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John Stone John Stone is offline
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Default AR3a/AS103a speakers and the Heathkit AR1500 receiver

On 10/6/06 10:47 PM, in article , "Jerry"
wrote:

Now, one reason for that low output voltage is that I removed those blasted
pots from the AR xover circuit. This netted a huge gain in sensitivity on
just those drivers. So I must compensate by reducing volume or the
mid/tweeter will overpower the woofer. To give you a feel ... the average
voltage swings in the woofer amp are 5 times higher!


I thought all your bi-amping adventures were done with the purpose of not
altering the original design of your AR3a's. Well, now that you're in there
changing things around, I'm wondering if you did anything to compensate for
the removal of those pots from the circuit. They place a 16 ohm load across
the mid and tweeter crossover circuits, and that load forms part of the
filter network. Did you put a fixed 16 ohm resistor in the circuit in their
place? If not, you've certainly altered the crossover responses and
consequently, the speaker response. (I can't wait to see whether you're
going to agree with this). I'm also trying to figure out how you got such a
huge gain in sensitivity by removing the pots. Turned all the way up, the
mid and tweeter are directly connected to the crossover outputs, so the pot
is out of the circuit other than presenting a parallel 16 ohm load. Unless
those were the world's most defective pots-and you would have easily been
able to tell from the intermittent operation-then I don't see where you're
picking up all the sensitivity from.
I'm also amazed at how much work you've gone through to deviate from the
original design intent of the AR3a's. If it was me, I would put them back to
stock and sell them. They still bring decent money. Then I would invest in
some real DIY loudspeaker building using the much more robust and better
performing loudspeaker components that are available today. You could then
tweak to your heart's desire without the worry of blowing fragile drivers
that are no longer available. You seem like the type that loves to
experiment. Why limit yourself to such old technology that will never reach
today's performance levels no matter what you do?