[Jack[_6_]]

Good day group,

Perhaps someone can clear something up for me.

I just came into possession of some rather large 3-way speakers and I
took the woofers and midrange and tweeters out to have a look-see.

The hots for the mids and tweeters are connected from the terminals in
back of the cabinets in series respectively with 10 mfd and 4.7 mfd
electrolytic caps to pots on the cabinet face and then to the drivers.
The hots for the woofers are directly connected to the speaker wire
terminals, as are the grounds for all the speakers.

The question I have arises from how the mids are wired. The woofers have
a '+' and '-' stamped near the connector lugs, so its easy to tell which
wire goes where inside the cabinet. The mids have a red band near one
lug and the tweeters have a red dot near one lug. I am assuming that red
means hot or positive and 'no red' means ground or minus. The confusion
arises from the fact that the grounds coming from the amp are connected
to the red side of the connector lugs on the mids. The tweeters have the
hot, or positive, wire connected to the red side and the woofers have
the hot, or positive, wire connected to the side stamped with the '+'.

I checked the woofer against the midrange with 1.5 volt battery and the
red side on the mid corresponds to the '+' on the woofer. Connecting the
plus side of the battery to the red side of the mid caused the cone to
move out, and connecting the plus side of the battery to the '+' on the
woofer moved the cone in the same direction.

But the the speakers were wired inside with the negative wire from the
amp going to the red or positive side of the midrange driver.

Is it normal for a 3-way speaker box to be wired this way? I would think
that all the individual drivers in a box should be phased the same. I am
basing that on absolutely nothing but pure logic and a knowledge of how
a speaker moves air to create sound and that if two speaker boxes are
connected out of phase, their individual output of sound would tend to
cancel each other out.

Can anyone shed some light on this?

Thanks,
Jack, in beautiful, sunny Berkeley

[Don Pearce]

On Tue, 31 Jul 2007 12:49:58 -0700, Jack
wrote:

Good day group,

Perhaps someone can clear something up for me.

I just came into possession of some rather large 3-way speakers and I
took the woofers and midrange and tweeters out to have a look-see.

The hots for the mids and tweeters are connected from the terminals in
back of the cabinets in series respectively with 10 mfd and 4.7 mfd
electrolytic caps to pots on the cabinet face and then to the drivers.
The hots for the woofers are directly connected to the speaker wire
terminals, as are the grounds for all the speakers.

The question I have arises from how the mids are wired. The woofers have
a '+' and '-' stamped near the connector lugs, so its easy to tell which
wire goes where inside the cabinet. The mids have a red band near one
lug and the tweeters have a red dot near one lug. I am assuming that red
means hot or positive and 'no red' means ground or minus. The confusion
arises from the fact that the grounds coming from the amp are connected
to the red side of the connector lugs on the mids. The tweeters have the
hot, or positive, wire connected to the red side and the woofers have
the hot, or positive, wire connected to the side stamped with the '+'.

I checked the woofer against the midrange with 1.5 volt battery and the
red side on the mid corresponds to the '+' on the woofer. Connecting the
plus side of the battery to the red side of the mid caused the cone to
move out, and connecting the plus side of the battery to the '+' on the
woofer moved the cone in the same direction.

But the the speakers were wired inside with the negative wire from the
amp going to the red or positive side of the midrange driver.

Is it normal for a 3-way speaker box to be wired this way? I would think
that all the individual drivers in a box should be phased the same. I am
basing that on absolutely nothing but pure logic and a knowledge of how
a speaker moves air to create sound and that if two speaker boxes are
connected out of phase, their individual output of sound would tend to
cancel each other out.

Can anyone shed some light on this?

Thanks,
Jack, in beautiful, sunny Berkeley

At the crossover frequency, where the speakers "meet" each other, the
crossovers have a phase shift, as do the speakers themselves.
Depending on how they add up, it is quite probable that they needed to
wire the speakers in apparent antiphase to get them as close as
possible to in phase at the crossover frequency.

Ultimately they will have just chosen the polarity that gave them the
flattest response.

d

--
Pearce Consulting
http://www.pearce.uk.com

[Jack[_6_]]

Don Pearce wrote:
On Tue, 31 Jul 2007 12:49:58 -0700, Jack
wrote:

Good day group,

Perhaps someone can clear something up for me.

I just came into possession of some rather large 3-way speakers and I
took the woofers and midrange and tweeters out to have a look-see.

The hots for the mids and tweeters are connected from the terminals in
back of the cabinets in series respectively with 10 mfd and 4.7 mfd
electrolytic caps to pots on the cabinet face and then to the drivers.
The hots for the woofers are directly connected to the speaker wire
terminals, as are the grounds for all the speakers.

The question I have arises from how the mids are wired. The woofers have
a '+' and '-' stamped near the connector lugs, so its easy to tell which
wire goes where inside the cabinet. The mids have a red band near one
lug and the tweeters have a red dot near one lug. I am assuming that red
means hot or positive and 'no red' means ground or minus. The confusion
arises from the fact that the grounds coming from the amp are connected
to the red side of the connector lugs on the mids. The tweeters have the
hot, or positive, wire connected to the red side and the woofers have
the hot, or positive, wire connected to the side stamped with the '+'.

I checked the woofer against the midrange with 1.5 volt battery and the
red side on the mid corresponds to the '+' on the woofer. Connecting the
plus side of the battery to the red side of the mid caused the cone to
move out, and connecting the plus side of the battery to the '+' on the
woofer moved the cone in the same direction.

But the the speakers were wired inside with the negative wire from the
amp going to the red or positive side of the midrange driver.

Is it normal for a 3-way speaker box to be wired this way? I would think
that all the individual drivers in a box should be phased the same. I am
basing that on absolutely nothing but pure logic and a knowledge of how
a speaker moves air to create sound and that if two speaker boxes are
connected out of phase, their individual output of sound would tend to
cancel each other out.

Can anyone shed some light on this?

Thanks,
Jack, in beautiful, sunny Berkeley

At the crossover frequency, where the speakers "meet" each other, the
crossovers have a phase shift, as do the speakers themselves.
Depending on how they add up, it is quite probable that they needed to
wire the speakers in apparent antiphase to get them as close as
possible to in phase at the crossover frequency.

Ultimately they will have just chosen the polarity that gave them the
flattest response.

d


Thanks, Don

I've had to get up to speed on just what the term "crossover" refers to.

I think I misused the term "3-way", as that seems to refer to crossover
circuits and not drivers.

There doesn't appear to be any real crossover circuitry in these
speakers, just a couple of electrolytic caps in series with the hots to
the midrange and tweeter.

I will just leave the phase on the midrange drivers as I found it. It
sounds fantastic and if it ain't broke I don't see how I can fix it.

[dizzy]

Jack wrote:

It sounds fantastic

Hmm....

Tin ears?