Anyone built the Decca Corner Horn (TQWP)?

[DrBoar]

I built the Trike pipes as published in HFN&RR, then I found the Decca Corner Horns DCH(really pipes with the driver facing into the corner angled slightly uppwards).
The history of the DHC dates back to 1949, the HFN&RR publication is much later in the early 60s. It it built in 9mm plywood (3/8" in Imperial units) and the only improvement is to remove a brace! As is is said to sound better that way. There is no damping material what so ever in the enclosure

I have some Philps 9710 that are very shouty when facing forward, so upward or backward might work better. The smoth front of the enclosure uninterupted by any drivers inites to all kind of decorations...

Having a thin-walled enclosure devoid of damping material and having flexing wall as absorbers of resonans make me feel a bit uneasy.

My initial plan is to build two boxes, one by the book in 10mm OSB and one conventionally built with thicker material more braces and damping material in the first part of the pipe. But if anyone already have tried I would like to know before I start.

[planet10]

Have you got pictures? The original article?

dave

[hm]

Hello DrBoar,
the 9710 with my satellite horns Schalmei , Trumpet, or Horn and you will get
~100 dB from ~130 Hz, so you need a strong sub,
take a look at my HP.

[DrBoar]

There is drawing athttp://img89.imageshack.us/img89/295/247wk.jpg
To get a feel for it size and looks
AudioJumble - Previous Events
I can scan the original article and put it online tonight

[planet10]

It is quite small....

dave

[Colin]

I've read the original article and from recollection, the thin wall cabinet was deliberate. I'm not quite sure what it meant to achieve. I think the HFN article was by Ralph West, so a Google might find it. There was also a more modern version (forward-facing) published by Electronics Today in the UK in the 1980s.

I've heard Lowthers in a similar enclosure, designed to face into corners. The sound was quite pleasant if diffuse. Bear in mind that the reason for this arrangement dates back to mono, when the designers wanted to achieve a nice spread of sound from one speaker enclosure.

PS David Weems has more about them here

http://tqwp.narod.ru/Theory/Weems/Weems-en1.htm

[DrBoar]

OK here goes with the pictures

[DrBoar]

The pictures are all screwed up. All my images hosted at photobucket are suddenly thumbnails. So my total account is now down to 430kb...
I will look into other hosts

[sreten]

Hi,

FWIW my first speaker was a Decca corner "horn" used against a wall, along
with a tripletone mono ampliifier, and a ceramic equipped BSR turntable.

As I recall the back section was made of ~ 3/8" plywood, but the veneered
sections, the front, top and sides where made of ~ 3/16" plywood, no damping.
Cannot recall the internal partition, but I would say ~ 1/4" is the most likely.
All joints as I recall used ~ 1/2"x1/2" battening, except the back top faceting.

The 8" unit eventually expired, and putting in an 8" fane dual cone did not
work at all, it turned into a boom box, damping did not help at all. I'd say
it needs a fairly low Q but fairly high Fs 8" driver.

rgds, sreten.

Only an American would think a pair of them are not imposing ......

[DrBoar]

pictures removed by moderation