LMS 5400 18" 6.1 cu ft sealed

**ISLAND1000** · **01-24-09, 12:55 AM**

This project began on a Friday afternoon and was ready to use Sunday evening. You might call it a weekend project.

The Driver is an LMS 5400 18" and the Amp is a Crown XTi 4000.

The LMS is rated @2500 watts and the XTi is rated 1200 watts per channel @ 4 ohms, 3200 watts bridged mono @ 4 ohms.
The LMS has a reputation for being ultra linear with a huge XMAX and powerful. The XTi is a modern PRO amp with included 6 band PEQ and extremely versatile when connected to a laptop.
The sealed box is 6.1 cu. ft. including driver and braces made with 3/4" MDF. Outside dimensions are 22.5x22.5x24.5. Box inside is sound deadened to prevent internal reflection with 1.5 inches of egg crate foam.
Construction is glue and screws with battens at every panel intersection and braces from side to side, top to bottom and back meeting at midpoint fastened with glue and screws.

Gluing and screwing batten to a side

Band clamp holding side and top at perfect 90 degree angle.

Sides, top and bottom glued and screwed.

Back glued and screwed to sides top and bottom.

Speaker terminals installed.

Battens and braces installed inside box.

Speaker baffle installed. Size comparison of LMS and Cadence Heavy Weight 18" sit on top.

LMS installed, box complete.

Cadence installed. Cadence was blown up . . . . only a 400 watt driver!

XTi and laptop showing one screen shot with two control panels

Glue is Titebond Wood Glue, screws were 1 1/4 drywall screws pre-drilled and counter sunk.
I had a 4x8 foot sheet of MDF cut to my dimensions at "Home Depot" at 4PM on Friday. I had the driver mounted and electrical connections completed by 8PM on Sunday. I fired it up gently at 9 pm not wanting to blow out any glue.
To say the immediate effect upon startup was startling would be an understatement. The bottom end was huge! I didn't throttle up for three days to give the glue a chance to cure correctly. When I did throttle up I blew up my older Cadence 18" Heavy Weight series driver. It was rated at 400 watts RMS.
I mounted the LMS driver, it eventually broke in and I became competent at using the PEQ of the XTi after 3 months. The sub and amp are excellent together. The driver is more potent than the amp. By that I mean the amp will go into protection before the driver reaches XMAX. My guess (not measured) is that the amp will deliver about 700 to 900 watts at around 20hz. That's enough to set up a noticeable vibration in my concrete floor.
The XTi allows you to make a response curve be anything you want including the best "boom box" I ever heard. Or for the purists, you can have the flatest response and have your New York Philharmonic sound like it's right there in your HT area.
Where the excitement really gets to me is watching DVDs. Explosions, Dinosaur footsteps, animations, Transformers, chopper blades, gunshots, aliens etc. are all amazing. And if you want, you can outdrive practically any set of mains there is.
My listening area is large and opens up to the rest of the house. The ceiling is cathedral and is 33 feet high at the peak. No matter, the LMS and XTi can fill it with so much bass you can't hear to talk.

View of 33 foot cathedral ceiling.

HT area.

HT area

HT area from above.

I actually completed this build last year and have lived and played with it and for sure have gotten my money's worth out of it.
What would I do differently? I'd redo the box, change the shape from almost square to more of a rectangle and add a different more substantial brace system. I might make another box out of oak or birch plywood and finish it in a nice stain and varnish. I might try the driver in a ported box just for fun. I'm curious too about an amp that's more known for driving subs like the I Tech 8000 amp from Crown. Other than that I don't think there's much reason to change anything. I go to sleep at night well pleased with my choice of sub and amp. I'm guessing I sleep with a big grin on my face.

I've got to give this forum a lot of credit for gettin me going. The experts on here were a huge help identifying the LMS as THE driver to have and all sorts of DIY secrets along the way. Some of the members and some of the admins were inspirations with the projects THEY built. There are many JAW dropping, eye popping, breath stealing projects to see on here. I can spend all evening rereading the planning and building of these monster projects. It's all good.
Let me suggest to any reader thinking about whether a "super sub" is worth your time and resources . . . . YES IT IS! GIT ER DUN!

**kryptonitewhite** · **01-24-09, 01:28 AM**

Incredible. Solid looking enclosure, no need to comment on the sub or amp...speaks for itself. I am still mind blown having received my IB3 18 today.... I can not fathom your super sub... I am still taking mine in. I enjoyed your reveiws...thats a large room to fill!

38mm! 44mm! 4 10.1" slugs! 2500rms/8000 peak! Titanium former.... where does it end??? 4" coil...

**ISLAND1000** · **01-24-09, 01:51 AM**

LOL, it ain't over till it's over. Stay tuned there's gotta be more on the way!

**kryptonitewhite** · **01-24-09, 01:53 AM**

Quote:

ISLAND1000 wrote:

LOL, it ain't over till it's over. Stay tuned there's gotta be more on the way!

Only thing more I would want is turn that into an LLT... and back the knob down a notch, cuz that's just TOO much!

Can you make a vid?

**Pinhead-227** · **01-24-09, 01:57 AM**

Holy cow!

**ISLAND1000** · **01-24-09, 02:08 AM**

The LMS doesn't model well as an LLT but who's to say I shouldn't.
I did make a vid of the sub bouncing a tennis ball. I tried to synchronize hitting the spl just as the ball hit the cone. I got the ball to bounce half way to the ceiling once. I don't know if I saved vid or not. I'll look.
The cone does move! I did solid tones from 10hz through 125hz. That is when I could get the cooling fan in the XTi to turn on. Those low hz s really suck up a lot of juice from the amp. The cone really moves. I thought I had bottomed the driver voice coil twice but it turned out that the amp limiter was making an oscillating sound almost the same as a voice coil bottoming. Now THAT was scary.

**Blaser** · **01-24-09, 02:58 AM**

Great Job Phil

Any chance we could see a REW FR?

**joorge** · **01-24-09, 03:40 AM**

I knew someone would get around to weaponizing a woofer.

**Mike P.** · **01-24-09, 07:52 AM**

Looking good Phil! It must be nice to be the proud owner of one of the best subwoofers ever built that is no longer available. You are one of the lucky few!

**tcarcio** · **01-24-09, 08:28 AM**

Great job, I use Crown amps also and love them. Congrats....

**kryptonitewhite** · **01-24-09, 10:30 AM**

Quote:

ISLAND1000 wrote:

The LMS doesn't model well as an LLT but who's to say I shouldn't.
I did make a vid of the sub bouncing a tennis ball. I tried to synchronize hitting the spl just as the ball hit the cone. I got the ball to bounce half way to the ceiling once. I don't know if I saved vid or not. I'll look.
The cone does move! I did solid tones from 10hz through 125hz. That is when I could get the cooling fan in the XTi to turn on. Those low hz s really suck up a lot of juice from the amp. The cone really moves. I thought I had bottomed the driver voice coil twice but it turned out that the amp limiter was making an oscillating sound almost the same as a voice coil bottoming. now THAT was scary.

reminds me of the clipping vid from wiggins with a 10" Brahma

http://realmofexcursion.com/videos/A...rahma12.13.wmv

**ISLAND1000** · **01-24-09, 06:12 PM**

Quote:

Blaser wrote:

Great Job Phil

Any chance we could see a REW FR?

Hi Ahmed, thanks.
Ilkka tested the LMS 5400 in a 100L sealed box and later a 200L sealed box. Those results cover all aspects of a drivers performance. My LMS and box are almost identical in terms of size 190L vs 200L. Ilkka was testing his LMS at about the same time I was building mine and I never felt the need to acquire the equipment and do my own FRs.
I've always wondered though about the in-room FR and what it was I was achieving by using the PEQ of the XTi.
Using REW would answer a lot of the in-room questions. I really should do it. I've been such a procrastinator.

**ISLAND1000** · **01-24-09, 06:20 PM**

Quote:

kryptonitewhite wrote:

reminds me of the clipping vid from wiggins with a 10" Brahma

http://realmofexcursion.com/videos/A...rahma12.13.wmv

LOL, I gotta laugh every time I see one of those "excursion" videos . . . . especially the ones where the driver burns up or the sub actually loosens the windshield of the car!
The Titanium cone of the LMS (actually an inverted dome) was able to keep the tennis ball centered as it bounced. Don't get me wrong . . . . I wasn't playing tennis all day with the LMS and I didn't try to bounce anything heavier like a truck battery

or anything like that!

**ISLAND1000** · **01-24-09, 06:23 PM**

Quote:

joorge wrote:

I knew someone would get around to weaponizing a woofer.

"Weaponizing a woofer" . . . . I kinda like that.

**Warpdrv** · **01-24-09, 06:47 PM**

Very Nice Phil.....

Thanks for finally posting the info on your LMS Build....

I hope to finally hear one for my self, I'll be hosting a SE WI GTG for Subs - Feb 28th '09
Mostly in the realm of DIY More info here if anyone gives a hoot....

http://www.avsforum.com/avs-vb/showthread.php?t=1111483

**ISLAND1000** · **01-24-09, 07:15 PM**

Hey Warp,
Thanks for the warning. I'm supposed to fly to Rhinelander around that time in February with a stop in Milwaukee. Wouldn't that be something to actually do voice coils together?
Keep me informed of any changes, I'm flying non-rev and can change my fly dates.

**Warpdrv** · **01-24-09, 07:42 PM**

Wow.... that would be awesome buddy.... !!!!!

Hope you would make it.... Would love to see ya come by....

**Ricci** · **01-25-09, 02:58 PM**

That'd be cool if you could attend Phil. I'm gonna be there with some of my "weaponry".

**ISLAND1000** · **01-25-09, 03:44 PM**

Quote:

tcarcio wrote:

Great job, I use Crown amps also and love them. Congrats....

Hey TC, have you down loaded the 1.9.0 version of System Architect? I see Crown has made additions and adjustments for XTi's. I have not yet down loaded it.

**ISLAND1000** · **01-25-09, 03:52 PM**

Quote:

Ricci wrote:

That'd be cool if you could attend Phil. I'm gonna be there with some of my "weaponry".

Ahhhh, the weapons meister! Ricci this is sounding more like a "theater of war" rather than a "Home Theater" get together. I'll do the Recon.

**robertcharles123** · **01-27-09, 02:36 AM**

Just came across this thread. Before I read the whole thing, I have to say I want one of those suits of armor!!!. Now back to the reading.

Great job,

Robert

**robertcharles123** · **01-27-09, 02:52 AM**

Well, seems like the LMS was the right choice for you. I hope to be experiencing some of the happiness you have had from your sub build soon. I only have paint and "ammenities" to go, , and assembly , of course.

Is your LMS on the effects channel- the .1 in the 5.1 setup?

What crossover do you use for HT duty?

Mine is going to be .1 effects channel. The other channels will be full range as they are now, but a filter will be in place to prevent extreme subsonics from the main 5 channels.

How is yours set up?

Excellent job.

Thanks,

Robert

**ISLAND1000** · **01-27-09, 07:03 AM**

Quote:

robertcharles123 wrote:

Just came across this thread. Before I read the whole thing, I have to say I want one of those suits of armor!!!. Now back to the reading.

Great job,

Robert

LOL gmmmph . . . . . My grand kids named the suit of armor "Sir Robert". no kidding! He watched over everything that weekend of the build and after it was done, we toasted with an imaginary stein of the bubbly.

**ISLAND1000** · **01-27-09, 07:32 AM**

Quote:

robertcharles123 wrote:

Well, seems like the LMS was the right choice for you. I hope to be experiencing some of the happiness you have had from your sub build soon. I only have paint and "ammenities" to go, , and assembly , of course.

Is your LMS on the effects channel- the .1 in the 5.1 setup?

What crossover do you use for HT duty?

Mine is going to be .1 effects channel. The other channels will be full range as they are now, but a filter will be in place to prevent extreme subsonics from the main 5 channels.

How is yours set up?

Excellent job.

Thanks,

Robert

Yes I use the (sub-out) IE: the .1 effects channel to drive the XTi which drives the sub and is connected by an unbalanced RCA to XLR cord. I cross over the sub at 80hz most of the time but use 120hz for some CDs, music only. The other 5 channels on my Pioneer AVR run full blast through the various sound stage options included in the AVR. The "mains" speakers are set via the GUI for large. Those are AR 15" 4 ways 400 watt. The surrounds are AR 10" 3 ways.
The sub is run without a subsonic filter, no High pass. In fact for DVDs I have the the 20hz EQ boosted, set at plus 12db and have the parametric spread set to include to 10hz.
If I have the XTi volume set too high when playing a 10hz signal, the face guard on "Sir Robert" flips up.

**kryptonitewhite** · **01-27-09, 10:09 AM**

Quote:

ISLAND1000 wrote:

If I have the XTi volume set to high when playing a 10hz signal, the face guard on "Sir Robert" flips up.

I just woke up (lazy day) and that just made my day already. It's normally to early to smile, let alone actually laugh out loud. I am totally disappointed in you HT people that think your too good to make speaker pron... an 18" LMS at 10Hz making a metal face guard on an armord suit flip up... SEALED! Look, now I made my smile go to 1/2 in disappointment

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