Mid Side Speakers

"I made a comment two days ago about designing a mid side speaker array. Ted Fletcher and a few others have designed speakers that are based on the mid side technique (but using speakers to reproduce stereo instead of mic's to record stereo) Airsound etc. 

I have put a lot more thought into this since the comment and I'm not sure how it can actually make sounds appear left or right as the time of arrival differences would be next to non existant (which is part of the idea) and I don't understand how you recieve the guitar for example at a higher level at one ear than the other. It does make sense though that by altering the amount of a sound in the side speakers the image can be made wider, or further away, maybe general area left or right based on the reflections from the left side of the room vs right side, but if that were the case the more you tried to make an instrument appear left or right the further away the sound would appear."

I don't think M/S speakers will be able to create a real soundstage. IMO even stereo speakers don't create a perfect illusion of a sound stage. I would say that M/S speakers create a sense of space and width. The main advantage is the sweet spot being not limited to one specific point including improved clarity and lack of distortion which is normally caused by having 2 speakers playing a mono signal.

Stereo is more often used for stereo effects and to make reverb sound more impressive rather than to use it to create a soundstage I think. It is also often used to give instruments which are in the same frequency zone more room to breathe. I would say it's rather a thing that is used for creativity and to have the option of lighten up the mix than to actually help create an illusion of a real sound stage.  

Edited by hond - 01 December 2012 at 1:51am

when you compare those binaural recordings with that matchbox recording supposedly done with holophonics by that guy Zuccarelli I'm always amazed that the holophonics recording succeeds at giving you the illusion that the sound is front of you when wearing headphones; I haven't heard this with binaural recordings yet

I have been doing some serious testing with this mid/side technique and the results are interesting:

1. You don't get a stereo image at all:
the point of this mid/side technique (with mono center and inverted sides) is to create some sort of an illusion of a room or a concert hall with sound bouncing off the side walls. Directional information? Do not count on it.

2. Reverb sounds amazing:
yes reverb sounds even better than on regular stereo AND it sounds the same no matter where you stand in the room

3. the mono/inverted sides create a very different mixdown of a track. Certain intruments, heavily panned can disappear or become too loud. Sometimes vocals just disappear and sometimes you hear instruments you never heard before when you were listening to a normal stereo system.

One note: although sometimes you hear an entirely different mixdown: it still sounds very good and pleasing and balanced.. just very different from what you're used to. It's quite strange actually.

4. you do get a nice soundfield that is the same no matter where you stand in the room. No more sweet spot!

5. Bass clarity improves!
This doesn't need much explanation I think.

6. movies are amazing! if you place the system below the screen, the voices appear to come out of the screen and they have a lot of clarity.


All in all; I think this is pretty interesting.. but if some one knows a way how to filter out the unique left and right information from a stereo signal, please tell me because IF there's a way to do it... that would just be awesome.


my test setup:
center speaker: mono signal (L+R)
left side speaker (very close to the center speaker): side signal (L-R)
right side speaker (very close to the center speaker): side signal (L-R) -> inverted

I ran everything through ableton. You can also do it the analog way by changing the polarity of XLR cables.



Edited by hond - 18 January 2013 at 3:30pm

I did not know plugins like that existed. Looks like I've got some new material to test out :)

I use MSED too.  When producing I find that I can get nice surround sound effects by adding gain to the side and reducing it to the mid.

Edited by b grade - 18 January 2013 at 5:19pm

the encode mode sends L-R or R-L to your right speaker.
the decode mode probably sends L-R to the right speaker and R-L to the left (and the other way round) but with a bit of mid mixed in i think

the incline mode sends L-R to the right speaker and R-L to the left (or the other way round)


Edited by hond - 18 January 2013 at 5:51pm