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Originally this build was for 8 Maelstrom-X 18s , but after the QC and build house issues, I've modified my cabinets to take 18" LMS Ultra 5400s.


The drivers are shipped and will arrive on Tuesday. I'll start this off with some pics of my cabinets from the other thread. The only change to the cabinets needed was some routing on the driver hole and the bracing needs to be moved an inch out to make room for the bigger motors. Since I can't move bracing that's glued in place, I just cut out the pieces that would hit the motor and attached new pieces to the back sides of the braces which will not interfere.


I'm powering them with 4 Lab Gruppen FP14000 clone amps. They are remotely triggered and run through 30 amp industrial relays . However, the graphs below are all done with 2 then 4 Marathon MA-5050 amps. The FP14000s do not have any of the issues I was having with the Marathons.


You can see a video of the rig in action here . The real fun starts around 40s in.



Sketchup model of the enclosure, all new from previous:


The models and cut lists are designed for 21/32" thick ply.

http://countercultured.net/pics/ht/lms/enclosure.skp






Cut lists.. All new to match new model.




Made some sawdust...





Two enclosures ready for bracing and front baffles.



Time to make the bracing.



I got the center braces in, and just made the first of sixteen of the other braces.




All the bracing is cut. I need to position it and secure it next.




This is how everything lines up. The front baffle is on the left of the screen, bottom/top plate on the right.



More building pics.





The one on the left is ready for filling and sanding. I move it around on the speaker cutouts so I don't screw up the bottom.



Ghetto clamping.



All assembled.



With me for scale.



Shot of the baffles.



Nail holes filled.



Sanded and ready for paint



First coat of paint.



Boxes stuffed.



Drivers assembled.



These things are huge




All installed.






Some distortion measurements. These were taken with only two amps. Can get 5-6db louder with the additional amps since they didn't like 2ohm duty so much.



This was really hard to get since my power strips want to give up at this level. Need to get some 20a ones.



Some fr measurements with decay.


New power strips (rackmount PDUs actually) and double the amps



I think I was starting to hit the limits of my mic here. I only measured from 20hz since my amps will protect at this level if I send DC.


I got a new mic and took some measurements from -50 to -10 on the receiver. The subs are boosted like 11.5db here since I was listening to some dubstep before. I would have taken a reading at 0, but the wife is sleeping upstairs




This was taken with the new WM-61A mic I put together. It looks like I'm about to max this out as well as my mic input.


The distortion would be lower, but my house was going CRAZY and I was clipping the input.



I just realized I didn't take close mic measurements, so I took a few more today. I did these quick and without a mic stand, so it may not be perfectly smooth, but close enough to get an idea of what's going on.


All measurements taken at the same level.


This is a measurement at the LP with and without Audyssey


This is close mic vs LP with and without Audyssey


This is close mic without eq, close mic with eq of left, and close mic with eq of right.


Looks like I have about 10db of gain at 10hz, and almost none at 20. Wimpy



Measurements after adding MiniDSP.

 

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we'll hope for the best this time.


btw, how are you running your bass? are you running your mains full range and using the subs for just lfe or crossing some of the bass from the mains to the subs? just curious.
 

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Im so jealous, 8 $900 drivers. That's $7200 in all. Boy, have you just won the lottery. I hope this goes much better for you and I hope you have strengthened everything in your house!
 

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Discussion Starter #5

Quote:
Originally Posted by LTD02 /forum/post/19997075


we'll hope for the best this time.


btw, how are you running your bass? are you running your mains full range and using the subs for just lfe or crossing some of the bass from the mains to the subs? just curious.

I cross at 80. It should be cool to directly compare these to 8 malx 18s.


I was thinking about getting two more amps, but that would only boost me from 10kw to 15kw. Each driver is dual 2 ohm coils, so I have the option to either power each driver at 4ohms at 1900w, or each cab at 8ohms bridged at 3600w (1800w per driver).


Currently, I can just power each cab at 2ohms at 2500w, one cab off each output (1250w per driver).


Doesn't seem worth it for like 1db.


Are there any other gains that I don't know of by powering running at 4ohms vs 2ohms aside from less stress on the amp? The other benefit is that these amps (or any amp) cannot sustain more than 2400w continuous from a 120v/20a circuit.


I don't think I'll need to, but it's nice to know the option is there.
 

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Most of the strain is on the amp. Without having detailed tests done on the Marathon ma5050 there is no way to know for sure if it becomes a distortion machine when pushed hard at 2ohms per channel. You should be okay though. The good thing about your current position is that if you feel the need to get more amps, it's just a plug and play situation.
 

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Nice !!!!

Huge benefit that you built the cabs with no inner baffle, makes this swap - so incredibly simple and no special work or mod needed to drop them in coming off the Mal - X .... So sorry about the problems with all this, big huge effort on to end up with problems... big time drag bro, my heart goes out to you, and to kevin...


This is the problem with the LMS's lack of coil options when you put 2 of them in a box and want to drive the together off a single amp. Need some serious powerhouses with these bad boys....


To get most out of those drivers - 1 large amp pushin out 4000w @ 4 ohms per driver is what I did.

HealthNut got 2 of Lab Gruppen 14000w amps for a scary price.


Ricci is selling his QSC - PL9.0 amps and will deliver 4500w at 2ohm per channel.... http://www.hometheatershack.com/foru...-cba9000s.html


Too bad the 5050 isn't stable in 2 ohm bridged, just add a couple more and you'd be good to go...
 

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Man, I have (8) Dayton 15s and 3200 (real) watts. I thought my system was badass until I see what you are building. lol


I heard good thing about the Marathon 5050 but I have never seen any measurements of it. But I think 2 of them should do the trick.


BTW, what was you last sub setup and what was wrong with it?
 

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Quote:
Originally Posted by Warpdrv /forum/post/19997316




Too bad the 5050 isn't stable in 2 ohm bridged, just add a couple more and you'd be good to go...

You might want to try it.

I tested all 3 of my CEs and they will all do 1 ohm stereo/ 2 ohm bridged all day long, never miss a beat, never get hot, never clip, and with fan mods.

I have been running the one that way for 3 years.


There is a good chance it may work. I am not sure what the real world impedance is for the LMS.
 

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That was the CE's - not a QSC clone right jpmst3...?


Might be worth a try with 1 amp bridged on a single box but I would watch it closely that for sure... thing is he's already got the box wired up with 2 connections, 1 for each driver, not that it can't be changed, just sayin....


I would be watchin that amp like a hawk with that load until your certain your not overheating...


Your gunna be the guinea pig with the 5050 notnyt....
 

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Yep, CE4000s. I tested them all so I know it's not a fluke.


I would think that any amp of even minimal quality level would shut off, either from thermal protect or load sensing long before any damage could possibly be done.


So, I wouldn't worry to much as all of that protective circuitry is built in by design.

I know the CEs are pretty robust, but I suspect that others may do it just as well.


I would love to try it with a MA5050, hmmmm.
 

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duuuuuuuuuude


SIIIIICK!!!!!!!!!


words can't not express how jealous I am of this build!!!! (and how badly i would love to rock 8 lms')



Matt
 

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Discussion Starter #13

Quote:
Originally Posted by Warpdrv /forum/post/19997316


Nice !!!!

Huge benefit that you built the cabs with no inner baffle, makes this swap - so incredibly simple and no special work or mod needed to drop them in coming off the Mal - X .... So sorry about the problems with all this, big huge effort on to end up with problems... big time drag bro, my heart goes out to you, and to kevin...

It's not that simple. I have to route the driver holes, and I had to make 32 brace reinforcements and cut out a good deal of each of my inner braces, and reinforce them from the outer side so that the motor can fit.


I won't be experimenting with the 5050s unless it seems I need more power. And I won't be running them bridged at 2 ohms. The problem there is just that they can put out very high voltage, and not have the current to back it, since the limitations of a 120v/20a circuit is 2400w.
 

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so ummm, err


The 5400 is about 3db less effiecient then the Mael-x at least that is how it models per equal power applied. Have you figured out how you are going to deal with that though?


of course I am probably missing something blatently obvious.
 

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Discussion Starter #15
You're probably using the old driver and not the ultra, or using the malx 21". They model nearly identical except the lms 5400 ultra is more sensitive above 50hz or so.


I plotted them side by side and the 5400 has a bit of an advantage over the malx. If you go to the winisd thread on hts, make sure you get the 2010 version of the lms 5400 ultra 18" as its down further than the earlier versions. They're both listed as having about 89.x db sens
 

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Quote:
Originally Posted by notnyt /forum/post/19999066


It's not that simple. I have to route the driver holes, and I had to make 32 brace reinforcements and cut out a good deal of each of my inner braces, and reinforce them from the outer side so that the motor can fit.


I won't be experimenting with the 5050s unless it seems I need more power. And I won't be running them bridged at 2 ohms. The problem there is just that they can put out very high voltage, and not have the current to back it, since the limitations of a 120v/20a circuit is 2400w.

Oh yeah I forgot about your bracing scheme, I went a with a different bracing config on my Mal-X boxes so there was no hassle dropping the LMS's right down in...
except for the driver recess was about 1/4" too narrow and couldn't accommodate the rubber gasket, but that was my fault for making it too tight... I just removed the rubber gasket


When people worry about power delivery I tend to go back to this post by Mark Seaton.....

Quote:
Even when pushing into the limits you are very unlikely to draw more than ~5A for a long enough duration to pop a circuit breaker. Home circuitry is not concerned with the peak capability of audio amplifiers, just the real power averaged over time to insure wires do not overheat. It's very rare that a subwoofer amplifier ever draws more than 1/3rd-1/2 its maximum current, and more commonly it's 1/6th to 1/10th when we look at the time/current intervals that will affect a circuit breaker. Pumping a sine wave test signal into a subwoofer can certainly draw more power, but very little of what we listen to has that sort of power vs. time.
 

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With $7.5K tied up in drivers, I was wondering why you didn't opt for baltic birch instead of the soft cored ply. I'm sure the bracing will be effective but BB would have been a nice match for those high quality drivers.


So, were you planning on shaking your neighbor's house to the ground too or just your own?

 

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Discussion Starter #18

Quote:
Originally Posted by fnt62 /forum/post/0


With $7.5K tied up in drivers, I was wondering why you didn't opt for baltic birch instead of the soft cored ply. I'm sure the bracing will be effective but BB would have been a nice match for those high quality drivers.


So, were you planning on shaking your neighbor's house to the ground too or just your own?


Its not soft core ply. Its arauco, its not as pretty but its good wood and void free.
 

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Quote:
Originally Posted by notnyt /forum/post/19999558


Its not soft core ply. Its arauco, its not as pretty but its good wood and void free.

Actually, it is a soft composite core plywood. According to Arauco, it consists of 100% Radiata pine. Pine is a soft wood. We've used this Chilean pine plywood on several of our designs. As long as it's well braced and there are no large unsupported panels, it has worked well with an MDF external layer or in a three layer sandwich. However, if used alone in a single layer, it is prone to significant warpage and rings like a bell. Baltic Birch is far stronger, more dimensionally stable, and resists lower frequency resonances better due to higher stiffness. In contrast, Baltic Birch is in fact made of multiple layers of hard wood (Birch) veneer layers.

http://www.boisenortheast.com/boisen...co/arauco.html


And actually, it's not void free - at least the stuff we've used, going on four pallets now. It's better described as "low void". The Boise blurb above states that it's "minimal internal void". We've found most grades of Baltic Birch to have fewer voids although both types of plywood are good enough for enclosure construction in terms of having the kind of consistency needed to produce reliable joints.
 

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Discussion Starter #20

Quote:
Originally Posted by fnt62 /forum/post/0



Actually, it is a soft composite core plywood. According to Arauco, it consists of 100% Radiata pine. Pine is a soft wood. We've used this Chilean pine plywood on several of our designs. As long as it's well braced and there are no large unsupported panels, it has worked well with an MDF external layer or in a three layer sandwich. However, if used alone in a single layer, it is prone to significant warpage and rings like a bell. Baltic Birch is far stronger, more dimensionally stable, and resists lower frequency resonances better due to higher stiffness. In contrast, Baltic Birch is in fact made of multiple layers of hard wood (Birch) veneer layers.

http://www.boisenortheast.com/boisen...co/arauco.html


And actually, it's not void free - at least the stuff we've used, going on four pallets now. It's better described as "low void". The Boise blurb above states that it's "minimal internal void". We've found most grades of Baltic Birch to have fewer voids although both types of plywood are good enough for enclosure construction in terms of having the kind of consistency needed to produce reliable joints.

Interesting. Unfortunately that's all I can really get around here and its still $50 a sheet. I did not run into any voids while working with it. My enclosures are well braced thankfully, and the top, bottom and front are doubled up. The sides are all well braced. When I was running the malx drivers, I didn't notice any issues.
 
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