Bicor Horns

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Not new, but it is to me ! & appears interesting in several ways.

The "Academy" Lowther enclosures which this test is about are a little unusual: there are two drivers, both full-range. One of them is located in the top panel and points back and up at 25 degrees from horizontal.

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The front driver is loaded by a quarter-wave horn whose mouth is placed at the bottom of the rear panel. It is folded many times within the enclosure, for a total length of about 1.7 metres. This horn is partially shared with the top driver. The top driver's compression chamber in fact has two openings, the first being connected to the one for the front driver, the second opening into a tuned chamber with a laminar vent. This vent is 36 cm. (about 14 in.) long and is placed on the rear panel just above the horn mouth. No absorbent material whatever is used because the design, dubbed a "Bicor system", prevents the formation of the standing waves that are typical of labyrinth enclosures.

Lowther SonImage

There are various different models, but all share the Bicor concept.

1 - Has anyone heard such a design, doesn't have to be a Lowther, if so ?

2 - Concentrating on only the bass aspect, any Real benefits ?

3 - Can this be modelled ?
 
Hi Zero D,

I think Lowther is the only company that used this combination of design features.

- It could well be that there are some benefits to be had with this design, but, it looks like too much effort/complexity if you're just looking @ the bass range.

- It would be hard to come up w/ an AkAbak simulation that reflects all aspects of the design. The internals would not be too bad individually, but, this loudspeaker interacts so strongly with the environment, that any simulation would have to include environmental features like walls, location of drivers and direction of radiation.

Also, it is a full range loudspeaker, so maybe you'd have more luck in the Full Range Forum?

Regards,
 
You talkin about this thing?

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


There's a better picture of it here - http://www.lowtherloudspeakers.com/drawings/academy.pdf

You can sim it with Akabak and if built as a subwoofer you don't have to worry about the drivers being in different positions and pointed in different directions, the sim will be fine because it will be mostly omni at sub frequencies.

So you've got two drivers, each entering the line at different positions. You've got three chambers and two vents.

Theoretically if you wanted to spend a few hours (or days or possibly even weeks or months) trying to perfect a sim you might see some advantage over a regular BLH.

BUT in this case, these designs are probably decades old and designed without any strategy or simulation aids so they are probably just a mess in terms of measurable metrics.
 
@ tb46

I found other companies still offering these designs & builds for sale.

One of the main benefits they "claim" to provide that interested me was, prevents the formation of the standing waves that are typical of labyrinth enclosures

@ just a guy

Yeah, that's one of several options i saw. Yes i expect they were originally trial & error designs = a Lot of sawdust etc ! If someone could sim it, one day, that would be Very revealing :)
 
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