Covering midbass pods with cloth

     In this post I will describe steps that I have done to build cover-ups for midbass speakers in my car. Here you can see how I made midbass speaker pods in the front doors of my car. As you can see, these pods look awful although they are very useful for any car audio installation. In this post I'll try to make them less ugly not to say "good looking". :)

     Since I have some minor experience working with fiberglass, it was decided, that the covers for pods will be made out of fiberglass because you can get whatever forms you like. The technology or the way to make them can be very different. It depends on the door trim itself, your skills and desire to ruin few days of your life. Different styles can bee seen on the Internet. If you want to have interior of the car as original as it could be, it is possible to have the pods be built in the door trim so it looks like factory made. It requires a lot of skills, material and fabrics selection etc.

      I went the easy way. 

     The first step is to take food film, fold it in several layers and attach that film over the speaker pod. You should align the film on every curve and edge of the pod. The film it self can be fixated with some paper tape or something that wouldn't allow the film to move out of the correct position. This is done to protect the door trim from resin that will be used to glue fiberglass while replicating curves and form of the pod.

     Unfortunately I didn't take a picture of this process. But I think you get the idea. Be extra careful to cover all of the pod and its surroundings, because if the resin (glue) will touch the door trim, you won't be able to clean it off.

     The next step is to apply glue (resin) and fiberglass squares so you would have fiberglass form of the speaker pod. I have described in details how to handle fiberglass and resin, so I won't do it again. You can look for older posts in this blog. If you are very talanted, you might apply fiberglass with one try and get the perfect form. I wasn't, so I was prepared to apply another layer of fiberglass afterwards.

     After few hours or minutes (depending on the proportions of resin vs hardener) you can peal off the food film with fiberglass cover and cut off the excess fiberglass.

This is how it looked for me:

       

      As you can see, it is far from perfect. But with the next layers of fiberglass I made the form to look as it should be (in my opinion).

     

      After I got the form right, it was time to cover it with cloth.
      I chose Alcantara "wannabe" cloth (something like suede).
      In this step I will not go in to details as it is described in my previous posts (Tweeter podiums).
     The only difference is with the stitching where cloth made wrinkles. Covering tweeter pods I sew cloth peaces together. This time I used only glue. And it turned out better then I suspected. 

After that speaker pod cover was attached to the wooden ring fo the speaker pod with few screws.

Audio Spectrum Analyzer Step #1

     Some time ago I decided that I want audio spectrum analyzer in my car. Not for any practical reasons. Just BECAUSE I CAN. :D Well, the idea started as a rotating center console with iPhone attached to it, which should display live audio spectrum using microphone as an input signal.

     I got far with that project, as you can see in this blog (read "Motorized gadget"), but unfortunately I encountered some major problems.

     1. iPhone was a bit too big for the space in which it should rotate. When the console is being inserted in car, it has less space than it is while console is on my table. So iPhone gets stuck.

     2. Microphone is a bad way to "capture" input signal. Every microphone and every speaker has its audio range which it can sense and play. So microphone couldn't display/analyze audio spectrum precisely. And I didn't want to mess with iPhone's electronics and OS/apps.

     Although previous project is unfinished (and it seems that it will stay that way) I still wanted to integrate audio spectrum analyzer in my car.

     You can buy already pre-assambled kits, but hey - building it on my own sounds more exciting and interesting.

So here it goes.

     Since I'm an IT specialist with some background in programming I'm used to develop programs building one small module, then test it. Then build next module and integrate it with previous. And again - test it. So this project will be held similar.

     I started by creating one LED bar graph which would work as an audio spectrum analyzer.

     Started by reading some tutorials, gathering information and buying electronic stuff.

     The most fundamental part of this schematics is dot/bar display driver integrated circuit (IC) LM3914.

     There are three IC types in the LM39 group. Although LM3916 would be more suitable for this project, as it is working better with audio signals, I bought LM3914.

Schematics are pretty much the same for all LM39 IC, so I used the following schematics:

Scheme taken from: CircuitsOnline.net

The parts needed for this are:
IC = LM3914 or LM3915 or LM3916
R1 = 1k Ohm
LED = led bar graph (I used Kingbright. You can use seperate LEDs, but then resistor for each LED must be applied)
C1 = 2.2uF 50V (electrolytic)

In this scheme on the pin5 audio signal must be applied.
My input voltage ~9 V.

This is how it looks on breadboard:

This is the video:

PROBLEM:

     1. Input signal from computer is ok. Input signal taken from phone is too weak. Signal amplification is needed and also possibility to adjust signal gain with potentiometer.

NEXT STEPS:

     1. Signal amplification with Low Voltage Audio Power Amplifier IC (LM386) and potentiometer for signal gain adjustment.

Covering tweeter pods with cloth

    In 2010 I started to create tweeter pods for my car. I really liked that black cloth called Alcantara which usually comes in Lamborghini or Audi RS series. So I thought - why couldn't I use it for my little project. When I saw the actual price for genuine Alcantara cloth I started to look for alternatives. Alcantara cloth costs about 160 $ per meter. :) Luckily I found alternative - cloth that is something similar to suede, so it looks almost as Alcantara. And it costs only 20$ per meter.

   I won't describe the steps needed to create customized tweeter pods from fiberglass since I already described it in my previous posts:
Tweeter pods: Step #1
Tweeter pods: Step #2
Tweeter pods: Step #3

   So in this post I'll write only about covering tweeter pods with cloth.

   The actual steps for applying this cloth is almost the same as in the given links above. The only thing that is different - I tried my luck in sewing.

   If you read my previous post you would already know that I'll be using two peaces of cloth which will be joined by sewing them right next to the tweeter. This is necessary because by applying only one peace there would be a lot of wrinkles.

   Since I didn't have sewing machine I tried my luck sewing by hand. I'll try to illustrate:

   In the picture above you can see how the sewing was done. The part that is in the picture vertically will be as the lower side so it won't be seen. The stitches won't be seen as well.

   It's important to put both cloth on the fiberglass trim (tweeter pod) and see that everything is ok. Than sew it together and only then glue it to the fiberglass trim. 

   Unfortunately I don't have pictures from the actual process. 

   I can only suggest to be very careful because it is very hard to sew and cut both peaces of cloth precisely. There will be wrinkles at first attempt. As you will see in the following pictures, I had wrinkles on the cloth also. Some day I'll reapply the fabric to get rid of the failures. 

   This time these tweeter pods didn't fit perfectly so I had to glue the original clips to the fiberglass trim.

Now the hardest thing was to understand - where to glue these clips. 

Clips look like this:

   In the following picture you can see the actual car front pillar and holes which are meant for the clips. 

   The next picture shows the back side of fiberglass pillar trim. 

    So how to find - where to glue the clips on the fiberglass trim?

   I used plasticine (molding clay). I put a lump of it on the back side of the trim approximately against the holes in the pillar.

   Then pressed the trim to the pillar in the position as it should be staying. Then took the trim of the pillar. In the best case, plasticine lump should stay on the fiberglass trim with a shape of the hole for clip. 

   I have illustrated it in the picture:

   The blue stuff in the picture is plasticine and the gray rectangle is shape that formed after pressing trim to the pillar. The black lines are drawn with marker so that when I remove the plasticine, I can see the place, where clip should be.

So that's it.