How does a speaker interconnect cable work?

bryan cordell duffy

unread,

Jul 4, 1997, 3:00:00 AM7/4/97

to

I recently noticed, while hooking up a set of Polk SDA Compact
Reference speakers, that some speaker have an "interconnect" cable
running between the two speakers. This is supposed to improve
phasing, I presume. Could someone speculate how / why this works and
how it is attached internally? I have heard speakers without such a
cable also have good phasing.
I am just curious and would like to have imput to what others
think of this system, and which manufacturers use it.

Bryan Duffy
bc-d...@uiuc.edu

Chuck Ross

unread,

Jul 6, 1997, 3:00:00 AM7/6/97

to

In article <5pj9uc$7...@agate.berkeley.edu>, bc-d...@students.uiuc.edu
(bryan cordell duffy) wrote:

This cable is a proprietary feature of some Polk speakers, and as far
as I am aware, is not present on any other brands.

The cable connects two networks on the speakers together. The networks
allow some information from one channel to be propogated by the other
channel's speaker, and vice versa, giving a sort of "holographic"
effect, as intended by Polk. It's similar to the "processing"
circuitry present in HeadRoom's headphone amplifiers, supposedly
filling in the center of the soundfield and also extending the sound
outside the boundaries of the speaker.

However, having owned a pair of Polks with the "feature", I found it
added severe coloration to the sound and preferred to listen to the
speakers without the interconnect cable.

Chuck Ross
_-_-

"Time's fun when you're having flies." -- Kermit the Frog

James Hess

unread,

Jul 8, 1997, 3:00:00 AM7/8/97

to

I had only one experience of the Polk SDAs, in a dealer's showroom. I
found them very musical and very revealing with Ry Cooder's "Jazz", an
album I thought I knew well from several other systems.

Not to dispute your perceptions, just to offer an alternative
experience.

-Jim Hess-

Michael R. Clements

unread,

Jul 8, 1997, 3:00:00 AM7/8/97

to

Chuck Ross wrote:

> However, having owned a pair of Polks with the "feature", I found it
> added severe coloration to the sound and preferred to listen to the
> speakers without the interconnect cable.

I concur with Chuck on this one. I've had a pair of prototype SDA2s
for over ten years. They are revealing, musical, detailed, powerful
and I really love them. But the SDA had to go. I rewired the
crossovers so the signal from the amp sees both crossover networks in
parallel and in phase. They image even better without the SDA; I
don't know why Polk ever used it. You can turn off the SDA just by
unplugging the cable, but then you have a bunch of "dead" drivers
sitting in the cabinet. They sound better with the SDA driven
speakers in phase with the rest of the drivers.

Now that they are "normal" speakers I really love the sound -- the
bass is amazingly good, deeper than many subwoofers I've listened to,
but very subtle if not downright deemphasized somewhat so it doesn't
overpower the music. It's not a speaker that you listen to and say
"Wow! great bass" because it's so subtle. But when listening to
certain recordings it really comes out -- especially with drums or
contrabass.

The only speaker I'd consider replacing them with would be ML Requests
or similar medium to large sized electrostats like the Magneplanars.

uh OH!

unread,

Jul 10, 1997, 3:00:00 AM7/10/97

to

On 6 Jul 1997 14:41:54 -0400, ckr...@enteract.com (Chuck Ross) wrote:

>The cable connects two networks on the speakers together. The
>networks allow some information from one channel to be propogated by
>the other channel's speaker, and vice versa, giving a sort of
>"holographic" effect, as intended by Polk.

That sounds similar to "Sonic Holography" which Carver marketed.
Slightly delayed, out of phase information taken from the other
channel. Kind of a neat effect, but just kind of spread everything
all over the place.

>It's similar to the "processing" circuitry present in HeadRoom's
>headphone amplifiers, supposedly filling in the center of the
>soundfield and also extending the sound outside the boundaries of the
>speaker.

I get this anyway, without the extra drivers. It did require careful
room setup, but it was in no way an isolated case. Surely I'm not the
only one, so why bother with this weirdness?

>However, having owned a pair of Polks with the "feature", I found it
>added severe coloration to the sound and preferred to listen to the
>speakers without the interconnect cable.

I would imagine that frequency reponse would suffer, as it must
interfere with the drivers carrying the intended information. Anybody
measured it?

colin