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Exodus Audio Maelstrom-X Pre-Order Thread - Page 2

post #31 of 480
Quote:
Originally Posted by armystud0911 View Post

I assume you ordered the Maelstrom's?

I have some parameters on the PR18 also. These are still likely to change a little but this should be pretty close to the production parameters. The final mms might be a few grams higher and the Cms a little lower.

PR-18"

Sd: 1120 cm^2
Mmd: 210g
Qms: 6.3
Vap: 1106L
Cms: 0.63mm/N
Fp: 13.8Hz
Xsus: 43mm
post #32 of 480
Will those use the same basket as Jon's 18" PR's? I just need mounting info, thats all.

Thats a touch low on the sd, if its using the same cone as the Maelstrom, why don't the sd's line up?
post #33 of 480
Quote:
Originally Posted by armystud0911 View Post

Will those use the same basket as Jon's 18" PR's? I just need mounting info, thats all.

Thats a touch low on the sd, if its using the same cone as the Maelstrom, why don't the sd's line up?


They should on the production ones. They used a different surround and I've asked for another revision with a matching surround. I want them to look just like the active driver.

Same basket. Who is Jon?

The mass kit is going to look like this:




They slip down inside the former and are held in place by a bolt screwed into a T-nut that is epoxied down at the base of the former under a layer of MDF.

post #34 of 480
Jon Janowitz of Acoustic Elegance
post #35 of 480
Quote:
Originally Posted by armystud0911 View Post

Jon Janowitz of Acoustic Elegance

Oh... long day. I thought it was John Janowitz?

This is a common 18" basket. It is one of the only open tool baskets suitable for drivers with this much stroke.
post #36 of 480
Yeah it is, I got mixed up too, it looks like the baskets of your PR's are different from the basket of the Maelstrom, the Maelstrom pics on your site have the same basket as the Soundsplinter RL-p18 and the PR1821's that John sells. While the basket in the picture above has a similar spoke style to the other subs in your lineup.
post #37 of 480
So am I correct in assuming that the maximum mass you intend to be loaded on the PRs is 1200g or so?
post #38 of 480
Quote:
Originally Posted by armystud0911 View Post

Yeah it is, I got mixed up too, it looks like the baskets of your PR's are different from the basket of the Maelstrom, the Maelstrom pics on your site have the same basket as the Soundsplinter RL-p18 and the PR1821's that John sells. While the basket in the picture above has a similar spoke style to the other subs in your lineup.

That is because it is. That picture above is the PR-15. Same concept with the PR-18".
post #39 of 480
Ahh ok, thx
post #40 of 480
Quote:
Originally Posted by armystud0911 View Post

So am I correct in assuming that the maximum mass you intend to be loaded on the woofers is 1200g or so?

Well..... your starting mass is around 200g so with the mass kit you can get up around 1500g.

I'm starting a little conservative because I don't want to tell people to load them up to 2500g and have them rip the things apart. They are probably safe up to 2000g though.

If you need more mass you can easily go to Walmart and get some modeling clay. It could be squashed between a couple of the mass washers. Or... if you want fine adjustment fender washers will drop right on there.
post #41 of 480
Well, as you know the idea of PR's is to get the effects of porting with a smaller box, with a powerful sub like the Maelstrom, this works because you don't need a large box to get the free output down low, the motor handles that. If you can't tune the PR's low, then there is no point to using them, a port will do. In this case, ports can handle everything up to what the PR's do with upto 850 grams of mass (8" port 36" long) now if you really drive the maelstrom hard, it will chuff that port, however, your PR's will also be giving out at these outputs as well so the comparison is pretty equal. Where things start to get fun is when the PR's make a box/tuning combo that is simply unheard of with a ported design, the rules are fudged around 1200grams, stretching things nicely in favor of PR's, but the added cost really makes them a toss up with that kind of added mass. When you start to add 1500-2000grams is where things get really fun, which is why I asked. The deeper you tune, the more of the Maelstroms excursion you can utilize with a given input power/box size, you don't want to have to spend more on your amps than you do drivers, so $700 options like the XTI4000 are impractical for many people. Your other option to utilize this excursion is use a larger box, but lets face it, we are using PR's we don't want uber boxes, so the only way to use that excursion is with a deeper tune, deeper tunings require more mass though, which continues the downward spiral. (I'm not telling you this so you need to know, Kevin, just so others will fallow my train of thought)

The sweet spot for this combo looks to be around 1600-1800g of mass on the PR's.
post #42 of 480
You are not kidding! Over 123 db at 20 herz with a pair of maelstroms in 8 cubes each with dual 18 prs per driver. This with 1500 watts eachbefore any room gain! wow!
post #43 of 480
I found I kinda like two PR's in 8ft^3 with 1500g added to each for a 16Hz tune. Only ~6dB down unassisted at Fb. With 2400 watts it should be scary.

Good points, army, something I've long believed. No sense building a really big PR box.
post #44 of 480
Another thing of note on "PR Theory" is that drivers that work well for small sealed boxes also work well for PR's, if a driver models well for a large ported sub, its not a good candidate for a PR sub because in the smaller box, the rolloff will be much more severe. This is why drivers like the LMS5400, ED13Av.2, TC3000, tumult, and Maelstrom work so well for PR's, they have a powerful motor which gives them good response curve for the small ported, deep tuned subs. Drivers like the Tempest, Ficar Q18, Rl-p18 and Avalanche 18 are not very good candidates for PR's because they are made to go large ported, their motors don't dish out the sound down low like these other drivers do. Rather, I should say, they naturally rolloff too early, with EQ, they could do it, but it really isn't ideal. Its like using one of the above mentioned drivers in a small sealed setup with a Q of 0.9 and an F3 of 50hz and EQ'ing it flat.
post #45 of 480
Of course, since the Maelstrom is such a bargain, a second driver in a sealed box would be $~150 more, plus another amp. Looks like max output's a wash around the reflex Fb, with the sealed in the lead everywhere else by a good margin. Box size about the same.
post #46 of 480
I agree, except the difference is the amount of cost involved, it may not be worth it to some folks, after amplification you are looking at between $400 and $800 more depending on how high end you wanna go with your amp. The truth is, you really don't NEED that much extra output in the upper registers, it will most likely need to get EQ'd away in the first place and distortion up there is seldom an issue with subs. Between 30 and 45Hz, distortion just about always shoots down to well under 10%. Furthermore, the amount of subsonic output you want is up to you, a PR sub will get you down to 12Hz or so in room and a sealed pair will get you down to little below 10Hz. Furthermore, with the PR's, its not like your gonna be saving any space by going sealed, for a pair of sealed Maelstroms, you need between 6 and 10 cubic feet, the very same goes for a PR sub. Also, Kevin has talked about offering the package for $500, but he would prolly give a similar discount for a pair of Maelstroms.
post #47 of 480
Quote:


I agree, except the difference is the amount of cost involved, it may not be worth it to some folks...

Agreed. Just noting it as a possibility, since it might not be too big a jump for folks to grab another Behringer, etc., maybe around $500 total. Do mere mortals need that much headroom, or 5Hz...nahh.
No size advantage either way.
post #48 of 480
Actually, with the cost that you can get an EP2500 for, its more like $400 difference, not bad at all. I'd prolly swing for the sealed in separate boxes, 6-10cubes is kinda big for a dual opposed setup when you can just put them in separate boxes and get the added flexibility and mobility. What it comes down to with either alignment is, how much do you wanna spend on your amps? If you want to do the EP2500 route, a larger box will be the trick, if you can plunk down some serious coin for a PLX3402, XTI4000 or (drool) CE4000, you can afford to use a smaller box to get the same output, down to 6 cubic feet. One thing to consider is the wiring for these subs, Kevin isn't offering multiple impedances so you have to find a way to make dual 4ohm vc's work, this will give you 1300watts with the EP2500 instead of 2000 had it been dual 2ohm's. Wiring a pair suddenly becomes a nice option, get a single better amp and wire them for 2ohms per channel.
post #49 of 480
Quote:
Originally Posted by armystud0911 View Post

One thing to consider is the wiring for these subs, Kevin isn't offering multiple impedances so you have to find a way to make dual 4ohm vc's work, this will give you 1300watts with the EP2500 instead of 2000 had it been dual 2ohm's. Wiring a pair suddenly becomes a nice option, get a single better amp and wire them for 2ohms per channel.

Hmm...since the page lists "Re: 3.1 Ohms (Voice Coils wired in parallel)" I had assumed they were dual 8ohm coils. What'd I miss?
post #50 of 480
Jack,

This was my thought too.

Quote:
Originally Posted by Jack Gilvey View Post

Hmm...since the page lists "Re: 3.1 Ohms (Voice Coils wired in parallel)" I had assumed they were dual 8ohm coils.
post #51 of 480
I am ordering more today...I will give you a call Kevin. I NEED POWER !!!!!
post #52 of 480
LOL

Quote:
Originally Posted by TheEAR View Post

I am ordering more today...I will give you a call Kevin. I NEED POWER !!!!!
post #53 of 480
Quote:
Originally Posted by Jack Gilvey View Post

Hmm...since the page lists "Re: 3.1 Ohms (Voice Coils wired in parallel)" I had assumed they were dual 8ohm coils. What'd I miss?

Sorry, my bad, I got confused for a second there.
post #54 of 480
Quote:
Originally Posted by armystud0911 View Post


The sweet spot for this combo looks to be around 1600-1800g of mass on the PR's.

Are you stuffing your enclosure for the model? No reason not to go 100% fill and keep the box smaller, tuning frequency lower.

I'm modeling 8 cubic feet with a pair of PRs and a 16Hz tune and staying under 1500g of mass. It looks good to me.
post #55 of 480
Quote:
Originally Posted by Jack Gilvey View Post

I found I kinda like two PR's in 8ft^3 with 1500g added to each for a 16Hz tune. Only ~6dB down unassisted at Fb. With 2400 watts it should be scary.

Good points, army, something I've long believed. No sense building a really big PR box.

Ditto.... sorry. Hadn't read down this far.
post #56 of 480
Quote:
Originally Posted by Jack Gilvey View Post

Of course, since the Maelstrom is such a bargain, a second driver in a sealed box would be $~150 more, plus another amp. Looks like max output's a wash around the reflex Fb, with the sealed in the lead everywhere else by a good margin. Box size about the same.

The math is going to work like this:

x2 Maelstrom-X: $698 + shipping


Maelstrom-X + PR-18 Package: $525 + shipping

Shipping isn't cheap so there is about a $25 advantage to the PR package in shipping weight. The PRs + driver has about a $200 advantage in terms of the driver cost. The dual Maelstrom-X requires another amp, so even if we consider the cheapest solution, the EP-2500 we are talking another $300 there. The math favors the PR system by about $500.

I shouldn't be pointing this out because I make more money on the dual Maelstrom-X build but hey.... there it is.

The driver is dual 8 Ohm VC.
post #57 of 480
Quote:
Originally Posted by Kevin Haskins View Post

Are you stuffing your enclosure for the model? No reason not to go 100% fill and keep the box smaller, tuning frequency lower.

I'm modeling 8 cubic feet with a pair of PRs and a 16Hz tune and staying under 1500g of mass. It looks good to me.

Yup, I like a little lower tune though, stuffing is alright, but it doesn't get me where I want to be, 13-14Hz tune, the fr isn't changed much, but it doesn't work the PR's until lower down, giving them a few hz more protection. Its important to note that while stuffing lowers tuning, it doesn't provide the low end sensitivity boost that a larger box would provide.
post #58 of 480
Personally I will only be rocking a single maelstrom. The cost is for this sub will exceed what I spent on my dual ehqs12 budget beast. However, the cost is still in the realm of affordability.

pre-order maelstrom
$300
two 18" PR's
$200
ep2500
$250
materials
$100

total
$850

closer to $1k when including shipping and gas to home depot
post #59 of 480
Wait, so your spending MORE on the Maelstrom than your dual EHQS sub? I think I spent $200 total on the whole ehqs build, thats less than 1/4 the cost of the maelstrom, yet, 4 of the dual EHQS subs wouldn't even match the output, they'd need around 50-80 cubic feet.
post #60 of 480
"the idea of PR's is to get the effects of porting with a smaller box, with a powerful sub like the Maelstrom, this works because you don't need a large box to get the free output down low, the motor handles that."

You can only step on Hoffmann's toes a little before feeling the iron undeneath.

In an 8 cf box the Maelstrom gives only 1 dB more at 10 Hz, is equal at 17 Hz, and slightly less above that.

The advantage seems more worthwhile if you translate it to a 25% reduction in box size, which makes them equal at 10 Hz.

So Kevin did a pretty good job of bullying Hoffmann after all
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