I decided that since the budget was a little more open now, I could re-design my old "dual FiQ18 powered by Behringer EP2500 (2000w RMS) 118dB 13hz $1000 total 15-amp Circuit" low-cost low-quality parts design into this new high-quality design.
I've shown the design plan thus far to my dad and he asked why to not just buy one. I explained the thing about the value and commercial equivalent of this design. Then he understood.
Now he's getting excited.
After the designing process is complete this should be getting underway around January...which were my plans last June IIRC.
I'm sure it will change a bit, but only for the better.
Amp is now Crown CE4000 (3800w RMS approximate) .. 220v circuit
I got an e-mail back and he heavily supported the design as I described it to him. In terms of power, he said I can have more than needed, but he recommended limiting the maximum continuous output, with a limiter of course.
That's the only update. Oh, and all of the sudden large quantities of money are going out. January should still be possible, though.
Ok... now the amp is a Crown MA5002Vz. It's much better than the CE and the ratings are much more comprehensive and detailed. 4200w is the output into 20hz and that's with a 42-amp draw from 120v service. I doubt I'll be above 100w much as that would be a stress to my house if done too long.
Anyway... Sometime next week I should know when I can get started. We'll see what happens.
It's not really an advanced design, but it's really just doing everything I can to minimize resonance.
1.5" MDF on all sides with heavy bracing throughout
Heavy bracing, especially on the long sides and around the driver and port
Four 10" ports (one per driver) for minimal port distortion
Then it's tuned extra low (13hz) to pull the port distortion into the infrasonic range where it's less critical.
I also would've chosen opposing drivers, but I thought that a four corner placement would be more advantageous than that. It would also be a lot harder to move half-ton enclosures than quarter-ton (those are high estimates).
I remember you're post on The Home Theater Forum. Thats gunna be allot of space taken up by the boxes. 20-22cuft each, you are really going all out this time.
I have a FiQ 15" in a LLT tuned to ~14hz powered by a ep 2500. I really like it, given more is always better but i must say that a single is very impressive. I cant imagine what 4 18 LLTs would sound like.
You must have quite some room to be able to handle all that space/pressure/wattage.
Well i must say that my room ( im a college student) is in a 120 year old house with plaster walls. so my single 15" LLT can make allot of pressure in my room.
It is very impressive to say the least. But i totally agree with you're approach of more is better but limit it by the house and no the subs.
4 18" LLTs will be extreme. if you ever actually get it turned up be careful, seriously that will do some damage which im sure you have thought about. Eventually ill get a house with a not finished basement and make a theater with 4 LLT subs, but thats 10+ years away.
Just something to think about... what are the dimensions of the room, as you dont want the waves to cancel them selves out. I would imagine that to be an issue when placing in all 4 corners.
what did you think of you're dual FI Q sub? Mine sounds super good for the price. although i listened to a F113 at my boss's place and it is phenomenal, maybe mine would sound better in his room (special room treatments)but i dont have the time or energy to get it down there for a listen.
