Cornwall vertical horn

[Serge_S]

I've read someplace that Cornwall model that had midrange (or was it high freq) horn mounted vertically is the best.  Why is that?  Wouldn't this increase floor/ceiling bounce. Thanks

 

Serge


[Thaddeus Smith]

here ya go. I've been playing with this just in the last few days.

 

https://community.klipsch.com/index.php?/topic/151678-tinkering-with-my-cornwalls/?p=1767143

[Serge_S]

here ya go. I've been playing with this just in the last few days.

 

https://community.klipsch.com/index.php?/topic/151678-tinkering-with-my-cornwalls/?p=1767143

 

Thanks for the link! Lots of great info in there.

[WMcD]

There is always the notion that in the ancient past things were better and that so called improvements were compromises.

 

I think some of the early Cornwalls and Heresy used EV midrange horns which were of a diffraction design.  The mouth aspect ratio was about 10:1.  The theory was that diffraction would make for wide polars.  Though I have not seen any polar plots.  So the issue is where this diffraction effect would do the most good.

 

Also in that time, there was consideration of where in the front baffle a driver should be placed.  It was thought, IIRC, that a driver should be not symmetrically placed relative to an edge of the cabinet.  So nothing can be in the middle.

 

And there was a thought that if bass, mid, and tweeter were too close together they would interfere with each other. 

 

Further, maybe it was better to have some drivers spaced far to edge of the box to improve wide stereo effect.  But then you need left-right pairs, or right-left pairs. Even up-down issues.  Which is the best position?

 

Additionally, there was a consideration of floor bounce versus wall bounce, as you mentioned.  Which is worse or better?

 

As you can image, the above requirements are contradictory or at least difficult to achieve at the same time.

 

IMHO, PWK cut the Gordian Knot with what was then called the Cornwall II.  It used his mid horn design based on something from Jensen.  The K-400 (Klipschorn and LaScala), K-500 (Belle), K-600 (Cornwall), and K-700 (Heresy) are variations on the same theme. 

 

In all these, the mid and tweeter are close together and symmetric to the left-right edges.  This seems to be followed to this day in the many Klipsch speakers.

 

Best,

 

WMcD

[djk]

 

"I think some of the early Cornwalls and Heresy used EV midrange horns which were of a diffraction design."

[Serge_S]

Thanks WMcD.   I started wondering about this when looking at Volti Audio Alura with its vertical midhorn.

[mungkiman]

I strongly prefer the vertical Cornwall speakers that I own to the horizontal Cornwall speakers that I don't...

[Chris A]

The Cornwall midrange horn is like the other K-400 series midrange horns: they use the idea of "collapsing polars" (select the link to question #24).

 

If you turn the midrange horn to be vertical, what you are doing is putting that band-passed energy between 400-1700 Hz on your side walls instead of your floor and ceiling.  What's interesting is that this difference is significant in terms of timbre shift of the speaker(s). When you couple this insight with the need to toe-in your speakers in order to get them to start imaging the soundstage, then you can begin to see that this becomes a large issue.

 

I recommend horizontal orientation of the midrange horn, with some carpet on the floor and a ceiling height of at least 8 feet (2.4 metres).  If lower than 8'/2.4 m, then I recommend ceiling acoustic tiles be used to absorb that extra midrange energy.

 

The tweeter, however, is another story.  EV actually recommends that the T35A be oriented vertically instead of horizontally as Klipsch Heritage uses them.  However, in this case the polars vertically vs. horizontally aren't significantly better, only marginally so, and the directivity index changes more with frequency (just like the midrange).  In the case of tweeter frequencies (6-20 KHz) they really don't bounce off the walls as much as midrange frequencies before being diffracted or absorbed.

 

YMMV.

 

Chris

Edited September 21, 2014 by Chris A

[Serge_S]

The Cornwall midrange horn is like the other K-400 series midrange horns: they use the idea of "collapsing polars" (select the link to question #24).

 

Thanks a lot for the link Chris.  Very useful.  Took me some time to absorb all the info. 

Edited September 30, 2014 by Serge_S

[WMcD]

Thanks djk for posting the picture of the K-1000.  I had never seen it before.

 

I was thinking of the EV 8HD.  I see there was a 6HD.

T10A, T25A, 8HD and 6HD EDS.pdf