# Creative Sound Solutions SDX10 Sub Kit



## Mike P.

I had been thinking of building a small sub for the A/V system in our work out room at home. Space is limited so it had to be a small sub. The sub will be used for 50/50 HT and music, so a ported sub is what I wanted. CSS had just introduced a line of small subs with Passive Radiators, and after looking over the various kits, I choose the QUARTET10 subwoofer kit.
The kit comes with the SDX10 subwoofer, 2 APR 10 Passive Radiators, a 300 watt Bash amp, 4 cabinet spikes, and all mounting hardware. The kit is priced at $379, a quick check shows the individual parts total $475, the kit is definitely an excellent value. I ordered the kit and 4 days later it arrived. The kit arrived in two boxes.









The first box contained the amp, the chart of boost tables for changing the high pass filter, the cabinet spikes and the mounting hardware.









The second box contained the SDX10 subwoofer and the two 10 inch Passive Radiators.









The PR's were well packaged, with recessed firm foam top and bottom protectors to prevent the PR from moving around in the box.









Each PR comes with 20 45 gram tuning washers, a lock washer and a wing nut to hold them in place.









The SDX10 was equally well packaged, with the same firm foam top and bottom protectors.









Here's a couple pics of the sub. It's well built and the quality shows.
















This is everything the kit comes with.


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## Mike P.

Here is some modeling of the sub. The recommended cabinet size is a cube with an external measurement of 18 inches, so the net volume will be 66 liters or 2.3 cu.ft. Adding 270 grams of mass to each PR will tune the cabinet to 22 hz.








Here is the SDX10 cone excursion with 300 watts input, a high pass filter at 20.4 hz, and 1 db of boost form 31 to 35 hz. 








Here is the Passive Radiator excursion.


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## Mike P.

The next month or so will be busy for me with work and family commitments, hopefully by the middle of March I'll be able to get this project going. I'm definitely looking forward to it. :yes:


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## salvasol

Congratulations!!! ...:T

I'll be waiting for your new build thread :yes:


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## Canadian_Dude

What are the box dimensions you are going to use?


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## Mike P.

I haven't got that far yet. I still need to find out the displacement of the sub and PR's.


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## Rodny Alvarez

I have the same sub in my truck, tuned to 28hz with 300 watts and it rocks, by far the best sounding sub that I have heard, really nice subs, I'm thinking about doing a 15" for my living room:bigsmile:.

Cant wait to see the results!!

Good luck!:T


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## Mike P.

Finally got some work done on the sub. Dimensions worked out to a 18 inch cube. Here's a couple pics of the box. All cut outs done and Hurricane nuts installed.
















I mounted all the components so I could figure out the bracing.















I used hot glue around he perimeter of the Hurricane nuts to ensure they don't come loose. Although I've never used it, Gorilla glue works well also from what I've read.








Some general pics of the sub.


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## Rodny Alvarez

Nice!!!:T

That looks like a nice set up, cant wait to hear your thoughts!!:hsd:


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## tcarcio

Looks great.....:T


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## ironglen

tcarcio said:


> Looks great.....:T


I 2nd that! Really want to see how you decide to brace it with the four walls occupied.


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## Mike P.

Bracing made easy. Use the width of the wide end of a framing square to draw a "I" on a 16.5" x 16.5" square.















The cut out brace.








The brace installed on the driver and amp side.








Add 4 pieces from the center of the "I" brace to the top and bottom of both PR sides.


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## Mike P.

Cabinet lined with egg crate foam. This is my own personal choice, the foam is not included with the kit. The purpose (supposedly) is to damp the back wave of the sub so it doesn't have a "hollow" sound to it. Some people say it has no effect on the sub, some say it does. More testing is needed to verify the benefits or lack of. I have always lined my subs with foam, this one is no exception. 








Foam has to be cut away from the Hurricane nuts. If not, the bolt will snag the foam and the foam will wrap around the bolt and cause binding.


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## Pinhead-227

That's some pretty impressive work there. One question about the bracing, wouldn't it be advantageous to support the PR's with a brace between the two to cancel out each others' vibrations?


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## jmuir

Looks good Mike!


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## Mike P.

> wouldn't it be advantageous to support the PR's with a brace between the two to cancel out each others' vibrations?


Since the PR's are mounted opposed to each other I don't think vibration will be an issue.

I have the cabinet completed and all components mounted for a test run.








It's time to tune the Passive Radiators. The sub design calls for 270 grams to be added to each PR. The PR's come with twenty 45 gram washers, so 6 washers need to be added to each PR. With the CSS PR's tuning couldn't be simpler. First unscrew the cap on the PR's center tube.








Add the required washers.








Tighten down the supplied lock washer and wing nut.








Replace the center cap. It's that simple! 








With 270 grams added to each PR the box tuning will be 22 hz. Since changing the weights on the PR's is external, I be experimenting with different tuning just because it'll be so easy! :T Listening test will be next.


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## ironglen

Thanks Mike for taking the extra time to share your progress with us! (Makes contemplating a build easier as well as great ideas)


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## Mike P.

I did a quick listening test on the sub. Testing was done is a 15' by 30' room that is open to other areas. I must say I'm impressed! Music was a Celine Dionne CD that has some demanding bass tracks. The sub had no problem producing loud levels in such a large room. Test tones from 15 hz to 80 hz show what this sub can do. This little guy digs deep! The sub was not corner loaded, it was in the center of the 15' wall and about 2 feet away from the wall. Very impressive performance for a 10 inch sub. I will post a frequency response vs. SPL graph as soon as I get a chance.


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## Sonnie

I am beside myself. That is one very nice kit and your work is super impressive... :T

Now... the "workout" part... I don't know if I am buying that. :whistling:


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## Mike P.

I did some SPL tesing today to see what the sub is capable of. The sub was placed in a corner of the room with the SPL meter one meter away on a tripod stand. I used the R.S. 33-2055 Digital Meter and applied the correction file to the readings.

10 hz - 104 db
12 hz - 106 db
16 hz - 101 db
18 hz - 103 db
20 hz - 104 db
22 hz - 100 db
25 hz - 102 db
30 hz - 103 db
35 hz - 108 db
40 hz - 113 db
45 hz - 110 db
50 hz - 103 db
55 hz - 101 db
60 hz - 98 db
65 hz - 96 db
70 hz - 95 db
75 hz - 96 db
80 hz - 95 db

The SPL meter was set to fast response and "C" weighting. The effects of room gain are obvious in the 10 -12 hz range, as well as a room interaction issue in the 35 - 45 hz range. I'll get REW setup on my laptop and post a graph, hopefully next week when I get home from work. All in all, I'm impressed with the performance of this 10 inch sub.


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## robertcharles123

The way the mass is loaded is fantastic. That is a truly unique design. Nice job on the build. 

Good luck,

Robert


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## Wildcard26

I am impressed with just the look of that little bad boy. Cheers!


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## Owen Bartley

Mike, you work fast! I almost completely missed this thread! I knew about halfway through that you would be happy with this little sub, it really is impressive for a 10 incher. Great work on the design and build. I can't wait to see it finished and with the spikes.


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## Mike P.

Yes, I'm very impressed with this sub. After seeing Rodny's fantastic piano black finish, I'm not sure how I'm going to finish mine. Maybe I'll do a "Canadian Piano Black", spray on truck bed liner! :bigsmile:


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## Ricci

robertcharles123 said:


> The way the mass is loaded is fantastic.
> 
> Robert


+1. That's really convenient.


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## Rodny Alvarez

Mike P. said:


> Yes, I'm very impressed with this sub. After seeing Rodny's fantastic piano black finish, I'm not sure how I'm going to finish mine. Maybe I'll do a "Canadian Piano Black", spray on truck bed liner! :bigsmile:


Just pay the shipping round trip and I"ll painted for you!!:bigsmile:


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## Pinhead-227

Just one question, what is the advantage of PR's versus ports? According to WinISD, with the exact same box size, using the same sub, the ported enclosure beats the PR enclosure all through the freq range. What am I missing?


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## Mike P.

Apply the HPF on the models so the cone excursion is the same and ported has a 1 db advantage which is unnoticeable. What caught my attention with the CSS kit is the PR's are externally adjustable, I can change the tuning depending on how the sub interacts with the room.


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## Pinhead-227

Ah, I see. Other than that, though, nada?


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## Mike P.

You get a slightly smaller box since the PR's displace less than a port, no port noise, and it looks cool! I have read that some people prefer the sound of a PR compared to a ported, I haven't had enough time with the sub yet to see if there is a difference.


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## fredk

Your measured output is amazing. How do you get that sub playing flat to 10Hz when, in modelling, it has output that falls off a cliff at around 23Hz??


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## Mike P.

That's the effect of room gain, which are specific to the room I measured the sub in. Bear in mind the sub was corner loaded and the SPL meter was one meter away. This was just a test to see what the sub would do. I'm hoping to post a REW graph next week when I get home from work.


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## Owen Bartley

Mike P. said:


> Yes, I'm very impressed with this sub. After seeing Rodny's fantastic piano black finish, I'm not sure how I'm going to finish mine. Maybe I'll do a "Canadian Piano Black", spray on truck bed liner! :bigsmile:


Yeah, Rodny's piano black really put us all to shame. :foottap: Is that a bannable offense!? Can someone at least put him on probation for outclassing us like that? :whistling:


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## Mike P.

Here's a quick update. All holes filled and sanded, 3/4 inch round over done to all edges and final sanding done.
















First coat of sealer done. I'll do a second coat later on tonight after this one dries. Tomorrow hopefully it'll be warm enough outside so I can paint the box. I have all the parts cut and glued together for the grills and will start on that tomorrow as well.


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## Rodny Alvarez

looking good Mike!!!!:T


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## Owen Bartley

Yeah, it looks great! Are you going to cover the PR's too, or will they be left exposed? I guess since you said "grills" you're building more than one. Either way, I like the roundover all around.


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## Rodny Alvarez

Mike, did you used the wood putty or the bondo to sealed the holes?


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## Mike P.

I had to use wood putty as it was too cold outside to use the bondo. (I don't have a shop)


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## Mike P.

Got the grills done. Since the sub and PR's are surface mounted the grills are simple to build using a "friction fit" method. First glue two pieces of MDF together and cut a circle 12 inches in diameter.








Round over the out side edge.








Cut out the inside of the grill just a hair smaller then the diameter of the sub and the PR's. A few minutes of hand sanding the inside ensures a perfect fit.








Grill frame sanded and painted black.








Grill cloth attached to frame.








Cabinet painted and components installed.








Grills installed.


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## Owen Bartley

Mike, that's a good lookin' cube. Are the grills pretty snug on there? No worry they'll rattle loose? How do you have it set up in the room... is the non-driver side facing a wall? Would there be any negative effects of one of the PR's facing a wall if it was placed in a corner?


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## Mike P.

There's no chance of the grills rattling loose, they are on so tight they have to be pried off. I currently have the sub set up in the living room as shown below. Once the sub is moved into the work out room it's place will be a a corner. The sub will sit 45 degrees to the corner so no PR is firing directly into a wall.


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## Ricci

Nice work on the grills there Mike.


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## Mike P.

Thanks. They are on tight, no rattle issues whatsoever.


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## focusrocker

Great looking build. I just ordered the kit. I am still interested in more listening impressions. Does it provide enough output to feel in your chest? How well does it blend with your speakers. These are my main concerns. I really want it to sound tight and snappy with enough output to feel.


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## Mike P.

I'm away at work until next Tuesday, then off to a family gathering for 3 days. Then I'll be able to give it a good workout and post my impressions.


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## Muzikal-JRNE

Great build Mike, thanks for documenting it! I have a few questions about your project, as I am getting started on doing my first DIY home subwoofer build.

(1) What grit sandpaper did you use?
(2) Did you sand the sealer coat.
(3) Can you roll on the sealer coats or should they be sprayed on?
(4) How many coats of the black bed-liner paint did you do?
(5) Did you cover the hurricane bolt holes while painting.
(6) Did you support the box through one of the speaker holes so you could paint all faces of the box at once? 
(7) It looks like you used screws to secure the panels together while the glue set. What type/size fasteners did you use, and were there any issues with them interfering with using the router to do your 3/4" round-over an the edges.

Sorry to inundate you with so many NOOB questions, but your build looks very nice and I want to give it my best effort for my build to look as clean as yours. All of my previous experience has been with car subs where I could cover all of the box imperfections with carpet. 

Cheers, Joe


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## Mike P.

1. Initial sanding was 80 grit, then I finished with 180 grit.
2. No.
3. I used a roller and a brush. The sealer was a latex primer.
4. 2 coats. Make sure you spray it on evenly, it is noticeable if the liner is thicker in some places.
5. Yes.
6.No. I sprayed 5 sides, let them dry and then sprayed the bottom. I used a spray can, it had to held upright. 2 cans did a 18 inch cube and I put it on thick.
7. I use screws and glue due to a lack of clamps. I used coarse thread drywall screws 1.5" long. You have to pre drill the holes or the MDF will split. I countersunk them 1/4 inch so not to cause problems with the round over bit. The holes were filled with wood filler, sanded down with 80 grit, and wood filler applied a second time as it shrinks. 

http://www.onlinedrywall.com/PhotoDetails.asp?ShowDESC=N&ProductCode=1+5/8+COARSE


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## Muzikal-JRNE

Thanks for the info Mike, you have been extremely helpful! :yourock:


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## sub_junkie

What is the dimmensions of the room that you did the frequency tests in? Hopefully, my 13x13 room will be similar, if not have better room gain... :bigsmile:


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## Mike P.

15' x 30' living room/dining room that is open to other areas.


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## sub_junkie

So, considering that my room is much smaller, and not open to other areas, besides a small closet, could I expect similar room gain??


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## Mike P.

Probably, but no guarantees. How a sub reacts is different for every room. That would be another Christmas gift you can ask for, a SPL meter.


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## sub_junkie

That's what I was planning on doing :T
How did you know? haha


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## Barumba

Mike P. said:


> You get a slightly smaller box since the PR's displace less than a port, no port noise, and it looks cool! I have read that some people prefer the sound of a PR compared to a ported, I haven't had enough time with the sub yet to see if there is a difference.


I have a quote to help explain the difference/advantages of the PR vs Port. It helped me make up my mind when I was deciding on my project, but not sure if it is OK to post it here. The dialogue is from another forum. I could quote it, but I think it appropriate to give credit to the source.
Is it OK, or should I drop it? Sorry, guys, just want to stay within the forum guidelines.

Thanks, and Cheers!


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## fackamato

Barumba said:


> I have a quote to help explain the difference/advantages of the PR vs Port. It helped me make up my mind when I was deciding on my project, but not sure if it is OK to post it here. The dialogue is from another forum. I could quote it, but I think it appropriate to give credit to the source.
> Is it OK, or should I drop it? Sorry, guys, just want to stay within the forum guidelines.
> 
> Thanks, and Cheers!



Forum guidelines? :coocoo: 

Quote and give source + URL :T


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## Barumba

Some tips and explanations on PR vs Ported subs... source http://www.diysubwoofers.org/prd/
"Passive radiator systems are very similar in operation to ported systems. However, instead of a port, the passive radiator system uses a passive radiator (also known as a "drone cone") to extend the system's low frequency response. 
The response of a passive radiator system is similar to that of a ported system using the same driver. However, the cutoff (-3dB) frequency is slightly higher, and the cutoff slope is deeper, mostly due to the presence of a "notch" in the frequency response corresponding to the passive radiator's resonance frequency. However, this notch is normally located far outside of the passband of the system, and therefore usually of little audible significance. The larger the passive radiator, the lower the passive radiator's resonance frequency (for the same target Fb), and the further the notch is out of the passband."
To design a passive radiator alignment, start with a simple ported alignment using that driver that provides the desired box size and frequency response. Then, use the diameter of your chosen passive radiator as the "port diameter", and use this to calculate the required port length. Work out the volume occupied by this port and then use this to calculate the mass of air occupied by this port. The result is the required mass of the passive radiator. If it is too small, use a larger passive radiator and repeat the calculations.

Example:

Driver:
Vas: 2 cu.ft.
Qts: 0.30 
Fs: 30 Hz
Diameter: 8 in.

Ported Alignment (QB3):
Vb = 0.70 cu.ft.
Fb = 39.4 Hz

Now, we need to select an appropriately-sized passive radiator. ALWAYS use a passive radiator that is larger in diameter than the active driver, as the displacement of the passive radiator usually has to be 1.5 to 2 times that of the driver. If it's not possible to use one large passive radiator, then you can use two or more smaller ones, and tune them by working out the effective diameter from the combined surface area of the radiators. 

Note that the effective diameter of the radiator is approximately equivalent to the diameter of the passive radiator's face plus 1/3 of the surround. If unsure, use the quoted Sd for that radiator, then use the following equation to determine the effective radius:

R = (Sd/PI)^0.5

In this case, we choose to use a passive radiator that has an effective radius of 5 inches (roughly corresponding to a "12-inch" passive radiator). 

"Port" Radius = 5 in.
Required Port Length = 186.1 in.

"Port" Volume = (PI*R^2)*h 
= (3.14 *5^2)*186.1
= 14609 cu.in. = 8.45 cu.ft. = 0.2393 m^3

Mass = "Port" Volume * Density of Air
= 0.2393 * 1.21
= 0.289553 kg
= 290 g

The passive radiator therefore has to have a weight of 290g. To achieve this, start with a passive radiator with lower mass, then add weight to make up the difference. To measure the resonance frequency of the passive radiator, install it in a free-air baffle (e.g. the box it's going in, without the driver in place), then hold a driver, driven by a sine wave generator, as close as possible to the passive radiator, then vary the frequency. At the passive radiator's resonance frequency, you should see the greatest peak to peak excursion of the passive radiator.

Like their ported cousins, passive radiator systems are much more sensitive to misaligned parameters than sealed enclosure systems, which makes their construction more difficult for the beginning DIYer. I advise that you don't attempt to build these systems, unless you're certain that the T/S parameters for the driver that you want to use are correct. 

Almost any driver can be used in a passive enclosure system, however, only drivers which have a Qts value between 0.2 to 0.5 will generally give satisfactory results. If the driver has a Qts above 0.4, try using it in a sealed enclosure or single reflex bandpass system instead."

I found this quite informative, and based my decision on going with the PR on this advice.
I hope this is of some help. And like Mike said, they look cool!:T


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## Mike P.

Regarding tuning PR's, a inconvenience in the past with conventional PR's was fine tuning the resonance frequency which involved taking the PR out of the cabinet and adding the mass to the back side. Now, with the CSS APR's, you simply add or subtract washers to the front side, it's so simple. 

I'll be rebuilding my wife's music sub this fall (her request :T) that has a Mach 5 Audio IXL-15. I'll be using a pair of the CSS APR 15's to adjust the response to suit her tastes since she likes a "thump" in the 30 hz range. It will be as easy as removing washers and raising the tuning to get it where she wants it.


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## Barumba

That is definitely a handy feature, having the weights in the front. If I move my box to the TV room downstairs, I'd have to re-tune. That would mean removing the PR, adding or removing weights, then re-assemble.


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## Mazza

Hi there, I am considering this Kit but want to have a Sunfire True Sub kind of mini cube look, mainly because I don't have the space in my living room. I've built several subs over the years but this would be my first PR implementation. I have used Boxplot over the years but does not handle PR's. Can I simply shrink the cabinet to the kind of size I'm looking for (11"x11"x11" external) and still get a decent result? :dontknow: I have an RB 1092 to power this (thinking of building two, 1 for each channel) so I would not use the plate amp and therefore save some internal volume.


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## ISLAND1000

I just found this build Mike. What an excellent project and what excellent assembly and finish. 
Your presentation is clean, articulate, and has all the necessary pictures and explanations needed by a "newby" to do a good job on their own same project. I especially liked the picture where you have carefully lined up all the components including the bolts in a fashion show. LOL
You've become THE man to go to for sub info on the web. Congratulations.


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## Badbob

I know this is an older thread and hope it's alright to post to it. I am new here and found this thread fasinating. Quite a work of art as well as funtionality. I have a question or two about the "I" brace and the other brace pieces that is mounted in the case. It's kind of hard to see in the photos but it looks like the "I" brace is secured with only one screw on the top and bottom,(I am presuming on both sides), but it looks like the other brace pieces are being held with hot glue. Are there screws that are not visible for the other added brace screws? Also, with the bass frequencies you are dealing with, would it not be better to secure all of the brace points with 2 screws where they contact the cabinet to keep down any abberations of unwanted vibrations? From the looks of it you may have had it so tightly together that it won't matter. I am also curious if the bracing was secured from the top and bottom sides or is the foam there to help that? I havent dealt much with PR's and found your research and building techniques very awesome. You must be a woodworker as well. Thank you.


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## Mike P.

There are two ways to build a cabinet, glue and clamps or glue and screws.

There is wood glue between the brace pieces and the cabinet walls, all that screws do is take the place of clamps while the glue is drying. The smaller brace pieces opposite the main "I" brace were very tight fitting and didn't require any screws to hold them in place. 

I use hot glue on the seams of all six sides of the cabinet to make absolutely sure there are no air leaks, while doing that seam I glued around the brace and continued on the other side.

Thanks for the compliments! As for my wood working skills, this was my 9th sub build, it gets easy after you've done it a few times!


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## Badbob

Thanks Mike, That clears it up for me. I have been a woodworker for years but reading a few of the posts here have made me realize I have to step up my game quite a bit to compete with what you guys are building. A lot different than building furniture in the intricacies as well as the mathmatics. I appreciate you guys letting me pick you brains. I will definitely enjoy the learning experience!!!!!!!!!!!:T As well as looking at the quality of workmanship.


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## Mike P.

Actually DIY subs are simple if you can build a square box. As for the math, there's plenty of help with that here on the forums, it's what we're here for. If you have any questions, just ask. :T


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## daren_p

I have been thinking about trying the DIY route for a sub as well & this setup caught my eye. As someone mentioned earlier in this thread, does anyone know the results if box volume is reduced? He mentioned an ~11" cube, it would be nice to make it this small but I have a feeling the bottom end would suffer. What about something more like ~14" cubed?

Also, still don't have many listening impressions on this setup? The results look impressive on paper but how does it really sound for both music & movies?


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## Jesmin

Creative Sound Solutions SDX10 Sub Kit is really very nice..


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## caper26

I read through the entire thread and couldn't find the REW charts you promised? Did you ever do any, or take measurements from the LP instead of @ 1M ? Nice job bud. I think you just convinced me to get the quartet TRIO12 with the SPA500 amp...


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## Mike P.

Truth is I fought with REW for awhile, gave up, and was going to get at it at a later date when I had time. Then my external sound card mysteriously disappeared, probably got mistakenly thrown out. :huh: I'm happy with the sub, for me that's what counts. You'll love the Quartet TRIO12 and amp, that's an excellent combination in a small package.


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## skinney6

i'm just starting the box for this kit and i dont see that you use some kind of gasket for each component. i saw somewhere else that a gasket is important to seal the box.
did you use or fashion some kind of gasket or mounted straight metal to wood.
thanks! this build post inspired me to do this proj.


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## caper26

I have a kit too, just need to find some time to build the box, which should go a lot faster this time around. Use something like this, 1/4" thick, but 5/16" thick is ok too. [Weatherstrip seal]


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## bgarcia17

Skinney, I believe all of these drivers come with a rubber gasket mounted, so that's it. You'll see when you get your kit.


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## skinney6

sweet, thx!


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## caper26

here is what I did and is recommended:


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## skinney6

ah, cool
i appreciate the pic
thx


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## CortGideon

One thing I can't find much info on is bracing and the "science" behind it if there is one. Is bracing to eliminate standing waves or is it just to make the box sturdier? 

I've been to several sites and there are all sorts of funky materials and designs inside the box. Why is this, and does it matter what you put in there? If so, how do you figure out what to put inside (noob)?


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## ISLAND1000

CortGideon said:


> One thing I can't find much info on is bracing and the "science" behind it if there is one. Is bracing to eliminate standing waves or is it just to make the box sturdier?


`
The "science" behind bracing is pretty simple ie" make the enclosure add as little sound of it's own as possible and at the same time be light in weight. There is NO connection between bracing and standing waves.
There are some logical design considerations:
1) a sealed box is easy to make strong especially if your willing to move a heavy object when needed, over 100 pounds if it's a sub.
2) Making the sealed box "THICK" can eliminate the need for lots of specialized bracing. The "baffle" (front board with the driver) is sometimes double or even triple thick in an attempt to make the box strong and inert. No vibrations can be excited by the driver at any Hz.
3) A thinner skinned box will require those specialized systems of braces that you've seen. A box designed with a system of braces placed at node points can reduce unwanted vibrations by creating smaller sized panels that will only vibrate (resonate) at frequencies above those produced by the sub woofer driver and have no consequence except for the harmonics of the original notes.
`
Ported enclosures, generally larger than sealed will of course need more bracing and since the enclosure includes a port, bracing becomes a more difficult design problem. The bracing will have to include space for the driver and the port and also not interfere with the air movement within the enclosure especially not blocking the port.
`
Other than that, build your box out of 3/4 inch MDF, dbl the baffle, put in a couple pieces of bracing to reduce the size of unsupported panels to about 11" square or less and you'll be golden for most listeners.
Add a little damping material to the inside of the box to reduce internal reflections and "pass thru" audio through the cone itself.
Damping material in a ported box has to be placed to avoid blocking the port.


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## CortGideon

Hmm... I'm making a 18x18x18" cubed box now 3/4 MDF... what kind of bracing do you suggest? Any good links that have DETAILS for noobs? I have the idea of how to build on the box but it seems finding all the small yet important details is the hard part...

Ie. having trouble finding instructions for gluing and sealing things too... where, how much, inside, out, etc...


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## skinney6

This is what CSS recomends for their 18" cubed box

http://creativesound.ca/pdf/Quartet10SD300 Kit.pdf

it has 2 apr's so the bracing works around them


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## CortGideon

Yea thats what I was looking at, and basing my design off of. I'm just gonna have 1 sub in the box though, so would I still need all that bracing? What about just the single, "I" fixture without all the small pieces.... would it still be necessary?

Do you guys recommending screwing everything in and putting wood glue together on the pieces to join them tightlY?


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## skinney6

i think a good glue and clamp job is fine 
i'd just do + instead of an I
you know wheat i mean?
i did the quartet10 using css design but i've seen other peeps build proj using +


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## CortGideon

I forgot to mention I modded the box a bit. Mine is 20" high and will have the sub firing downward onto another piece of MDF at the bottom. So its like a cube within a box if that makes sense.... I guess I should screw the sub in because gravity might break that glue huh


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## ISLAND1000

CortGideon said:


> ... I guess I should screw the sub in because gravity might break that glue huh


`
I hope that was a joke! Under NO circumstances G L U E the driver to the box.
There are holes in the rim of EVERY driver for screws or bolts. 
YES, SCREW the driver to the baffle, don't glue it.
`
And the CSS box will work well with just the ' I ' brace between BOTH the sides and the top and bottom.
In your case (down firing driver) it'll be BOTH sets of sides with the ' I ' braces.


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## CortGideon

Sorry I meant "baffle"... screw the baffle into the sides of the box, not glue it... 

Update: I tried screwing 2 corners together and missed my edit: PILOT holes (or didnt make port holes big enough) and cracked the MDF... DAm 
Not a huge crack but there are some nevertheless. Noob noob noobb.... woodworking skills are very primitive I should mention.

Should I skip the screws and use glues for everything, including the downward facing baffle? Will glue be sturdy enough (gravity and sub's force)?

Any tips on making a box guys?


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## caper26

look at Mike P's build thread, and mine TRIO12 build thread. Lots of pics.


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## ISLAND1000

CortGideon said:


> Will glue be sturdy enough (gravity and sub's force)?
> Any tips on making a box guys?


Glue will be fine if it's evenly spread on both mating surfaces and held together with clamps for a day while the glue dries.
I haven't heard you mention CLAMPS yet. If you don't have any get some. If you have some use them. The more the better.
`
How much space are you going to have between the driver and the bottom piece? Try 3 inches.


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## caper26

glue plus clamps OR glue plus screws. Problem with screws in MDF is that if you are off slightly, it will split...so just use glue, spread it out, and clamp it with pipe clamps if possible and let it dry 24 hrs.


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## CortGideon

Okay clamps, got it.... thanks guys.

Any tips on how to cut a hole for the driver? I don't have any fancy saws so I'll have to borrow or rent something. Also I see some people have a nice groove in the wood where the screws are inputed for the driver. How do you do this? Do you put something in between the wood and the driver like rubber or???

EDIT: I'm gonna move my discussion to the thread I started in the forum called "NOOB Subwoofer questions"
http://www.hometheatershack.com/for...iscussion/60109-noob-subwoofer-questions.html

Can you post there? THanks guys!


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## caper26

Mike P. said:


> Got the grills done. Since the sub and PR's are surface mounted the grills are simple to build using a "friction fit" method. First glue two pieces of MDF together and cut a circle 12 inches in diameter.
> View attachment 13826
> 
> 
> Round over the out side edge.
> View attachment 13827
> 
> 
> Cut out the inside of the grill just a hair smaller then the diameter of the sub and the PR's. A few minutes of hand sanding the inside ensures a perfect fit.
> View attachment 13828
> 
> 
> Grill frame sanded and painted black.
> View attachment 13829
> 
> 
> Grill cloth attached to frame.
> View attachment 13830
> 
> 
> Cabinet painted and components installed.
> View attachment 13832
> 
> 
> Grills installed.
> View attachment 13831



Hey Mike,
Since getting a nice router, I am now going to make the grills like this (great idea). A couple of questions: 
Did you apply glue everywhere between the mdf panels, or leave the center alone since you would be cutting it out?
The problem I am anticipating is the circle jig pin is not going to be long enough for 2 pieces of MDF, so did you clamp the inside of the circle too while cutting out the circles? 
Did you use primer on the finished frames before painting? 
Thanks.


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## Mike P.

I totally glued both 3/4" pieces together. Then I routered the outside diameter. I then placed 3 1" x 4"s on the circle and used 1 1/4" screws to attach them as shown. I flipped it over and screwed the ends of the lumber to a couple of sawhorses and cut out the center piece. 

You'll have to vacuum out the grove after each pass. MDF cuttings are murder on carbide bits and if the bit over heats it's done. Even if you have it professionally sharpened it will never keep an edge.

No primer on the frames, just painted them flat black.

Excuse my Microsoft Paint diagram. :whistling:


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## caper26

thanks a lot for taking the time to post all that. Makes perfect sense. I appreciate you sharing your tricks! So what is the width of the frame after it is cut out?


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## Mike P.

I think it was 1.5". I'm away at work for a week so I can't check to be sure. I do remember the round over was 3/4". If you do a round over that has to be done before you cut out the center piece.


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## caper26

Mike P. said:


> If you do a round over that has to be done before you cut out the center piece.


Yes of course, thanks. And disk has to be cut before the hole...


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## Mike P.

Sounds like you have a plan. :bigsmile:


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