Here is a short description of my sub bass project which is finished now.
This is my previous horn system, flat downto 55Hz, and uneven below 55Hz, it required some more sub bass:
So it decided to install 8*15 inch drivers to cover 16Hz-55Hz. Here is the simulation:
So now the drivers are arrived, very quick travel from US to Europe. I installed them on top of the bass horns:
Then measurements. First there were not very good because of a room null at the listening position. To solve it I had to put another 15 inch IB15 driver in 210 liter sealed box in a rear corner of the room. And finally here is the total frequency response, 7*IB15 in a infinite baffle load + 1 IB15 in 210 liters + bass horn + filters but without EQ:
It really improved the sound, it is as fast as it used to be but very low frequencies are just fine now!
Then I just had to hide the drivers, sorry John:
My other hifi topics: