thats awsome man. i hadnt heard of these 4hpz motors....i thought that was u just saying 4hp with a z ont he end to make it sound rad...lol. im such a fan of my 4hp that i can only imagine how much fun a custom 4 slug motor simular to the 4hp motor.
speaking of which no one asked it. what are the major differances between those motors and the regular 4hp motors? also i noticed it seems you're 4hp motor has a top plate much higher than mine.
alright- to start with- there is only 4 of these in the world...
machined a bigger diameter and longer solid low carbon pole
cut the off the T and machined the backplate for a hot/cold press
machined a smaller diameter steel ring to fit inside the topplate gap
machined an alum core to take up the inside of the motor
machined copper rings to fill around the alum
added and extra .75 magnet slug
engraved a small logo on the backplate
used a super tweaky edge wound underhung coil
pole larger and longer and also added a ring to the inside of the top plate to make the gap even tighter. (the force of the motor and efficiency of the sub is ridiculous)
"I still don't want to give out the params but I have to say that they were over 5db more efficient than the custom neo's and 4hp's I made..
(and the neo's hit a 158 at a slap show with too small of boxes and no testing, and the 4hp's in a way too big box and also no testing hit a 152 on the 190 sensor at a iasca show, in 12" size...)" -quotes from the designer, builder..
the motor is actually designed for an underhung coil (which is unusual anymore...) here is a pic of the coil-
Also interesting to note is that the motors were magnetized at 940volts 2 times.. (standard 4hp's are magnetized at 450volts 1 time...)- in the builders tests this alone gave over 1db increase in sensativity
and some of the parts-
along with a SUPER lightweight cones that i have- the whole assemblies weigh only 116grams (thats REALLY light...) although im actually not going to run those cones, im gonna run the nomex/fiber 18" cones w/rubber surround, and ill prolly add another spider.
as far as the topplate on my 4hp- im assuming you have the quickchange assembly? if so- thats it right their, mine isnt threaded... (this is an older 4hp, about 2002-3? i believe)