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If you had your time again, what sized sealed Maelstrom-X box ?

3764 Views 26 Replies 8 Participants Last post by  Lonely Raven
Hi guys,

For those of you who have played with Maelstrom-X's what size box would you do (sealed) if you had your time again ?

Assume EQ can be applied.
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Hi guys,

For those of you who have played with Maelstrom-X's what size box would you do (sealed) if you had your time again ?

Assume EQ can be applied.
Assuming a GenII Maelstrom-X, I'd do a 120-150L box with 100% fill, LT (20Hz, Q 0.5), and an EP2500 to power the thing.
I currently run mine in a 168L effective cabinet volume with a Qtc of around 0.65. This thing is a beast, leading me to thinking that a 87L volume with a qtc of 0.8 would be something I would like to try out. I have more than enough headroom, slam and it's alot more powerful than I imagined tbh.

It effortlessley shakes my entire living room of 2500 cubic feet and I seem to have hit a good EQ setting at the moment with plenty of slam and punch.
Thanks guys for the responses.

I ended up going for a compromise of two sealed 125L Maelstrom-X's :) Can't wait.

What EQ devices did you guys use out of interest?
I'm considering a sealed 15 cf box for the new Mael-X 21"

Though I could probably save money and have pretty similar output with a ported 18" in the same space.
I'm considering a sealed 15 cf box for the new Mael-X 21"

Though I could probably save money and have pretty similar output with a ported 18" in the same space.
Jaysus! If you're going to make it that big, why not port it? ;)

15 cubic feet, 50% fill tuned to 17Hz (8" ID, 45" long) and a HP @ 12Hz. Excursion never goes over 23mm meaning you only get quality bass! (90 volts input). 120dB @ 18Hz without room gain and with plenty of excursion left.
Jaysus! If you're going to make it that big, why not port it? ;)

15 cubic feet, 50% fill tuned to 17Hz (8" ID, 45" long) and a HP @ 12Hz. Excursion never goes over 23mm meaning you only get quality bass! (90 volts input). 120dB @ 18Hz without room gain and with plenty of excursion left.
I get everyone throwing options at me, but I can't tell which one is really the best...because no two suggestions seem to be alike. It doesn't help that I keep on coming up with more options myself. My fiance is pretty open to my building a big box for the theater, it's mostly my own aesthetic that keeps me from building a 20cf ported 21", and my own budget that keeps me from building TWO of them! LOL
I get everyone throwing options at me, but I can't tell which one is really the best...because no two suggestions seem to be alike. It doesn't help that I keep on coming up with more options myself. My fiance is pretty open to my building a big box for the theater, it's mostly my own aesthetic that keeps me from building a 20cf ported 21", and my own budget that keeps me from building TWO of them! LOL
That is the way Internet forums work. If you want a plethora of opinions, none of them the same, just ask in an Internet forum. :laugh:

If it were me, I'd just build a big sealed 21". Ignore the people saying you could get more output. The sealed 21" has PLENTY of output and it goes smooth and deep. I love sealed subs but you need a lot of swept volume for them to work well for HT. The smaller drivers NEED to be ported, to give the extra headroom. The 21" has an abundance of output, without the need of porting. It goes subsonic with ease because you don't have the roll-off under the port tuning. It sounds awesome.....

Kevin Haskins
Exodus Audio
That is the way Internet forums work. If you want a plethora of opinions, none of them the same, just ask in an Internet forum. :laugh:

If it were me, I'd just build a big sealed 21". Ignore the people saying you could get more output. The sealed 21" has PLENTY of output and it goes smooth and deep. I love sealed subs but you need a lot of swept volume for them to work well for HT. The smaller drivers NEED to be ported, to give the extra headroom. The 21" has an abundance of output, without the need of porting. It goes subsonic with ease because you don't have the roll-off under the port tuning. It sounds awesome.....

Kevin Haskins
Exodus Audio
Kevin, you are such a very bad influence on me.

Alright, as soon as I get the birthday funds lined up, I'm getting a 21". Get a pair of those little give away drivers ready for me, because I'll post photos of my 21" build in here as well.

Thanks for the gentle prodding.
, glad you talked the bloke into doing the 21", thats going to be awesome.

The smaller drivers NEED to be ported, to give the extra headroom. The 21" has an abundance of output, without the need of porting.
By 'smaller' do you mean anything smaller than the 21"? :gulp:
, glad you talked the bloke into doing the 21", thats going to be awesome.

By 'smaller' do you mean anything smaller than the 21"? :gulp:
Yes, it's a done deal. I gave Kevin a call to hammer out a few details...get this, he's actually talking me down from a 15 cf cabinet to a 10-12 cu cabinet! Anywho, he's got my Credit Card and I'll have a 21" on the way soon. Expect a build log here in the X forums.
Yes, it's a done deal. I gave Kevin a call to hammer out a few details...get this, he's actually talking me down from a 15 cf cabinet to a 10-12 cu cabinet! Anywho, he's got my Credit Card and I'll have a 21" on the way soon. Expect a build log here in the X forums.
Top stuff mate. Can't wait to follow your build thread.
Top stuff mate. Can't wait to follow your build thread.
The sad thing about a sealed box...is that nobody will see all the wonderful work that goes into bracing, and the motor of a fine sub driver.

If I could afford it, I'd go old skool car sub and build a 1" plexi window on one side of the box...that's just outa my price range right now considering plexi of that size and quality would cost more then all the MDF combined.
Sweet!

I already have 2 Mal-X 18's but Kevin keeps on coming out with even crazier designs that make me want to spend more money:help:

Would a EP2500 be enough for the 21"? I tried running a single 18" off of a PLX2502 which wasn't enough but my PLX3402 matches up great......too bad I don't have another 3402 for the second 18":crying: My room is on the large size though and open to other rooms besides the fact that I am a sub nut.
Sweet!

I already have 2 Mal-X 18's but Kevin keeps on coming out with even crazier designs that make me want to spend more money:help:

Would a EP2500 be enough for the 21"? I tried running a single 18" off of a PLX2502 which wasn't enough but my PLX3402 matches up great......too bad I don't have another 3402 for the second 18":crying: My room is on the large size though and open to other rooms besides the fact that I am a sub nut.
According to the owners manual, the EP2500 will run 750watts @ 4Ohms per channel. I think Kevin mentioned to me that is plenty by itself, let alone 2500watts bridged. So even if the numbers are fudged a plenty on the amp, it should have enough juice to drive the 21".

Once I get mine built, I'm going to try the 21" on one channel, and my current dual 10" folded horn on the other channel. But I'll probably just bridge the EP and run the 21" alone.

The EP2500 (or the EP4000 that has replaced it) is a great bang for the buck amp...otherwise it wouldn't be so widely used by so many DIY builders.
According to the owners manual, the EP2500 will run 750watts @ 4Ohms per channel. I think Kevin mentioned to me that is plenty by itself, let alone 2500watts bridged. So even if the numbers are fudged a plenty on the amp, it should have enough juice to drive the 21".

Once I get mine built, I'm going to try the 21" on one channel, and my current dual 10" folded horn on the other channel. But I'll probably just bridge the EP and run the 21" alone.

The EP2500 (or the EP4000 that has replaced it) is a great bang for the buck amp...otherwise it wouldn't be so widely used by so many DIY builders.
No... the 18" & 21" will eat up all the power you can give them. The EP4000 is listed at 2 x 2000W into 2 Ohms. You won't get that out of it because you would trip the breaker immediately and the voltage on the AC line will drop like a rock, but that is not overkill.

Both the M-18" & M-21" have highish DCR 2-ohm coils. The impedance is always above 2-ohms so you won't have any issue using the EP-4000 with each channel driving a coil. That combination should give you plenty of output.

Kevin Haskins
Exodus Audio
According to the owners manual, the EP2500 will run 750watts @ 4Ohms per channel. I think Kevin mentioned to me that is plenty by itself, let alone 2500watts bridged. So even if the numbers are fudged a plenty on the amp, it should have enough juice to drive the 21".

Once I get mine built, I'm going to try the 21" on one channel, and my current dual 10" folded horn on the other channel. But I'll probably just bridge the EP and run the 21" alone.

The EP2500 (or the EP4000 that has replaced it) is a great bang for the buck amp...otherwise it wouldn't be so widely used by so many DIY builders.
Maybe in theory that is correct but in practice I need more power. If you have a small to medium sized room that is closed off then less power can be had but if you are trying to energize a large open room the the more power the better.

I was not bashing the EP2500, just mentioning I had the PLX2502 as they have comparable numbers. I think the EP2500 is a fine amp that I listened to at a friends house who I built a sub for. I plan on picking up either a EP2500 or 4000 to see about saving some $$$$ by selling my PLX2502's.

The M-18 ran good with the PLX2502 but I could hear spots were the amp struggled, with the PLX3402 those struggles are gone and the M-18 loves it. I would have to think the M-21 is going to like plenty of juice as well. Somehow I don't think a single channel of a EP2500 will be enough in a sealed alignment for the M-21 especially if any boost is added down low.
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No... the 18" & 21" will eat up all the power you can give them. The EP4000 is listed at 2 x 2000W into 2 Ohms. You won't get that out of it because you would trip the breaker immediately and the voltage on the AC line will drop like a rock, but that is not overkill.

Both the M-18" & M-21" have highish DCR 2-ohm coils. The impedance is always above 2-ohms so you won't have any issue using the EP-4000 with each channel driving a coil. That combination should give you plenty of output.

Kevin Haskins
Exodus Audio
I must have misunderstood.

I also read (on the intarwebs) that the EP-4000 really doesn't output what they claim. Or maybe that's just typical internet talk.
I must have misunderstood.

I also read (on the intarwebs) that the EP-4000 really doesn't output what they claim. Or maybe that's just typical internet talk.
None of these amps will in the real world. Your AC line doesn't have the ability to do so either.

The EP-4000 should be more than sufficient for the job. When you compare it to plate amps, there is NO comparison. The pro-amps are much more capable and they are much more reliable on average too.

Kevin Haskins
Exodus Audio
None of these amps will in the real world. Your AC line doesn't have the ability to do so either.

The EP-4000 should be more than sufficient for the job. When you compare it to plate amps, there is NO comparison. The pro-amps are much more capable and they are much more reliable on average too.

Kevin Haskins
Exodus Audio
My EP2500 will have a dedicated 20 amp circuit by the end of November. :bigsmile:
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