I added a 2nd sub to my Elac's last Friday.
I did not do any placement tests(will check every possible combination/placement in my room).
I did not make any measurements(will not do, as I can't).
So as my observations will be subjective and generic, I will only say that this the 2nd bigger sound improvement I experienced since I started taking this hobby more seriously.
The bigger one was the addition of my first sub(with my previous speakers).
There is something I would like to share with you though as it quite surprised me.
I own these speakers till last November.
I listen to them from 08:00 - 00:00 daily.
These are extremely comfortable speakers, in the sense that I have a feeling that I could listen to them for 4 consecutive lives without even the minimum suspicion of ear fatigue.
On my previous comments I also stated that if I would need to complain about something, this would be the recessed highs which sometimes are giving me an impression of lacking energy/dynamics and can make the speakers sound even a bit boring with some recordings.
Guess what?
During the weekend I caught myself needing to turn down the volume as I was clearly feeling ear fatigue.
The speaker did not give me only fatigue though.
But also this energy and excitement I was missing.
Not sure if this is something that is expected, can be explained or makes sense to someone who is not a noob like me.
It is also worth mentioning that when I had the single sub, gain was set to 21db.
So that's how I started with the 2nd sub as well.
On Sunday evening(after 48h with the new sub) I changed gain from 21db to 22db.
And I have the impression that this made a big improvement eliminating this fatigue sensation, 'cleaning' the base, giving more 'air' to the mid's and removing this kind of harshness(yes harshness!) from highs on some songs.
It seems way exaggerated to me that a drop of 1 db gain caused all that.
Even if the difference it is not so impressive as one might think by reading my previous sentence.
It can also be the effect of me getting used to the new sound.
But it is clearly better and I still have to feel this fatigue sensation since the change.
I am not looking for any specific advise as I am super happy(if not excited!) with my new addition, and I also still need to do all my testing with moving the subs around the room.
I just wanted to share my experience with other owners of the speakers who have or think on adding a 2nd sub.
Comments(and advises) are more than welcome of course.
We are addicted to fun and
learn after all
ps1: low pass filter is set to 60Hz on both subs
ps2: the new sub is the one on the side of left speaker. I placed my first sub using the crawling method, and I remember this was the 2nd best place. That's why it was my best bet for initial placement.