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8x sealed Maelstrom 18s build thread

post #1 of 781
Thread Starter 
Well, this was a fun ride. The build is complete

EDIT: Not complete. Malfunctioning maelstroms and lack of replacements, so switching to LMS-Ultra 5400s.

My solid state relay boxes for pro amps: I created a guide on how to build your own.

These are the amps I'm using: Marathon MA-5050 pics

Fan mod complete on MA-5050, before/after here.

Finally ran the system. The fan mod works well, and the air coming out of the amps after being pushed hard was just about room temperature.

I've taken THD measurements, they can be found here.

I'm leaving the original post below here without editing:

I'll be powering them with 2 Marathon MA5050s to start with, which I just ordered. They should be able to put out 10kw of power at 2ohms and have a selectable sensitivity on the input so I can run consumer gear outputs to them without any issues. I was using two EP4000s to start with, but ended up canceling the order since these amps seem to be much better suited for this build.

I also ordered a pair of solid state relays (Omron G3NE-220T-US-DC12 20A rated 12V SSR), which I will have my Denon AVR triggering so the amps don't remain on drawing power.

Two 10' male RCA to male XLR cables were also ordered.

As for the build, I'm going to build four cabinets, each with two drivers. The enclosures will be between 9-10 cubic feet. I'll post some sketchup drawings that will be used for the cabinets as soon as I design them

I went with Arauco 23/32" plywood for this.

I'll be using Audyssey MultEQ XT. In the past it has EQ'd my sealed setups flat to single digits. If it cannot do it with this setup, I'll pickup a MiniDSP to apply a Linkwitz Transformation.

Here is the modeling with two amps outputting 10,000 watts, eight drivers, and 40 cubic feet of enclosures.





Hopefully UPS doesn't hate me after this:





sketchup model. This link was updated to the LMS cabinet I built. The sketchup file is a bit cleaner:

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

You can find the old sketchup file here.









cut lists..





Made some sawdust...







Two enclosures ready for bracing and front baffles.



Time to make the bracing.



Bracing that will go around the cutouts for the woofers.



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.



Close call here. This is why I use bit holders with a sleeve, and apply pressure outwards, so when this happens, you don't poke a hole in the surround.



All in order



After Audyssey (1/3 octave smoothing, crossed with mains at 80hz, subs leveled slightly higher).



Carnage.
post #2 of 781
Awesome!!! What made you change your mind?
post #3 of 781
Kick ass. It's getting fun around here! I wonder how these will compare to MKTheater's old 8-18s and Brians IB 8-18s!

IMveryHO I think 2 EP4000s is severely cramping, 8 EP4000s one per sub wouldn't be over kill, but four of them two subs per EP4000 would be taking it easy.
post #4 of 781
Awesome.... I will be watching this one closely!
post #5 of 781
that 18" Avalanche IB build, is that four or 8 Avalanches?

Who has that room FULL of sealed LMS ULTRA 5400s, MX18's, and a few others?
post #6 of 781
Quote:
Originally Posted by kryptonitewhite View Post

that 18" Avalanche IB build, is that four or 8 Avalanches?

Who has that room FULL of sealed LMS ULTRA 5400s, MX18's, and a few others?

I think there was a member by the name of theEAR or something like that with a huge wall of mostly tc sounds stuff.
post #7 of 781
I see you changed your mind about the 21's. Just curious, what is the cone excursion like when you up the power on the 18's? I remember us going over that with your previous setup thoughts. And, I dont quite understand why you are modeling these input numbers based on the output of these amps. It seems like you will be using 4 subs ran at 4ohm bridged to each amp? That would throw out the smaller input graph all together wouldnt it?

2 amps running 4 speakers at 4ohm bridged to each amp would be 8000 watts minus the frequency range factor. This is why I dont understand your modeling numbers. Am I missing something here?

4 amps running at 2ohm per speaker stereo would be 11,200 watts before frequency factor, so not really worth the upgrade, but throw 8 amps then the upgrade would be worth it.

This is why I mentioned in your last thread that you need to make sure you get the amps that you know you will be happy with at first.
post #8 of 781
Quote:
Originally Posted by Drisco Z71 View Post

I think there was a member by the name of theEAR or something like that with a huge wall of mostly tc sounds stuff.

Thats it thanks Drisco!
post #9 of 781
Thread Starter 
Quote:
Originally Posted by audiovideoholic View Post

I see you changed your mind about the 21's. Just curious, what is the cone excursion like when you up the power on the 18's? I remember us going over that with your previous setup thoughts. And, I dont quite understand why you are modeling these input numbers based on the output of these amps. It seems like you will be using 4 subs ran at 4ohm bridged to each amp? That would throw out the smaller input graph all together wouldnt it?

2 amps running 4 speakers at 4ohm bridged to each amp would be 8000 watts minus the frequency range factor. This is why I dont understand your modeling numbers. Am I missing something here?

I put all of that information in the first post, graphs and everything

I'm going to run 2ohm stereo on the amps, which should provide 1200 watts per channel, or 600 per driver. I modeled with 4400 watts total from the two amps to try to factor in some inefficiency of the amps. They'll each have their own 20a circuit.

I know the drivers can take more power, but an extra two amps will only provide +3db. Staying further from xmax should provide cleaner output as well. At 20hz with this setup, it will be hitting 16mm excursion, and goes up to 18mm at 10hz, and 20mm at 5hz. I think it will be able to reach painful levels with just two amps, but if it needs more, I have the available power to add the amps if necessary.

I decided to go with 8x18 due to more Vd. EP4000's are overrated relabeled EP2500s. How are you going to get 4000 watts out of a 20 amp circuit? 20a @ 120v is 2400 watts.
post #10 of 781
Quote:
Originally Posted by notnyt View Post

I put all of that information in the first post, graphs and everything

I'm going to run 2ohm stereo on the amps, which should provide 1200 watts per channel, or 600 per driver. I modeled with 4400 watts total from the two amps to try to factor in some inefficiency of the amps. They'll each have their own 20a circuit.

I know the drivers can take more power, but an extra two amps will only provide +3db. Staying further from xmax should provide cleaner output as well. At 20hz with this setup, it will be hitting 16mm excursion, and goes up to 18mm at 10hz, and 20mm at 5hz. I think it will be able to reach painful levels with just two amps, but if it needs more, I have the available power to add the amps if necessary.


Reread my post. I edited it but obviously not fast enough. Running stereo with 2 amps is pointless isnt it?
post #11 of 781
Thread Starter 
Quote:
Originally Posted by audiovideoholic View Post

Reread my post. I edited it but obviously not fast enough. Running stereo with 2 amps is pointless isnt it?

Stereo in parallel. I can either run each enclosure at 2ohms using each output of the amp for each enclosure, or I can bridge it to mono at 4ohms and power two enclosures. I edited my reply as well, so please reread

EDIT: to further clarify, Each driver has two voice coils, but in series each driver is 4 ohms. Each enclosure has two drivers, in series 8ohms, parallel 2ohms.
EP4000 can drive a 2ohm load on each channel and produce 1200w per channel. 1200 * 4 is 4800w. I tried to factor in some inefficiency and modeled at 4400w instead of 4800, not that its a huge difference, under 1db.
post #12 of 781
I gotcha just that 4400 threw me for a loop.

I just looked up the manufacture data and it said 2x2000 at 20hm stereo or 1x4000 at 4ohm mono
post #13 of 781
I agree on one hand, youre going to have more output than you need already, and super-duper clean with minimal excursion.

Im more iffy on "only 3dB". Every time I hear that, I think "it's only twice as loud?" But that always opens up the 10dB is perceptual doubling yadda yadda..

But where I am set back, is going sealed vs IB is not just loss of easy low Q, but loss of efficiency as well... and the "inefficient small motored" IB3 18 is rated to take 550 watts infinitely baffled, while these, though more efficient drivers, will only be getting 50 more watts with *only* 5 cubes vs "infinite" cubes.
post #14 of 781
Thread Starter 
Quote:
Originally Posted by kryptonitewhite View Post

I agree on one hand, youre going to have more output than you need already, and super-duper clean with minimal excursion.

Im more iffy on "only 3dB". Every time I hear that, I think "it's only twice as loud?" But that always opens up the 10dB is perceptual doubling yadda yadda..

But where I am set back, is going sealed vs IB is not just loss of easy low Q, but loss of efficiency as well... and the "inefficient small motored" IB3 18 is rated to take 550 watts infinitely baffled, while these, though more efficient drivers, will only be getting 50 more watts with *only* 5 cubes vs "infinite" cubes.

Doubling Vd (displacement), or Pe(input power) will add 3db. 3db is not twice as loud. To perceive sound as twice as loud, it will need a 10db increase. You need about 10 times the amount of power, for every time you want the system to sound twice as loud. It's logarithmic.


I don't have a place to do an IB, and would not want to shake the **** out of my house (even more) or piss off my neighbors either

I'm going with these drivers since I can add more power if necessary, and if I want to re-purpose them, it will offer me flexibility.
post #15 of 781
Quote:
Originally Posted by kryptonitewhite View Post

I agree on one hand, youre going to have more output than you need already, and super-duper clean with minimal excursion.

Im more iffy on "only 3dB". Every time I hear that, I think "it's only twice as loud?" But that always opens up the 10dB is perceptual doubling yadda yadda..

But where I am set back, is going sealed vs IB is not just loss of easy low Q, but loss of efficiency as well... and the "inefficient small motored" IB3 18 is rated to take 550 watts infinitely baffled, while these, though more efficient drivers, will only be getting 50 more watts with *only* 5 cubes vs "infinite" cubes.

Yeah it will deff sound great! I can hook up two of my 21's to a QSC 2450 and it still really rocks but just need to monitor the amp for clipping a lot closer. Thats the only thing youre gonna need to do when setting these up is make sure youre not clipping the amps too much from all these speakers.
post #16 of 781
Quote:
Originally Posted by notnyt View Post

Doubling Vd (displacement), or Pe(input power) will add 3db. 3db is not twice as loud. To perceive sound as twice as loud, it will need a 10db increase. You need about 10 times the amount of power, for every time you want the system to sound twice as loud. It's logarithmic.


I don't have a place to do an IB, and would not want to shake the **** out of my house (even more) or piss off my neighbors either

I'm going with these drivers since I can add more power if necessary, and if I want to re-purpose them, it will offer me flexibility.

agreed.
post #17 of 781
Does doing eight in 40 cubic feet just give you more headroom and less excursion than four in 20 cubic feet? I mean could you do the same thing with just four of them but then youre getting more excursion therefore more distortion, or would *only* four not be enough?
post #18 of 781
I'm not meaning to hijack your thread here, I completely dig what youre doing... Ive done my thing and so I am taking much interest in other large builds seeing how people are getting there in different ways. I completely get that I went the budget rout because I had to. Please don't be annoyd!

Are you going to Linkwitz Transform these flat to a specific frequency? Is EQing flat the same but different?

Just playing around I plotted yours vs mine with 4kW, yours is the perfect roll off, mine has it's peaks and valleys... and room gain not taken into consideration. I'm sure I could EQ mine flat and we could end up with at least similar sounding but yours just much louder?

My FR vs yours



SPL though I expect much less power from my two amps since I don't have dedicated



my excursion is nuts, surpassing Xmax but still within Xmech. I have an untrained and unsophisticated ear, so as long as my spiders havent pulled tight, I can't even tell. But I expect if you EQ/LT flat, your excursion goes up as well?

post #19 of 781
Thread Starter 
Quote:
Originally Posted by kryptonitewhite View Post

Does doing eight in 40 cubic feet jsut give you more headroom and less excursion than four in 20 cubic feet?

Yes.

Quote:
Originally Posted by kryptonitewhite View Post

I mean could you do the same thing with just four of them but then youre getting more excursion therefore more distortion, or would *only* four not be enough?

They hit xmax much faster, and run at higher excursion levels.

If you look at the excursion graph in the first post, with double the power, that's exactly what 4 drivers in half of the space with the same power looks like, however the SPL graph would be down 3db.

So, by going to 8 drivers over 4, you drop excursion by over 6mm, and gain 3db.
post #20 of 781
Quote:
Originally Posted by notnyt View Post

Yes.



They hit xmax much faster, and run at higher excursion levels.

If you look at the excursion graph in the first post, with double the power, that's exactly what 4 drivers in half of the space with the same power looks like, however the SPL graph would be down 3db.

So, by going to 8 drivers over 4, you drop excursion by over 6mm, and gain 3db.

Got it. you hit Xmax at 3.5Hz with four, never hit Xmax with eight, and eight is always 6mm less so still sounds better all along. I'm guessing you audiophiles can still tell the difference between say 12mm and 24mm even when thats below the 32mm Xmax? Glad I can't
post #21 of 781
Thread Starter 
Quote:
Originally Posted by kryptonitewhite View Post

I'm not meaning to hijack your thread here, I completely dig what youre doing... Ive done my thing and so I am taking much interest in other large builds seeing how people are getting there in different ways. I completely get that I went the budget rout because I had to. Please don't be annoyd!

Are you going to Linkwitz Transform these flat to a specific frequency? Is EQing flat the same but different?

Just playing around I plotted yours vs mine with 4kW, yours is the perfect roll off, mine has it's peaks and valleys... and room gain not taken into consideration. I'm sure I could EQ mine flat and we could end up with at least similar sounding but yours just much louder?

SPL though I expect much less power from my two amps since I don't have dedicated

my excursion is nuts, surpassing Xmax but still within Xmech. I have an untrained and unsophisticated ear, so as long as my spiders havent pulled tight, I can't even tell. But I expect if you EQ/LT flat, your excursion goes up as well?

That's what I'm trying to avoid. You will gain some db down low, but then you have to deal with excursion and porting issues. I've used Audyssey MultEQ XT in the past and have gotten very flat response curves out of sealed enclosures. The sealed enclosures offer me the benefit of less space, and being able to stuff more drivers in my room to make up that db difference =]

This was 4 13av.2 drivers in small sealed enclosures corner loaded.

post #22 of 781
Thread Starter 
Quote:
Originally Posted by kryptonitewhite View Post

Got it. you hit Xmax at 3.5Hz with four, never hit Xmax with eight, and eight is always 6mm less so still sounds better all along. I'm guessing you audiophiles can still tell the difference between say 12mm and 24mm even when thats below the 32mm Xmax? Glad I can't

I don't consider myself an audiophile, but when I hear a driver bottoming out or making noise, it drives me crazy. I definitely suffer from OCD. That's the main reason I'm switching out my THTs. I don't need more output, but firing THT's directly into a corner and transferring all that energy directly into my walls rattles a bunch of stuff. I've already removed the springs and stuff from the windows near my HT Also, I just want to build something, and something big and ridiculous.
post #23 of 781
Quote:
Originally Posted by notnyt View Post

That's what I'm trying to avoid. You will gain some db down low, but then you have to deal with excursion and porting issues. I've used Audyssey MultEQ XT in the past and have gotten very flat response curves out of sealed enclosures. The sealed enclosures offer me the benefit of less space, and being able to stuff more drivers in my room to make up that db difference =]

This was 4 13av.2 drivers in small sealed enclosures corner loaded.


OK. I got it before, but I understand it even better now.

That is extremely flat to 10Hz.
post #24 of 781
Quote:
Originally Posted by notnyt View Post

I don't consider myself an audiophile, but when I hear a driver bottoming out or making noise, it drives me crazy. I definitely suffer from OCD. That's the main reason I'm switching out my THTs. I don't need more output, but firing THT's directly into a corner and transferring all that energy directly into my walls rattles a bunch of stuff. I've already removed the springs and stuff from the windows near my HT

Though that makes sense not loading THTs off walls, I'm not sure eight Maelstrom-Xs will be much nicer :-D
post #25 of 781
Quote:


I just looked up the manufacture data and it said 2x2000 at 20hm stereo or 1x4000 at 4ohm mono

Bit confused why people look at power ratings on amps as that is peak power and pretty worthless.

The EP2500 was tested at around 1800-2000 watts rms bridged into 4 ohms and about half that for 2 ohms stereo and the EP4000 is pretty much the same unit.

Looking forward to the results in this build. Should be fun.
post #26 of 781
Quote:
Originally Posted by notnyt View Post
Well, it's official. I've ordered most of my parts so I'm starting a build thread. I'm waiting on Kevin to get back to me so I can place the driver order, but I've purchased just about everything else so far. I'll update this first post as the build progresses.

I'll be powering them with 2 EP4000's to start with, which I just ordered. If I need more power, I'll add two more. I'm not sure 3db is worth an extra 5kw of power to start with.

. . .

As for the build, I'm going to build four cabinets, each with two drivers. The enclosures will be between 9-10 cubic feet. I'll post some sketchup drawings that will be used for the cabinets as soon as I design them

I'm still trying to decide to build the cabs out of ply, or out of mdf. Any input?

I'll be using Audyssey MultEQ XT. In the past it has EQ'd my sealed setups flat to single digits. If it cannot do it with this setup, I'll pickup a DCX2496 to apply a Linkwizt Transformation.
How big is your room?
I have 2 sealed Mael 18"s, one is a gen 1 and the other is gen 2. Each is in a 6.5 CF enclosure. I'm powering them with 2 EP2500's in bridge mode. My room is ~5500 cf sealed, and the speakers are ~1/3 to 3/8 up in the side walls, across the first row.
I'm certain that the EP2500 could handle both drivers at ref levels without a Linkwitz boost. I'm not so sure they would do as well with a transform at max levels.
post #27 of 781
Quote:
Originally Posted by gperkins1973 View Post
Bit confused why people look at power ratings on amps as that is peak power and pretty worthless.

The EP2500 was tested at around 1800-2000 watts rms bridged into 4 ohms and about half that for 2 ohms stereo and the EP4000 is pretty much the same unit.

Looking forward to the results in this build. Should be fun.
The amp is 1300W (650 W x 2) at 4 ohms continuous.
http://www.avsforum.com/avs-vb/showt...8#post10753638
post #28 of 781
Thread Starter 
Quote:
Originally Posted by Swampfox View Post
The amp is 1300W (650 W x 2) at 4 ohms continuous.
http://www.avsforum.com/avs-vb/showt...8#post10753638
At 2 ohms its 1200 per channel, which is how I'll be running it.


Quote:
Originally Posted by Swampfox View Post
How big is your room?
I have 2 sealed Mael 18"s, one is a gen 1 and the other is gen 2. Each is in a 6.5 CF enclosure. I'm powering them with 2 EP2500's in bridge mode. My room is ~5500 cf sealed, and the speakers are ~1/3 to 3/8 up in the side walls, across the first row.
I'm certain that the EP2500 could handle both drivers at ref levels without a Linkwitz boost. I'm not so sure they would do as well with a transform at max levels.
The entire first floor of my house is open, about 10k cubic feet. The seating area is in a space that's about 25x13x8. The 8 drivers should help

If I need more power, I'll get another pair of amps. We'll see.
post #29 of 781
Quote:
Originally Posted by notnyt View Post
At 2 ohms its 1200 per channel, which is how I'll be running it.

My bad, you're right.

Quote:
The entire first floor of my house is open, about 10k cubic feet. The seating area is in a space that's about 25x13x8. The 8 drivers should help

If I need more power, I'll get another pair of amps. We'll see.
That's a big space!
post #30 of 781
Thread Starter 
Quote:
Originally Posted by Swampfox View Post
My bad, you're right.



That's a big space!
Yep, you can see the buildup in my sig that gives some scale kind of.
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