Discuss The Viv Lab Rigid Arm

@lewm , you did not check out those programs. I can measure distortion both IM and harmonic. I usually do not do that as it is a PITA. I trust in the specifications of the equipment I buy. Distortion also is not something I can adjust aside from optimum set up whereas frequency response and group delays I can to great effect. 

Yes, we live with some phase distortion. The point is to minimize it. I used fairly potent sound absorption behind the speakers from floor to ceiling. The Sound Labs being the dipole line arrays they are minimize reflected sound otherwise to a degree impossible with any other speaker type including horns.

The Viv arm's bearing is floating which makes it worse than a unipivot which is pretty bad. 

The digital filters I use do not change phase. They will ring if you get carried away with the slope.

I have done the experiment of twisting the cartridge and underhanging it. The image is distorted and the blackness between instruments and voices disappears filled in by high frequency hash. Things like cymbals and triangles become harder to localize.

The Viv arm is a very poor design perpetrated by people who have no idea what they are doing. If I prevent one person from getting one I have done humanity a service. 

If the Viv bearing is “floating“ as you say, I would not like it either. I mentioned this very early on in this thread. Their literature is unclear. Can one of the owners and users of the Viv tonearm comment about whether the pivot point is fixed in space and not floating and also not a Uni pivot? That would be helpful to me anyway. but the main subject of our discussion has been underhung tonearms in general versus overhung tonearms, and the effect of TAE on sound quality. 

@intactaudio  : " on a solid foundation " but your observations on the VIV owners has not that " solid foundation ".

Observation must be under control with very specifics targets to look for.

First observation on the VIV is the manufacturer site that's a " bs " for say the least.

R.

What about the phase anomalies you and I happily live with, caused by dipole speakers where the rear radiation is 180 degrees out of phase with the front?

@lewm @mijostyn The reason any speaker with rear firing information should be at least 5 feet from the wall behind it has to do with how the ear processes near term reflections. When 5 feet from the wall behind the speaker the delay time is about 10ms. When the ear hears a sound, it makes a short term copy and looks for other examples in near term. If less than 10ms or so, the ear interprets similar examples as harshness (which is why side wall reflections have to be tamed), but if 10ms and over the ear can use it as echo location information, which means the sound stage of such speakers can be more palpable.

So I'd be unconcerned about 'phase anomalies' in this regard. 

@atmasphere With diffusion panels directly behind the speaker is it possible to shorten that 5 foot distance by a small amount? I have always considered trying planars but my listening room is moderate in size. 22'L x 16' W x 8'H. The most useful set up would only allow pull the speakers 3.5 to 4 feet off the front wall. Wonder if that is a viable option?