(4) 2x 18" LMS Ultra 5400 in 15hz 27cube slot ported enclosure

[nyt]

My current low end setup consists of 8x LMS Ultra 5400s in sealed enclosures with 4x FP14000 powering them, pictured below. Kind of absurd to upgrade, but that's what this project is about. I feel the sealed enclosures I built left a lot on the table between 10-35hz that I can pick up by going with a vented alignment.

The outer dimensions of this measure 48" long, 46" high, and 30" deep. Ports will be oriented on the sides as I will be stacking these. These dimensions were chosen mainly to fit in the current space that I have, stacked two high.

I've got one of these built, and I consider it a great success. It output as modeled, though the tuning ended up around 14.7hz, with an effective port length of about 55". I need to order some duratex to paint it and bring it inside, then order some wood for 3 more.

Bracing was accomplished with strips of left over ply from the build. Handy since it was almost all cut to size already.

Sketchup file: download
Cut list: download

Current setup. The new enclosures will be stacked in the same place as the old.


Modeled at 6200w with 13.5hz 3rd order butterworth highpass.

Compared to current sealed subs with 8000w input and 11hz 3rd order filter (I have massive room gain in this area, filter prevents over excursion below 7hz).



Excursion:


Port Velocity:



Enclosure:

It weighs about 400lbs with the drivers in it. This was built from maple ply, which was excessive, but the selection was poor when I went out to get the lumber for this.








Results, as modeled. Huge gains. This measurement was outdoors next to my house, so sorry about some of the artifacts. It's hard to move these things. This was back-to-back with a sealed enclosure in the same location. No changes otherwise. REW files can be downloaded here.

[thekorvers]

Re: (4) 2x 18" LMS Ultra 5400 in 15hz 27cube slot ported enclosure

Do you really intend to produce 125dB in your listening space?

[nyt]

Re: (4) 2x 18" LMS Ultra 5400 in 15hz 27cube slot ported enclosure

Do you really intend to produce 125dB in your listening space?

125db is nothing, I'm already far beyond that. That's just one enclosure anyway, factor room gain and +12db for the rest of them.

[thekorvers]

Re: (4) 2x 18" LMS Ultra 5400 in 15hz 27cube slot ported enclosure

125db is nothing, I'm already far beyond that. That's just one enclosure anyway, factor room gain and +12db for the rest of them.

To each his own, I suppose.

[nyt]

Re: (4) 2x 18" LMS Ultra 5400 in 15hz 27cube slot ported enclosure

To each his own, I suppose.

well that was constructive.

[[email protected]]

Re: (4) 2x 18" LMS Ultra 5400 in 15hz 27cube slot ported enclosure

You could fill a theater with those. Nice build. Hide the kids.

[jstslamd]

Re: (4) 2x 18" LMS Ultra 5400 in 15hz 27cube slot ported enclosure

You can scatter brain matter with those. Still lookin good.

[Tin_Ears]

Re: (4) 2x 18" LMS Ultra 5400 in 15hz 27cube slot ported enclosure

Dang... and I thought my six IB 18's are gonna be overkill.

[JeffKnob25]

Re: (4) 2x 18" LMS Ultra 5400 in 15hz 27cube slot ported enclosure

I am looking forward to seeing this completed.

[tomzarbo]

Re: (4) 2x 18" LMS Ultra 5400 in 15hz 27cube slot ported enclosure

You like to play your movies a bit on the loud side?

Awesome setup BTW. Scary, but awesome.

I was hitting 115+ db in room at 20 Hz with my "Beast" setup using four ported 12" Titanics. I never could crank it up to where it gave out because my head felt like it was going to implode. Made the window on the gable end of the attic vibrate 1/2" each way during sweep testing. I turned it down after that. I can't imagine what your setup would do. Where is this at, basement?

TomZ

[bkeane1259]

Re: (4) 2x 18" LMS Ultra 5400 in 15hz 27cube slot ported enclosure

Holy crap.....is this a dream?? :eek:

I gotta show my 19yr old bass head son this pic. Wait...maybe that's NOT a good idea.

[saabracer23]

Re: (4) 2x 18" LMS Ultra 5400 in 15hz 27cube slot ported enclosure

I'm excited to see the outcome of this over your previous setup. Your personal reaction that is. Most on this forum aren't accustomed to the ridiculously over the top systems like people on avs are.

Dan

[ryanc]

Re: (4) 2x 18" LMS Ultra 5400 in 15hz 27cube slot ported enclosure

Good GOD!! My neighbor already complain about my crappy Polk PSW10 you know the $99 deal? My house shakes like a methhead on a withdraw with a sloppy 50 watts. I could not imagine that much power in my basement. It would crumble my foundation to dust!! I do like the set up though........I suppose I might need to reinforce the house because I got a woody seeing this one :D

[dstmbgh]

Re: (4) 2x 18" LMS Ultra 5400 in 15hz 27cube slot ported enclosure

I'm slack-jawed, not because of the SPL, but because of the $$L -- that's $7,400 worth of subwoofer drivers. Oh, my :eek:. Looks like quite a home theater setup. I hope your internal organs are as resilient as your wallet.

I see now what you meant by the port being side-oriented -- you're using the side and much of the back for a front-ported slot-port. Looks like the tuning you achieved was extremely close to target. Did you come that close to target based on your initial calculations, and, if so, what K factor did you use. Seems like these often end up being tuned lower than calculated, I think because the K factor typically used is incorrect. Perhaps you adjusted port length after initial testing. At any rate, good job.

Are the cabinets for these lined with any damping material, or are they left naked?

I assume you built the rest of your setup (L, R, & C). Anything you can tell us about those?

Welcome to the forum,
David

[dstmbgh]

Re: (4) 2x 18" LMS Ultra 5400 in 15hz 27cube slot ported enclosure

Just curious...

...filter prevents over excursion below 7hz.

How, i.e., from where, would they get anything below 7 Hz? No mocking or ridicule intended here; this is an honest question.