Grateful Dead Music Forum

A place to talk about the music of the Grateful Dead 

 #107936  by TI4-1009
 Mon Jan 16, 2012 9:28 am
I found this browsing the Dark Star Place, this seemed like the best place to post it?

"On using one of Bear’s buckles on a custom amp stand for the Dead’s old MC2300/MC275/MC75’s at Dark Star Palace:
•Why use a perfectly good buckle- a wearable, signed piece of art- on a bunch of antique, obsolete amplifiers?
•I could send you a cast, plastic GD just like it which would let the light through (or not if you like).

On options for Dark Star Palace’s surround-sound setup with the Dead’s old gear (vs. using Bear's system instead):
•I have no clue as to why you want to do this.
•I am just mounting a set of five Meyer UPJuniors with a UMS-1P sub as my surround system- it can only be beaten by a set of HD-1s (I only have three of them).
•The slew rate alone on those old amps is absurd, let alone the harmonic distortion at operating level and the severe problems with the wires from the amps to the speakers, this without mention that there are no good 'speaker cabinets' available (never were). Beyond all this, John Meyer's systems are the only ones which can actually reproduce in the air the sound as recorded (in the medium). Standard systems have a huge asymmetrical distortion product built in, due to the laws of physics- a simple piston will drastically shift the zero-crossing point, resulting in all asymmetrical signals being badly distorted- only a pure sine wave can handle this kind of zero shift- this is the reason this severe and quite audible distortion is not shown by distortion tests, all of which use sine waves. In other words, as a speaker moves to follow the electrical signal actuating it, it will have to take a much more rapid movement backwards- twice the distance- as the movement forwards, if it is to create a balanced pressure wave in the air corresponding to the driving signal. Meyer achieves this by monitoring the pressure produced by the moving cone and predistorting the signal so as to correct it. No one else does this, primarily due to John's patents.
•My advice is: save your money and get the best- you can push this along by selling off the vintage stuff. ('Vintage': buzz word for old rubbish).

On his sound theories that were used in the Grateful Dead’s Wall of Sound:
•There is a simple rule: every source must be in time with all other sources (no separation), but a particular source must not be carried in more than one channel (no panpots or 'center' switch positions. This is true no matter how many channels the system has: 2, 6... 100. ALL channels must have a common even if virtual source point. The audience does not have to be in any particular place, there is no 'sweet spot' and the sound is everywhere.

On one of Unterfunken’s ideas for the DSP Hall of Sound:
•FUNKEN: I was thinking as a music source you could run a DAW at 24/192k with some great outboard D/A's on as many tracks as the computer can handle and have a software interface designed so you could pan to 8-buss, each buss being able to be located anywhere in the room. The other idea was to explore the concept of Ambisonics and do the encoding and decoding w/ plugins...
•A recipe for very shitty sound.
•Yes, I know what is right and works, and what is not and doesn't.
•No matter how attractive the idea may be, the laws of physics such as the speed of sound and single-wave interference (think hologram) can not be adjusted to your liking..
•It has to do with your brain- which contains a highly evolved sonic signal-processing ability. If a source of sound enters the room from one and one only point, and there are other sources also unique in origin pointing in various directions, the human brain will process all these sounds into a complete sonic image in 3D, it will include the direct and the reflections of the sounds, subtract any time discrepancies and present the listener with a full rich, stereophonic soundscape. I've done it many times. I like to compare it to a bowl of gelatin- a sound entering anywhere into it is heard as if it is everywhere. Ever examine a Bose speaker? 9 drivers point away, only one towards you. It works, a kind of lovely spacious sound- but the maker hasn't a clue as to how or why. I just told you- it is inside your head.

On “believing” in things:
•I don't deal in conjecture. If I say something, it has been researched, measured, tested and proven. Otherwise I just say I don't know. You suffer from a very common delusion, that things are just what they 'logically' appear to be- or perhaps what others say (loudly) about them. I only trust my own perceptions, then set them to the test. I don't 'believe' in anything.

On collecting the Dead’s old Wall of Sound amps and cabinets:
•I hate to pop your bubble, but...The cabinet you bought is basically a nostalgia piece, something to brag about owning not using. It is just antique rubbish. It is not suitable for guitar, and was used only in a specially assembled line radiator. Moreover, if it is really one of the ones used in the system it is probably worn out- worthless even for that purpose. We replaced cabinets frequently during the life of the array- but ceased doing that toward the end. Any left are likely not good." ... -results=4