Do different speaker stands can really make a big sound improvement?

I’ve used the Pangea DS-400 4 post stand when I owned that speaker. I never filled it with anything!

https://www.audioadvisor.com/search-results/?q=pangea+ds+speaker+stand

BTW, if you want to fill the stands this product is a great filler!

Traeger 20 lb. Bag Signature Blend All-Natural Wood Grilling Pellets PEL331 - The Home Depot

Your HARBETHs - like all HARBETHs - share an attribute requiring an “open” design and open construction speaker stand, instead of a “dulled-down” filled inert design cheap speaker stand. The latter make HARBETHs sound very flat, and comparatively dull ….. and these mass loaded heavy stands work opposite to how HARBETHs were originally designed to operate …… ergo: think TonTragers

- why?

- because the HARBETH speakers cabinet design is a bespoke and unique very thin-walled cabinet design, that resonates like the sound board on a Stradivarius violin, or a Steinway grand piano. HARBETH recommends an “open” and “airy” speaker stand design like the TT’s with their bespoke dimpled tonebeds and extended tenons to facilitate this .

I have the M30.2XD’s ….

NO! More malarkey from Harbeth!