Fixing shoddy speaker install

Hey! After long time isn't it?

Anyways, Rosemary got an ECE recently. A Sony head unit and a set of 4 JBLs. Two of these went into the rear parcel shelf.

Even thought the installer was known around the city as among the best ones, more than one flaw met my eye. Checked out with friends and came to know that this is how it is done everywhere. That argument was not satisfying so in the back of my head I kept on thinking of the ways to fix it. I share the very fix here.

(You can click on the images to open in high res).

First of all, the flaws:
1. The cuts on the parcel tray were not exactly oval or to-the-size as was needed. Reason, lack of proper equipment. Lack of equipment at a professional installer! Strange.

Poorly finished edges

2. Protruding screws. The screws that were used to fasten the Speakers to parcel shelf were projecting beyond the shelf into the storage area. I got pricked by them a couple of times while manipulating stuff inside. Not done!

3. Shoddy connections. The speaker wires from the Head unit were simply twisted around the speaker terminals. That is so not acceptable. Got to fix that also.

Yukk!

 4. Difficult to remove. The clips that they installed were supposed to be removable. When it came to removing these, I was out of luck even after using all my strength. Imagine if a lady had to remove the shelf for some reason. Should be easy.

Those clips never came of manually. Were supposed to!

5. The biggest issue, my cricket kit won't fit in there anymore because the speakers hanged 3 odd inches into the storage compartment. I was serious about reclaiming my storage space. Also, running the risk to speaker damage from the stuff there.

Compromised storage

6. Rattle, the speakers weighed on the hinges and increased weight caused the shelf to bounce up and fall down with a big thud even on relatively small bumps. Earlier, the shelf was lighter and did not make that much noise. A fix was needed here too.

Now that all the issues are known, I thought for a few days and following is what I came up with.


Purchased some scrap cuttings from a sub-woofer enclosure manufacturer. Got these cuttings for one fourth the price of new board so it was a great deal:

Scrap pieces were perfect for my 9 X 6 inch speakers

10 of these for 100 INR.  I estimated like 400 for raw board. Now that is a deal

5 of them add up to approx 3 inches, enough for my application (Flaw number 5 above)

Next I traced out the outer shape of the speakers on a transparent plastic sheet (sourced from an old strip file):

Simply took the cover and marked the outline

 I wanted to give the setup a bit conical shape narrowing upwards, as my circular peices were bit larger then the speaker's longest diameter, I decided to make another line wider than the actual speaker size.

Carefully made 1/4-th of an arc of the larger oval on a plain paper with hand

The 1/4 th outer side traced on plain paper

 This quarter of an oval was good enough to be used to trace all the 4 quarters on the trace by twisting and turning it over and around. So the overall shape of outer oval remained symmetrical.

From paper to original transparent sheet.

Complete oval after 4 traces (each for one quarter of the oval)

Now for the inner side of the trace. Measurements from the speaker's lower side were taken and used as a basis for inner oval shape.

Paper's marks are based on measurements from speaker's underside

This fitment was used to create oval by connecting the 4 dots above. Worked nicely :-)

Cut the inner part to create the hollow that should now match the speaker

Size check. Its an A-OK!

Primary school tricks: Tracing inner oval to the final template. The line marked X is not to be used.

Next step was to patiently trace the above lines with a craft knife and cut out a template for use in rest of the project. I placed a piece of glass below for perfect cuts. Here is the cut out template:

We will soon see that it was worth creating this template.

Now I had to create symmetrical ovals that will together act as spacers for the speaker. So, markings were made and the ovals were cut for further assembly.

On your marks!

All marked. Template ensured exactly same sizes.

Drill a starting hole for the cutting out the inner hollow

Enter: my Dad's Jigsaw cutter

Takes some control and patience to make those cuts

One done. Nine to go. The width is equal on all sides. Apparent difference is because of camera.

Cutting those ovals was not easy, the Jigsaw had to be guided precisely along the cut line and takes some effort to guide a running motor on the line as well as push it forward at the same time. Also had to replace blade three times with new ones as the adhesive used as binder in the board wears out the regular wood blades. Luckily, had exactly three of them spare with me. :-)


Once these were done, next came gluing them together with wood-glue to make a set of 2 equal to height of 5 rings stacked one above the other:

Joining them: Step 1

 

Joining them: Step 2

Joining them: Completed

A bleak glimpse of the future :-)

Now for the fine work, because we used a bit oversize outer diameters, now we had to get rid of the extra material and shape them into nice looking towers closing in on the top.

Markings first. I used the speaker cover to make the marks. X sections will have to go

The first three will also be tapered down

Took away bigger chunks with a Hacksaw

Then used a carpenter's file purchased especially for the purpose. 125 INR

Closer to perfection. Filing the inner side as well

Done. Have a closer look!

Both spacers are ready for next steps

For scale, that is a 6 inch long Square. All debris created by filing! Lots of sweat.

Filing them down was the hardest step and took most labor. I wish I had a portable Belt-Sander or something to work this out. I had aching triceps and wrists the next day. :D

I did not told that an upholstery cloth was also purchased from the same vendor that provided the board scraps. This was to be used along with Synthetic Rubber glue to finish the spacers with some elegance.

Apply glue to the first surface

Apply glue to the second surface (cut out from the cloth with some margin for sides)

Margin for the sides to wrap up around

Apply, let dry, paste the sides too

Cut the excess

So what next? Remember the shoddy wiring? Here is the solution:

Bought the stuff, soldered together to make these connecting wires

Now, even a child will be able to connect-disconnect the speakers :-)

Affixing the speakers to tray needed some new holes in the tray. I used the same template to make perfectly spaced holes:

Red mark is a placeholder for a screw. Total 8 screws were added. 4 each for diameters and diagonals

Attached the template with marks and attached securely. Then used a drill to make holes for the screws

.

The spacers were now  secured to the already sandpapered holes in the shelf using a C-Clamp (again, bought specially for this purpose). Fixing the screws was a piece of cake with the spacer already in correct place.

Fixing the spacers temporarily. This is the underside of the tray. Note the holes and spacer held below the holes.

Gypsum screws were used for maximum bite into the soft board

Nice!

Protruding screws all gone! That makes me happy enough :-)

Rest of the work was related to attaching and screwing the speakers to the other side of the arrangement and connecting the wires:.

Following images are pathetic. Please bear with me.

Nice looking connections. The other side will be plugged in to the wires from Head-Unit

Storage space reclaimed

Finished product: View 1of 2

Finished product: View 2 of 2

Last issue was shelf rattle on road. That one still remains. Maybe a task for this weekend!
That was all.



Questions/Comments are welcome.


Good night,
-Akashdeep

PS: The above actions were not performed by a professional. Feel free to try these at home :-)