Once you have heard a well designed, modern, speaker using a 15" woofer it's hard to go back. I am not a heavy bass person, I listen mostly to acoustic, vocals, some classic rock and electronic and it all just seems right through these speakers but the ability to reproduce deep bass is there if needed. Transparent, space around instruments, and detail. Never congested or edgy.
These speakers have a better than average sensitivity at about 90dB 1w/1m the impedance plot has a healthy 8 ohm load on average with an impedance minimum of 5 ohms at 39Hz. This shouldn't pose any problem for most amplifiers as the corresponding electrical phase is very smooth, staying within the +/-30 degrees range from 40Hz upwards and even in the bass it is within +35/-50 degrees. So your amplifier doesn't need to be very powerful although is it a lot of fun when it is! Even my 2 watt SE amp works well.
These 3-way speakers and components are based on Tony Gee’s “Mezzo Galactica”. Tony Gee is a respected speaker designer in the Netherlands.
I used the same Seas Excel T29CF001-E0038 tweeter, the same PHL 1130 but, because of availability, I used Ciare’s NDH 15-4 instead of the NDH15-3 only because of availability at the time. I did confer with Tony about this change. I used the same crossover design and the crossover is easily accessible in a sealed, separate compartment at the rear.
The cabinets are constructed using 1″ thick Baltic Birch plywood with extensive bracing. The front baffle is constructed of a double layer making it 2″ thick. I kept the interior volumes the same as the Mezzo Galactica design. I have used extensive interior cabinet bracing. This all adds up to some heavy cabinets. Each cabinet measures 46.25"h X 16.5"d X 18”w )
The interior of the bass cabinet is lined with 1/2" felt and mineral wool.
there are 2 rear ports that are tuned to 39hz.
The mid range cabinet is well braced, lined with 1/2” felt and filed with sheep's wool.
The crossover components are Jantzen Superior Z-Cap, Mundorf Supreme, Obligato, Jantzen and Mundorf inductors and Mundorf MOX resistors. It is a 3-way parallel crossover.