• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). Come here to have fun, be ready to be teased and not take online life too seriously. We now measure and review equipment for free! Click here for details.

omnidirectional loudspeakers = best design available

Wombat

Master Contributor
Joined
Nov 5, 2017
Messages
6,726
Likes
6,211
Location
Australia
Yes, do you read what's written before responding? We're talking about home theater usage specifically in relation to dialogue. As such I'm baffled as to what it has to do with music. Care to fill me in on how that's suddenly relevant to the conversation?

You can separate clear reproduction of dialogue from high fidelity music reproduction?

Please enlighten me.

One test I use for HiFi is how male vocals sound. I don't see movie sound as HiFi, in general - just part of and usually subservient to the visual presentation.

By the way my 15 inch Altec drivers were designed for vocal fidelity. My Yamaha pro amp ditto. The Altecs, yes. The Yamahas probably a marketing ploy justifying the use of better capacitors.
 

Wombat

Master Contributor
Joined
Nov 5, 2017
Messages
6,726
Likes
6,211
Location
Australia
Bose cubes sound much better when you throw them somewhere out of the way.

On axis, they're really awful.

I think they were designed as room sound-fillers for a non-critical, but image savvy consumer - not so different to the Google, Apple, Amazon 'talk-to-me' stuff and not as price accessible.
 

EJ3

Addicted to Fun and Learning
Forum Donor
Joined
Dec 10, 2019
Messages
573
Likes
400
Location
James Island, SC
Bose cubes sound much better when you throw them somewhere out of the way.

On axis, they're really awful.

Perhaps the ones that Amar Bose actually claimed to design, the 901's? That seemingly only worked right when hung from a ceiling at a certain distance from both the ceiling and the wall? I heard that Amar (Mr. Reflective sound at the time) saw Paul Klipsch at a an electronics show and yelled to the wall "Hello, Paul" and that Paul (Mr. direct sound all his life) turned directly facing Amar, cupped his hands around his mouth and yelled "Hello Amar".
 

watchnerd

Grand Contributor
Joined
Dec 8, 2016
Messages
11,463
Likes
8,925
Location
Seattle Area, USA
Perhaps the ones that Amar Bose actually claimed to design, the 901's?

But the 901s weren't cubes.

They were designed to be listened to on-axis, for some weird backwards definition of axis.

Man, now I want to get a pair just for the funkiness.
 

Shike

Member
Joined
Apr 27, 2020
Messages
59
Likes
104
You can separate clear reproduction of dialogue from high fidelity?

Please enlighten me.

That's not what's being said, I'm referring to coverage issues in home theater (3.1 and above)

Say you have a home theater with a dedicated center - this is used for dialogue 99.9% of the time. Intelligibility of the center is critical for movies. In-spite of this many living rooms (IME), especially those with lots of seating for children/visitors, have seats far enough off-axis that even some of the best traditional designs have a non-trivial drop in SPL. As such, even if the content is the same the level difference can result in intelligibility issues. This results in complaints regarding volumes from those on-axis v. off-axis. Differences of 3dB can cause potential intelligibility issues, so trying to maintain SPL across seating is a consideration.

An omni design simply helps alleviate this SPL drop. A good 3-way can mirror the spectral content off-axis well, but the SPL may not be sufficient for all viewers. Effectively it becomes a coverage issue. Rooms that have seating at severe angles, with people unwilling/unable to adjust seating for better coverage, may find a solution in omni designs. When I sold my Mirage's it was to a family with that exact use case.

Obviously since I sold them I prefer other designs, but horses for courses.

I don't see movie sound as HiFi, in general - just part of and usually subservient to the visual presentation.

Sound reproduction can make or break movies. An original score for a climax, an action scene that demands full bandwidth and placement, a chilling monologue from an antagonist. I've had a range of displays, but even those that weren't great I could enjoy. The sound was infinitely more important to me. Good sound to me allows a higher degree of immersion.
 
Last edited:

EJ3

Addicted to Fun and Learning
Forum Donor
Joined
Dec 10, 2019
Messages
573
Likes
400
Location
James Island, SC
But the 901s weren't cubes.

They were designed to be listened to on-axis, for some weird backwards definition of axis.

Man, now I want to get a pair just for the funkiness.

Yes, odd rectangles full of funkily arranged speakers that supposedly did something correct. I have had the situation where listening to them was thrust upon me. They were supposedly set up to perfection. I was underwhelmed.
 

watchnerd

Grand Contributor
Joined
Dec 8, 2016
Messages
11,463
Likes
8,925
Location
Seattle Area, USA
Yes, odd rectangles full of funkily arranged speakers that supposedly did something correct. I have had the situation where listening to them was thrust upon me. They were supposedly set up to perfection. I was underwhelmed.

The last pair I heard was sitting in a corner, on top of a Klipschorn.
 

Wombat

Master Contributor
Joined
Nov 5, 2017
Messages
6,726
Likes
6,211
Location
Australia
That's not what's being said, I'm referring to coverage issues in home theater (3.1 and above)

Say you have a home theater with a dedicated center - this is used for dialogue 99.9% of the time. Intelligibility of the center is critical for movies. In-spite of this many living rooms (IME), especially those with lots of seating for children/visitors, have seats far enough off-axis that even some of the best traditional designs have a non-trivial drop in SPL. As such, even if the content is the same the level difference can result in intelligibility issues. This results in complaints regarding volumes from those on-axis v. off-axis. Differences of 3dB can cause potential intelligibility issues, so trying to maintain SPL across seating is a consideration.

An omni design simply helps alleviate this SPL drop. A good 3-way can mirror the spectral content off-axis well, but the SPL may not be sufficient for all viewers. Effectively it becomes a coverage issue. Rooms that have seating at severe angles, with people unwilling/unable to adjust seating for better coverage, may find a solution in omni designs. When I sold my Mirage's it was to a family with that exact use case.

Obviously since I sold them I prefer other designs, but horses for courses.



Sound reproduction can make or break movies. An original score for a climax, an action scene that demands full bandwidth and placement, a chilling monologue from an antagonist. I've had a range of displays, but even those that weren't great I could enjoy. The sound was infinitely more important to me. Good sound to me allows a higher degree of immersion.


I will defer to some degree.

Most professional theatre installs do not use omnis but endeavour to relate(pinpoint) sound in relation to screen image. Omnis are not preferred. Get in first and get the best seats.

Omnis and altruism may go together in home(tiny space) HT.
 

Frank Dernie

Master Contributor
Forum Donor
Joined
Mar 24, 2016
Messages
5,748
Likes
13,129
Location
Oxfordshire
Are you really going to argue that there isn't an issue with these speakers in terms of level at 60~75 degrees off-axis compared to the direct sound? 3dB can make a large difference in intelligibility, a common reason center levels are often run hot for example.

Have you actually had to deal with such a sub-par position for listening first hand?
If you are sitting at 75 degrees off axis your biggest problem will be seeing the picture, surely, not intelligibility of dialogue?
 

bigx5murf

Addicted to Fun and Learning
Joined
Nov 6, 2018
Messages
522
Likes
318
The only omnis I've owned are the DCM TF600. I still have them, and like them enough I think their keepers. But what I like most about them is the bass response, and they've gotta be placed really close to the wall for that. I really don't notice any of the apparent omni strengths when using them.
 

Shike

Member
Joined
Apr 27, 2020
Messages
59
Likes
104
I will defer to some degree.

Most professional theatre installs do not use omnis but endeavour to relate(pinpoint) sound in relation to screen image. Omnis are not preferred. Get in first and get the best seats.

Omnis and altruism may go together in home(tiny space) HT.

There's definitely better options if you can control everything, you won't get an argument from me there. If you can't move furniture though and have coverage issues omni can be a band-aid or nuclear option. This would of course only pertain to small room HT, like a modest living room or den. When Mirage was still sold in stores it was one of the first recommendations when people complained about not hearing center channels from oddball listening positions.

The other poster and I disagreed if there was a use case for omni v. 3-way for coverage and that's why the discussion about dispersion and off-axis levels came up.

If you are sitting at 75 degrees off axis your biggest problem will be seeing the picture, surely, not intelligibility of dialogue?

Are you referring to issues related to panel types? Depending on the panel viewing angles can go to 178 degrees (given not practical at that extreme). The viewing experience from ~60-75 isn't great, but you can generally see what's going on. The way I'd look at it is like this though: odds are for a good amount of movies you could turn off the TV and still have a good idea of what's going on. If you can't hear or read the dialogue following the plot can prove much more difficult.

Ideally you wouldn't want anyone that far off-axis, and no one serious about HT would consider it unless their hands were tied. Nonetheless I've seen it more than I'd like. Thankfully the last time I got relegated to such a seat myself was with a CRT many years ago. ;)
 

Frank Dernie

Master Contributor
Forum Donor
Joined
Mar 24, 2016
Messages
5,748
Likes
13,129
Location
Oxfordshire
There's definitely better options if you can control everything, you won't get an argument from me there. If you can't move furniture though and have coverage issues omni can be a band-aid or nuclear option. This would of course only pertain to small room HT, like a modest living room or den. When Mirage was still sold in stores it was one of the first recommendations when people complained about not hearing center channels from oddball listening positions.

The other poster and I disagreed if there was a use case for omni v. 3-way for coverage and that's why the discussion about dispersion and off-axis levels came up.



Are you referring to issues related to panel types? Depending on the panel viewing angles can go to 178 degrees (given not practical at that extreme). The viewing experience from ~60-75 isn't great, but you can generally see what's going on. The way I'd look at it is like this though: odds are for a good amount of movies you could turn off the TV and still have a good idea of what's going on. If you can't hear or read the dialogue following the plot can prove much more difficult.

Ideally you wouldn't want anyone that far off-axis, and no one serious about HT would consider it unless their hands were tied. Nonetheless I've seen it more than I'd like. Thankfully the last time I got relegated to such a seat myself was with a CRT.
Thanks, I don't watch many films myself, a couple a month perhaps, so my system is mainly for music in stereo with and added centre and rear speakers which are used for a film, mainly with a lot of us watching.
I have a projector and screen but they are at the narrow end of the room so even the worst seats are not at a bad angle to the screen or centre speaker. With tv on the screen stereo still sounds clearest for speech, though that could be a setup problem with my processor, I need to re-do the setup.
 

thewas

Major Contributor
Forum Donor
Joined
Jan 15, 2020
Messages
3,074
Likes
6,593
Best design? A pulsating sphere would be a good start.

Real world try:

https://www3.jvckenwood.com/english/press/2006/pulsating_sphere.pdf
Such dodecahedrons are used for acoustic measurements like reverberation or excitation of reverberation chambers (we use them too at work), for example
https://www.muellerbbm.com/products/dodecahedron-loudspeakers/
https://www.nti-audio.com/en/products/ds3-pa3-tm3-noise-sources/ds3-dodecahedron-speaker
https://web2.norsonic.com/product_single/dodecahedron-loudspeaker-nor276/

and were even tried by some hifi companies in the 70s
https://www.hifi-wiki.de/index.php/Grundig_Audiorama_7000

but for me personally their very diffuse soundfield was never to my liking.
 

anmpr1

Major Contributor
Forum Donor
Joined
Oct 11, 2018
Messages
2,245
Likes
3,664
There is at least one instance where a true omni will satisfy the requirements of reproducing a recording naturally. A percussion instrument recorded in an open (anechoic) space. Take the kettle drum. It radiates equal sound within a 360 degree space. With no reflections, a microphone will pick up an equal signal regardless of placement around the drum.

Reproducing the signal in a very large space (say if you lived in Biltmore or Windsor castle) a single omni in the center of the room would essentially recreate the drum's sound, and would do so regardless of listening position. You could walk around the speaker like you were walking around the actual drum, and hear the same sound. You couldn't do that with a direct radiator, because once you got off-axis the sound would change.

So, if your listening tastes run to single (or a combination of closely spaced) percussion, then the omni would be the best bet, if you liked to walk around the room while listening.
 
Top Bottom