@gavman I have had Stacked ESL 57's as the mainstay speaker for many many years.
In conjunction with these as a means to create an alternative end sound, I have used Cabinet Speakers as both Stand Mount and Floor Standers throughout many many years.
It is the use of Cabinet Speakers that got me interested in removing Cabinet Influences and being able to identify the location of the source of the End Sound being produced.
ESL Speakers are quite capable of not being present in the room, there is not a source for the sound that is easily located, my ears at this stage in my life has it as not locatable. This for my own purposes id very very attractive and is wanted to be available from all Speakers in use.
What have I learnt over the years:
1, A selection of Cabinets tried out are not able to be tamed, the Cabinet Influence is always to be present even though reduced in its effect, when mounted on a particular configuration for a Sub Support.
2, A selection of Cabinets tried out are tamed, the Cabinet Influence is not present when mounted on a particular configuration for a Sub Support. In a selection of used Speakers a Weight Placed on the Top of the Cabinet and positioned in different resting points can be the added treatment to tame the Cabinet in use.
3, A Speaker can really deliver in a way that is extremely competitive to the used ESL when the Support Plinth Configuration, added treatment and Speaker Positioning is given a variety of set ups. Certain Set Ups have enabled the Speaker to excel beyond its offerings when used as a Basic / Typical Set Up.
4, A Cabinet Speaker when either on a Stand or Floor Standing is able to present much improved as a result of introducing a Sub Support produced as a certain configuration.
5, The most difficult part is the positioning of the Speaker within the listening Space. This has to be worked with and records taken of the positioning being used. Using a Decorators 3" Masking Tape as a demarcation on the Floor is ideal, it can also be Pencil / Pen demarcated produce easy to use incremental changes for an orientation. Taking dimensions to local structures from the Cabinet, i.e adjacent Walls, Dimension from Listening Chair to plane of speakers. These combinations of dimensions are the records to be kept. as when the real hot spot is being discovered, small increments can really hone in on the End Sounds Impression able to be made, i.e an instrument or vocal can easily be missing if the final tweaks are not meticulous.
6, Symmetry of the Toe In is very important, accuracy of a dimension that is not to low mm's, can diminish or accentuate a certain sound, i.e, a Vocal Harmony can have a Tonal Parity or one Voice has the most noticeable presence, backing vocal can be very very far back vocals.
7, The Cabinet Side Wall being Vertically Plumb is critical and checked periodically to tweak to correction as this can slip? i.e, possibly movement occurs as the load settles.
8, The Front Baffle is rarely vertical Plumb in a Speaker I set Up, depending on the Speaker Cabinet Dimension, I have had cabinets set 70mm leaning forward. In general the Cabinets are leaning between 10mm - 40mm and that can be the front baffle leaning towards the listener or away from the listener.
Raising the height of a Speaker and then working with it, has never proved a negative for myself.
As stated in earlier posts, I use a Five Tier Sub Support, which elevated the Speaker.
I have also used double stacked AT 616 Suspension Footers, but the configuration is not creating anything that can be claimed is discernible as the impact on the End Sound. I have also Spiked onto the AT 616 Footers and that does create change to the End Sound that is discernible. More is achieved in my trials by adding a Sub Plinth and a Particular Separator under and Above the Sub Plinth. Even More is achieved through the use of 2 Sub Plinths with an additional Separator, making a Five Tier Sub Support.
The Link contains a Post from myself, that adds to the Options on how a Suspension Support can be produced.