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Dual 18" Mael-X Build

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I have 2 18" exodus audio Maelstrom-x sub moofers.

They will get powa from my QSC PLX2 3102

I have the original mael-x with which is SCV but only one pair of posts. Same specs as current 18". Resistance is 3.8 ohms.

So basically the PLX will put 1000 into 4 ohms and 1550 into 2. Basically 1000 watts per speaker, even though their rated at 1500 I think I'll be ok.

The goal is only to stay "reasonably flat" for sub bass, and play as low as possible as loud as possible. My only processing now is my receiver. I will need to pick something up. I know far too little about box design. I would probably use something like Neo Dans cut sheet. I think I would like more bracing though maybe?

My sealed Maelstrom-X build... - AVS Forum

Give me some imput and we can see where this goes. Once I get the 2 subs built I promise I will do some measurements for you fellas.

Here's is the TS parameters

# Fs: 17.4 Hz

# Le: 4.0mH

# Re: 3.8 Ohms (Voice Coils wired in series)

# Qms: 3.62

# Qes: .42

# Qts: 0.37

# Mms: 525g

# Cms: 0.16 mm/N

# Vas: 313L

# Sd: 1182 cm^2

# BL: 22.9

# X-max: 32mm

# Pmax: 1500W

# SPL: 87.8 db/1W/1M

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I would rather not sonotube, but I'm open to anything.

No real size limits... It could limit placement if your thinking insanely huge. I would like to keep it under 28" high so it can be place in the front of the room. If your thinking sono then the ceiling is only 6'7".

I have 45" total on the sides of the screen.

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Would IB work?

I've usually seen them in sets of 4 and the IB specific speakers usually have a pretty high QTS. And would two be sufficient in terms of output?

I plan to do one someday when I have my own home. :shrug:

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Would IB work?

I've usually seen them in sets of 4 and the IB specific speakers usually have a pretty high QTS. And would two be sufficient in terms of output?

I plan to do one someday when I have my own home. :Jim:

No IB. I cannot seal them off.

Well I could... but it would take more work that i think it's worth.

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This might help.

These can all be "flat" but in my opinion for HT one of them is more exciting than the others. All will need some electronic help.

transferonmael.jpg

Here is that one with some eq. (now you know why I asked). In this case they both have a LP at 80Hz, 12dB and the green curve has one parametric applied. You will notice that to get the flat frequency response you lose overall output. Trade-off as always. Think about the trade-off you'll make.

transferonmaelwithfilte.jpg

Also need to know if you are willing to run more processing later, how much power you are going to use and how much restraint you have to not wallop on them until you get more filtering to help them deal with the power. Then we can make a specific box that should be a pretty damn good guess for starters.

Oh and the reason for the how much space question, the green curve box is around 32cuft. Depending on what you can handle and power/processing we can talk about the trade-offs.

And yes, I'd use more bracing :Jim:

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28" high, what width?

well, I guess 1/2 of the room at max per sub...

I think the room is 11' wide? I will have to measure. Depth would be about 3-5'

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Hrm, is the 32 cubic feet per woofer?

I have 1000 watts per woofer on tap according to the QSC chart.

the PLX will put 1000 watts into 4 ohms and 1550 watts into 2ohms

I don't think that extra .2 ohms will mean anything

:Jim:

I can throtle back big time actually. I cannot imagine that I would want to listen to them anywhere near max power unless testing or showing off.

I hate to be vauge but I have no idea what processing to use but I'm definately open to it. The more controll the better usually. I got these woofers with the thought in mind that if doing some EQ neuters the overall force I'm going for to get lower/decently flat.... I could buy 2 more. Double that with the fact I don't run my little velo' with bosted bass because I hate when I get distorted bass or it sounds boomy I was thinking 2 18" subs would do ok.

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I want processing for cuts, not boosts :Jim: Just to tame excursion and enclosure peaks. *obviously room peaks as well :drink40:

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I want processing for cuts, not boosts :Jim: Just to tame excursion and enclosure peaks. *obviously room peaks as well :drink40:

that makes sense I think I would be fine. I think the ability to get lower frequency with authority would outway overall total SPL.

Do you think I would be way off base with that kind of philosophy? Considering how much overhead I will have already.

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Exactly what I'd do and hoped/expected you'd say. :Jim: Gotta run out now, but I'll play around some more later. :drink40:

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Truly okay with using all that space?

For both, 50cuft, 30cuft?

I'm really liking a 12Hz tune atm and even without a HP you are safe down to about 10Hz with 1kW.

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My original practical thinking was an absolute max single box size(to hold both moofers) of internal dimentions 4x8x2(DxWxH). It makes sense as i could use good old 4x8's. That's bit less than ~64 cubes after bracing.

Basically, yes I can do it no problem. It was my original intent to make a huge box that would go where my entertainment center is. I have just had many recomendations to go sealed in a 2x2x2.

The biggest problem for a uber huge box is I would have to literally glue it up in the room. It would be for eva. It would also have only in front, behind or to the right of the seating postition in the room. If I did on the side or behind I do have more room to play with there also.

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Not sure where the itty-bitty sealed rec'd came from.

For music it may work well, and it will be louder down to about 30Hz where the ported will take over. For HT I'd choose LFE.

splmael.jpg

Some filtering, within cone excursion limits, and at 2000w total. Yellow is sealed, Green is 32cuft at 12Hz

Obviously we can move the green curve up in SPL, but it will lose LFE. Your choice on the trade-off. Going bigger in the box just buys you excursion issues at low frequencies.

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... I think 118 at 12 hz would be ok... I probably don't get 118 at any hz with the velo.

:)

LFE FTW!

Smaller sealed with boosted bottom end are popular for these Mael-x's at AVS man. lots of dudes go sealed. It seams counter-intuitive to me.

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Yes. There is a lot of excursion left in the sealed design though. Probably why so many choose that route, however, boost eats that up quick.

That is 32cuft shared :)

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Depends on the room. If you have more than one choice, I'd try them both as the results will be different. Two 16cuft boxes might be easier for that though. Sort of depends on the space.

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Pictures are worth a bunch, although it sounds like trial and error is your friend. If you can't do that you might just have to build and leave it and take care of whatever other issues there are electronically.

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Pictures I can do.

Here is one from the seating position. Basically the subs would take up position where I currently have the entertainment system. Or I would have to make them tall and narrow to have them in front.

3389079800_b6aa9c4694.jpg

I don't know if I would consider it ideal to move the center, but it's been on my mind to move it for a while. It's just very nice having all the electronics right there.

Here is a picture from the entertainment center looking back. I could do 2 sonotubes Or 2 big boxes and place them on either side of the first couch Or between the couches after I mount the PJ. Finaly it could go behind the raised 2nd row.

3389077784_a2c3584e11.jpg

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