Suggestions on theory behind Co-entrant horns?

[pinkmouse]

Hi all you theory types...

On another thread- http://www.diyaudio.com/forums/showthread.php?s=&threadid=4372

I asked for anyone with any ideas about this type of design, because it seems to offer the efficencies of both coupled drivers and horn loading.

I know the system controller for the Renkus Heinz boxes has a delay built in to compensate for the differing acoustic centres of the drivers, and they sound very good, but that is about all.

I have attached a cleaned up scan from an old trade mag to give you all an idea on the basic design.

 

[roddyama]

Pinkmouse,

I'm assuming you noticed that your pic show the horn has the further efficiency of being a dual (frequency) range horn. I like how they mix the blue (high) and yellow (low) to get the combined range in green.

Rodd Yamashita

 

[pinkmouse]

Yup Rodd, its all part of my confusion!

 

[AGGEMAM]

Hmm .. there seems to be no reason why you couldn't use a single HF driver instead of a pair, that would simplify calculating the acoustic centers accurately.

However, a guesstimate of the acoustic centers being equal to the front of the poleplate, would be a good starting point.

The co-entrant horn is a very interesting design, although not very suitable for hi-fi speakers.

 

[planet10]

You could probably get some insight from Tom Danley's Unity horns. His patent has just been issued and there is a discussion over on Audio Asylum.

An externally hosted image should be here but it was not working when we last tested it.

A whole bunch more pictures at Lambda Acoustics.

dave

 

[pinkmouse]

thanks Dave ,

I think I need to seriously study that thread, although I know for a fact that Renkus Heinz already have a patent on multiple drivers loading a single horn, so I wonder where the novelty aspect comes in, in Tom's patent....

 

[planet10]

I think I need to seriously study that thread, although I know for a fact that Renkus Heinz already have a patent on multiple drivers loading a single horn, so I wonder where the novelty aspect comes in, in Tom's patent....

Tom went thru it all on a long post to the Joe List. Can't recall the detail, but he deserves his patent.

dave

 

[AGGEMAM]

I think I need to seriously study that thread, although I know for a fact that Renkus Heinz already have a patent on multiple drivers loading a single horn, so I wonder where the novelty aspect comes in, in Tom's patent....

The difference between the patents is that while both (and several other patents) embodies multiple drivers loading a single horn, the Unity horn has a single horn with multiple horn mouths at differing depths according to frequency of coverage of the individual horn mouths, while the Dr. Heinz version has a combined single mouth from different drivers driving a single horn.

Correctly made the Dr. Heinz version is the superior one, IMHO.

 

[planet10]

The difference between the patents is that while both (and several other patents) embodies multiple drivers loading a single horn, the Unity horn has a single horn with multiple horn mouths at differing depths according to frequency of coverage of the individual horn mouths, while the Dr. Heinz version has a combined single mouth from different drivers driving a single horn.

Correctly made the Dr. Heinz version is the superior one

Are you sure you don't mean throats? The Unity-type horn has the drivers at each frequency of driver load into the horn at a different place optimum for the frequency they cover. Further, the XO + this separation ensures perfect phase matching.

I haven't heard or seen either, but the Unity-style horns get pretty high marks from those that have.

dave

 

[AGGEMAM]

Are you sure you don't mean throats?

Correct, it is throats, off course, translation of loudspeaker theory across languages is apparently not easy.

I haven't heard or seen either, but the Unity-style horns get pretty high marks from those that have.

Correct, but theoretically the Dr. Heinz design should sound better.

 

[Brett]

...theoretically the Dr. Heinz design should sound better.

Why, in your opinion.

Cheers

 

[AGGEMAM]

Why, in your opinion.

Because of the inevitable reflections the additional throats along the length of the horn will produce.

And the horn apenture (I really not sure this is what it is called, but anyway, I mean the shape of the horn) is compromised by additional throats giving an uneven amplification in the frequency range.

 

[pinkmouse]

Tom went thru it all on a long post to the Joe List. Can't recall the detail, but he deserves his patent.

Gosh, that list is deep...

Well, I think Tom deserves his patent, but I'm not sure if I'm any more knowledgable or not!

So, In the Renkus Heinz design, I assume the common drivers, (hi-hi and mid- mid) are actually loading separate horns, but just with the hi horn located in the middle of the mid horn, and the shape of the mid horn has no effect on the dispersion or loading of the hi-frequencies.

But how does the mid horn, which starts as two separate paths, cope with the sharp disconuity as it steps around the hi horn mouth, or is it a case that the two mid horns ( one from each driver) then load the front horn when they combine?

Help!!