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Peter Wieck[_2_] Peter Wieck[_2_] is offline
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Default Horizontal vs. Vertical bi-amping

LOTS of Kool-Aid being dispensed here. But lets look at a little bit of the=
math, if possible. Not knowing whether these assumptions are true or not, =
let's just put them out the

1) Bi-Amping will deliver more total current to the bass drivers than if th=
ey were powered from one amp.=20

2) In the article cited, a statement was made that there was far more energ=
y in the bass than in the treble. Which seems to mitigate towards bi-amping=
..=20

3) There is some stuff within the article and elsewhere that suggests that =
multiple power-supplies are better than a single power-supply of the same a=
ggregate capacity.=20

So:=20

a) Let us take the case of two 30-watt amps vs. one 60 watt amp.=20
b) Let us take the "far more" to be 2 x current required.=20
c) Let us allow the Peak-to-Average to be 20 dB. Somewhere between Chamber =
Orchestra and Full Orchestra.=20
d) let us make the speakers at 85dB - as Maggies were cited in the article.
e) Let us assume that the source used is well recorded and well mastered.=
=20
f) Let us assume that the electronics are of excellent quality and fully fu=
nctional. =20

The Mid/Tweet will be capped at 100dB without clipping.=20
If the Mid-Tweet is making 98dB at 20 watts, and the bass needs 2 x the cur=
rent, the bass will be starving at the available 30 watts.=20

Whereas a single 60-watt amp will be able to divide the current at a 2:1 ba=
sis - 40 watts to the bass, 20 watts to the mid/tweet.=20

Add these discrepancies to the Saint-Saens Organ Symphony where the P/A is =
30 dB (if properly recorded) and bi-amping this way just will not work (nor=
will the fairly anemic single 60).=20

The only way this works, horizontal or vertical is if both amps are capable=
of driving the entirety of the speaker independently. Or the amps are diff=
erent in capacity but chosen to handle the differing loads. Either is fine,=
and either is practical, but the utter, complete and irredeemable BS about=
"power supplies" and such is neither.=20

Now, on the practicalities of horizontal vs. vertical - I have the capacity=
to do both, using up to four (4) theoretically identical amps. I will tell=
you by direct experience that four amps adding up to the same wattage as m=
y single brute-force power amp does not compare to that single amp. Brute h=
as the capacity to send whatever is needed to whatever section of the speak=
er (Maggies) that needs it at levels approaching the absurd, and handle tra=
nsients of up to 120 dB without breathing hard, the four smaller units cann=
ot do this.=20

On bi-wiring, I use 12-gauge 19-strand THHN wire twisted in a drill to abou=
t 6 turns per foot. Runs are about 10 feet or so. Seems sufficiently robust=
not to need bi-wiring. And at ~US$110 per 500' (250' paired) with tax and =
shipping, not so terribly expensive, either. With the additional virtue of =
being able to be pulled around corners and across abrasive surfaces without=
damage.=20

Peter Wieck
Melrose Park, PA=20