7.6 cu.ft Maelstrom- X 18" build

[sub_junkie]

My Uncle and I have started working on my box. It will be around 7.6-7.8 cu.ft after bracing and everything is accounted for. There aren't many pictures becuase it is only about half way done. I will hopefully be getting more before it is done, and with the driver installed and in my room.

The box dimmensions are 48" tall and 20" deep and wide. We will have two window pane style braces. One near the top of the port about 2 inches away, and one about 5 inches above the driver. We will be runing a strip of thin wood between these two braces to help keep those braces "braced." lol.

The port is 18.50 inches wide, 2 inches tall, and 55 inches long. The length is divded into two parts, one 34 inches long, and another is 17 inches. There is a 45 degee piece of MDF that will go between these two pieces of wood which will keep the port at two inches from the back wall; I don't remember how long that one was though. There is also another 45 degree piece of MDF that is on the bottom of the port so that it will have better air flow. That also was cut the right length to keep the two inch spacing correct.

Drawing everything out first:



The cut outs ready for nailing and gluing:





The 45 degree angle for 17 inch part of the port:



Don't remember what this one was for, just looks like another cut out picture:

IMG]http://i536.photobucket.com/albums/ff323/airsoftsniperm4/UTGM324Gen3forSale034-1.jpg[/IMG]

Assemblig the slot port:





Roundover on the top of the port:



Port exit. The lighter piece of wood is for a better screwing place for the front pannel, as it will be just screwed on so it will be easier to maintain if needed. I will make sure that the holes will be pre-drilled so the wood won't split, although I am pretty sure my Uncle already knows this becuase he is a very experienced wood worker.

The port exit will have a roundover to help with chuffing and port noise.



A quick look at a Ford Ranger Pre-Runner by my house. They have around $150,000 tied up in that easily.







There is one neat thing that we might be doing for this box. Since the Mal-X wieghs in around 50 pounds we will be taking 1/2 inch steel and making a mounting ring that will go on the inside of the box, right where the mounting screws will be, so the screws have extra strength to support that weight. Hopefully, we will have it done, but my Uncle is really busy and might not be able to get that finished. We might be spraying on a bed liner to protect the box, but I will have to see how much it is first. Otherwise, I will just go with Flat Black. It will have a small roundover on all outside edges of the box to keep it from splintering if it hits a wall, of something, and it just looks better to boot.

Any questions or comments are welcome.

That's about it for now. More to come later.

[robbo266317]

Congratulations on finally getting underway, I'm sure you won't be disappointed as I'm still amazed at what the Shiva 12 can do in a big enclosure. Gotta love that Toccata & Fugue.
looking forward to more pics.
With the mounting ring are you going to tap it and use bolts to mount the driver?

[Jugix]

Nice, you got things going, eh.

So I threw the data in the unibox and it says you are going to end up with 14,6Hz tune when box is 7,6cf (215L). Pretty nasty port resonance just after 100Hz though.

[Mike P.]

The first port resonance is 114 hz which may not be an issue since the port is folded. If it does cause an issue he can always use a lower crossover point.

[sub_crazy]

Nice to see you got the build underway.

What are you going to use for a high pass filter?

I am most interested to see how it turns out as I still have another Mal-X sitting in the box waiting to be used and abused.

Have fun.

[sub_junkie]

robbo266317 wrote:

Congratulations on finally getting underway, I'm sure you won't be disappointed as I'm still amazed at what the Shiva 12 can do in a big enclosure. Gotta love that Toccata & Fugue.
looking forward to more pics.
With the mounting ring are you going to tap it and use bolts to mount the driver?

I listened to Toccata and Fugue with my current sub, and needless to say, it was very overwhelmed.
The steel plate will be cut with a Plasma cutter as far as I can remember, and it will be tapped and I think we will use bolts. Not sure about that yet though.

Jugix, thanks for the graphs. When I modeled the slot port in WinISD, it said that the maximum port air speed was 26 or 29 m/s. I don't have WinISD on me right now, but will check again when I get back home. I am currently at Texas for my Grandpa as my dad, mom, and I drove his motorhome down for MD Anderson Cancer Treatment.

sub_crazy, I will be using a Reckhorn B-1 for the HPF, and a EP2500 in bridged mono as the amp. I will have a modest HPF set as not to stress the driver too much, and I will keep the levels down some
Didn't the EP2500 put out around 1900w in bridged mono operation?
Also, is the mounting cutout still 16.6 inches as the notes on Diycable says it is?


Thanks

[sub_crazy]

You ever thought about using the ED eQ.2 instead of the Reckhorn? It is about $25 more but adds 2 bands of EQ along with the subsonic filter. I used one for my brothers set-up and for the price works well.

There was a place were you could get a refurbished eQ.2 for about $75 but I don't recall the site. If anyone knows the site for the refurbs could you post it here as I would not mind picking one up myself.

[sub_junkie]

I would get the eQ.2, but it doesn't have the input voltage boost which I would need cause my receiver only puts out 1v for the pre-out channel

Thanks for the suggestion

[sub_junkie]

Some more pictures. I have a feeling I am going to love how it will sound.









That's my KLH 10" driver next to the Mal-X. Pretty big comparison lol







I am going over to my uncle's tonight and will hopefully have the box finished, except for the truck bed liner. More pictures to come then also

Thanks again for all of the help everyone

[sub_junkie]

Finally got the box finished. It will be painted soon, just didn't have time last night as my uncle and I fnished it at 2 am.

Posting pictures in a litle bit.

The sound quality is awesome. I can' believe how low it goes. But, my current amp clips horribly at high volumes, and sounds like the driver is bottming out, but, of course it's not
On Down 4 Tha Krown, is hits harder and lower than my brother in law's truck that has two Kicker COMP C10's on the Kicker 200.2 amp. His can go louder than mine right now, but it's becuase my amp clips up loud.
Quick question; I have 2 inch thick Egg Crate foam grey colored, and was wondering if it is open cell or closed. When I pore water on it, it just absorbs it like a sponge, but if I take off about an inch of thickness, it goes right through it. Does this mean that it is open cell?

Thanks

[sub_crazy]

Are you using the EP2500? Do you have the HPF in already?

I wouldn't run it too crazy without the HPF yet as you could do some damage

It is a excellent sub which I use in a sealed enclosure and blows me away. I can't imagine how crazy it must sound in your ported box.

Head the warning of the HPF though as I have read of someone already toasting his Mal-X

[Mike P.]

Your egg crate foam is open cell. Looking forward to the pics!

[sub_junkie]

sub_crazy wrote:

Are you using the EP2500? Do you have the HPF in already?

I wouldn't run it too crazy without the HPF yet as you could do some damage

It is a excellent sub which I use in a sealed enclosure and blows me away. I can't imagine how crazy it must sound in your ported box.

Head the warning of the HPF though as I have read of someone already toasting his Mal-X

No, I'm still just using the Yamaha 150w plate amp. It does appear to have a pretty high HPF sadly enough.
I wouldn't use an amp that could damage the sub without a HPF on it.


I will be installing the foam tonight. What will it change for the sound? Just make it go lower?

Thanks

[mdrake]

GREAT JOB so far!!!!!!!!!!!
Driving the amp into clipping is not exactly healthy for the Mal-x and making noises is even worse.
Be careful!

Matt

[sub_junkie]

Thanks for the kind words

As soon as I heard the noises, I immediately stopped. I am taking it easy now
Why would clipping be bad for the Mal-X also?

[sub_junkie]

Some more pictures:

I found out that pictures do this driver no justice at all...



Cutting the holes for the braces:




Me cutting those holes:



The finished brace. We rounded over all edges of the wood and used sand pape to make it more smooth to keep airflow good:



We put a little crossbrace to help keep the two braces from vibrating too much:









Siliconing around the port and in the inside back of the box:







The braces installed. We rounded over all edges of the wood and used sand paper to make it smooth to keep airflow good:














The top braces is about half an inch away from the top of the port, to keep the airflow smooth:



Test fitting the driver:









Temporary bolts until it gets painted. We used T-nuts to keep it secured:





The box in my room:





I wish that there would be a way that I could make the box around 13 cu.ft and keeping the same dimmensions. But, that's the way it goes. Hopefully it will REALLY shake the walls when I get a new amp? lol. It's already impressive with the current amp, but I can't imagine what it will be like with the EP2500 and the Reckhorn B-1.

Hopefully this is a good build thread haha.
I will post pictures of the foam when I get it in the box.

Thanks again to everyone for the help.

[robbo266317]

It looks like it's all coming along nicely. Well done.

[sub_junkie]

Thank you

[sub_crazy]

Nice!

Just a tip on using T-nuts. Use some Gorilla glue to keep them secure as they always seam to back out or lose there grip on the MDF.

[Mike P.]

It appears you used washers and the mounting bolts are on the outside of the rubber ring. Remove the washers and screw the bolts down to the subs metal frame. You should also use some foam weather striping between the rubber ring and the box to ensure an airtight seal.

[sub_junkie]

Alright, I'll fix the bolts. I'm pretty sure we just did that until we got it painted, then we are going to use other bolts that blend in better.

Thanks for the help.

[sub_junkie]

Got the foam installed. Might cut some down and put it all around the braces.

[sub_crazy]

sub_junkie wrote:

Alright, I'll fix the bolts. I'm pretty sure we just did that until we got it painted, then we are going to use other bolts that blend in better.

Thanks for the help.

The mounting holes on the Mal-X are bigger than normal so make sure you check the fit before mounting or the driver will work its way loose. I actually use small washers that are not visible from the front but secure it better.

[sub_junkie]

Ok. The current bolts barely fit in the mounting holes for the Mal-X. I also used a bit of Blue Lock tight to keep it all tight.

Thanks

[robbo266317]

If you use hex bolts it looks better and they have round heads that fit into the frame better.
Like the ones in the bottom of this picture from http://www.made-in-china.com/showroo...-Hex-Bolt.html