I just bought a pair of PAC passive bass blockers to keep the low
frequencies out of my rear 5x7 speakers which are sharing the same amp
speaker output terminals as a Bazooka 8" tube subwoofer...both are
attached to the rear speaker terminals on a Fosgate 4600X 4-channel
amp. The sub gives me plenty of low end so I don't want or need low
frequencies going to the rear speakers, so I decided to try these PAC
bass blockers.

My question is about the installation of the PAC bass blockers. Can
they be installed inline with the speakers right at the amp or do they
need to be installed right at the speakers? I'd rather not have to
remove my door panels and then remove/reinstall the speakers in order
to hook them up if I can help it.

Thanks!

You can do it at the amplifier no problem, but my question is, isn't
there an active x-over in your amplifier, because a passive capacitor
is really the worst way to do it.
Bob wrote:
I just bought a pair of PAC passive bass blockers to keep the low
frequencies out of my rear 5x7 speakers which are sharing the same
amp
speaker output terminals as a Bazooka 8" tube subwoofer...both are
attached to the rear speaker terminals on a Fosgate 4600X 4-channel
amp. The sub gives me plenty of low end so I don't want or need low
frequencies going to the rear speakers, so I decided to try these PAC
bass blockers.

My question is about the installation of the PAC bass blockers. Can
they be installed inline with the speakers right at the amp or do
they
need to be installed right at the speakers? I'd rather not have to
remove my door panels and then remove/reinstall the speakers in order
to hook them up if I can help it.

Thanks!

wrote:
:You can do it at the amplifier no problem, but my question is, isn't
:there an active x-over in your amplifier, because a passive capacitor
:is really the worst way to do it.

Yes, the amp has an active x-over in it but the rear channels have to
be in "full pass" mode since it's driving the subwoofer and the rear
door's full-range speakers. I can't "high pass" the rear channels
since it's providing the sub it's juice, unlike the front channels
which I have "set in "high pass" mode since the amp's front channels
are driving just the front door full-range speakers. I suppose I could
run both the rear and front speakers both off of the amp's "high
passed" channels, but I'm worried about the impedance I would end up
with, or is that a problem since I think the amp is 2-ohm stable? Or
for that matter is there any difference between doing that and having
the sub and the rear door speakers driven by the amp's rear channels?
Same scenario, just different speakers involved.

Some day perhaps I will run speaker leads from my head unit back to my
sub, and then I can "high pass" the amp's rear channels, but that's a
whole 'nuther project for another day. I know this setup is not ideal,
but it works well and sounds very good except for the bass to the rear
speakers, hence the purchase of the blockers to see if they might be
able provide me a low cost, easily installed solution for that issue.

Sorry for the long post...wanted to try to explain the entire setup I
have.

:Bob wrote:
: I just bought a pair of PAC passive bass blockers to keep the low
: frequencies out of my rear 5x7 speakers which are sharing the same
:amp
: speaker output terminals as a Bazooka 8" tube subwoofer...both are
: attached to the rear speaker terminals on a Fosgate 4600X 4-channel
: amp. The sub gives me plenty of low end so I don't want or need low
: frequencies going to the rear speakers, so I decided to try these PAC
: bass blockers.
:
: My question is about the installation of the PAC bass blockers. Can
: they be installed inline with the speakers right at the amp or do
:they
: need to be installed right at the speakers? I'd rather not have to
: remove my door panels and then remove/reinstall the speakers in order
: to hook them up if I can help it.
:
: Thanks!
:

Bob wrote:
: wrote:
::You can do it at the amplifier no problem, but my question is, isn't
::there an active x-over in your amplifier, because a passive capacitor
::is really the worst way to do it.
:
:Yes, the amp has an active x-over in it but the rear channels have to
:be in "full pass" mode since it's driving the subwoofer and the rear
:door's full-range speakers. I can't "high pass" the rear channels
:since it's providing the sub it's juice, unlike the front channels
:which I have "set in "high pass" mode since the amp's front channels
:are driving just the front door full-range speakers. I suppose I could
:run both the rear and front speakers both off of the amp's "high
assed" channels, but I'm worried about the impedance I would end up
:with, or is that a problem since I think the amp is 2-ohm stable? Or
:for that matter is there any difference between doing that and having
:the sub and the rear door speakers driven by the amp's rear channels?
:Same scenario, just different speakers involved.

Follow-up:

I remembered that I did not want the front and rear full-range speakers
to share the amp's front channel speaker outputs. It seems to me that
having the "less important" rear door speakers (less important
sonically speaking to those sitting in the front seat, which is 99% of
the time as I rarely have passengers in the rear seats) and the sub
both sharing the same speaker output terminals on the amp makes more
sense.

snip

So have you ever concidered not hooking up the rears at all, or getting
a dedicated subwoofer amplifier? It would provide much better results.
If not, I'd run the front and rears off the same channels if it's 2
ohms stable, and run the subwoofers low passes so you can get more
power for them.
Bob wrote:
Bob wrote:
: wrote:
::You can do it at the amplifier no problem, but my question is,
isn't
::there an active x-over in your amplifier, because a passive
capacitor
::is really the worst way to do it.
:
:Yes, the amp has an active x-over in it but the rear channels have
to
:be in "full pass" mode since it's driving the subwoofer and the rear
:door's full-range speakers. I can't "high pass" the rear channels
:since it's providing the sub it's juice, unlike the front channels
:which I have "set in "high pass" mode since the amp's front channels
:are driving just the front door full-range speakers. I suppose I
could
:run both the rear and front speakers both off of the amp's "high
assed" channels, but I'm worried about the impedance I would end up
:with, or is that a problem since I think the amp is 2-ohm stable?
Or
:for that matter is there any difference between doing that and
having
:the sub and the rear door speakers driven by the amp's rear
channels?
:Same scenario, just different speakers involved.

Follow-up:

I remembered that I did not want the front and rear full-range
speakers
to share the amp's front channel speaker outputs. It seems to me that
having the "less important" rear door speakers (less important
sonically speaking to those sitting in the front seat, which is 99%
of
the time as I rarely have passengers in the rear seats) and the sub
both sharing the same speaker output terminals on the amp makes more
sense.

snip

Follow-up:

I remembered that I did not want the front and rear full-range speakers
to share the amp's front channel speaker outputs. It seems to me that
having the "less important" rear door speakers (less important
sonically speaking to those sitting in the front seat, which is 99% of
the time as I rarely have passengers in the rear seats) and the sub
both sharing the same speaker output terminals on the amp makes more
sense.

So then how is the subwoofer being filtered??

In my opinion, you'd improve things dramatically if you just removed the
rear speakers altogether, or ran them off the head unit's amplifier, or, at
the very worst, ran them in parallel with the fronts. You won't rob very
much power from the fronts in doing so.

MZ wrote:
: Follow-up:
:
: I remembered that I did not want the front and rear full-range speakers
: to share the amp's front channel speaker outputs. It seems to me that
: having the "less important" rear door speakers (less important
: sonically speaking to those sitting in the front seat, which is 99% of
: the time as I rarely have passengers in the rear seats) and the sub
: both sharing the same speaker output terminals on the amp makes more
: sense.
:

:So then how is the subwoofer being filtered??

The sub has a built in x-over. It's an amplified 8" Bazooka tube (EL8A).

:In my opinion, you'd improve things dramatically if you just removed the
:rear speakers altogether, or ran them off the head unit's amplifier, or, at

It would be very easy to unhook the rear door speakers from the amp, put the
amp's rear channel into "low pass" mode and see what it sounds like. I
think though that I will miss that "fill in" sound I get from the rear
door speakers.

BTW, this is all installed in a 4-door Ford Explorer.

:the very worst, ran them in parallel with the fronts. You won't rob very
:much power from the fronts in doing so.

Really? That's one of the things I was concerned with. I do want to
be sure I have clean power coming to the front speakers.

I'll have to try these options and see which one sounds best.

Thanks for the suggestions.

Bob

If the bazooka tube is amplified, why are you using a 4 channel
amplifier to amplify it?

Maybe you could describe your system again?


Bob wrote:
MZ wrote:
: Follow-up:
:
: I remembered that I did not want the front and rear full-range
speakers
: to share the amp's front channel speaker outputs. It seems to me
that
: having the "less important" rear door speakers (less important
: sonically speaking to those sitting in the front seat, which is
99% of
: the time as I rarely have passengers in the rear seats) and the
sub
: both sharing the same speaker output terminals on the amp makes
more
: sense.
:

:So then how is the subwoofer being filtered??

The sub has a built in x-over. It's an amplified 8" Bazooka tube
(EL8A).

:In my opinion, you'd improve things dramatically if you just removed
the
:rear speakers altogether, or ran them off the head unit's amplifier,
or, at

It would be very easy to unhook the rear door speakers from the amp,
put the
amp's rear channel into "low pass" mode and see what it sounds like.
I
think though that I will miss that "fill in" sound I get from the
rear
door speakers.

BTW, this is all installed in a 4-door Ford Explorer.

:the very worst, ran them in parallel with the fronts. You won't rob
very
:much power from the fronts in doing so.

Really? That's one of the things I was concerned with. I do want to
be sure I have clean power coming to the front speakers.

I'll have to try these options and see which one sounds best.

Thanks for the suggestions.

Bob

In article .com,
wrote:

:If the bazooka tube is amplified, why are you using a 4 channel
:amplifier to amplify it?

I tried hooking it into my head unit's preamp outs but got very little
volume from the sub, so it was suggested by a Bazooka tech rep that I
attach it to my amp's speaker terminals. Doing that made a HUGE
difference.

:Maybe you could describe your system again?

Sure thing. My system installed in a '96 Ford Explorer 4 door:

- Nakamichi CD-35 AM/FM CD player (35wx4, 0.1% THD internal amp; single
set of preamp outs)
- Rockford Fosgate 4600x 4 channel amp (30wx4 20-20k Hz, 0.08% THD)
- 4 ea. Boston Acoustics 5x7/6x8 speakers (2 in front doors; 2 in rear)
- Bazooka EL8A amplified (50w) tube sub (in rear hatch)

Follow this closely if you can:

Each channel of the sole set of preamp outs from the Nakamich head unit
is split (using RCA y-splitters) and then fed into the Rockford 4
channel amp (one set rear, one set front). The Boston speakers are all
run off of the Rockford amp...fronts off the amp's front speaker terminals,
rears to the amp's rear speaker terminals. The sub is also attached
to the rear speaker terminals on the Rockford amp, sharing those
terminals with the rear speakers. The front crossover card in the
Rockford amp is set to high pass position (100 HZ cutoff) and the rear
crossover is set to full range in order to get the full bass response
to the sub.

Many have suggested I attach my sub to the head unit's speaker
terminals since they are not being used now, and that would allow me to
set the Rockford amp's rear crossover card to "high pass". I get great
sound now and I bought the PAC bass blockers hoping in hopes that they
would give me a very easy way to block the low bass to the rear door
speakers, as opposed to having to pull the head unit, and then attach
and run speaker wires back to the sub. Doing this would probably solve
all my issues and would also allow me to use the HU's fader as a
subwoofer level control without affecting the signal going to the front
and rear speakers. I don't really want to install another amp to drive
the sub or install any other active components if I can help it.

Other suggestions?

Thanks,
Bob

:Bob wrote:
: MZ wrote:
: : Follow-up:
: :
: : I remembered that I did not want the front and rear full-range
:speakers
: : to share the amp's front channel speaker outputs. It seems to me
:that
: : having the "less important" rear door speakers (less important
: : sonically speaking to those sitting in the front seat, which is
:99% of
: : the time as I rarely have passengers in the rear seats) and the
:sub
: : both sharing the same speaker output terminals on the amp makes
:more
: : sense.
: :
:
: :So then how is the subwoofer being filtered??
:
: The sub has a built in x-over. It's an amplified 8" Bazooka tube
EL8A).
:
: :In my opinion, you'd improve things dramatically if you just removed
:the
: :rear speakers altogether, or ran them off the head unit's amplifier,
r, at
:
: It would be very easy to unhook the rear door speakers from the amp,
ut the
: amp's rear channel into "low pass" mode and see what it sounds like.
:I
: think though that I will miss that "fill in" sound I get from the
:rear
: door speakers.
:
: BTW, this is all installed in a 4-door Ford Explorer.
:
: :the very worst, ran them in parallel with the fronts. You won't rob
:very
: :much power from the fronts in doing so.
:
: Really? That's one of the things I was concerned with. I do want to
: be sure I have clean power coming to the front speakers.
:
: I'll have to try these options and see which one sounds best.
:
: Thanks for the suggestions.
:
: Bob
:

Bob wrote:
SNIP
Follow this closely if you can:

Each channel of the sole set of preamp outs from the Nakamich head
unit
is split (using RCA y-splitters) and then fed into the Rockford 4
channel amp (one set rear, one set front).

This sounds like you are running the entire system without stereo sound. The
fact is that each y-splitter represents a single channel (left or right) so
if you are using one y-splitter to run the fronts channels of the amp, then
you are only sending either left or right into both front speakers. Or am I
misinterpreting your post?

The Boston speakers are
all run off of the Rockford amp...fronts off the amp's front speaker
terminals, rears to the amp's rear speaker terminals.

SNIP

Wow ... idea is posted above in appropriate place ... Wow

--
Dan Snooks

Daniel Snooks wrote:
:Bob wrote:
:SNIP
: Follow this closely if you can:
:
: Each channel of the sole set of preamp outs from the Nakamich head
: unit
: is split (using RCA y-splitters) and then fed into the Rockford 4
: channel amp (one set rear, one set front).
:
:This sounds like you are running the entire system without stereo sound. The
:fact is that each y-splitter represents a single channel (left or right) so
:if you are using one y-splitter to run the fronts channels of the amp, then
:you are only sending either left or right into both front speakers. Or am I
:misinterpreting your post?

Thanks for the input, but I am getting stereo, trust me. :-)

To clarify, the left and right channel line levels from the HU has it's
own y-splitter attached just before the amp and those split signals are
fed each front/rear and left/right line level inputs on the amp
properly.

: The Boston speakers are
: all run off of the Rockford amp...fronts off the amp's front speaker
: terminals, rears to the amp's rear speaker terminals.
:
:SNIP
:
:Wow ... idea is posted above in appropriate place ... Wow

????

Bob wrote:
Daniel Snooks wrote:
Bob wrote:
:SNIP
Follow this closely if you can:

Each channel of the sole set of preamp outs from the Nakamich head
unit
is split (using RCA y-splitters) and then fed into the Rockford 4
channel amp (one set rear, one set front).

This sounds like you are running the entire system without stereo
sound. The fact is that each y-splitter represents a single channel
(left or right) so if you are using one y-splitter to run the fronts
channels of the amp, then you are only sending either left or right
into both front speakers. Or am I misinterpreting your post?

Thanks for the input, but I am getting stereo, trust me. :-)

To clarify, the left and right channel line levels from the HU has
it's own y-splitter attached just before the amp and those split
signals are fed each front/rear and left/right line level inputs on
the amp properly.

I thought that might be the case, but have learned to NEVER assume :-)

--
Dan Snooks

In article ,
Daniel Snooks wrote:
:Bob wrote:
: Daniel Snooks wrote:
: Bob wrote:
: :SNIP
: Follow this closely if you can:
:
: Each channel of the sole set of preamp outs from the Nakamich head
: unit
: is split (using RCA y-splitters) and then fed into the Rockford 4
: channel amp (one set rear, one set front).
:
: This sounds like you are running the entire system without stereo
: sound. The fact is that each y-splitter represents a single channel
: (left or right) so if you are using one y-splitter to run the fronts
: channels of the amp, then you are only sending either left or right
: into both front speakers. Or am I misinterpreting your post?
:
: Thanks for the input, but I am getting stereo, trust me. :-)
:
: To clarify, the left and right channel line levels from the HU has
: it's own y-splitter attached just before the amp and those split
: signals are fed each front/rear and left/right line level inputs on
: the amp properly.
:
:I thought that might be the case, but have learned to NEVER assume :-)

No problem...better to ask then assume. Thanks again.

Bob