Hello,

I am overhauling my car audio system and I want to get a 6-channel to
bi-amplify my front components (will be Illusion Audio mid-bass with
tweeters yet to be determined).

I had originally looked at the JL Audio e6450, which I can get locally
for about 540 Canadian dollars. The shop also had a Zapco AG650 that
had remained in inventory for a few years that they wanted to get rid
of. Its also 6 channels, and I'm aware that it's a better quality
amplifier than the JL, but I'm not sure if the difference will be
audible. They were asking 770$CDN for the Zapco, saying that that was
their cost for it.

Do you think it's worth the extra 230$ for the Zapco, or would the JL
be sufficient for use with those speakers?

I might also try to get the rice of the Zapco down even more if I can
but I'm not certain whether they'll budge or not.

Thanks for your input to a newbit to this group.

Luc Delorme
a.k.a. RFMan

I had originally looked at the JL Audio e6450, which I can get locally for
about 540 Canadian dollars. The shop also had a Zapco AG650 that had
remained in inventory for a few years that they wanted to get rid of. Its
also 6 channels, and I'm aware that it's a better quality amplifier than
the JL, but I'm not sure if the difference will be audible. They were
asking 770$CDN for the Zapco, saying that that was their cost for it.

Who said it was a better quality amplifier? How is it better?

On 2005-06-01 02:55:41 -0400, "MZ" said:

I had originally looked at the JL Audio e6450, which I can get locally
for about 540 Canadian dollars. The shop also had a Zapco AG650 that
had remained in inventory for a few years that they wanted to get rid
of. Its also 6 channels, and I'm aware that it's a better quality
amplifier than the JL, but I'm not sure if the difference will be
audible. They were asking 770$CDN for the Zapco, saying that that was
their cost for it.

Who said it was a better quality amplifier? How is it better?

Well, I have to admit that I have not heard the two amplifiers
side-by-side. The fact that it can drive lower-impedance loads and has
more bridging possibilities tells me there is more headroom in the
output stages, but I con't really verify that. Also, I heard that
their built-in crossovers are some of the best in the field. I am also
going by the general concensus that I've seen in forums that place
Zapco amplifiers above most any others.

I did do a little more research after posting this, and there is a
feature on the AG650 that I think I is worth the extra: the crossovers
have a x10 feature, so I can use the to bi-amp the front components
without even needing external crossovers.

Just for that feature, I may get the Zapco, unless someone in this
group can recommend some other 6-channel amplifier that has the x10
crossover feature.

Luc

Who said it was a better quality amplifier? How is it better?

Well, I have to admit that I have not heard the two amplifiers
side-by-side. The fact that it can drive lower-impedance loads and has
more bridging possibilities tells me there is more headroom in the
output stages, but I con't really verify that.

Headroom may not be the right term there. Headroom typically is a function
of rail voltage, which is (kinda) independent of load impedance. I think
you may be referring more to output impedance, but the ability to drive
lower impedance loads doesn't necessarily imply lower output impedance. I
think it just says how big the output transistors are. Unless your
application calls for driving low impedance loads, I wouldn't let this
factor in your judgment.

Also, I heard that
their built-in crossovers are some of the best in the field.

Internal crossovers are a snap to build, and despite the claims of
manufacturers like Audiocontrol, they're all the same - at least in terms of
sound quality. They basically consist of some resistors, some cheap
capacitors (even the expensive designs use cheap ones - I've experimented
with various types without much of a difference), and a few $1.39 op amps
(op amps are so advanced these days that the $1.39 are equivalent to the $8
ones for 100kHz designs; really, op amps are literally perfect circuits -
at least that's what I keep trying to tell old fuddy duddies who insist on
using transistors in every application). They're all even using the same
Sallen-Key topology, not that it matters anyway - hey, fewer
components...that's a good thing.

I am also
going by the general concensus that I've seen in forums that place
Zapco amplifiers above most any others.

Tough to associate one level of quality to an entire manufacturer when
they're putting out different lines under the same name. There are, or at
least were, some cheapo Zapco amps being sold by sounddomain and others not
too long ago. Those ugly little white things. I bought one. I saw nothing
that set it apart from any other amp I've owned. I think you have to avoid
saying "so and so makes the best amplifiers", because just about everyone
these days makes several different lines - some cost a fortune and are well
built and have some sort of feature that makes them special - others are
simply generic. I shouldn't say this is a new thing, because Sony and
Kenwood have been doing it for years. Nowadays, when you look at Pioneer
they're putting out the cheapest crap imaginable to some outlets, and then
some very nice equipment elsewhere. For years, Autotek has had their Mean
Machine line which is very good and then their el cheapo line which is
generic. From what I hear, Lanzar is doing the same sort of thing.


I did do a little more research after posting this, and there is a
feature on the AG650 that I think I is worth the extra: the crossovers
have a x10 feature, so I can use the to bi-amp the front components
without even needing external crossovers.

Just for that feature, I may get the Zapco, unless someone in this
group can recommend some other 6-channel amplifier that has the x10
crossover feature.

That'll probably be pretty useful, and may be justification enough for the
added expense. I've been "tri-amping" for years, and for most of the time
I've done it with a/d/s/ amps. They don't have a x10 feature, but their
xovers go up to the kHz range and are HP/LP/BP selectable. The little knobs
usually aren't accurate anyway, so I use my ear moreso than the numbers on
the dial. I recently bought an Orion 4-channel that has pretty extensive
crossovers too, and that thing's a beast and reasonably priced. I don't
know if they make a 6 channel. There are of course external crossovers to
buy, but I can understand trying to keep the number of components down -
besides, some have been known to be prone to ground loops which is just an
added hassle.

MZ wrote:
Who said it was a better quality amplifier? How is it better?

Well, I have to admit that I have not heard the two amplifiers
side-by-side. The fact that it can drive lower-impedance loads and has
more bridging possibilities tells me there is more headroom in the
output stages, but I con't really verify that.

Headroom may not be the right term there. Headroom typically is a function
of rail voltage, which is (kinda) independent of load impedance. I think
you may be referring more to output impedance, but the ability to drive
lower impedance loads doesn't necessarily imply lower output impedance. I
think it just says how big the output transistors are. Unless your
application calls for driving low impedance loads, I wouldn't let this
factor in your judgment.

Also, I heard that
their built-in crossovers are some of the best in the field.

Internal crossovers are a snap to build, and despite the claims of
manufacturers like Audiocontrol, they're all the same - at least in terms of
sound quality. They basically consist of some resistors, some cheap
capacitors (even the expensive designs use cheap ones - I've experimented
with various types without much of a difference), and a few $1.39 op amps
(op amps are so advanced these days that the $1.39 are equivalent to the $8
ones for 100kHz designs; really, op amps are literally perfect circuits -
at least that's what I keep trying to tell old fuddy duddies who insist on
using transistors in every application). They're all even using the same
Sallen-Key topology, not that it matters anyway - hey, fewer
components...that's a good thing.

I am also
going by the general concensus that I've seen in forums that place
Zapco amplifiers above most any others.

Tough to associate one level of quality to an entire manufacturer when
they're putting out different lines under the same name. There are, or at
least were, some cheapo Zapco amps being sold by sounddomain and others not
too long ago. Those ugly little white things. I bought one. I saw nothing
that set it apart from any other amp I've owned. I think you have to avoid
saying "so and so makes the best amplifiers", because just about everyone
these days makes several different lines - some cost a fortune and are well
built and have some sort of feature that makes them special - others are
simply generic. I shouldn't say this is a new thing, because Sony and
Kenwood have been doing it for years. Nowadays, when you look at Pioneer
they're putting out the cheapest crap imaginable to some outlets, and then
some very nice equipment elsewhere. For years, Autotek has had their Mean
Machine line which is very good and then their el cheapo line which is
generic. From what I hear, Lanzar is doing the same sort of thing.


I did do a little more research after posting this, and there is a
feature on the AG650 that I think I is worth the extra: the crossovers
have a x10 feature, so I can use the to bi-amp the front components
without even needing external crossovers.

Just for that feature, I may get the Zapco, unless someone in this
group can recommend some other 6-channel amplifier that has the x10
crossover feature.

That'll probably be pretty useful, and may be justification enough for the
added expense. I've been "tri-amping" for years, and for most of the time
I've done it with a/d/s/ amps. They don't have a x10 feature, but their
xovers go up to the kHz range and are HP/LP/BP selectable. The little knobs
usually aren't accurate anyway, so I use my ear moreso than the numbers on
the dial. I recently bought an Orion 4-channel that has pretty extensive
crossovers too, and that thing's a beast and reasonably priced. I don't
know if they make a 6 channel. There are of course external crossovers to
buy, but I can understand trying to keep the number of components down -
besides, some have been known to be prone to ground loops which is just an
added hassle.

Thanks for the good advice. I think headroom wasn't really the right
term there, I really meant they they are "overdesigned" in a general
sense. Whether the difference is audible or not is debatable, but
reliability-wise, it can't hurt.

And I do want to avoid external crossovers, since my setup is going to
be really, really non standard (there is no head unit, everything is
run off a PC in the trunk, with a touchscreen in the dash, with oudio
output run from a M-audio professionnal PCI sound card, striaght into
the amp with very little wire in-between (probably 12 inches). I
have an oscilloscope to set the crossovers, and I have access to a
portable spectrum analyzer from work if need be (I work in wireless
telecom research, mostly in the GHz range though). And the fact that
there's a computer in there means that I can use a software RTA in the
cabin to see what's happening as I tune.

I will take a look at a/d/s/ amps though, I've heard good things about
them.

Luc

Thanks for the good advice. I think headroom wasn't really the right
term there, I really meant they they are "overdesigned" in a general
sense. Whether the difference is audible or not is debatable, but
reliability-wise, it can't hurt.

And I do want to avoid external crossovers, since my setup is going to
be really, really non standard (there is no head unit, everything is
run off a PC in the trunk, with a touchscreen in the dash, with oudio
output run from a M-audio professionnal PCI sound card, striaght into
the amp with very little wire in-between (probably 12 inches). I
have an oscilloscope to set the crossovers, and I have access to a
portable spectrum analyzer from work if need be (I work in wireless
telecom research, mostly in the GHz range though). And the fact that
there's a computer in there means that I can use a software RTA in the
cabin to see what's happening as I tune.

I'm also running a car PC. I just bought a pair of these crossovers:

http://www.behringer.com/DCX2496/index.cfm?lang=ENG

Digital input. 6 individually adjustable outputs per unit - separate
crossover settings, delay, phase, level control for each speaker...all
adjustable from the PC. You can download the software on the site to try it
out.

In article 2005053122512916807%luc@rfmanca,
Luc Delorme wrote:

Hello,

I am overhauling my car audio system and I want to get a 6-channel to
bi-amplify my front components (will be Illusion Audio mid-bass with
tweeters yet to be determined).

I had originally looked at the JL Audio e6450, which I can get locally
for about 540 Canadian dollars. The shop also had a Zapco AG650 that
had remained in inventory for a few years that they wanted to get rid
of. Its also 6 channels, and I'm aware that it's a better quality
amplifier than the JL, but I'm not sure if the difference will be
audible. They were asking 770$CDN for the Zapco, saying that that was
their cost for it.

Do you think it's worth the extra 230$ for the Zapco, or would the JL
be sufficient for use with those speakers?

I might also try to get the rice of the Zapco down even more if I can
but I'm not certain whether they'll budge or not.

Thanks for your input to a newbit to this group.

Luc Delorme
a.k.a. RFMan


a better comparison would be between the AG650 and the 500/5. i have
owned amps from both companies and don't think you would go wrong either
way.