Mixer Technology
Speaker Technology
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Impact Resistance
Days after the 1994 Los Angeles earthquake, Mackie Designs
compact mixers had been dubbed "Mackie Throw Pillows" by San Fernando
Valley studio owners who had begun the painful process of cleaning up.
Why? Because CR-1604s and MS1202s had survived being hurled clear across
studios. They'd taken the full impact of falling monitor speakers without
so much as a broken knob. Several were even buried by collapsed ceilings,
only to be unearthed, tested and declared in perfect working order.

CLUNK! Scrunch! @#%&*$%!

Many other mixers make three mechanical design mistakes that
can lead to expensive repair bills. First, they use un-sealed potentiometers
containing brittle phenolic as a base for the potentiometer's wiper. Next,
they mount the pots on vertical circuit boards. Finally, many mixers have
pots whose bushings extend through chassis holes. This is a deadly combination
when something heavy drops on the mixer.
When downward force is exerted on this kind of knob, all of the shear
force is transmitted to the control and circuit board solder connection.
Even if the phenolic material inside the pot doesn't crack, the whole
thing can still get yanked off the vertical circuit board or break electrical
contact. If a number of knobs get bashed from above at one time, the repair
bill can be hefty.

Our mixers head off all three design errors.

Mackie's first line of defense against external damage is right
there, in the knobs. They're designed to "ride" just thousandths of an
inch from the metal surface of the mixer chassis. When downward force
arrives, it is transferred from knob to steel – instead of from
knob to potentiometer.
Next, we employ a co-molded potentiometer that doesn't use brittle material
at critical mechanical points; if the mixer really gets whacked, our knobs
withstand far more abuse than regular ones.
Finally, to eliminate force transferred to the circuit board, we use a
braced, horizontal circuit board and shock-absorbing structure. The board
is thick fiberglass and is connected at regular points to the chassis
by metal stand-offs. Ultimately, extremely brutal knob impact is absorbed
by broad pressure on a tough circuit board instead of acute stress at
a few solder joints that weren't meant to take physical abuse.
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