I noticed that my amp (a Zapco Reference 350) has a swich on it next to the
crossover dial that can be set to one of three setting; "High", "low" or
"full". The amp is running in stereo mode to power my Dynaudio System 240 MKII,
where should this switch be set?

I'm sure someone that knows this amp in particular will also respond, but
I'll answer anyway.

"High" setting will set the amp's built in electronic xover to High Pass.
Useful in sending high frequencies (or eliminating lower frequencies) to
tweeters or other smaller speakers.

"Low" setting will set the amp's built in electronic xover to Low Pass.
Useful in sending low frequencies (or eliminating higher frequencies) to
subwoofers.

"Full" setting will bypass the amp's built in electronic xover to send a
full range signal covering the entire frequency spectrum.

The crossover dial changes the cutoff frequency whenever the aforementioned
switch is set to low or high.

Where this switch is set at is up to personal preference. In your case, it
should be set to either high or full. Using the high setting, you can limit
the low bass frequencies to the midwoofers in your 240 set. If you have a
subwoofer, those bass frequencies you have eliminated from the 240s can now
be soley reproduced by the sub. If you don't have a sub, then you can flip
the switch to full and enjoy your bass frequencies through the 7" midwoofers
in the 240 set.

If you have a sub you'll most likely keep the switch in high mode. Adjust
the crossover dial so your 7" midwoofers don't distort too badly during
higher volume listening of what you would consider a bass-heavy song you are
familiar with. Try a few songs and go from there. I've found 70Hz to be a
good starting point, if not ideal.

Tony


--



What's more likely? That an all-powerful mysterious god created the
universe and then decided not to give any proof of his existence? Or, that
he simply doesn't exist at all? And that we created him so that we wouldn't
have to feel so small and alone. -Eleanor Arroway, Contact

"Steve Grauman" wrote in message
...
I noticed that my amp (a Zapco Reference 350) has a swich on it next to
the
crossover dial that can be set to one of three setting; "High", "low" or
"full". The amp is running in stereo mode to power my Dynaudio System 240
MKII,
where should this switch be set?

If you have a sub you'll most likely keep the switch in high mode. Adjust
the crossover dial so your 7" midwoofers don't distort too badly during
higher volume listening of what you would consider a bass-heavy song you are
familiar with. Try a few songs and go from there. I've found 70Hz to be a
good starting point, if not ideal.

Thanks for the help Tony. I've got the amp set to "full" with the crossover in
my deck set at 80Hz, although I can set the low pass filter down as far as
63Hz, it almost seems as if I'm asking my mids for to much in this instance.
Once I add a sub to the system, would it be better to keep the amp on "full"
and simply adjust the crossover in my deck, or would it be better to set the
amp to "high"? I'll be using a 2nd amp to drive the sub if it makes any
difference.

Thanks for the help Tony. I've got the amp set to "full" with the crossover
in
my deck set at 80Hz, although I can set the low pass filter down as far as
63Hz, it almost seems as if I'm asking my mids for to much in this
instance.
Once I add a sub to the system, would it be better to keep the amp on
"full"
and simply adjust the crossover in my deck, or would it be better to set
the
amp to "high"? I'll be using a 2nd amp to drive the sub if it makes any
difference.

The only difference I can forsee is if there is an SQ disparity between the
xover in the amp vs. the one in the HU. I honestly don't know the answer to
that. I would personally use the one in the amp, unless you like having
control at the HU where you can adjust it easier. I would use whichever
sounds best, although I'm guessing you probably won't be able to hear a
difference.

Tony


--



What's more likely? That an all-powerful mysterious god created the
universe and then decided not to give any proof of his existence? Or, that
he simply doesn't exist at all? And that we created him so that we wouldn't
have to feel so small and alone. -Eleanor Arroway, Contact

"Steve Grauman" wrote in message
...
If you have a sub you'll most likely keep the switch in high mode.
Adjust
the crossover dial so your 7" midwoofers don't distort too badly during
higher volume listening of what you would consider a bass-heavy song you
are
familiar with. Try a few songs and go from there. I've found 70Hz to be
a
good starting point, if not ideal.

Thanks for the help Tony. I've got the amp set to "full" with the
crossover in
my deck set at 80Hz, although I can set the low pass filter down as far as
63Hz, it almost seems as if I'm asking my mids for to much in this
instance.
Once I add a sub to the system, would it be better to keep the amp on
"full"
and simply adjust the crossover in my deck, or would it be better to set
the
amp to "high"? I'll be using a 2nd amp to drive the sub if it makes any
difference.

The only difference I can forsee is if there is an SQ disparity between
the
xover in the amp vs. the one in the HU. I honestly don't know the answer
to
that. I would personally use the one in the amp, unless you like having
control at the HU where you can adjust it easier. I would use whichever
sounds best, although I'm guessing you probably won't be able to hear a
difference.

There's not much complexity in a crossover circuit, so that probably won't
be an issue. There are different design types and different alignments,
however, so it could be worth investigating. But I would make the
determination primarily based on adjustability. I doubt the head unit
crossover is continuously adjustable, so that may be a feature he wants -
which would then require using the amp. On the other hand, he may want the
ability to adjust on the fly, so that would leave the head unit xover
suitable for that task.

I doubt the head unit
crossover is continuously adjustable

What does this mean? Sorry, I'm still a bit of a newbie when it comes to
technical terms.

I doubt the head unit
crossover is continuously adjustable

What does this mean? Sorry, I'm still a bit of a newbie when it comes to
technical terms.

Put simply, it means analog. It uses a knob to dial in the crossover points
rather than predetermined discrete settings.

Put simply, it means analog. It uses a knob to dial in the crossover points
rather than predetermined discrete settings.

I have to turn a knob on my deck to get the crossover setting to change, but
it's not analog. It's variable from 63Hz up though. What advantage does the
analog crossover have?

Put simply, it means analog. It uses a knob to dial in the crossover
points
rather than predetermined discrete settings.

I have to turn a knob on my deck to get the crossover setting to change,
but
it's not analog. It's variable from 63Hz up though.

If it's not analog, then that means you have various choices of xover point,
no?

What advantage does the
analog crossover have?

It only has an advantage if the options of xover freq aren't sufficient for
your needs. This is often not the case unless the options are coarse or the
range isn't broad enough. For example, if you want to set a crossover for
400 Hz and you have an option of 200Hz and 800Hz but nothing in between,
then it's too coarse.

On 02 Mar 2004 23:46:55 GMT, (Steve Grauman) wrote:

I doubt the head unit
crossover is continuously adjustable

What does this mean? Sorry, I'm still a bit of a newbie when it comes to
technical terms.

I'ts not really an "analog versus digital" distinction, it's
more a description of how finely you can control the crossover
frequency. There are three major types. There's
"continously-variable", where you turn a potentiometer to adjust the
crossover, and there are no detents ("clicks") in the potentiometer
movement. If you have a crossover that continously-variable from 30
Hz-300 Hz, and you wanted to adjust it to 73.8 Hz, you could do it.
This has the advantage of ultra-fine control, but the drawback is that
it's hard to look at the potentiometer and tell exactly where it's
set.
Then you have the other extreme, where you only have a few
different crossover points to choose from. If you can only set your
low-pass crossover to 50 Hz, 80 Hz, 120 Hz, or 150 Hz, you've lost the
fine control over the crossover point, but on the other hand, you know
exactly what it's set to.
In the middle is the "not-quite-continously-variable"
crossover. As an example, PPI uses these on some of their amps. It
has a potentiometer like the continously-variable crossover, but
instead of turning smoothly from one extreme to the other, it has
several dozen detents in it that correspond to different crossover
frequencies. This means that by counting clicks, you can know exactly
which frequency you're setting the crossover to, and there are so many
detents that even though you might no be able to set it to the exact
frequency you want, you can get within a couple of Hz by using one of
the available detents.

Scott Gardner

I'ts not really an "analog versus digital" distinction,

Right. Both are (usually) analog circuits. I should have clarified.