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Re: Would you add Blumlein to that list?

7/3/2000 5:56 AM
Re: Would you add Blumlein to that list?
OK, NOT "much more nicer"; how about much nicer, or much more open, or something a tad more grammatical?  
And now, a word from our sponsors:

7/3/2000 1:55 PM

grammar notwithstanding, I think you expressed it more accurately the first time . . . ;)
7/4/2000 3:45 PM
Mark Hammer

Hey, I've got the 12V car version, and the AC home version, and the home version is even much more nicer than the car one. :)  
Personally, I think the most interesting aspect of this category of devices is that they seem to reduce listener fatigue. It's as if the spatial cues the effect provides reduces the amount of unconscious mental work the listener has to do when they normally process instrument location in a conventional stereo mix. I find I can listen through VERY cheap speakers (though I've never tried those 3-inch "250wattPMP" computer speakers they sell for $10) for long periods of time without feeling exhausted by it the way I normally would. I think the best analogy I can think of is the difference between looking at menu boxes in the old DOS screen, and looking at menu boxes in WIN or MacOS, with dropped shadows and shading. Allowing the perceiver to easily spatially locate, and organize, objects in 3-D space reduces the onus on them to *imagine* that location. It just *feels* more effortless. Indeed, when you hit the "cancel" button, and go back to regular stereo, you feel like you've gone from freshly paved divided highway to gravel 2-lane in terms of effort and attention required.
7/5/2000 5:45 PM

I use a Quadraverb Q2 for effects with two amps--dry and wet. I have decided that for me, Leslie, phase, and flange seem to work better on my dry signal, but echo, verb, and/or chorus sound best through the other amp. It must have something to do with the delay times involved....  
Anyhoo, It sounds pretty big already with the right verb, echo, or chorus in there, even with the amps sitting right next to each other, but I'm always looking for a little bit of "extra"....  
What do you think this spatial effect would do for the "size" of the sound in this setup?  
C ya,  
7/5/2000 7:55 PM
Mark Hammer

Well, "size" can mean a few things.  
At one level, adding in long delays, even in a mono mix can create the illusion of a large space, simply by providing the cues that normally exist in large spaces.  
You can also make the soundstage for a single source seem bigger by inserting a delayed version of a single signal into a second channel. This is what was traditionally done with 1st generation analog delay lines like the Memory Man, where the delayed signal would go to one amp and the straight signal would go to another. Also interesting, but beyond regular mono cues for space size (provided by delay time and delay bandwidth in the case of these simple devices), the stereo split simply "busies up" the sound. It makes no attempt to explicitly simulate how sound spatial location occurs.  
These imaging gadgets are different in several ways:  
1) They introduce delay into BOTH channels, not just one.  
2) The delay itself is largely undetectable AS a delay. It is long enough to be heard as a difference between ears, but not long enough to be heard as a delay, or even that "box-ey" sound you get from using the "filter matrix" function of a flanger, whether EH or other.  
3) The goal is to enhance the locatability of a signal source nested WITHIN a pool of other signal sources. So, within the space that extends about 80 degrees off to each side of you, and from the floor to about 80 degrees up from there, the drums should seem to be coming from somewhere other than where the bass, guitar, lead vocals, background vocals, percussion, keyboards, and roadie belches are coming from. Likewise for all those other things.  
Again, bear in mind that all the FX you describe are applied to a single instrument in your case, whereas the imaging effects are applied to a MIX. Moreover, unless you play and everyone you play with play direct to a board and then out to two big speaker banks, you will generally be locatable in space by virtue of your own amps (or sheer acoustical volume alone in the case of drums). The upshot is that spatial image enhancement is used to mimic that locatable quality when absolutely everybody in that 64-to-2 mix is coming out of two 5" full range speakers in your car door or out of your headphone.  
Of course anybody who has played with one knows that the magical qualities of Leslies are that they scatter the sound around so that you sound like you are playing over here, over there, and over THERE.  
Good old Fender Rhodes pianos had a great tremolo that pumped through distinct power amps and speakers and produced a nice spacious sound.  
Roland JC60's and 120's used two power amps and speakers to generate true stereo chorus as well.  
All 3 of these attest to the pleasantness of gadgets or designs that provide multiple staggered sources of the same signal, whether through time delay or amplitude modulation.  
One additional tact is to use the sum/difference option for your time-based FX. The old yellow MXR stereo chorus used this, where the delay signal was summed and subtracted from the dry signal, with the sum coming out of one jack and the difference out another. This was qualitatively different than the typical "stereo" of some other units where stereo meant dry and wet coming out of separate jacks. Craig Anerton published a neat little add-on in GP called the Retro-Stereo, which you could use to add stereo sum/difference outputs to any modulated effect. This schematic is posted in a number of places, so you shouldn't have much trouble finding it, even without me remembering the URL and site.  
Not sure if this answers your concerns, but there is enough to think about for a while.
7/6/2000 6:07 PM

These imaging gadgets are different in several ways:  
2) The delay itself is largely undetectable AS a delay. It is long enough to be heard as a difference between ears, but not long enough to be heard as a delay, or even that "box-ey" sound you get from using the "filter matrix" function of a flanger, whether EH or other.  
Thanks for the reply!  
So it's using some variation on the Hass pan effect, then, to make the stereo image wider? Cool.  
I'm basically looking for something that creates that "sound coming from outside the stereo field" effect, which (if my memory serves me) the imaging effect did for a friend's stereo--kinda like a cheap, 2 speaker version of "3D surround sound". I guess, basically, I'm trying to make it sound like the amps are farther apart ( in other words, to reduce the level of "locatability") without having to move one to the other side of the stage. You can't always count on the luxury of space on a bar stage, yaknowhatimean? :^)  
What kind of delay times do these things use, anyway? Something in the 100us to 10ms range, I guess, and with a bit of top-end rolloff on the delayed sound, right? I have an old SAD1024 chip that I bought at RS and held onto for the last 15 years, and it would probably be perfect for the kind of micro-delay thing that would be needed here....  
I guess another tack I could take would be to send the delay/verb signal to an open-back combo set sideways, for the "SFX" effect.... That wouldn't require building or setting up anything, and would be real easy to test.... :^)  
I'll report back what I find out.  
C ya,  
7/6/2000 7:33 PM
Stephen Conner

Hi Dutch,  
Whenever you say 'sound coming from outsie the stereo field' I immediately think of negative phase effects. (Made by sending the signal to one channel normal and to the other channel phase-reversed) Your brain can't localise a negative-phase signal in the stereo field, so it ends up sounding like it's coming from just about anywhere, off to one side, behind you, whatever. If you use the effect too much it can be disorientating and uncomfortable for the listener. And of course the signal will disappear in mono!  
Steve C.

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