For the sake of conversation...

[Nipper]

I have been trying different configurations of speaker cabinet designs for a while and have noticed something. Its just my opinion but it seems like mounting my 811B horns vertically greatly increases the channel separation. It makes sense because they are projecting the sound more up and down vs. left and right.

I cant say I ever saw any Altecs with the horn mounted vertically. Anyone know why they always mounted them horizontally or care to speculate as to why? The difference is rather dramatic in a smaller room.

[gearfreak]

I think the elementary answer, is "just a matter of the desired dispersion (90? v 40?)"

http://www.altecpro.com/pdfs/vintage...0HF%20Horn.pdf

(oops, that's the link to the 511... but the concept does not change per se)


Others may comment about the choice of dispersion pattern, in it's relation to matching the (assumed) LF section - and perhaps specifically matching @ the crossover frequency.

They're also a bit dangerous when freestanding vertically. ouch! :-)

[LICORNE]

The Multi Cellular horn was a great invention coupled with a 288 driver it covered a wide area
with a high Q . Perfect fo cinema applications. The CD horn MR 94 with it's 300 hertz cross over point combined with a 288 or GPA 399 is even better offers greater Q and has less
sound holes compared to the multi cellular it even outperforms the JBL 2446H driver with the 2360A Horn eavry time.

So if you'r a cinema owner with very litle money you can upgrade these Altec systems instead of buying new gear.

[whitebroncoii]

Mounting the 811B horn vertically can reduce the amount of energy directed at the side walls and the lack of these reflections may center your attention to the front of the room.

Altec Lansing products were rarely designed for home stereo applications. The stuff that we all love and lust after are professional/commercial components that were readily available and simply used for those few models built for consumer sales.

A professional/commercial coverage pattern delivers sound for large spaces (theater, church, etc.) not small living rooms. 40 x 20 for long-throw, 60 x 40 for medium-throw and 90 x 40 for the front rows. Should the coverage be 40 x 90 instead of 90 x 40, the reflections from the ceiling and floor would be very destructive in a theater or church, as well as cause massive feedback from open microphones in most churches.

[LICORNE]

Yes 90 X 40 In the medium format for compact screens. 40 feet to the back.In the large size 400 seats to 700 seats go with the large format long throw 40X20 . 5 A5 and or A4 speakers behind the screen.I'ts a lot easier to handle when oversized .

[Nipper]

Everyone seems to agree mounting the horns horizontally would be the only way to go in a large room. Cant argue with that.

I wonder if the Engineers at Altec ever considered vertical mounting for their home speakers. Perhaps the benefit of enhanced separation is outweighed by something else. They probably never dreamed anyone would ever use these in a small room.

Maybe thats why my ears ring!

[Panomaniac]

"Bear" over at diyAudio.com has advocated vertical horns for years.

I've tried it with the 811 and thought is was pretty good. It depends a lot on your room and walls.

[Altec Best]

[QUOTE=Panomaniac;1843543 It depends a lot on your room and walls.[/QUOTE]

Most definately ! And does not work in my listening room at all.Sounds like an echo chamber from the reflections off the ceiling.

[gearfreak]

...they probably never dreamed anyone would ever use these in a small room.

and

...It depends a lot on your room and walls.

In a narrow room, I've rotated my duplex/coaxial drivers to have the HF section 'vertical'.
This was to increase vertical dispersion - as opposed to improving separation - as they are not at an ideal elevation. It may have done the latter as well. Levels are not extreme, so have not noticed perhaps. As well, have not noticed bad reflections (yet) but it makes sense.

[GM]

I wonder if the Engineers at Altec ever considered vertical mounting for their home speakers. Perhaps the benefit of enhanced separation is outweighed by something else. They probably never dreamed anyone would ever use these in a small room.

What's most critical is no early reflections in front of the listening position in our most acute hearing BW and keeping the driver's acoustic centers close enough to be perceived as one at the listening position.

Rotating a radial horn 90 deg can help with the former, but usually mucks with the latter, so all things considered, especially in a consumer product where the 'bean counters' rule, is to pander to our more acute horizontal hearing and toe in the speakers as required to lower any side wall early reflections.

DIYers of course can choose their own trade-offs based on room configuration/WAF/whatever, but for me, timing errors due to large driver acoustic offset(s) completely dominates mine, so in my current room a vertically oriented radial is an absolute no-no.

GM