sound better than the rest of the pack.
Some manufacturers have an "upscale" line sold by
mid-fi dealers rather than big-box stores. I’ve found that these upscale lines sound
barely better than the pedestrian big-box models. Even when the brand touts the attention
paid by their designers to sonic detail, the actual listening experience has been dismal
-- all due to those awful-sounding internal amplifiers.
If you have a big A/V receiver, you don’t need to dump
it and get a surround processor and separate power amps to get better sound, but you
should consider getting separate amps and the interconnects needed to connect them to the
receiver. If the rest of your system is decent, your system will get a big sonic shot in
the arm. Unless your speakers are really bad, getting rid of your A/V receiver’s
amplifiers will make the largest single improvement in the sound quality of your
home-theater system. If you think you can’t afford the separate amplifiers needed to
abandon the A/V receiver’s amplifiers, consider buying used equipment from a local
dealer or from www.audiogon.com,
which has become the eBay of audio gear.
Short speaker cables and long interconnects sound better
than short interconnects and long speaker cables. Using five mono amplifiers permits the
use of the shortest possible speaker cables because each amp can be placed close to the
speaker it powers. A good alternative is a three-channel amp up front and two mono amps in
the back. However, there probably isn’t much difference between using a five-channel
amp for the entire system and a three-channel for the front and a stereo for the rear --
the rear amp will probably need long interconnects and moderately long speaker
cables.
The search for sound is a journey and a destination. Enjoy
it. See you next month.
...Doug Blackburn
db@hometheatersound.com |
