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A Visit with Bob Carver and His Amazing Line Source Speakers

Blumlein 88

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#42
The idea is the left speaker sends sound rays to both ears. The right ear gets the left speaker rays .8 millisecond later. If you delay the left signal by .8 millisecond, and broadcast it from the right speaker inverted it cancels out the left speaker at the right ear. You have to reduce the inverted cross feed a few decibels too. Do the same in the other direction and each hear is hearing only the nearest speaker or so the spiel goes. Of course the left ear will get the inverted, delayed, reduced level signal from the right speaker an additional .8 millisecond later. I don't know if he had multiple levels of feedback and forth for that or not. I know it sounded different than if you manually do the inverted delay in a sound editor and try it that way.

Perhaps the Scrutinizer can do some black box experiments and tell us what it really does. :)
 

RayDunzl

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#43
TFM35 if you need a matching piece.
No, thank you, this will be enough for a while, I think. It's just an impulse eBay buy. It's come up in conversation here at Neverland East in the past.

Perhaps the Scrutinizer can do some black box experiments and tell us what it really does.
That's my job.

It will make an interesting Beer Saturday conversation piece.
 

RayDunzl

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#44
Did anyone else think



even for just a moment?
 

Sal1950

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#47
I just used Shazam to discover
OK OK, I get it, but not really? If your familiar with the music why do you need Shazam. whats the deal with this app? I think you must have a undisclosed piece of this company, that's like the 500 time you repeated it this week? ;)

Anyway thanks for the report would have loved to be there and met Bob. Also many thanks also to Joe for the video. Just had time to start watching the first segment, good stuff.
 

Kal Rubinson

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#48
The idea is the left speaker sends sound rays to both ears. The right ear gets the left speaker rays .8 millisecond later. If you delay the left signal by .8 millisecond, and broadcast it from the right speaker inverted it cancels out the left speaker at the right ear. You have to reduce the inverted cross feed a few decibels too. Do the same in the other direction and each hear is hearing only the nearest speaker or so the spiel goes. Of course the left ear will get the inverted, delayed, reduced level signal from the right speaker an additional .8 millisecond later. I don't know if he had multiple levels of feedback and forth for that or not. I know it sounded different than if you manually do the inverted delay in a sound editor and try it that way.

Perhaps the Scrutinizer can do some black box experiments and tell us what it really does. :)
I do not think it is the same thing at all. The patent describes a channel cross-feed while this is a delay inserted between the inner and outer arrays of midrange drivers in each speaker. This will have some effect on what the listener hears but the justification is, imho, simplistic and has nothing to do with head dimensions but, perhaps, more with the dimensions of the speakers themselves.

The delay between the ears at the head is equal to the thickness of the head (let's say .8ms for a big head) but only if the source(s) are entirely lateral and is zero if the source is directly in front. Normal stereo speakers are somewhere in-between and no single delay can fit all speaker distances and angles. Besides, with his laterally-opposed midranges, most of the energy from them will be dominated by reflected energy and the treble drivers (and, to a lesser extent, the inner midranges) will dominate the direct radiation. However, for such treble, localization relies more on intensity (and HRTF) than on timing. I did sit through Carver's entire presentation in NYC (with a little discomfort).
 

amirm

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#49
I think as soon as you add delay to things, "stuff happens" to sound. :) You will likely experience an effect of spaciousness, etc. But as Kal says, you are not getting cancellation of crosstalk that way.
 

amirm

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#50
OK OK, I get it, but not really? If your familiar with the music why do you need Shazam. whats the deal with this app?
Are you trying to discover all of King's secrets? Beheading still goes on in my kingdom just in case you don't know!!! :D
 

amirm

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#52

Sal1950

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#53
Are you trying to discover all of King's secrets? Beheading still goes on in my kingdom just in case you don't know!!! :D
We have ways of dealing with the Emperors in Rome. (and Chicago too) ;)
 

amirm

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#55
This is my piece of Carver history I still own (model 2000):



It is sitting in the garage. Likely I will take it to my new workshop when it is done to play tunes there. :)
 
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#57
He said the amps also used the back EMF from the speakers to pick up characteristics of the room and compensate. Sad to say, neither the theory or the sound in practice showed any evidence of that.
So this is impossible? I don't understand why a designer like him would make wild claims about the speaker/room/amp interaction.
 
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