or Connect
AVS › AVS Forum › Audio › DIY Speakers and Subs › SI HT18 D4 16cuft 15hz build
New Posts  All Forums:Forum Nav:

SI HT18 D4 16cuft 15hz build - Page 2

post #31 of 61
What port air speed did that slot model at? I am doing this in a slightly larger enclosure and needed 11.5"x5.5" to stay under 25 m/sec with 800 watts.
Zach
post #32 of 61
Thread Starter 
With a protective highpass at 15hz air velocity peaks a little above 30m/s with 1000 watts, I feel that is an acceptable velocity number. Keeping the first port resonance well above the subwoofers bandwidth to minimize any detrimental effects from said resonance was also a goal, in this case is comes out to be just about 340 Hz.


Some very cool custom parts arrived for these yesterday, but no teasers until I get to the point when I can install them.

Today I started laying out and installing the bracing on the first enclosure. I also marked the driver mounting hole positions and drilled some holes for the hex drive wood inserts that will be used to mount the drivers.






I got most of the bracing glued in on this one tonight. I still have 4 more of those horizontal braces to glue in and another 4 braces that will run lengthwise to both cut and glue.




Edited by mtg90 - 2/16/13 at 8:39am
post #33 of 61
Wow! Looking fantastic. First rate for sure, and I really like the design.
post #34 of 61
Bracing galore!

I really like the L-shaped profile idea.

It definitely looks like a more time consuming approach than what you did with your subs. I really appreciate you doing this.
post #35 of 61
Thread Starter 
Thanks Brian, the basic design shape was zheka's idea though it does share the recessed driver baffle with yours.

You’re very welcome Gene. The L-shaped bracing makes it easier to glue the braces together and also keeps them strait as the plywood had a tendency to warp when cut into such thin strips. I feel like this style of bracing installed much faster then the bracing I did on mine.
post #36 of 61
Quote:
Originally Posted by mtg90 View Post

The L-shaped bracing makes it easier to glue the braces together and also keeps them strait as the plywood had a tendency to warp when cut into such thin strips.

I bet you would not get more rigid, warp proof braces by doubling the thikness of the ply. I think it's very clever and effective use of the material.
post #37 of 61
Thread Starter 
So over the week I finished up the bracing for both subs.






I also installed some t-nuts for the rubber feet that will get put on later. I glued them in using hot glue, my favorite glue BTW, I've even assembled am entire enclosure using only hot melt glue biggrin.gif I will use Teflon on the bolts for an air tight seal.




I also made the cutouts for the terminals. They are going to be dual binding post terminal cups so the coil wiring configuration can be switched just by moving the jumpers around.




Yesterday I got around to putting some dampening material in. These huge boxes almost used up the rest of my denim. I placed it around the middle of the enclosure vs. the walls as that is where it should be most effective at killing any unwanted midrange resonances/harmonics.




Then I glued on the last panels, and finished up for that day.





I also found someone else who likes them. biggrin.gif




I had to install some doors at my grandmother’s today so half the day was used up doing that but I did manage to flush trim and apply some filler in a few spots that needed it.




I'll have to see if I can get to the first coat of duratex tomorrow.
post #38 of 61
1) That is some crazy bracing

2) Those are turning out awesome

3) Great idea on the wiring switch (wish I would have thought of that when I mounted mine)

4) What is it with cats and sub boxes. Maybe they think it's a giant litter box. eek.gif
post #39 of 61
Thread Starter 
Thanks BA,

Actually the switch does nothing, the coils can be wired in different configurations (series, parallel or each coil separate) by changing the how the jumpers are positioned. That terminal cup just costs half as much as the normal bi-amp cups.
http://www.parts-express.com/pe/showdetl.cfm?partnumber=269-080

Although a series/parallel coil selector could be setup with a DPDT switch but you loose the option of driving each coil on its own.

I am unsure if I will leave that little switch in there or pull it out and tape the hole.

Quote:
Originally Posted by bass addict View Post

Maybe they think it's a giant litter box. eek.gif

I really hope not. eek.gif
Edited by mtg90 - 2/23/13 at 10:22pm
post #40 of 61
awesome stuff. thank you!
post #41 of 61
Nice work. Subscribing.
post #42 of 61
Great bracing, curious why using "L" pieces of wood vs just rectangular or round.
Is that so you can attach them to each other as they cross/touch?

Did you specially cut them that way?

900x900px-LL-1044c1b8_DSC_5072-sm.jpeg
post #43 of 61
Thread Starter 
I had originally planed on using strait 2.5" wide strips of plywood but after cutting them I decided it would be too hard to attach them to each other where they cross, also some were warped a little bit which makes it even harder. I ripped each one into a 1.5" and 7/8" strip then glued them together to make the L-shape. It worked out really well in the end although I did had 100+ pieces of bracing to glue together biggrin.gif

I am working on applying the second coat of duratex now, I am worried if there will be enough for three coats so I am taking my time trying to get the second one looking really good. I'll get some pictures up later today.
post #44 of 61
I am sure two coats would be enough, Matt. I am not planning to tour with the subs.
Thank you!
post #45 of 61
those are going to be some mean looking subs!!
post #46 of 61
Thread Starter 
The duratex on this one is finished I still need get one more coat on the top and a side on the other cab. I should be able to get that done, install the rest of the hardware/drivers tomorrow and get some pictures of the finished cabs up.

I will say duratex is one of the harder finished to apply without getting roller lines in the finish. You can see some faint ones on the top and side in the photo; I don't think I have to technique mastered just yet. I do like how quickly and tuff it dries though.

post #47 of 61
Quote:
Originally Posted by mtg90 View Post

The duratex on this one is finished I still need get one more coat on the top and a side on the other cab. I should be able to get that done, install the rest of the hardware/drivers tomorrow and get some pictures of the finished cabs up.

I will say duratex is one of the harder finished to apply without getting roller lines in the finish. You can see some faint ones on the top and side in the photo; I don't think I have to technique mastered just yet. I do like how quickly and tuff it dries though.


It looks great!
I could post pictures of duratex application I did on 4pi boxes but I am too embarrassed.
Would you use duratex in your future builds? I mean if the finish does not have to be tough, would you say that there are easier less time consuming options ?
post #48 of 61
Thread Starter 
I would use duratex only if I wanted the durability it offers or the texture/covering ability without needing primer.

My two 10cuft subs I just used some cheap black latex paint from Menards ($15 a gallon) and I think they turned out great. I put three coats on those two enclosures and used about 1/4 the gallon, though the finish is not nearly as durable as the duratex and I needed to use primer.

Primer: Zinsser FastPrime 2, Water Base Primer This stuff works great on MDF only needs one coat then sanding and its ready for paint.
Paint: Lucite Interior Acrylic Latex Satin Paint The guy in the paint department added three times the black pigment recommended as it is more of a dark gray normally.

I also like Rust-Oleum’s latex paint which seems more durable then the cheap latex but the largers size I have found it in is quarts. Rust-Oleum Painter's Touch Multi-Purpose Flat Black

Their oil based flat black is even better then the latex for durability but it is more of a mess to clean up. Rust-Oleum Professional High Performance-Flat Black Low VOC

One other I want to try is this stuff: Conco Interior Exterior Flat Acrylic Water Base Paint But my other black latex will last me a while.
post #49 of 61
I had no idea. The finish on your subs is excellent, I would've been very happy with something like this. But I thought going with duratex would save you time since priming is not needed. Sorry about that.
post #50 of 61
Thread Starter 
They are done cool.gif











Here is a close mic response of one as well:
post #51 of 61
Outstanding. Great work!!!

You've though of everything; even a built in handhold. biggrin.gif
post #52 of 61
yes! biggrin.gifbiggrin.gifbiggrin.gif
post #53 of 61
Looks awesome Matt!! Bet they sound just as great too. biggrin.gif
post #54 of 61
Awesome job Matt!! The subs look fantastic.
post #55 of 61
Agree, looks very impressive!! Your duratex skills > my duratex skills. smile.gif
post #56 of 61
Quote:
Originally Posted by mtg90 View Post

Here is a close mic response of one as well:

Matt, what do you make of the notches in the 80-200Hz region?
it would not be the room because this is a close mic measurement, would it? And if not, do you think it is internal reflections that are causing this?
the 80+ Hz offset would indicate a boundary cancellation at about 4 feet which is approx the depth of the enclosure. It would be interesting to see if the notch remains unchanged after you move the sub to a different spot.
post #57 of 61
Thread Starter 
Thanks guys, I only tried one out for a little bit last night and not even setup correctly or anything just sitting in the middle of the floor. Your could feel your pant legs flapping from 6' away during the mech scene on Terminator Salvation and that was with one channel of my old Sony receiver for power. biggrin.gif

The pair with some decent power should be awesome.


I think where I had the mic positioned (between port and driver) may have amplified those notches there, I took some more measurements further back and they smooth out quite a bit. There may be some internal reflection/cancellation happening but I am sure placement in the room will have more of an effect on the overall FR.

This is at 6", 1', 2', and 3'
post #58 of 61
Makes sense, thank you
post #59 of 61
Wow looks solid ! What price is one speaker ? Where can I buy it ?
post #60 of 61
Thread Starter 
Quote:
Originally Posted by Sil3nT View Post

Wow looks solid ! What price is one speaker ? Where can I buy it ?

The subwoofer driver used is the Stereo Integrity HT18: http://stereointegrity.com/index.php?id=60 Currently they have a preorder set at $162 for the next production run of those drivers since the first round was so popular and sold out quickly. Price goes up to $175 after the preorder.

The enclosures were custom built, I used 9 4'x4' sheets of 1/2" plywood to construct them. Total materials cost for both enclosures came out to right about $300 but the grills alone were $100 of that. The grills where ordered from Reliable Hardware
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: DIY Speakers and Subs
AVS › AVS Forum › Audio › DIY Speakers and Subs › SI HT18 D4 16cuft 15hz build