The Advantages of Floor Coupled Up-Firing Speakers

[6.283]

Originally Posted by graaf

no problem - Klippel results are valid for typical listening rooms

Good point about the terminology used !
The practical way, though, will lead you via the RT60 route and that value is theoretically only valid in a diffuse field. But even if you use RT60, the result ("a little less than twice the critical distance") in a typical listening room is close enough. The last cm (or inches) are subject to taste anyway.

[midrange]

I first heard of the Jimmy Hughes ideas from one of his magazine articles, where he suggested that his readers try it, with whatever speakers they had.

If you have your speakers on stands and a suitable back wall, it would only take a few seconds to try it out. It is sort of whacky, and so pondering whether or not it would work, if it only works with midrange horns etc, is far more time consuming and inconclusive than simply trying it.

[graaf]

Originally Posted by midrange

pondering whether or not it would work, if it only works with midrange horns etc, is far more time consuming and inconclusive than simply trying it.

unfortunately the usual way of things here is that...

Originally Posted by el`Ol

...[m]ost people will rather invest an hour to tell you it can´t work than five minutes to test it themselves.

an hour? how about many hours in 4 years??

[Elias]

I want to point out that diffuse field is a modern mathematical concept, and has existed on earth only a few hundreds of years after build up the first big churches and concert halls. Diffuse field is no requirement for anything. Human perception has not been excelled in perception of it in any way during the evolution.

[a_tewinkel]

Exactly. But this may also make a generalization about the required level of "reverberant" sound fields in small rooms (< 30 ms or so, above that pulse density would probably be sufficiently high, see also Bech's experiment) difficult since the direction and delay of the discrete components can be very different. That would not be the case if the sound fields would approximate a diffuse field (although a diffuse field is indeed not a necessity for spaciousness).

[graaf]

Originally Posted by a_tewinkel

Exactly. But this may also make a generalization about the required level of "reverberant" sound fields in small rooms (< 30 ms or so, above that pulse density would probably be sufficiently high, see also Bech's experiment) difficult since the direction and delay of the discrete components can be very different. That would not be the case if the sound fields would approximate a diffuse field (although a diffuse field is indeed not a necessity for spaciousness).

perhaps therefore Toole makes recommendations both as to the required general level of the "reflected sound" vs "direct sound" and as to the angle/direction and delay and also frequency spectrum of individual early reflections

[SEdwards]

Does anyone know which speakers/placement Toole himself uses?

[graaf]

Originally Posted by SEdwards

Does anyone know which speakers/placement Toole himself uses?

a home theater type multichannel setup

[graaf]

Originally Posted by graaf

thanks!

I believe this one belongs in this thread:


Snell Type 1's

a thought experiment: imagine a "Type 1" shaped loudspeaker but higher and wider and instead of just one tweeter a directional horizontal line of small tweeter-size fullrangers like for example Visaton BF32, sixteen of them for example - a horizontal array around 50cm long

let's forget about the (mid)woofer for a moment as for frequency band <500 Hz it can probably be placed almost just anywhere in the box as far imaging and soundstaging are concerned

in such a case of a floor level horizontal line array situated at the bottom of large tilted back baffle there would be no first order floor reflection, no first order front wall reflection and first order side-wall reflections will be very significantly attenuated because of high directivity of the array
only there would be a first order ceiling reflection and a lot of later ceiling and floor reflections

I wonder if such a speaker - with attenuated side-wall reflections - would retain the realistic recreation of space ability of a horizontally omnidirectional flooder, there would be still a lot of reflected sound

[Elias]

Originally Posted by graaf

a thought experiment: imagine a "Type 1" shaped loudspeaker but higher and wider and instead of just one tweeter a directional horizontal line of small tweeter-size fullrangers like for example Visaton BF32, sixteen of them for example - a horizontal array around 50cm long

let's forget about the (mid)woofer for a moment as for frequency band <500 Hz it can probably be placed almost just anywhere in the box as far imaging and soundstaging are concerned

in such a case of a floor level horizontal line array situated at the bottom of large tilted back baffle there would be no first order floor reflection, no first order front wall reflection and first order side-wall reflections will be very significantly attenuated because of high directivity of the array
only there would be a first order ceiling reflection and a lot of later ceiling and floor reflections

I wonder if such a speaker - with attenuated side-wall reflections - would retain the realistic recreation of space ability of a horizontally omnidirectional flooder, there would be still a lot of reflected sound

Wouldn't that be the same as placing the 1 element flooder in front corner ? No 1st order floor, 1st order side wall and 1st order front wall reflections.


- Elias