The Shure V15 V with a Jico SAS/B stylus VS The Soundsmith Hyperion MR and Lyra Atlas SL

@richardbrand Having low bass is a lot of fun. Digital electronics do make it much easier to to get to the point where the subwoofers are invisible while still supporting the low bass. I promise you that if you get a second and digitally high pass your main speakers you will be even more amazed by a factor of four. 

@lewm Which reminds me, I find your speakers to look fat and bulbous (Captain Beefheart). The dimensions are wrong, but take just four inches off the girth and they become graceful. Screw the bass, it's WAF that counts. Anyway, go here https://www.stereophile.com/content/mark-levinson-hqd-loudspeaker-system. The article mentions a dealer in Florida. That was us and we did have them sounding great....for a few minutes until we blew something. The system was doomed from the start. It was way too difficult to set up and way to fragile. You are right, I have a very closed mind. 

@pindac The way I read your comment above was  if you used a subwoofer that radiated like the main speakers, both dipoles, it would be easier to integrate the subwoofers correctly. That is the assumption that is not true. It is logical to think that way, but subwoofers and main speakers are apples and oranges. The considerations for the best performance are vastly different. 

Stacked Quad 57s were hardly the brainchild of Mark Levinson or whosis. I am 10 years older than you, and I first heard stacked Quads in the home of one of my patients, when I was an intern, in 1970. He drove them with a Marantz 7C preamplfier (when the term "preamplifier" automatically meant built in phono stage) and Marantz 9 amplifiers. Harmony House in Manhattan also had them back then. Mark Levinson was a kid at that point in time. He can take credit for the HQD system, I agree. What you are not hearing me say is that the stacked Quad 57 system that I heard locally a few years ago was comprised of speakers wherein the onboard electronics, courtesy of Peter Walker in his attempt to turn them into a point source, were gutted and so too was the OEM audio transformer. In place of that stuff, Dave Slagle devised a tube amplifier with an output transformer that could directly drive the panel. In other words, only one transformer at the interface. And that transformer can have wider bandwidth and lower distortion than typical transformers used to couple tube amplifiers to ESLs, because the ratio of the two impedances, the output impedance of the tube output stage (which is very high, not like our OTLs that are designed to have a low output Z) vs the input impedance of the panels, are more nearly the same. Plus, Dave wound it himself. Like I also said, that system, owned by a local guy and unique in the world so far as I know unless Dave has built one or two for others, can play very loud and with very low distortion and may in fact incorporate a subwoof in its base. Like I also said, I have many hours listening to my friend’s Acoustat 2+2s. There is no contest at all. As I also said before, the guy who owns the aforementioned system uses stacked Quad 57 triplets at home, but he only saw fit to bring the doublet to CAF. So, you have a system with markedly enhanced durability in its ability to play at high SPLs and bandwidth, with reduced distortion even below that of the base Quad 57. It’s awesome; trust me.

Oh yeah, the reason the Sanders ESL amplifier is so large is because it has to develop the voltage to drive an ESL.  Most SS amplifiers are good at current (i.e., driving low impedance speakers) but not so good at voltage.  ESLs require voltage except at very high frequencies, which is why in general a tube amp is a superior match. OTLs are better yet, of course.

The most important point for me as a result of the recent Posts, is that a Speaker that is not fat off 70 Years being entered into the Market Place has serious support for it's Capabilities.

I often find 57's for sale in the UK, where a Pair can range between £300 - £1000

Most will be offered to be listened to under the guise they are quiet when charged.

The Last Pair I bought was not the prettiest, but were quiet and cost £120. There were the Donor Models referred to.

In my own home the Family call them the Wash Boards, fortunately I have my own Laundry Room   

https://www.facebook.com/marketplace/item/371140325552580/?ref=search&referral_code=null&referral_story_type=post&tracking=browse_serp%3Aed91271f-5755-4621-8851-eb130e7996ed

https://www.facebook.com/marketplace/item/1028071632350338/?ref=search&referral_code=null&referral_story_type=post&tracking=browse_serp%3Aed91271f-5755-4621-8851-eb130e7996ed

Dear @richardbrand   : " My Velodyne 18" subwoofer is ..."

Wel, you can be sure that 2 subs always is better than only one listening at the prefered seat position.

I own Velodyne too but with better wooferbuild material: pulp/paper.

R.