Topic: Threadlock's Diy stuff

[threadlock]

Hi All,

I hope it's Ok to post not my home theatre but my diy stuff here. 
Still not having the courage to post my ugly entry-level setup here, I thought it would be easier for me to just start on with some of my diy ideas.

It's been in my wish list to build a subwoofer of my own, something that can satisfy my crave for that tactile as well as musical bass. I have a sub driver in my storage just gathering dust so I want to give it a try.


UPDATED May 07, 2009
-----------------------
Some fone cam pics of the finished sub:




Making of the Grills:


With Magnetic Grills On:



Comparison with MA RS1 finish:

MA RS1 corners:


My Diy sub corners:


Features
--------
* Designed to reproduce frequencies 18Hz-80Hz at THX reference levels of 115dB for a subwoofer.
* Extensive bracing design for non-resonant panel
* Constrained-Layer-Damped wall to reduce vibrations like this:

* Using two high excursion flagship drivers from Elemental Designs
* using the subwoofer controller of master jojod
* will use the flagship amp of master pilyo: the Amp1
* box made by master in fine woodworks: Earl Estrera (maraming maraming salamat bro!)
* Rosewood high gloss finish
* black piano finish magnetic grill
* Specifically designed for 60/40 HT/music use and hopefully can compete with mid to high end subs in terms of sound quality and output


===============================================================================

Posted: Jan 26, 2009
--------------------

What follows is the preliminary design for my diy dual-driver subwoofer. This build is also posted in Home Theatre Shack forum.

Driver: Dual Elemental Designs 13Av.2
Box: 7 cubic feet internal usable, panels made of MDF
Bracing: own XYZ bracing design, made of 3/4" plywood
Usage: 60/40 HT/Music
Requirement: can do 115dB @ 18Hz

------------------------------
WinISD Modelling pics
------------------------------
(UPDATED: 02/13/2009)

Transfer Function:

Large Pic: http://i86.photobucket.com/albums/k104/nfalabi/TransferFunction.jpg

Group Delay:

Large Pic: http://i86.photobucket.com/albums/k104/nfalabi/GroupDelay.jpg

SPL:

Large Pic: http://i86.photobucket.com/albums/k104/nfalabi/SPL.jpg

Cone Excursion:

Large Pic: http://i86.photobucket.com/albums/k104/nfalabi/ConeExcursion.jpg

Air Velocity:

Large Pic: http://i86.photobucket.com/albums/k104/nfalabi/AirVelocity.jpg

---------------------------------------------------
Drawing for box and bracing(using Google Sketchup)
---------------------------------------------------

(UPDATED: 02/13/2009)
Panel Cut Sheet:

Large Pic: http://i86.photobucket.com/albums/k104/nfalabi/CutSheet.jpg

Exploded Bracing:

Large Pic: http://i86.photobucket.com/albums/k104/nfalabi/ExplodedBracing.jpg

Assembled bracing:

Large Pic: http://i86.photobucket.com/albums/k104/nfalabi/AssembledBracing.jpg

Exploded Box:

Large Pic: http://i86.photobucket.com/albums/k104/nfalabi/ExplodedBox.jpg

Assembled Box- Top View:

Large Pic: http://i86.photobucket.com/albums/k104/nfalabi/TopView.jpg

Assembled Box- Front View:

Large Pic: http://i86.photobucket.com/albums/k104/nfalabi/FrontView.jpg

Assembled Box- Perspective View:

Large Pic: http://i86.photobucket.com/albums/k104/nfalabi/Perpectiveview.jpg


BTW, Sketchup is superb!!! I downloaded it just this Saturday and by that day I was able to create a model for this diy sub, and Im not even a graphics artist or designer! Very simple commands and Very easy to use.


Im still negotiating with a diy box maker to actually build this box for me. I don't really have the space to make it and lay tons of dust in my rented room. 
The design is pretty complicated so construction is not that simple.
I really hope someone could help me with this build. Would it be you? 
That's it for now, I'll post some more pics later when the project has progressed.

Thanks for looking! 

[threadlock]

--------------------------------------------------------
Dual-Opposed Infinity Kappa 12dvq sealed subwoofer build
--------------------------------------------------------


Build updates
==========

------------
Nov. 9, 2009
------------
Finally got some time to finish my dual-opposed sub. Pics:

With grill:


Without grill:


Close-up:


Inside Room:


-------------
Oct 26, 2009
-------------

After a few months, ginanahan ulit ako ipagpatuloy ang build ng infinity sub.  
Medyo mahirap talaga gayahin wood pattern ng RS1 ko, anyway ok na rin ito para saken  



The 2 black piano grills and the rings for the front and the rear of the sub:


Planning to finish the box with polyurethane air spray.


--------------
July 21, 2009
--------------
Rounded the corners and attached the terminals on the under side


And before I do the finishing, I tested it first


Initial impresions:
* Sounds tight and is very agile, it rides with the beat
* Does not go very deep unlike my dual 13Av but I like its midbass punch when low-pass is set to 120Hz
* I was actually expecting to have zero vibration of the walls at high levels but it's not the case here, it still exhibits a some form of vibration but it decays very fast. I think it still meets my expectation to cut the vibrations, or maybe I still need some more damping.  

--------------
July 10, 2009
--------------

Panels Joined: Seems I need to buy some more clamps. You can never really have too much clamps especially when joining many panels at same time.


Front Panel Design: Screws and driver rubber ring is hidden for a less industrial looks


Front Panel Design: This top cover will hopefully be painted with black piano finish


Grill Design: I took a little more effort for the design of the grill. Inner ring with crossed design will be wrapped in grill cloth and outer ring will be corner rounded and painted black piano finish


* The topmost narra ply panel will be painted rosewood piano finish and corners rounded using 1 1/2 round corner router bit.
* Development is very slow as I can only give a few hours every weekend for it.
* The box is screwless, I believe wood adhesives are more than enough to strengthen the joints, so screws are not really needed. Besides, it would be hard to round corner the box if screws are used. And one needs to hide these screws for very fine outer finish.




--------------
June 15, 2009
--------------

One side of the bracing, the other is already mounted inside the box:

Larger pic: http://i86.photobucket.com/albums/k104/nfalabi/Ungluedbracing.jpg

I put some holes on the bracing to reclaim some volume and make it lighter:

Larger pic: http://i86.photobucket.com/albums/k104/nfalabi/Bracingwithholes.jpg

Bracing glued to the box:

Larger pic: http://i86.photobucket.com/albums/k104/nfalabi/Bracinggluedtobox.jpg


--------------
June 11, 2009
--------------

Im now ready to proceed with my second DIY build. This time it will be a simpler and smaller sealed sub. Actually this is the very first box that I will make by myself since the first one is only my design but was built by Earl Estrera.

The goal of this build is to make a sub for use with my music-only tube setup, target range would be 40Hz to 120Hz. The box should be very transparent and non-coloring to allow the sub driver to reach its full potential.

Here are the sub-goals:
1. The sub will be using 2 pieces Infinity Kappa Perfect 12" dvq in a dual-driver opposing configuration. The reason for picking the Kappa is because of it's measured linearity up to moderate listening levels. Although it has high distortion in the below 40Hz range, it has a very low distortion profile at 40Hz and above making it superb for music use IMO.
More info can be found here: http://www.hometheatershack.com/forums/subwoofer-tests/978-diy-infinity-kappa-perfect-12-a.html

2. The driver will be fitted in a dual opposed config in 2 cubic feet internal volume sealed box. I previously planned to make 2 separate boxes for the 2 drivers but I changed my mind as I really want to test myself how the dual opposing config will behave. According to my readings, a dual-driver in opposing configuration will cause the drivers to exert equal forces in opposite direction thereby resulting to a theoretical net force of zero which will then translate to a virtually vibration-free box. I hope this will work.

My reason for using 2 drivers is that since using 2 drivers will effectively double the cone area and power handling, it will result in a theoretical 6dB of more output, thus for a given output the excursion is effectively halved resulting in a cleaner output especially at moderate to high volume levels versus using 1 driver only.

3. The box will be thoroughly braced and will be stuffed with fiber fill for a non-flexing and non-resonating walls.

4. The outer finish will be glossy rosewood to match my MA RS1 fronts.

Here is my initial drawing of the box using Google Sketchup:


Larger pic: http://i86.photobucket.com/albums/k104/nfalabi/Dualkappa2cusealed.jpg


Larger pic: http://i86.photobucket.com/albums/k104/nfalabi/DualKappaouterfinish.jpg

==============================================================================

[mike c]

wow, ganda ng design - pati ng drawing sa sketchup (ang bilis mo naman matuto)

anong finish balak mo?

[iiinas]

nice design!

sir mike c, oks ba nag piano black for sub? 

[threadlock]

Yes, Sketchup is very easy to use, it's very simple and easy to model complex structures such as Train or house with it. The main idea is that all 3D objects comes from a simple 2D object. By pushing/pulling the 2D object, one can create a variety of 3D objects.  Try it, it's actually fun, you can create a simple chair model in just a minute.
Im still looking for a 1/4" ply that has a "woody" look and paint it rosewood-like color, just like  my MA RS1.

[mike c]

nice design!

sir mike c, oks ba nag piano black for sub? 

ok sir iiinas.  super nice to look at pero fingerprint magnet.

[mike c]

Im still looking for a 1/4" ply that has a "woody" look and paint it rosewood-like color, just like  my MA RS1.

i see, try to look for 1/8" veneers na stick on lang. 

[threadlock]

thanks for the suggestion, I'll try to look for it.
mike, di ba may behringer 2496 ka?
Ito yung ginagamit as crossover and filter right? Pwede rin ba yan to act like a subsonic filter?

[streetsmart]

Hi Noel! Have you talked to Jay2? Jay has made a lot of big DIY subs. He might be able to help.

Good luck!

[mike c]

thanks for the suggestion, I'll try to look for it.
mike, di ba may behringer 2496 ka?
Ito yung ginagamit as crossover and filter right? Pwede rin ba yan to act like a subsonic filter?

yes, i have the 2496, ito gamit ko for crossover (puwede rin siya mag EQ) - pero baka ang subsonic filter niya is for 20hz lang - unless madaya ng 20hz subsonic filter with 21hz EQ boost with wide Q. 

[looks]

Im still looking for a 1/4" ply that has a "woody" look and paint it rosewood-like color, just like  my MA RS1.

Hi,

try to look for a narra plywood in a local hardware store near you. almost double the price nga lang ng ordinary plywood.

hope this helps! 

[threadlock]

Hi,

try to look for a narra plywood in a local hardware store near you. almost double the price nga lang ng ordinary plywood.

hope this helps! 

Thanks for the tip, I'll take a look on it.

Im still negotiating with earl on the box build, hope kaya nya yung complicated design ng bracing ko hehehe.
Parang gusto ko na nga simulan yung bracing build, hindi naman masyado maalikabok magcut ng plywood unlike mdf. 

[threadlock]

I have revised the bracing design, I think satisfied nako sa ganitong bracing. 

[threadlock]

Good news, Earl Estrera is willing to do the box for me. Im just fine tuning the box dimensions and the bracing details.
We hope to start the build this week.
I'll try to post pictures along the way.

[mike c]

congrats on finding a box maker - and good luck in your build, im sure it will be a fantastic subwoofer!

[looks]

goodluck on your diy box! 

[threadlock]

Im very fortunate to find another talented person for my build, in the person of sir Jojo D.
Marami pala talagang magagaling at talented people dito sa Pdvd. 
Here is the list of the contributors to this build:

1. pilyo168 - will make the amp that will power up this sub
2. eestrera - will build the box and my complex bracing. Hope we can start this week
3. JojoD818 - will make the amp controller which features high pass filter(for over-excursion protection), low pass filter, phase switch, etc.
4. Me - dreamed of a diy sub, became obsessed at nagsimula ng kaguluhang ito. 

This is exciting, sana masimulan na para makapagtake na ng pictures.

[odyopayl]

Im very fortunate to find another talented person for my build, in the person of sir Jojo D.
Marami pala talagang magagaling at talented people dito sa Pdvd. 
Here is the list of the contributors to this build:

1. pilyo168 - will make the amp that will power up this sub
2. eestrera - will build the box and my complex bracing. Hope we can start this week
3. JojoD818 - will make the amp controller which features high pass filter(for over-excursion protection), low pass filter, phase switch, etc.
4. Me - dreamed of a diy sub, became obsessed at nagsimula ng kaguluhang ito. 

This is exciting, sana masimulan na para makapagtake na ng pictures.

Agree, isama mo na rin si DIY Master Anthony for the Box also!
More Power to PDVD Builders!
Great Help for DIY'rs!

[odyopayl]

Driver: Dual Elemental Designs 13Av.2
Box: 7 cubic feet internal usable, panels made of MDF
Bracing: own XYZ bracing design, made of 3/4" plywood
Usage: 60/40 HT/Music
Requirement: can do 115dB @ 18Hz

Me too Bro I'm on my way of building my HT Sub but I want to separate the two drivers instead of putting the 2 drivers in 1 box. By the way, I read an article that mounting two drivers in opposing pairs will be more practical (180 degrees back to back) so that the energy in the frames will be canceled.  I can't imagine how much energy will this 2 drivers will produced inside the Box, it should be very rigid all else there will be distortion cause by exploded box either inside or outside. You should made the box interlock with each other Glued and Screwed.
Hope to hear your project once you done with it!
More Power!

[odyopayl]

Yes, Sketchup is very easy to use, it's very simple and easy to model complex structures such as Train or house with it. The main idea is that all 3D objects comes from a simple 2D object. By pushing/pulling the 2D object, one can create a variety of 3D objects.  Try it, it's actually fun, you can create a simple chair model in just a minute.
Im still looking for a 1/4" ply that has a "woody" look and paint it rosewood-like color, just like  my MA RS1.

What Software you use for the 3D? AutoCAD? Much better if you can make an exploded drawing of each pc. so that the builder will just follow all the dimensions and will assemble the box based on your own specification.

[JojoD818]

Im very fortunate to find another talented person for my build, in the person of sir Jojo D.
Marami pala talagang magagaling at talented people dito sa Pdvd. 
Here is the list of the contributors to this build:

1. pilyo168 - will make the amp that will power up this sub
2. eestrera - will build the box and my complex bracing. Hope we can start this week
3. JojoD818 - will make the amp controller which features high pass filter(for over-excursion protection), low pass filter, phase switch, etc.
4. Me - dreamed of a diy sub, became obsessed at nagsimula ng kaguluhang ito. 

This is exciting, sana masimulan na para makapagtake na ng pictures.

wow ok kasali pala ako sa talentadong pinoy! 

good luck on your project bro, add ka na din ng bracing sa bahay ha, if you have a wall-mounted lcd better make sure it's secured, bluetac mo mga figurine ni misis lagot ka pag nahulog...   

[threadlock]

Driver: Dual Elemental Designs 13Av.2
Box: 7 cubic feet internal usable, panels made of MDF
Bracing: own XYZ bracing design, made of 3/4" plywood
Usage: 60/40 HT/Music
Requirement: can do 115dB @ 18Hz

Me too Bro I'm on my way of building my HT Sub but I want to separate the two drivers instead of putting the 2 drivers in 1 box. By the way, I read an article that mounting two drivers in opposing pairs will be more practical (180 degrees back to back) so that the energy in the frames will be canceled.  I can't imagine how much energy will this 2 drivers will produced inside the Box, it should be very rigid all else there will be distortion cause by exploded box either inside or outside. You should made the box interlock with each other Glued and Screwed.
Hope to hear your project once you done with it!
More Power!

Bro, parehas pala tayo may diy build. Yung configuration na two drivers in opposing pairs is I think it's called an isobaric configuration. There is a trade-off in that design bro, they will cancel each others backwave resulting in reduced efficiency and output but the vibration is almost reduced to zero. I have already thought also about this and I still went for huge box housing dual driver in front. That's why the box is braced extensively, yes, the bracing are interlocked with each other, and the walls will be lined with dynamat to further reduce vibrations. The box will be very heavy(about the weight of three MDF + 2 30Kgs driver) so it might also help in reducing box movement and vibrations. Because this is dual driver config, the excursion is effectively halved for the same output as the single driver. In my modelling in WinISD with about half power(1000W), excursion is 16mm but output is already about 117dB. Less excursion means lower motor movement, thus less vibrations and less distortion. I still don't know if my thoughts are correct or wrong until the box is actually built for evaluation. Pag hindi epektib, charge to experience na lang. 

What Software you use for the 3D? AutoCAD? Much better if you can make an exploded drawing of each pc. so that the builder will just follow all the dimensions and will assemble the box based on your own specification.

Yes, im already working on the exploded view of the box and bracing, it's quite easy to do in Google Sketchup . I have actually given to Earl some excel docs of my work for the details of the box dimensions, the bracing and all the cut sheets needed. Im just fine tuning the details.

Btw, share mo naman build mo para makita din namin. Parang curious ako dun sa "12Hz" sub mo. That's a very low tuned box.  

EDIT: I have researched on mounting the drivers with opposing sides, such that one is facing in front and one facing the rear. It's called Bi-pole configuration and not isobaric. It's tempting to try this kind of configuration but as of now I don't exactly know the other advantages and disadvantages of this so I will still go with my current config. 

[JojoD818]

here you go bro, one for you and one for June...



will drill component holes after it dries in the oven...

[threadlock]

Thanks bro. That circuit looks pretty cool. 
This pic officially starts the actual build. 

[JojoD818]

Thanks bro. That circuit looks pretty cool. 
This pic officially starts the actual build. 

You're welcome bro, wait until it's populated and it will look a lot cooler... 

[macdon]

here you go bro, one for you and one for June...



will drill component holes after it dries in the oven...

Lahat na talaga kayang gawin ni master ah! Congrats to the new owners of the build!

[keema]

ang galing naman ng pag kakagawa nun! congrats threadlock..unti unti matatapos din yan...
galing nyo sir jojoD more power!

[JojoD818]

@macdon,

di naman lahat hehehe... 



@keema,

salamats bro! 





@threadlock,

I forgot to tell you that there is a useful feature in the sub controller that deals with box EQ. It can electronically intervene to either boost/cut any nuisance peak or valley in your sub frequency response (below the cutoff frequency, of course) due to box resonance (if any).

All I need from you is the center frequency of the peak/valley and the gain (+ or -) in dB from your simulation so I can set and the controller will automatically compensate. Otherwise, I'll leave it flat.

Also, please don't forget to give me the overshoot frequency once you have checked it, I'll temporarily set it to 15Hz.

Cheers

[threadlock]

thanks bro.
yes, please do not include the EQ, we'll just deal with it later if I sensed that there is a major response problem. 
BTW, is it also possible to have a variable high pass frequency like adjustable from 12Hz to 20Hz? Or mahirap(at magastos  ) because there will a lot of changes in the circuitry, o hindi talaga pwede?

[JojoD818]

thanks bro.
yes, please do not include the EQ, we'll just deal with it later if I sensed that there is a major response problem. 
BTW, is it also possible to have a variable high pass frequency like adjustable from 12Hz to 20Hz? Or mahirap(at magastos  ) because there will a lot of changes in the circuitry, o hindi talaga pwede?

hindi naman sa hindi pwede, mahirap lang... pero sige challenge yan, I'll study it first...



Impossible is nothing, nothing is impossible.