The Advantages of Floor Coupled Up-Firing Speakers

[graaf]

yeah, ok!

thanks!

[el`Ol]

Originally posted by markus76
As "classic" stereo recording techniques are discussed in that paper I assume they speak of mono/stereo compatibility.

Mono-compatible recordings were often done with the Decca tree.

Originally posted by el`Ol


I don´t know the percentages, but I always thougth the 30cm setup is the most common for cardioid microphones. Maybe I am wrong.

I cleared it that way: looked at thomann.de and saw that virtually all expensive stereo microphones are dipole microphones (Blumlein pair, the most expensive are ribbons). So probably I was wrong that the BP is a rarity, but I think I was right about the common use of the cardioids.

[el`Ol]

Anyone who can tell us the percentages (XY, MS, Blumlein pair, 30 cm distance cardioid)?

[graaf]

Originally posted by el`Ol
Anyone who can tell us the percentages (XY, MS, Blumlein pair, 30 cm distance cardioid)?

yeah it will be useful to know

perhaps 90% or even more is multi-miked panpotted stereo?
which is not necessarily something wrong per se as stereo principle stays the same as in case of correct Blumlein stereo

we should also take into account that audiophile market can differ significantly in that respect
it is interesting to know how "true stereo" is understood for instance at Naim, a renowned audiophile gear and record company:

http://www.thenaimlabel.co.uk/true_stereo.htm

actually their "true stereo" microphone setup looks like so called ORTF and is not "true stereo" as understood by Blumlein
and it is simply incorrect from the perspective of theory behind the stereo patent but not as badly as AB-stereo (where no literally no theory explains what is going on)

why spaced microphone arrays cannot work properly is explained i.a. in this interesting essay by Robert E. Green: http://www.regonaudio.com/What%20Can...%20Stereo.html

also DW "Infotheque" leaves no space for doubt:

poor directional resolution, the displacement of remote lateral sound sources toward the middle and the risk of a so-called "hole" in the middle

here: http://old.hfm-detmold.de/eti/projek...tmikro_en.html
we can read that:

The coincident pair (also named XY) is best chosen for optimal sound localization in the room
(...)
AB stereophony (...) is best chosen for a most natural image of the real spatiality.

but why?

ORTF is a kind of compromise:

near-coincident pair (equivalence stereophony) is a combination of both level and runtime differences to create a pleasing room image in addition to good localization of sources.

not "optimal", not "most natural" - just "good", "pleasing"

best regards!
graaf

[el`Ol]

Will have to get this and do my own recordings:
http://www.thomann.de/de/haun_mbnm62...enzflaeche.htm

[el`Ol]

On the other hand, aren´t boundary microphones built to reduce room resonances and so reduce the "sense for the room"? And does the Carlsson as a "boundary speaker" reduce the sense for the listening room in order to enhance the sense for the recording room?

[pelanj]

Where should be the boundary microphone ideally placed? On a wall? On the floor? On the ceiling? And what does make any microphone a boundary microphone? My idea of this principle is very vague.

[graaf]

hi again!

take a look at those pictures:
http://www.diyaudio.com/forums/showt...95#post1634295
http://www.diyaudio.com/forums/showt...97#post1634297


and then at the image I attached to the post No 1 in this thread

how about that!

it is nice to see that Mr Linkwitz came to the same conclusion about omnidirectional speaker's placement in small rooms

best regards!
graaf

[graaf]

another one interesting "corner" speaker (representing an approach a bit similar to short Carlsson speakers):
http://www.gampermartino.com/project...corner-sounds/

best!
graaf

[el`Ol]

Update to the Carlsson project:
After listening to the prototypes for many months I now have the final version running with much better damping inside (rock wool instead of polyester fleece) and outside (Basotect instead of polyester felt). While I am very happy with the tonal improvement I dislike what happened to the imaging. The prototypes had an excellent imaging when fed with real-acoustic recordings and some problems with synthetic acoustic: The instruments were either fixed to the speakers or formed a clump of mud between them. Now the real acoustic recordings are diffuse and without depth, whereas the synth acoustic recordings are much better now and in fact the field where the speakers perform best.
I suspect that the basotect is to blame. I held the polyester felt to my ears and found that they have almost complete transmission, so the triangles probably formed reflectors rather than absorbers before.
Now I am trying to find a compromise. Thinner Basotect may be a solution, but I would be happy to get rid of it completely because it is very fragile. What about real wool felt?