The last Quartet 15 build?

[ripcard]

During my CLD Dynamics builds I had the idea of building a sub to complete my DIY HT setup. While doing some research on what I would build, I came across a slightly used HPSA 1000 plate amp for a great price. Since the Quartet 15 kit (http://www.creativesound.ca/pdf/Quar...woofer_Kit.pdf) was one of the subs I was considering (it uses this very amp), I contacted Bob to ask if he would sell me the kit minus the amp. We agreed on a price and I ordered it. That was six months ago! I see now that the SDX15 is sold out. This may be one of the last builds of this design. Hope I can do it justice.

I had finally cleared my plate of other projects and recently started in on the build. I'm making a few small modifications to the recomended box. I've decided to do the internal brace a little different and recess the driver and PRs. This changed the dimensions slightly. I added 1/4" to the internal height of the box to allow for the extra volume taken up by my larger brace, and the width also grew because I added another 5/8" layer of MDF on the three sides with the driver and PRs. This should allow a solid flushmounting of the driver and PRs.

Here is my Sketchup drawing showing the changes.


My brace being cut.


Gluing up the brace.


The top and bottom pieces were cut to exact dimensions and all the other pieces were cut slightly oversize. As you can see, I did the glue up in stages. This is a big box and I felt it would be easier for me to ensure square this way.



In order to accomodate the overhang of the sides, both top and bottom, I used some thin strips ripped from scrap MDF on top of the pipe clamps.


Added the second layer on two sides and the single layer back.



This work was done a few weeks ago. Just getting around to starting the build thread now. I'm hoping to be able to make regular updates as I make further progress. This thing is going to be heavy!

[mdrake]

Thanks for posting those pics. Very nice work!!

[RossMc]

I just finished one too. However, my amp seems to rattle. Has anyone else had this problem?

[mdrake]

Just noticed the flush mounting. Very nice touch.

The amp should not rattle.

[ripcard]

Thanks for the positive comments mdrake. Getting a little further along on the build, so I'll show you where I'm at as I pack for a flight out tomorrow morning. This is one heavy box...even empty.

In order to be able to do some "glue management" on the inside of the box when putting on the last side, I went ahead a did the cutouts for the PRs. This way I could reach in and ensure most of the glue stayed in the corners where it belonged, not running down the insides. This is the first of two layers of MDF for the front of the cabinet. Same as the PR sides.



After cutting the hole for the SDX-15, I droped it in to check the fit and drill the mounting holes.





Same thing for the PRs.





Then it was time to work on flush mounting the amp. I started by measuring the amp's radiused corners and using the circle jig to cut them. In this case 2.5". I then measured the distance from the edge of the router base to the bit and clamped straight pieces of scrap MDF to make a guide. The first pass gives the outside profile of the plate amp.




I then cut some strips 7/8" wide and long enough to fit inside the guide frame. This moved the cutter in to where I could plunge right through to make the opening for the body of the amp.




Then it was just a matter of using the router free hand to remove the material in between the two cuts for a nice smooth surface for the gasket.






Up next is flush trimming all the sides but that'll have to wait 10 days as I'm off on vacation. Next update will probably be around the weekend of the 8-9 of May.

[Bengoshi2000]

Flush mounting the amp FTW! Looks nice. How are you planning on finishing off the box?

[Mike P.]

Nice cabinet work!

[mwmkravchenko]

Great work on the sub enclosure. I particularly like the way you cut out the internal stiffeners. That's a good way to do it.

Mark

[ripcard]

Bengoshi2000 wrote:

Flush mounting the amp FTW! Looks nice. How are you planning on finishing off the box?

Thanks. I'm hoping to pull off a paper backed cherry veneer wrap with 3/4" round overs.

mwmkravchenko wrote:

Great work on the sub enclosure. I particularly like the way you cut out the internal stiffeners. That's a good way to do it.Mark

Thanks Mark. I've always liked the extra strength inherent in curves and circles.

I hope to have another update early next week.

[ripcard]

Well, it's been longer than I anticipated since my last update so I thought I'd post up what little progress I've made. Time to work on this is in short supply all of a sudden but I need to get this and a few other projects done before the summer really starts to kick in. Otherwise, they may not get done until the fall.

Enough whinging. The flush trimming of the box required a larger bit than I had on hand so I bought a 1/2" shank, 1 1/2" flute, double bearing flush trim bit. That was just enough to handle the double thick MDF sides and front. I then filled any imperfections with bondo and sanded everything smooth. I installed the hurricane nuts and some 3/4" Sonic Barrier on the top, bottom and the back. Not sure if I'm going to need any stuffing inside there as well. Any thoughts?





As mentioned earlier, I had thought I would try wrapping the veneer around some 3/4" round over’s but the box is simply too big for this to work with the veneer available to me. With the grains direction on the 4x8 sheets the way it is, I can't even go completely around two sides. So, a compromise is bevels. I now have much more freedom for selecting and cutting the pieces of veneer out of the sheet. Should be less waste too.

I used a guide with a circular saw to ensure nice straight bevels. A little sanding to clean up a few swirls from the blade and it was done.





Hopefully I can get going on the veneer this week. I don’t think I’ll predict when the next update will be. I’m not very good at it.