# Dual CSS SDX15s Inside Out



## epicentyr

I am starting a sub project with 2 SDX 15's. They will come to 5.25 ft^3 per box sealed. How much batting do I need. I am probably going to use polyester pillow batting from Michaels Hobby Store. See my .pdf to see a very crude drawing of what I have in mind. The driver will fire upward into a sealed box leaving the driver basket and magnet in full view "Inside Out".

View attachment SDX 15 Subs-Model.pdf


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## epicentyr

I forgot the amp is the EP2500. 
1" thick MDF ( I have left over from my factory)


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## Mike P.

I believe the recommended batting is one pound per cubic foot, but I'm not exactly sure. Hopefully someone else will chime in here.


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## thxgoon

Sounds correct from what I remember. What Q are you shooting for? There's a formula somewhere for amount of fill vs perceived box enlargement. I'll have to see if I can find it. Why the inside out design?


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## epicentyr

I have no idea what Q i am shooting for. I used this .pdf as a guide to box size and I ended up in between the 2 larger sizes. 

http://www.creativesound.ca/pdf/sealed-SDX15-131107.pdf

I thought the inside out design would add another design element that a store bought sub would not have. Plus the basket on the CSS SDX series looks better than the cone. I hope to have the pieces CNC cut by this weekend. :yay:


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## Mike P.

I hope you have a camera ready to go for the build pics! :bigsmile:


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## looneybomber

Just know the pole vent is a bit noisey when the excursion goes up.


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## tenzip

looneybomber said:


> Just know the pole vent is a bit noisey when the excursion goes up.


I have zero experience building subs, but how close is the baffle behind the driver? Could it limit air flow through the pole vent? It looks close, but I can't tell. I also don't know how much air moves through there, or if it's even a concern, just thought I'd say something.


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## epicentyr

The vent ends up about 1 1/4" away from the base plate. How loud are we talking. By the time that the excursion is high enough to make noise, I hope that there are other sounds on the movie track.


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## looneybomber

epicentyr said:


> The vent ends up about 1 1/4" away from the base plate. How loud are we talking. By the time that the excursion is high enough to make noise, I hope that there are other sounds on the movie track.


Click the link and watch in HQ
YouTube - SDX-15 video 1
youtube.com/watch?v=ODm5G4nAbOM

It's hard to hear, but when I get behind the woofers, you can hear the mechanical noise. I will say I don't know how noisey it is when it's mounted "upside down" in a box though. I've not tried that.


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## epicentyr

Cool video. I think that the movie or music would be pretty loud to get that kind of excursion to hear the mechanical noise. I wish this was going faster. My CNC has been booked with real jobs and I will have to wait until next week to get my MDF cut.


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## epicentyr

Progress finally!!! The only screws used were in the double thick bottom plate. I will be working on finishing the cabinets this weekend and painting next week.


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## Ricci

You have access to a CNC router! I'm so jealous.


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## Mike P.

> You have access to a CNC router! I'm so jealous.


No kidding! Must be nice! I'll guess this will be a sealed design. What is the net volume going to be?


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## epicentyr

Mike P. said:


> No kidding! Must be nice! I'll guess this will be a sealed design. What is the net volume going to be?


I AM indeed very lucky. I have many DIY projects that would not have been possible without that piece of equipment. 

YouTube - Motoro pair hand feeding.

YouTube - Epicentyr Stingray Bay 4-3-08

some would say I'm NUTS:jump::dizzy::coocoo::dumbcrazy:


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## thxgoon

Awesome! I love the design of the bracing.


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## epicentyr

UPDATES 9/16/08
I just finished 3 hours of block sanding and the first round of a polyester body filler. I am trying to get these as close to the piano black finish on the top of my Rocket 850s and Bigfoot. I am going to try to get the first coat of Hi-build primer on today so that I can do some more block sanding tonight. These things are HEAVY. 

How much is polyester pillow batting in your area? My wife just got a 1.25lb bag for $5 at Michael's. I thought that it would be closer to $1-2 /lb.


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## Owen Bartley

Cool looking project! I'll be watching to see the finished product. You're off to a great start with the CNC cut panels!


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## Mike P.

Looking good! :T Can't wait to see the finished product!



> How much is polyester pillow batting in your area? My wife just got a 1.25lb bag for $5 at Michael's. I thought that it would be closer to $1-2 /lb


Try your local Walmart.


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## F1 fan

Ricci said:


> You have access to a CNC router! I'm so jealous.


As am I.


Nice looking boxes.:T


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## epicentyr

Mike P. said:


> Try your local Walmart.


Thanks for the tip. $15 for a 10# box of polyfill. much better price. 

I have nearly finished one of the pair. I still need to add the brushed aluminum trim pieces. But the finish has come out very nice. I really wanted a high end piano black gloss finish and i think that I have gotten it right on. I think that the few light swirl marks will be a non-issue as soon as I get it out of the blazing factory lights and into my theater. I cannot get the pice off my iPhone until Monday when I am back in the office. I will post pics as soon as I can. 

Side Note: I have decided to call them the Thundercats. ( did anyone else grow up in the '80s?)


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## looneybomber

epicentyr said:


> Side Note: I have decided to call them the Thundercats. ( did anyone else grow up in the '80s?)


Thunder cats, Ho!

Now just add a big Thundercats logo


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## epicentyr

pics as promised. 

I will try to finish this one and get installed pics later this week.


























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## tenzip

Great job! Those will look even better when they start making noise! The finish looks really nice. Got lots of blankets for the move home? What's the final weight?


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## epicentyr

tenzip said:


> Great job! Those will look even better when they start making noise! The finish looks really nice. Got lots of blankets for the move home? What's the final weight?



The finish is better than the iPhone pictures will show. I have already made the move into the theater without a single scratch or smash. I am looking forward to putting them on a scale to get a final weight. I am guessing ~150# with driver. 

Epicentyr


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## epicentyr

11/21/08

Just finished the second one. The first is installed but is still without the brushed aluminum trim as shown in the pictures. I cannot wait to get the second home and calibrate them both. I think i used too much Poly in the first one (10#) so I only put about 6# in the second one. I also threw in a picture of my stingray bar. 

http://www.monsterfishkeepers.com/forums/showthread.php?t=181817&highlight=stingray+bar

and without further ado... Ta da! :R


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## epicentyr

OK guys. No how should I wire this to my EP 2500. I have dual 2ohm VC per sub. My amp is set to mono right now. I have a mono LFE signal going to it. Help is much appreciated. A paintshop type schematic would be great. Thnask


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## thxgoon

Wow nice build! :clap:

The best you can do would be to wire your vc's in series yielding a 4 ohm load and just put one on each channel. You can set the dip switches on the back of the amp so that it will use the signal from one channel on both.


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## tenzip

What he said. ^^^

Wire the + from one coil to - on the other, then use the remaining + and - terminal as your connection points to one channel of the amp. Then hook the other one up the same to the other channel.

One of the DIP switches on the back of the amp will put the amp in parallel input mode. You will get the same signal going to both channels from one input. Not sure which input, so read your manual. May be either.

They do look pretty. We'll need some more pics when all the trim and such is done, and they're in place. Did you get a final weight?


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## Mike P.

Simply gorgeous! Well done! :T


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## mrstampe

Awesome job! What technique did you use to get the piano black finish? Steps, products, equipment, etc? Some endorse waterbased stain or paint sealed with urethane, some use lacquer, brushes vs. HPLV gun. Just curious how you chose to tackle the issue so successfully.


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## epicentyr

Finishing method was quite a lengthy process. I used automotive body filler for any gaps or imperfections. High build epoxy primer sprayed with a HVLP gun. Wet sand with 600 and 1000. Topcoat with black gloss acrylic lacquer from a LVLP gun. Wet sand with 1000 - 1500 - 2000 papers. Polishing with a 3M product that I cannot remember the exact name for on an 1800 rpm orbital buffer. then Meguiers black show car glaze again with the orbital buffer. The physical build of the boxes took about 8 hours over the course of 3 days, but the finishing took about 20 hrs for the pair and spanned over a month because of other projects. I probably have about 36-40 hours into the two of these. They look awesome and sound great.


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## beolson

That Sub box is as nice as they come. How did it end up sounding? I just recently bought a single SDX-15 and I am using one channel of my Behringer EP2500 to power it. My box ... well ... it doesn't look that nice. I am really jealous and hope to hear what you thought of the SDX-15's. Do you end up hearing any of the mechanical noise?


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## Blaser

Great Subs (speakers too!!) :T


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## epicentyr

There is no mechanical noise from the driver. Overall they can shake when they want to, but I still miss my LLT Sono 18". That was amazing.


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## beolson

The reason I ask is because, I seems to hear so mechanical noise and my speaker is built in the "normal" way. Obviously this is only at higher levels. I think I may need a different box. The one I built has its issues. I'll be moving soon and I'm not taking the 27.5" cube box with me. I'll build a newer better one. Good luck with your speakers.


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## Owen Bartley

Very cool design, and great execution. Totally reminds me of the Terminator's brain chip.


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## bassman_soundking

All I can say is "WoW"


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## looneybomber

I don't know what I'm more awestruck about. Your bar (including the rays) or your subs?


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## epicentyr

Thanks guys. The bar definitely gets the most attention from guests. My close neighbors notice the subs more. :R


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## looneybomber

Yeah, I really want your bar now.


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## epicentyr

Hey everyone. Resurrecting a post from 3 years ago here. I just wanted to let everyone know that the subs and bar are now for sale. Subs are $600 ea and the bar is $3500. I am moving and will be ~2 years until I rock the new house with some 18's in SLLT! I am in Grand Rapids, Mi Pickup only. 1616-4four6- one five nine four. 

Epicentyr


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