[vili]

I figure I would make a thread with my build. I made a variation on SturmMDs build and made it 26" so that I could center the PRs in the cabinet. I am using a Crown XS1200 to power this, 3kw at 4ohm mono. I have a Gen II Maelstrom-X, I had a Gen I, but it was defective and Kevin replaced it, so Kudos to him for awesome customer service. After bracing and drivers the internal should be about 7.5 cubic feet and modelling in winisd gives a tune around 17hz. I am using 14 washers on the PRs and have about 1750g total weight on them. I have tried the sub with various levels of fill and will get into that later. Using an SMS-1 with a 17hz subsonic filter to EQ and a Pioneer SC05 crossed over at 100hz. Feel free to ask any questions.

At the time I didn't have any tools (just bought a used table saw for $60 last week) so I had a cabinet maker friend help me build the enclosure. This is my first DIY anything.

We rounded over the outer baffle with a 1/2" roundover bit and a 1.25" on the outside of the box if my memory recalls.

The most work was probably the prepping for painting really. Betwen filling imperfections with wood putty, sanding, wiping down the entire enclosure, do a coat of primer, then do the same thing a time or two before we just sanded/wiped down and painted. It was a lot of work.

Then we started the black paint, we did 2 coats of black and then 1 coat of high gloss. Some of the pics are kinda dusty/fuzzy...sorry about that.

I did a lot of sanding, perhaps a bit more than I needed to, but I wanted a good looking enclosure.

Here is the finished product in my room:

I also bought a custom made subdude HD in a 26" cube configuration, I can take pics if you want and put them up.

At the moment I've been playing around with fill and things of that nature.
This is the uneq'ed mael with fill in my room

Here is a pic of the mael with 6-7 pounds of fill eq'ed

About half that

And then no fill

After a suggestion by Ricci, turned off all of the EQ and did a measurement from about 2" away from the center of the mael just to see what it would look like and this is it

After I did that I rememebered that my Ascend Sierra's put out the test tone sweep as well so I disconnected them and this is a nearfield measurement with nothing but the Maelstrom.

It sounds great, but the graphs show something kind of weird, I assumed that a sub should be relatively flat to it's tuning, but I get a big hump in the mix with no EQ, any thoughts?

 

[Mike P.]

Awesome looking cabinet, I love the finish! How big is the room that the sub is in?

 

[vili]

My room is about 19x13x8. It opens up to the kitchen though. I have a small house which is only 900 square feet plus a 300 square foot attached garage.

2 bedroom/1 bath. Currently attending college, have 1 year left before I have my Bachelor's in nursing. My wife graduated this past December with her teaching degree, she is currently working at the university full time since there aren't any teaching jobs around here this year and we have a baby on the way...our first...just found out Tuesday we are having a baby girl in November. I also work at the university at an it help desk.

 

[Warpdrv]

Response looks good to me.... not sure what your worried about without EQ, that is what happens when you put the sub in your room... With EQ, your looking killer IMO, it could be far worse then what you are seeing here my good man...

 

[vili]

Since my house is small my theater room is the living room, I have a 125" DIY DW screen. I am using an Epson 6500 for the picture. Also have 3 Berkline 45003's with buttkickers although now with the new sub they don't have much use heh.

 

[vili]

Thanks Warp, I just thought I rememebered roughly a flat line doing nearfield measurements at the sub gtg at brandons. the last pic of the sms just looked kinda odd to me, didn't know if it was something on my part or what.

 

[vili]

In case anyone is curious, I did have to do a fan mod on the crown xs1200. It sounded like a little jet with the stock fans in it. I replaced them with the same fans as the ep2500. I didn't realize it until after I got it, but the stock fans are 60mm or something like that because the 80mm fans are much bigger than the stock, luckily the case still closes fine. All that holds them in is a zip tie, thats the way the manufacturer made it...no screws nothing...kinda crazy.

 

[Ricci]

Hey bro. The notch in your driver response in the un eq'd close graph should be your tune looks like it's 18ish. That was the main reason I wanted you to do that test. You forgot to turn off or raise your crossover in your Pioneer SC-05 didn't you? No big deal. That will roll off the >80hz frequencies and make the response appear a bit humped. Other than that I'm not familiar with the SMS-1 or it's mic, so it could have a bit of proximity effect to it or something.

 

[vili]

Ah, didn't know I needed to raise my pio XO...let me do that and get back with ya. I figured a crossover at 100hz on the pio would mean it would drop at 100hz flat.

 

[vili]

Here is a pic with the Pio at a XO of 150hz. Just the mael in the mix.

 

[vili]

Here's something kind of interesting/weird. I have a null at 80hz, well I tried boosting it and of course it didn't effect it all, the definition of a null right? Well I tried cutting it and low and behold it boosted it.

This may sound like crazy talk, but at 0db or at +6 db there is still a null there, but the more I cut it the more it levels out...and I don't mean that everything around it comes down to level out...the null actually reads higher in db with a -13db cut than a +6db gain. Is that not crazy or what?

I also found out that my bedroom door that is in the back of my living room...if I shut it it gives me a null at 50hz, but if I keep it open the null goes away....something else thats interesting! Although I can't boost/cut it...only that 80hz one works that way.

 

[altahometheatre]

The sub looks great! and congratulations are in order for your first child. You better get your bass fix in now because life will change for you after November.

 

[vili]

Hah, I know it! My wife already makes me turn the bass down to next to nothing when watching anything because she is afraid it will hurt something and she doesn't like the way it makes her feel. I can tell her all day long it won't hurt anything, but she won't listen to me so I have to oblige.

 

[altahometheatre]

vili

Did you end up using speakon connectors? I ordered some today. If you used them, did you get 4 connector or 2? And if you got 4 connector, did you wire all four connections?

I have never seen speakon connectors, thus I am a little confused how they work.

Thanks
Darryl

 

[vili]

I did decide go with the speakon connections. I honestly was boggled for a couple of weeks over how to wire it, for some reason it just seemed greek to me. I got the 4 pole connector. Basically if you are going to wire the sub bridged to an amp, go with 4 pole and if you are just using a single channel use 2 pole. My speakon has 2 + and 2 - for wiring with screws to clamp down the speaker cable. I have my maelstrom wired in series so I have one of the positives on the mael to one of the positives on the speakon and then I have that negative and the other positive wired to each other with the final negative wired to the other positive on the speakon. It sounds kind of weird I guess.

Here is a link...maybe it will explain it a bit better. I'm using a crown amp btw.

http://www.crownaudio.com/pdf/amps/126986.pdf

 

[Kevin Haskins]

Looks great.... nice finish job!

The reason you are getting a peak in the measurement is your mic placement. It is 2" in front of the driver so the contribution of the Maelstrom is what dominates the measurement. You see very little of the output of the PRs. Imagine if you stood in front of a speaker at a rock concert and someone asked you how loud the speaker on the other side of the stadium was. That is what your doing with the mic and the PRs are on the other side of the stadium.

The SMS-1 measurement system isn't set-up for doing the type of gated measurement you would need to do a proper close-mic test. It is designed for in-room measurements, where you don't want to gate out the room contribution (that is a large part of what your EQing). Use it per the Velodyne instructions with the mic at the listening spot and you should get a better idea of what is going on.

Oh.... I see why your taking the close-mic. You wanted to confirm the tuning point. Looks like it is right-on if your goal was 18Hz. The FR measurement from there isn't valid though. As I said above, move it back to the listening spot and you get a better idea of the combined response (driver + PRs).

Kevin Haskins
Exodus Audio

 

[vili]

Thanks Kevin. I guess it makes sense that I wouldn't be able to do a proper closed mic since the PRs work too, I didn't think of that.

So far it's awesome, with the wife being pregnant, she doesn't like it up too loud so I haven't gotten to really push it. Hopefully there will be another GTG around me and I can haul this beast to push it and see what it can do.

The front 3 feet or so of my room has that excellent tactile sensation, I may need to build another in order to get it to the rest of the room. That will probably be awhile though and I will probably be in a bigger house by then. I can still feel it at my listening position, but mostly through my furniture actually and thats with a subdude being used to decouple it from the floor. It pretty much eliminated the wall rattling with the subdude. I have buttkickers in my berklines and the maelstrom pretty much does the same thing as them with the seats, I can feel everything through the chairs.

 

[Ricci]

Vili,

If you did want to add another, the XS1200 should be enough to drive both of them pretty well. Did you end up doing a fan mod? I forget.

 

[vili]

I did end up doing a fan mod, I used the same fans that they use for the EP2500. I got the 80mm fans, but apparently the crown used 60mm or something. Luckily, it isn't screwed down or anything and is merely held in by a zip tie (I actually called Crown to confirm this is how they ship the units and they said it is) so I just put the bigger fan in there, luckily the lid still closes on the amp.

I need to mess with the settings to see where I can get the amp to clip with the mael, I feel like even though I'm running it about 6db hot and -10 on my Pioneer receiver that the mael still has a ways to go. Probably sometime this week I'll bump it up to -6 (highest I ever listen) and then play a scene thats recorded hot like kung fu panda skidoosh or WOTW and see how high I can take it before either the amp or the driver start complaining and then back it down slightly. Just so I can get the most from the experience

 

[Ricci]

Just be careful man. That is a LOT of amp for one driver to handle.