Marantz 5220 Manuel d'utilisateur télécharger pdf (Page 24)

31.5

100

315

IK 3.15K 10K

Fig.

2. Dynamic

spectrum of

a popular recording,

measured

the

same

analyzer as Fig.

At first glance,

the family

of curves

usually

available from

simple

tone

controls

(Fig. 3)

seems

like it would fit

well with

the classical material if

smooth

shaping

the final response

curve is the

object. The

pop

selection

looks

too chopped up

to be predicta-

ble. However,

having heard these two

recordings,

the

tone -control correc-

tion

I'd

choose

for

them would be: do

nothing to

the treble

the

pop selec-

tion

(which

was, after all, meant to

sound

little

strange

and electronic),

but add

a moderate

boost

the

deepest

bass

(which

might

handled

by the

sliding

inflection

point

the

bass

control's characteristic). For

the

classical record, I'd

want to tame

down the upper register

the violins,

which is

somewhat

strident. Unfortu-

nately, I

couldn't do this without

apply-

ing

a greater

cut to the extreme high

frequencies

and

losing

the attractive

sparkle of the percussion. In

this case

the

available tone

-control

characteris-

tics

suit

the

pop selection

better than

the

classical.

Figure

shows the tone

-control

re-

sults

for

one prominent product

which

a great

deal of designer

con-

cern was lavished. The

philosophy

was

to concentrate most

the

con-

trols'

effects

at the

frequency

ex-

tremes. As

you can

see (particularly in

the

treble), the

greatest influence

oc-

curs at 30 and 20,000 Hz.

Sliding in-

flection

points

are used for

both bass

and treble,

that moderate

settings

leave the range

from 100

3000

virtually

untouched,

while

greater ad-

justments move farther

and

farther

into the midrange.

During my

experi-

ence with these

controls,

I found

they

-5

-10

the frequencies

above 10,000 Hz

are

not further reduced,

that much

the

sparkle

remains.

This

sort of

characteristic will

do wonders

on,

for

example,

many

the

old Bruno Wal-

ter recordings from

Columbia and

its

subsidiary labels. At

the low frequen-

cies, you can

obtain a

reasonably

sharp bass

cut

(to reduce

rumble

and

similar noises),

but

affects nothing

above 60 Hz. If fact, the

bass control is

generally more

satisfactory

than the

unit's

rumble

filter for

this

purpose.

the

boost side, things

are less

s 11

r8 0

100

0 a e r a o r

FREQUENCY

(Hi)

Fig.

Tone

controls

giving these characteristics

were designed for

maximum

effect at

frequency

extremes.

were

at their best in providing

boost.

Treble

response

could

be tilted up-

wards

slightly without

a great

increase

noise

between 5000 and

10,000 Hz.

But reduced

treble was

just not

satisfactory, having

muting

effect on

the

extreme highs rather

quickly.

Another manufacturer

follows

a dif-

ferent route.

His

controls

really

shine

when it

comes to

reducing

bass and

treble. With

a moderate reduction,

the

treble

control ignores

the midrange

region,

but

really

acts sharply from

2000 to 10,000

Hz to

quash the

stri-

dency

violins

and

other

high -

pitched instruments.

the

same

time

Fig. 3.

Typical tone

controls

affect

upper

bass and

moderate highs

as well as extremes.

I e r 1 1 o r

10000

happy. The treble

control may readily

introduce

stridency when

all

you

want

a bit

top

-end

"tizz,"

while the

bass

has

excessive

effect above 100 Hz.

Knobs. While

some manufac-

turers

are eliminating tone

controls,

others -especially those in

Japan

are giving us more

and

more. Along

with

bass and treble knobs, a mid-

range

control

(usually

centered at

about

1000 Hz

in its action,

and

not

a great deal

of use

in my

view) is not

unusual. Many

tone

controls

now have

switchable inflection

"turnover"

frequencies.

Perhaps

the most useful

innovation in

terms

precise re-

sponse shaping

the

dual

tone

control

system, with bass and treble

controls

for relatively

broad -band ef-

fect

as well as for the frequency

ex-

tremes

(in other words, a

total

four

controls).

With more

controls comes

flexibility

but also

complexity

operation, until

get to the

paragon,

the multi -band

equalizer.

New

equalizers

have been appearing in

phenomenal

numbers

late,

and still

the

surface of

design possibilities has

barely

been

scratched.

Most

current

consumer

products

provide control

over

fixed frequency

bands spaced

(Continued

page 32.)

POPULAR ELECTRONICS

1 2 ... 19 20 21 22 23 24 25 26 27 28 29 ... 109 110

Commentaires sur ces manuels

Pas de commentaire

Marantz 5220 Manuel d'utilisateur Page 24

Commentaires sur ces manuels

Produits connexes et manuels pour Lecteurs de cassettes Marantz 5220