Eternal Commander MK-4 Lightsaber

All Lightsabers with the Attenuated sound type have the same sound, including the Eternal Commander MK-4 Lightsaber. This isn't the official name, and this Lightsaber sound type may be labelled something like weaponmeleelightsaber08 in the background of the game.

I do not have a video of the Eternal Commander MK-4 Lightsaber, but you can watch a video of the Interceptor's Lightblade (main hand) weapon to hear the Attenuated sound type, which is the same as the Eternal Commander MK-4 Lightsaber.

Read more about these weapons at the SWTOR Artifice Crafting Guide page on Swtorista.com.

Retired Crafted Eternal Commander Weapon is now-retired weapons that was introduced to the game in Update 5.0 and was designed for characters who were level 70 from endgame PvE content. The schematics are now retired and no longer obtainable, BUT, if you can find someone who has the schematic, they can still craft it for you and trade it to you, as the items are Bind on Equip. Although these are hard to find these days, look-alikes were introduced later so players could collect them as cosmetic looks - these similar look-alikes may have Eternal Commander in the their name, or may have a completely different name.