omni directional speakers

hi everyone,

i was reading the latest HiFi+ and came across a review of so called pseudo-omni speakers by a danish firm. ugly things, but they reminded me of the time i heard a pair of shahinians.

i was very impressed with the way the sound seemed to hover and music filled the room. this was a while ago but i always felt i would like to listen more to a pair of shahinians.

now apparently there is some controversy between omni speakers and direct drive (more traditional ones) and i would like to see what this forum's expert opinions are on this matter.

cheers!
Jack

 

Hi,

Omni's work by making what you hear maximally room dependent. They in effect make sure the recorded room acoustics are swamped out.

I find that Omni's "cram" the whole band/orchestra into the listening room, in other words it often sounds (with good recordings) as if the musicians are in the room with you.

The polar opposite would be a speaker that is highly directional and which thusly minimises the listening rooms contribution. With such speakers good recordings can give the impression of removing you completely from the room you are in and transporting you into the recording venue.

There is obviously a wide range inbetween these two extremes.

The ideal solution would (IMHO) be a speaker with continously adjustable directivity to match the recordings demands (eg. very "dry" studio recordings are definitly better using Omni's while minimalist classical recordings in a large hall sound most realistic on highly directional speakers).

Ciao T

 

Omnis tend to sound best when simple(e.g. crossed-pair) microphone arrangements are used for the recording.

 

'Direct' moving coil speakers tend to give out coherent waves of sound.

Live sound is a mixture of coherent and incoherent. For example, the output of a flute is mainly coherent while much of a piano's output comes from vibrations of its cabinet (incoherent).

This is one of the reasons that you can nearly always tell whether you're listening to speakers or live sound.

Omni-directional speakers are an attempt to solve this problem and give sound that seems more live. There are certainly advantages to this approach but, it generally creates as many problems as it solves (IMO). It's a question of how the speakers sound in the room, personal taste, and recording (as 3D said).

Regards
Steve

 

i've heard Duevel speakers.
it was very interesting expirience and "simple" jazz recording sounded very unusual.

it was hard to tell whether i liked it.
it was easy to tell that "the management" would hate those in the living room.

when switched to busy classic and rock music the sound presentation was odd..........

 

Thanks guys, very interesting. I certainly learned a thing or two now.

If it seems too good to be true, it probably is and here is another example. I guess if I ever get tempted to replace my current speaker s and try omnis i will have to hear them in my room and play many genres of music to see what effect they really have...

Still, it fascinated me how the speakers seemed to "disappear" and the sound was everywhere...

Cheers!
Jack

 

Hi,

Most correctly set-up speakers can pull this "disappearing" act, that is a impression that the sound doesmnot come from the speakers.

The difference between omnis and controlled directivity speakers is that the first indeed place sound everywhere, while directional speakers pretty truthfully convey the original recording acoustics, whatever they may have been.

An excellent demo of a systems capability in this regard is the very short track "Way down" from Tori Amos's "Boys for Pele". It has Tori + Piano recorded in a rather dry studio atmosphere with narily any impression of space, the choir that comes in towards the end however is recorded in a large and reverbrant space, placed in a semi-circle.

With a good system correctly set-up you get the initial just the Piano & Tori with no real feel of abience, untill the choir's voices seem to "light up" a huge acoustic space around the still extremely "dry" Singer & Piano. A system that images well will give the semi circle with a significant aparent distance between the choir memebers behind Tori and her, this is flattend more and more untill the choir appears merely flat and conicidental with Tori.

Try it.

Ciao T

 

Excelent! Thanks for that! I will see if I can find that cd. Even with my traditional speakers it will be an interesting test to my hifi setup. Always good to know.
Cheers!
Jack