[Labarum]

Are there any designs for horns built into or onto the wall of a room?

If a room were in for substantial redesign this might be an interesting project - big efficient horns very simply constructed.

I remember seeing a design 40 odd years ago for two such horns built into the alcoves ether side of a chimney breast.

In the modern context two mock pillars could rise to the ceiling either side of a flat screen TV, they could sweep down and out to the corners of the room for maximum efficiency.

Any designs? Any pictures?

[Mike Nomad]

Life magazine from 15 June 1953 (QE IIs Coronation on the cover) has an article, "The Hi-Fi Bandwagon."

The article includes a snap of "A.J. Hardy of Dallas" fiddling around with an 11 foot horn. It runs across his garage, and opens into his living room.

There is also a picture of "Richard Russell, St. Paul, Minn." posing with his array of 32 five-inch speakers (in a 4 row, 8 column configuration) built into an alcove in what looks like his dining room.

Sorry, I don't have a scan of the article.

[Labarum]

Thanks. The alcove horns I remember date some ten years later by which time stereo was well established. I have seen on the internet designs that use many wide range drivers in series-parallel. I have seen 60s designs by G. A. Briggs also using multiple drivers. That I don't understand. Wouldn't the cones flap around rather because of a very poor damping factor? But that is a digression!

I would be looking for two drivers positioned either side of a TV at suitable height and spacing with rear horn loading.

[Mike Nomad]

If I understand your "flapping" question, the answer is no, because of phasing. The thing that makes arrays so attractive is that you get a "snowball" effect (horrible analogy, but I can't think of a better one at the moment): The same signal is going across a number of speakers in close proximity to one another creates a higher dB output at a measured frequency. Tighter low frequency response is a little easier to achieve because there is less cone excursion to deal with.

About your two driver solution: How much space in the wall do you have? are you limited to the back board (which means, typically, half a foot or less.), or can the enclosure go completely through the wall?

[Labarum]

Let's assume the the wall may not be penetrated, but the higher part of the horn may be lost in about 9 or 10 inches (bookcase width), and the lower part under a wider shelf of (say 18 or 20 inches).

[Labarum]

Now these are not horns

http://diyaudioprojects.com/Speakers/Fostex-FE103E-Zigmahornets/

but they could be easily constructed against a wall  so as to look like an architectural feature.

[GBB]

Are there any designs for horns built into or onto the wall of a room?

Any designs? Any pictures?

Here's a picture that I pulled off of the web.  It's from a French audio enthusiasts site and belongs to a gentleman by the name of Marcel Roggero.  The article states that the he lives in the south of France and that these pictures were circa 2004.   More details here: http://www.melaudia.net/ecouteSud04MR-1.php

---Gary

[JLM]

Due to the high pressures involved with any horns, and especially horns capable of deep bass, the best solution for bass horns would be concrete.  The horns themselves would be garage sized (depending on how low you want to go).  I've only heard of a couple such being built, although several plywood horns can be found by doing a web search.  Anything other than a totally rigid material will evoke obvious colorations.

Steve Deckert founder/owner of Decware has a concrete one in his basement, but I don't believe he has listened to it for years.  He also has built large wooden horns (dual 15 inch drivers per channel).

[bunnyma357]

This is a link about someone who turned the basement into a pair of large horns.

http://www.gizmodo.com.au/2008/07/horn_subwoofer_takes_up_crazy_mans_entire_basement-2.html

Jim C

[Labarum]

The Organ Builder

http://www.copemanhart.co.uk/specification.htm

build large horns into churches to get the best out of the Pedal Organ - 16Hz needed!

But I was thinking only of a more modest domestic installation using a full range driver.

[doug s.]

This is a link about someone who turned the basement into a pair of large horns.

http://www.gizmodo.com.au/2008/07/horn_subwoofer_takes_up_crazy_mans_entire_basement-2.html

Jim C

for more info about those subwoofers, (and the rest of the system), check out this site:
http://www.royaldevice.com/customita3.htm

a coupla pics:




truly an over-the-top system, the sub horns are yust a small part of it. 

doug s.

[chrisby]

Doug - whenever my wife has any criticism of my funny looking little speaker boxes, I just show her something like this

[doug s.]

Doug - whenever my wife has any criticism of my funny looking little speaker boxes, I just show her something like this

and no matter how huge your speakers are, they are guaranteed to look small in comparison!   

doug s.

[Labarum]

I asked about building a horn into a room, not a room into a horn!

Any serious input?

[Labarum]

A less than serious but historically accurate response:

Parsons (of steam turbine fame) developed a "steam powered" horn that enabled a cello to be heard three miles away.

http://www.dself.dsl.pipex.com/MUSEUM/COMMS/auxetophone/auxetoph.htm

The Pasons' Factory in Newcastle upon Tyne was at the end of the road where my Grandmother lived.

[JLM]

Labarum,

I was being serious.  Few people appreciate what is involved in reaching 20 Hz.  Amps get much, much bigger.  The energy imparted to the room becomes huge and unmanagable as everything everywhere starts to resonant.  And most don't know what 20 Hz, let alone 30 Hz sounds like musically, because precious little material exists below 31.5 Hz.

Bass horns get big and their internal pressures get quite high.  If you try to "bend" the laws of physics the first thing folks try to compromise on is size.  But if you down size too much, the pressures go up and the air compresses in a non-linear fashion that produces distortions.  Depth of bass response must also necessarily suffer when size is reduced. 

Paul Klipsch had one of the best in room bass horn designs with the Klipschorns that use the corner of the room as the last folds of the horn.  Even then the speakers are quite large and heavy and are only rated down to 40 Hz.  The real challenge with the Klipschorns is the need for two adjoining corners that have at least 8 feet of uninterupted wall on each side.  (If you think about it, most rooms don't offer this with a decent listening position.)  The other problem is lack of depth/width of soundstage since they are tight into the corners.  BTW his design wasn't simply to build and not well braced.

Steve Deckert, who I mentioned above as having a small (5ft x 4 ft x 4ft) concrete single channel horn, also has plans on his website for the Imperial horn (about 7ft x 4 ft x 2.5ft) that uses two 15 inch woofers.  These are very heavy (probably over 300 pounds) and even bigger if you brace them sufficiently. 

[Labarum]

Labarum,

I was being serious.  Few people appreciate what is involved in reaching 20 Hz. 

O, I do understand the issues. Electronic organs are sold with 32ft stops to small churches where you cannot establish a 16Hz wave.

The digital electronics in these new instruments is superb, but the bass can let them down. Most makers just use disco subwoofers, but Copeman Hart use extremely large horns or reflex enclosure build in masonry. They win.

I am interested in seeing what can be achieved in general performance with a simple and modest in built horn. My interest has serious practical limits. I am not interested in a mega project. In recent years we have just thrown ore and more watts at smaller and smaller boxes - it must be time to pull back from that.

[JLM]

There are all sorts of hybrid designs, here's one:

http://decware.com/newsite/wo32.htm

Decware has 3 other horn designs of various sizes/applications that will give you ideas of what's available.  I've heard his corner horn (that only goes down to 40 Hz) and his double woofer Imperial subwoofer.  Neither impressed me (The corner horn was installed without a front wall to allow for image depth, so bass suffered.  The Imperial was poorly braced as can be expected for a cabinet that size.)

Pi speakers offer a hybrid bass reflex/corner horn, sort of similar to the Klipschorn.  They recommend expanding foam that creates a sandwich construction to help stiffen panels without excessive weight.  Like the Klipsch the tweeter/woofer are not time aligned, which is a challenge for most bass horns.  But the Pi corner horn I heard sounded horribly muddy and poorly tuned (one note bass).

If you're after "fast"/high efficiency bass, I'd start with Hawthorne Audio.  Daryl, Diane, and Dave are super people to deal with.  They offer 15 inch open/infinite baffle subwoofers and 10/15 inch coaxial open baffle drivers/speakers.  The coaxials are 93 - 98 dB/w/m and get down to 40 - 50 Hz.  Their prices are highly competitive and the build quality is great.  The recommended baffles are very small.  But note that dipoles offer a different (less defined) presentation than point source speakers.

[dmiller]

If you can't do bass horns, consider IB woofers/subs. You need an adjoining attic, basement, large closet or other utility space. Probably the easiest and least expensive way to get below 20hz. It also allows small in-room speakers.

[cryoparts]

Kevin Brooks, a friend of mine, has a stellar horn system himself, although I haven't heard the latest incarnation yet...I need to run up to his house one of these days.

However, the installation he did in Cyprus is a really amazing:



http://news.cnet.com/8301-17938_105-9810551-1.html

Peace,

Lee