But the real source is now fixed at the center (which consists of signals of both channels of stereo). I think it'd be better if the HF is not so clearly localized.
In the OSD trial I've experienced, the HF unit(s) near the center also brought me similar problem in localization. Up firing solves that issue partially.
In the OSD trial I've experienced, the HF unit(s) near the center also brought me similar problem in localization. Up firing solves that issue partially.
Why is that?
See Gerzon's Trifield configuration, there is low pass for center speaker.
- Elias
Up firing center could be sort of an auto LP for the listening position, no?
Yes, partially, but directivity pattern also changes so it's not identical to low pass of the center element.
You are on the right track !
It appears to me that any source of high frequency sound having high direct-to-reflection ratio can be perceived as a separate sound source and thus it spoils imaging (sound is coming from the speakers).
For anyone having this problem, indeed a cure can be aiming the high freq sounds towards ceiling !
But it also appears that this may not be perceived similarly among individuals, some may not be able to locate high freq direct sound into speakers whereas some cannot get the high freq image out of the speakers. That's why so many confusions when discussing about high freq phantom localisation.
- Elias
This is serving as a starting point: It delivers x = 0 and x = 0.5.
I think x = 0.5 is pretty close to optimal.
An externally hosted image should be here but it was not working when we last tested it.
- Elias
Single speaker stereo is a configuration where the left and right speaker are more or less at the very same location as the center speaker. The side speaker signal is part of the strong side reflections (which form the virtual side speakers) and the center speaker (at least at lower frequencies). So there is already more low frequency energy than high frequency energy coming from the center.
The situation is not much different in conventional spread three speaker configurations, e.g. Trifield (Gerzon) and Trinaural (Miles), because side speaker signal is in the general form
Lo = L - xR
And center speaker is
Co = xL + xR
Now because of commonly used mixing practises where low freqs are in phase and almost mono, the low freqs will partly cancel in side speakers, but they will sum in the center speaker ! Thus they also deliver more low freqs from the center. Despite of this, Trifield still utilises low pass for the center speaker.
- Elias
So what's you take on it?
I would try to get the freefield response of the axis that results in the first strong side wall reflection as flat as possible. Then work out the center speaker attributes from there.
After listening to the SSS prototype for more than a week now, I'm not sure how the responses should look like on graph !
Because SSS sounds totally different than conventional stereo triangle. Here there is no 'best practises' to follow ! That's partly what makes it interesting Hopefully there will be more insight after I perform more detailed measurements this weekend.
This sounds like more emphasis is put on the sound coming from the side than from the front. Does it work ? Because the benefit putting speaker in the center is to optimise sound from the front, then I think to optimise center sound first and define side sound according to what is available after that.
- Elias
I see. From what I've observed one of the most difficult thing to do is try to explain how something sounds to someone else. I also fail in that, constantly
That's why I recommend DIY ! Don't be afraid to do things differently
- Elias
The problem is that the sides partly define what's coming from the center (at lower frequencies) so you're not free to change the sides after having optimized the center. The other way around it should work better because you only need to adjust the higher frequency range for the center. The sides aren't effected by this because the center mid/tweeter driver is already beaming.
Yesterday I listened to the SSS added with Gerzonic psychoacoustic filter for several hours. It seems to improve the high freq imaging capabilities ! High freqs no longer stuck into the center but are moving with the rest of the image. So initial impression is positive.
With the filter high freqs are attenuated for a few dB at the center element, and amplified for a few dB for the side elements. This happends somewhere in the kHz region.
For anyone want to experiment, I used Rps = 4.7 ohm and Cps = 4.7 uF. These values seem to work with FRS8 elements.
- Elias
With the filter high freqs are attenuated for a few dB at the center element, and amplified for a few dB for the side elements. This happends somewhere in the kHz region.
For anyone want to experiment, I used Rps = 4.7 ohm and Cps = 4.7 uF. These values seem to work with FRS8 elements.
An externally hosted image should be here but it was not working when we last tested it.
- Elias
take a look at this too:
collection of tinitus' observations
it's post #638 in the thread "Why are OMNI speakers not more popular?"
yes, don't be afraid
Hello !
I did measure the SSS
The responses at different angles indicate the operation follows the theory !
Elias Pekonen Home Page - Stereophonic Sound from a Single Speaker
I don't claim perfection at this point yet, but your mind can be relaxed since it does work as intended !
- Elias
I did measure the SSS
The responses at different angles indicate the operation follows the theory !
Elias Pekonen Home Page - Stereophonic Sound from a Single Speaker
I don't claim perfection at this point yet, but your mind can be relaxed since it does work as intended !
- Elias
Hi Elias,
-------:-------
I did similar experiments (with 3 small bookshelf speakers) a year back or so to test the capabilities of simple rematrixing methods for "soundbar" speakers which are coming in fashion more and more, trying different (and frequency dependent) matrix factors -- inspired by Gerzon's Trifield equations. With multichannel convolver/DSP outputs there is complete freedom of choices.
While it basically works quite well, it's not my cup of tea, I prefer (and manipulate my stereo signals deliberately for) true stereo bass which is required IMHO to provide any sense of spacial realism (stereo reverb tails of bass signals even when those are panned center, that is). Oftentimes we hear people say that we cannot localize a SINGLE sound source sound below 150Hz or so, but this plainly ignores the fact that TWO speakers (signals) can provide a "sense of direction" down low there, either with two speakers or rematrixed to three in a conventional Trinaural/Trifield setup.
- Klaus
I own quite a few recordings, electronica genre mostly, and in general any modern stuff that doesn't care about mono compatibilty for vinyl and FM, which have bass signal panned all acrross the place.
-------:-------
I did similar experiments (with 3 small bookshelf speakers) a year back or so to test the capabilities of simple rematrixing methods for "soundbar" speakers which are coming in fashion more and more, trying different (and frequency dependent) matrix factors -- inspired by Gerzon's Trifield equations. With multichannel convolver/DSP outputs there is complete freedom of choices.
While it basically works quite well, it's not my cup of tea, I prefer (and manipulate my stereo signals deliberately for) true stereo bass which is required IMHO to provide any sense of spacial realism (stereo reverb tails of bass signals even when those are panned center, that is). Oftentimes we hear people say that we cannot localize a SINGLE sound source sound below 150Hz or so, but this plainly ignores the fact that TWO speakers (signals) can provide a "sense of direction" down low there, either with two speakers or rematrixed to three in a conventional Trinaural/Trifield setup.
- Klaus