Sound Splinter RL-p18 Giveaway build thread

**Mongrel714** · **07-21-07, 03:04 AM**

Thanks Sonnie, Quick question, what does everyone use to seal their MDF?? I'll use auto primer last but that stuff is expensive also. So, whats everyones favorite sealer??

**SteveCallas** · **07-21-07, 01:50 PM**

Wow, looks to be coming together nicely

If the port will now be downfiring, you'll want to make sure there is at least 8" of clearance between the port opening and the floor for optimal airflow. If the driver is now upfiring, you'll want to make sure the motor structure won't obstructed by the back walls of the eclosure, as it will be mounted at an agle if I am not mistaken. It's hard to tell how much depth you'll have to mount at that angle.

Lastly, you want a lot of thickness and weight on the baffle - if you are using 3/4" MDF, I'd go for no less than 3 layers. All these things kinda go to show why you rarely see upfiring drivers, but if you can pull it off, more power to you. Can't wait to see the finsihed sub.

**Rodny Alvarez** · **07-21-07, 03:04 PM**

Quote:

Mongrel714 wrote:

Thanks Sonnie, Quick question, what does everyone use to seal their MDF?? I'll use auto primer last but that stuff is expensive also. So, whats everyones favorite sealer??

Are you going to paint the box with base coat and clear??

I used Omni build up primer from PPG, its not to expensive and it works well, I don't know of any other stuff that you can use if you going with the base/clear coat.
You probably know the you need to fill all the gaps before spraying the primer, and one more thing.......I think the box needs more braces!

**Jerm357** · **07-21-07, 08:24 PM**

Definitely needs more braces.

**Mongrel714** · **07-21-07, 10:14 PM**

Here's some progress pics, and a brace detail, let me know if this will work, feel free to take the drawing
and add what you think it needs, Steve, looks like I'll be making more legs as the set I made yesterday only have 4" clearance, no prob though, also I have 25" to play with on speaker mounting. I will pull this off all though with the heat down here its ROUGH!! worked all day and came in this afternoon and passed out for a couple hours, but I will be hearing some bass by tomorrow night!!

**brucek** · **07-21-07, 10:28 PM**

Really looks great. Very inventive.

Quote:

If the port will now be downfiring, you'll want to make sure there is at least 8" of clearance between the port opening and the floor for optimal airflow.

Wow, 8" is a lot. If he had mounted the driver on the bottom, would it have required that much space - I always wondered that?

brucek

**Mongrel714** · **07-21-07, 10:47 PM**

Thank you Brucek, Since I have 4" legs I'll test it with them and see how they do, if I don't here any noise its going to be hard to change them.

**Mongrel714** · **07-21-07, 11:34 PM**

Quote:

Rodny Alvarez wrote:

Are you going to paint the box with base coat and clear??

I used Omni build up primer from PPG, its not to expensive and it works well, I don't know of any other stuff that you can use if you going with the base/clear coat.
You probably know the you need to fill all the gaps before spraying the primer, and one more thing.......I think the box needs more braces!

Thanks for the info Rodney, I'll try the PPG primer, Also,I have regular wood filler, and fiberglass body filler, which should I use to fill the cracks on th enclosure? and BTW, fantastic job on Sonnies cabnet, I've been drooling over that for a couple days.

**Sonnie** · **07-21-07, 11:40 PM**

I don't think it matters as much on the driver clearance, otherwise there are a ton of subs out there that are troubled, including my Behemoth and both of my SVS Plus/2's, which have a very few inches of clearance. I assume the port has to have more clearance because with its limited space it moves more air than the area in front of the driver. Of course the technical savvy can elaborate further.

**SteveCallas** · **07-22-07, 12:39 AM**

Don't need much clearance for the driver, as it is an 18" diameter radiating surface - the volume of air displaced is easily diffused. With the 8" diameter port, it's not as easy, as pressure is higher, making it more prone to experience turbulence. By all means, you should be fine with the 4" clearance at most listening levels, but with deep bass at spirited levels, when the port is being put to good use, you may hear some weird sounds.

How many layers are you planning on for that baffle?

**Mongrel714** · **07-22-07, 01:07 PM**

Steve, I'm going to have 2 layers on the baffle plus any extra bracing I can add once I start putting it together, (hard to say untill you actually see the interior), and Jerm, hope you don't mind, but I'm gonna steal your side bracing idea also, seems like it will be a big help.

**Rodny Alvarez** · **07-22-07, 01:33 PM**

Quote:

Mongrel714 wrote:

Thanks for the info Rodney, I'll try the PPG primer, Also,I have regular wood filler, and fiberglass body filler, which should I use to fill the cracks on th enclosure? and BTW, fantastic job on Sonnies cabnet, I've been drooling over that for a couple days.

Thanks for the comments!!

I always used bondo to fill the cracks, holes and sanded it pretty smooth before spraying the primer then I spray two coats of primer, for the first coat I used 80 grit sand paper, the second 120 grit if I'm using the texture (400 if I'm using base/clear coat) after that I spray it with texture paint to make it look like plastic, the texture paint is black but you need to paint it with some vinyl dye paint, if you're still going with the base/clear coat, you spray the base after the second coat of primer and then the clear

Make sure you cover the entire box with the primer!

A lot of work my friend!!

Good luck!!!

**SteveCallas** · **07-22-07, 02:01 PM**

Boy, I'll bet I'm sounding like a real pain in the

Is it too late to add another layer (or two) to that baffle? Doesn't even have to be MDF, it can be cheapo OSB if you prefer. You just want to have as much mass on that baffle as possible, especially in this case with a large baffle, a "box" enclosure, and not exactly a whole heck of a lot of rigidity at the top. You definitely don't want enclosure resonances to show up once it's done. It's worth the extra work and a couple more bucks now.

**brucek** · **07-22-07, 03:04 PM**

Quote:

You just want to have as much mass on that baffle as possible, especially in this case with a large baffle, a "box" enclosure, and not exactly a whole heck of a lot of rigidity at the top.

But isn't a double layer plus the braces (see arrows) enough? What are your thoughts on how it's different from a normal box?

brace.jpg

brucek

**SteveCallas** · **07-22-07, 03:29 PM**

I honestly don't think two layers is enough for a high excursion 18" driver. That baffle is pretty large, I'd guess maybe 36"x36" for ~1300 square inches? In a comparative sonosub design using a 28" diameter baffle, there is less than half as much surface area, and typically 3-4 layers are used for the baffle. Now while more surface area means less pressure per square inch, it also means it is more likely to flex or resonate for a given thickness of material. The braces will definitely help, but considering how cheap a sheet of OSB is, I wouldn't take any chances. Always better to overdo it now before it is completely assembled, because you could end up kicking yourself over $16 and another hour or two of work when it's too late.

**Rodny Alvarez** · **07-22-07, 03:50 PM**

Steve!!!!!
that will be to much weight to take off!

Slide1.JPG

**Mongrel714** · **07-22-07, 04:15 PM**

Quote:

Rodny Alvarez wrote:

Steve!!!!!
that will be to much weight to take of!

Attachment 3933

Oh wow, Rodney, I can't believe you figured it out! I'm using liquid hydrogen of course! But really, if I add any more height I'll have to cut a skylight out in my ceiling! but, I will lay some flat 2" x 3/4" bracing along the inside of the baffle also. and what about some sound deadening spray on the inside, I know they make it for automotive applications, and Rodney, thanks for the primer 101 info, its greatly appreciated!

**SteveCallas** · **07-22-07, 04:24 PM**

Quote:

Rodny wrote:

that will be to much weight to take of!

Lol.

You don't have to add any height, add the extra layer or two underneath the extrenal baffle layer. You'll lose a small amount of internal volume, but I think it would be worth it.

**Mongrel714** · **07-22-07, 11:26 PM**

Ok guys, after 10 hours and near heat exaustion today heres the "Monolith" alpha build, My son and I had a great time getting this thing inside the house, an Art clean box is in order, allthough I read somewhere that a BFD will boost the input voltage also, even though I don't have the output I should have, this sub will vibrate your pants from anywhere in the room, I can hear and feel bass everywhere I stand before you had to pretty much stand on the onkyo sub to feel bass, I'm very happy so far! but now I must SLEEP, talk to ya later.

I retract my earlier statement on hearing the lows all over the living room, I hear them all over the house! in the kitchen, bathrooms, bedrooms, its awesome!

OK Monolith has been taken, I'll come up with something good and Geeky here soon.

**SteveCallas** · **07-22-07, 11:39 PM**

It's a beast, way to go. I'd avoid the cleanbox unless you want to mod it, as it has severe low end rolloff.

**Sonnie** · **07-23-07, 12:50 AM**

Lookin' good...

Yeah... check out this thread on the ART CleanBox.

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