I have had my pair of New Large Advents for a few years now. I have had them fully serviced, re coned, capped and new crossover. I have also sanded them back and re oiled the walnut veneer and they look excellent. My NLAs sound great. I only really listen to vinyl tho. Mostly 50’s & 60’s rock and jazz music. I play punk music too. I’ve thought about adding subs, but I’m pretty happy with the sound so haven’t bothered. However when I play the same album via lossless digital file through my DAC I must say it sounds thin, tinny and horrible. So I wonder if this is just the difference between vinyl and digital..? Or perhaps the NLA were just designed to sound right for the popular playback of the time being vinyl records? I have found that adding better speaker cables, power supplies, dampening vinyl mats, vinyl weight, speaker placement, etc has done wonders to improve imaging and bass response. And I only always listen to them with dust covers off.
Hmmm. The Advents are one speaker that needs the grill cloth to help with dispersion and directivity, from what I've read and based on my experience.
And subs are the one thing Advents don't really need. What they need is treble extension and a better mid-range.
But I used Advents for 44 years, and never have I noticed that digital sources sound thin, tinny, and horrible compared to vinyl. But to make that comparison, first and foremost the levels must be matched--if the DAC is putting out a lower signal than the phono preamp, it will be lower in volume which can make it sound thin. Even level differences too small to notice as such will affect our perception of it. The only time I ever noted a thin sound from my Advents was when I had inadvertently wired one one of them out of phase. My NLAs have good drivers and I have restore the crossovers in them, too.
It is certainly true that Advents were designed to sound good given the popular sources of the day. The original OLA had a more rolled-off top octave than did the NLA, which Kloss cranked up a bit specifically to account for source material that had more useful information in the top octave.
As to those other things you did, are you able to demonstrate that those effects you noted as being "wonders" could be detected when you didn't know they had been done? The mind plays tricks on us. A weight on my records would eat up the suspension of my turntable and bottom it out. That might make it pick up vibration from the furniture, which might increase bass microphonic resonance, but it seems to me that would be a bad thing. Damping mats might help a table avoid microphonics, but then you really have to put it in a vacuum chamber to avoid some acoustic feedback from the speakers (which will emphasize bass, but unnaturally). All there is to get from Advents (or any other speaker) is had from copper wire of sufficient gauge, which for Advents doesn't need to be larger than 14-guage unless your speakers are further away from your amp than usual by quite a margin. I found zero difference between 12-guage speaker cables and 16-guage zip cord--and I conducted that test for myself in the 80's when I was able to hear the 18-KHz flyback transformer of computer monitors.
We hear claims such as yours routinely, but any form of controlled testing to demonstrate that the perceptions are repeatable, reliable, and unaffected by biases both conscious and unconscious never seems to accompany them. Thus, folks here are skeptical, because many have done those tests and they have not found the correlations implied by those claims.
Imaging is about placement, mostly. Gordon Holt, one of the progenitors of the use of that adjective and one who gave that feature higher attention than most other reviewers, didn't have any trouble with imaging using Advents. Placement matters. When I've had good placement with Advents, I've had good imaging. When not, I haven't. Advents usually won't do quite as well as later designs, simply because the tweeters are not centered, which means the tweeter sweet spot isn't in the same place as the woofer sweet spot, and the mid-range where both drivers are overlapped gets muddied a bit therefore (and there is also the phasing through the crossover region). My Revels provide better imaging, but they were designed with excellent directivity and better crossovers based on what the industry has learned since the Advent days.
Rick "anything that does 'wonders' ought to easily hold up to blind testing, and, for that matter, measurements" Denney