Have you considered using signal steered VCA will generate lot of modulation distortion? I think modulation preservation is very crucial because modulation contains all the information there is in music. Without modulation, no music. So if modifying modulation, modifying music. If that is what you want, that is ok of course.
- Elias
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After experimentation over 20 years ago and confirmed by continual experience since, I've come to the same conclusion. Early reflections from the ceiling are critical to accurate sound reproduction. For a conventional sound system this is especially true at high frequencies. As with other speakers intended to deliberately create controlled reflections the "flooder" speaker (never heard that term before either) should be independently adjustable as to loudness and FR to match the acoustics of the room and the efficiency of the forward firing speaker. Ideal location is above ear level with direct radiation to the listener blocked.
Since the indirect path is longer than the direct path, even if comb filtering were audible this would not create it since the relfected sound arrives after the direct sound, they are not coincident in time. The exception is for sustained tones, however all reverberant sound fields including those inadvertently created by loudspeakers and those created by musical instruments exhibit the same phenomenon. This may be hard to understand for the geometrically challenged. It's one of those mantras dragged out when someone argues against the superiority of bipolar panel speakers and other speakers that exploit room reflections. In the real world, you don't have to sit in a sweet spot with your head in a vice to enjoy the full rich sound of music performed live.
Elias, I do worry about the amplitude modulation I'm putting on the center channel. It's effectively a dynamic range expander, which I've never liked (more irksome). It's an experiment, and I'm limiting its range to 3dB tenatively. The alternative seems to be to do what Dolby did, where a five signal servo system maintains equal loudness in the room regarless of what the steering is doing at any particular moment. That seems a bit extreme to me when playing back music. Dolby prologic II is designed to have a good music mode with 2-3 controls to fine tune it, but many receivers don't include the 3 knobs and often not the music mode at all.
Right now my approach seems like the least of the evils. The other four speakers will never have any amplitude modulation related to steering, and that's what I'm trying to preserve. I figure worse case is that I turn off the center steering and go with a smaller amount of separation between the various speakers. It will still have the L-XR on the non-center speakers which will by itself improve the sense of separation. The trouble with the inter-aural cancellation circuit is that it makes imaging noticeably more confused when you're not in the sweet spot. Going five channel will greatly improve the situation outside of the sweetspot, even when the I.A.C. circuit is engaged. Again, it's all an experiment. It won't be perfect, that's for sure, but I think an improvement.
Right now my approach seems like the least of the evils. The other four speakers will never have any amplitude modulation related to steering, and that's what I'm trying to preserve. I figure worse case is that I turn off the center steering and go with a smaller amount of separation between the various speakers. It will still have the L-XR on the non-center speakers which will by itself improve the sense of separation. The trouble with the inter-aural cancellation circuit is that it makes imaging noticeably more confused when you're not in the sweet spot. Going five channel will greatly improve the situation outside of the sweetspot, even when the I.A.C. circuit is engaged. Again, it's all an experiment. It won't be perfect, that's for sure, but I think an improvement.
I may have chosen the right turn !
I'm so happy about that. After came this:http://www.diyaudio.com/forums/multi-way/200040-stereophonic-sound-single-loudspeaker.html
And I'm now almost convinced to say that reproduction of two channel stereo from two distinctive and separate points in a small room is a dead end ! The time of conventional stereo triangle is soon to be over !
What is needed is a reproduction where the stereo sound eminates from a single location ! It sounds so much better than any conventional stereo triangle so far. It truly is a technique which do achieve outstanding stereo imaging ! Honestly.
- Elias
may or may not
truth is that You have never given a proper try to Beveridge, line array is not needed - a flooder would suffice
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How proper is proper ?
Flooder + Beveridge = done. Was it satisfied? No. I've tried flooder in many locations along the room, from front to 90 deg side. Stereo. It did not show such a potential worth pursuing further on that road.
But SSS was totally different ! Immediately it was clear to me this is it ! No need to fine tune to find out the potential. Of course any system will be bettered by tuning but thats not the point. If it takes extraordinary amount of tuning to make it work it's not very robust and indicates some fundamental flaws existing.
- Elias
pity You didn't report on those tests when they were done, this is the first time You mention testing "Flooder + Beveridge"
perhaps You did sth wrong, check out Tinitus' or Radugazon's reports on their flooder tests, very basic (simple bare drivers) and even without Beveridge
The Beveridge in this context refers only to the placement of the speakers along the room side walls. The 'side walls' in my room I regard the long walls, my room is a shoe box shape.
What can be wrong. I cannot think any technical issue. Maybe me hearing and perception is not suitable for flooder, as it is not suitable for a stereo triangle. Or, it could be that I just don't like the sound presented in a way a flooder does it.
- Elias
perhaps these are just a bit too small, there is evidence from user's tests that flooder configuration may favour more directional speakers
I built a speaker system once based on something in Popular Electronics (?) a million years ago, that had an 8 inch woof and 2 inch cone tweeter on the front of a fairly conventional cabinet (similar to an AR4X), and an additional 2 inch cone tweeter on top aimed straight up. It actually sounded real good. I guess you could call the upward facing tweeter a flooder (?). It sounded particularly good when playing the drum solo song (?) on the Cream's Wheels of Fire album. Ginger Baker really knows how to make drums sound great.
I have quite good experience with ceiling firing dome tweeter above about 3kHz. It nicely hides the speaker locations from perception, maybe because also horisontal dispersion pattern is wide and there is no dominant direction at the treble freqs at the listening position.
I cannot imagine how a speaker with higher directivity could help ?
- Elias
I cannot imagine how a speaker with higher directivity could help ?
- Elias
My understanding is that above about 6kHZ we hear treble in a diffuse way no matter how directional a tweeter tries to be. The imaging criteria graph suggests that in the range of 2kHZ - 6kHZ, anything that delivers to the listener an amplitude response that is consistent over that range of frequency, would do the most for stereo effect. Since most cymbals have highest acoustic output on the up down axis, there may be some psycho-acoustic effect with that. Perhaps having high treble bounced off the ceiling can be a good thing. Below 6kHZ, I'm not as sure about.
I dont know why flooder did not work as explained it should.
First, there was no treble. Even FE126En has rising response but treble was severly lacking. That's why I cannot think how a bigger element could improve things in this regards? Ok, freq balance can be equed to taste, but:
Secondly, there was no imaging !
This is strange considering what others have explained ?? The sound is overly spacious, too much reverberance simply. It doesnt match the performance of many recordings. And thirdly, I can locate the speakers on the floor
Well, I think case closed for flooder for me in this room.
- Elias
Yes, Warfedale was, as I understand, a mono speaker ?
It would be interesting to know who invented direct firing treble, and when it bacame a norm
- Elias
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