Phasing question

[3dzapper]

I've seen discussions about phasing of the K-55 and K-77s in various Heritage speakers and must admit a bit of confusion. Do the pos outputs go to the red terminals on both drivers, one or the other. With ALKs and Khorns and Heresys with E2 networks?

I've read to put the red on neg on my JBL2494s, is that right?

I'm sure a discussion of this by the forum gurus will help many more than just myself.

Rick

[Deang]

PK flipped the connections on the Type E for the tweeter and midrange drivers. The Type AL is like this as well, though it might be just the tweeter, I can't remember right off hand. I'm also not sure about the Type E2 -- a lot of my schematics are at work. At any rate, connections for you should be "normal". Don't know about your JBLs -- but you can probably find documentation on those at the JBL Pro site. Simple enough to try both ways right? One way will definitely sound better than the other.

[Al Klappenberger]

I seriously doubt that tweeter phasing is important at all. The squawker and tweeter are over a foot apart. With a wavelength of only an inch or two and different at every frequency the two can't be in phase excpt at random points in the room and at multiples of certain frequencies anyhow.

Al K.

[D-MAN]

Yes, the phasing matters in that it tend to "suck up" most of the tweeter output when backwards from the midrange polarity; but you still get usable output from the tweeter.

But now here comes the tricky part: who knows how these things are wired by the manufacturer - for instance JBL says that their tweeter's RED terminal provides a forward motion on the diaphram with negative polarity. Just to be different, I suppose!

DM

[3dzapper]

Many musicians demand that the drivers go out on the downstroke and can tell the difference. Maybe Dodger with his ears can tell. I'm just a listener but do want to listen correctly. The area the troubles me is the upper bass/lower mid changeover. It would seem that those wavelengths are long enough to collide and cause a "suck out" which could be attributed to the room.

I subbed some Altecs for a test with K-400s yesterday, when I put the K-55s back in, I'll hook them up both ways and see if I can hear a difference.

In case you are wondering, the Altecs sound like Altecs with K-400s. A little soft and laid back on the attack v the K-55s. More speaker like. Not altogether bad but not better either, just different. Like padding the walls.

Rick

[dragonfyr]

While I have no idea offhand regarding what the manufacturer says, it is easy to determine the cone motion for each polarity configuration in a dynamic driver (woofer) (don't do this with a compression horn driver!).

Generally a 9volt battery can be safely connected to the woofer and the piston will move, reverse the terminals and it will displace in the opposite direction.

But if you are paranoid about this, start with a smaller voltage battery until you reach a voltage with sufficient EM to displace the cone.

[lynnm]

PWK changed the phasing of the tweeter in the Heresy as he discovered that doing so slightly smoothed the transition between the midrange and tweeter.

LOL

The suggestion regarding using a battery to check woofer phasing reminds me of the time I made the same suggestion but failed to specify how large a battery to use. One of the members wrote a hilarious response.I don't recall who it was or the exact wording but it went along these lines:

Thanks a bunch Lynnm!

Next time be more specific about the battery size to use!! I figured that since the woofer was big I should use a big battery. I hauled the 24 volt battery out of my backhoe and connected it as you suggested.

Now one of my woofers is in the swimming pool and the other is imbedded in my couch and my wife's cat won't come back in the house!