Project 1: Subwoofer Box - Part II

So I have spent more countless hours on the web looking at sub-woofer boxes, researching making them, buying them and working up what I might be able to do on the install in the trunk. So there are several obstacles on the Sonata Hybrid. Most importantly they have used the rear seat area and part of the trunk for the lithium ion battery. This makes it almost impossible to build a custom box as you have to be able to get to this area to disconnect the battery or for service. Additionally, you cannot mount any equipment to this area as you most likely will puncture the battery. So plan B.

I ran across an interesting box solution for the non hybrid sonata on eBay.

While this box is for the 2012 Sonata it will not work on the Hybrid as the builder took advantage of the space between the seats (where the battery is on the Hybrid) to build out the box.

Nice size box, but won't work for the Hybird. So plan C.

The above box on eBay made me think I could build my own for the Sonata Hybrid but it would need to be much thinner and longer. I started looking at truck boxes and shallow depth sub-woofers to see if there were items that might fit. I fond a couple of ready made boxes that I thought I could start with. Ultimately I settled on a box I found at BestBuy of all places. It was very thin and would actually hold a full size 12" sub-woofer. It had a neat trick of cutting out the back of the box, replacing the area with a hard plastic cover which gave the subwoofer depth another 1/2".

The box is ok quality, we will see how it performs, but it has given me a great start on the install. I don't have to build the box. I will most likely add more sealant to the seams. So the box fits nicely in the trunk area. Taking advantage of a small area that indents in the back of the trunk. The other thing I liked about using the truck boxes was that they would be angled. This would allow me to show off my electronics more when I finished the install (see below for more).

So off to make my custom enclosure for the trunk. I have several goals for the finished install. One of the most important was that I could "easily" remove the entire install to access the battery cut off switch (behind the sub-woofer box in the above picture) and also access the spare tire (yes I bought the spare tire which is why I was not using that space for the subwoofer). I also needed space for the electronics as there are not many places you can mount amplifiers, crossovers, line converters and power systems to the hybrid trunk area without losing access to the above mentioned items.

Given all of this I decided to follow the same idea as the ebay ad and make a plywood cover that would allow me to have a "semi-custom" install look and also give me areas to mount my electronics. I wanted to show them off in the finished install anyway. Most importantly, everything would be mounted to the box and I could remove the entire unit when I needed access to the other areas of the trunk.

First step was a cardboard template. I figured this would be the only way for me to try different things to see what would work. I left the sub-woofer box in the trunk and started cutting. After several attempts I came up with the following:

This was my starting point for adding the plywood to the box to give me the semi-custom look I wanted. I also decided to use 1/2 inch plywood to keep the weight down. I didn't need heavy MDF or 3/4 inch as the sub box was self-contained. The above template should also give me plenty of room to mount and show off my electronics.

One trip to the hardware store later I stared cutting my plywood backing. After making a few cuts I could see that my original plan for the template was not going to work as I could not get the finished piece, attached to the sub woofer box into the trunk and in place. So another trip to the hardware store I had a great plywood template to start the new cuts. Here is the final design and install:

You will notice the Kenwood subwoofer. I needed to mount the subwoofer in the box to get the hole correctly sized and in the right location on the plywood cover. Two nice benefits of this install, one, the subwoofer will be flush mounted when I am complete and two there is a lot of space for my electronics. I actually like the asymmetrical install of the sub. Give's a different look. Once the electronics are in place I hope to have a nice show piece

Project 1: Subwoofer Install for 2012 Hyundai Sonata Hybrid - Part 1

I have recently acquired a 2012 Hyundai Sonata Hybrid and while I was able to get the upgrade Infinity Stereo, which doesn't sound too bad, it is sadly lacking in bass. It even comes with a a sub-woofer. However, as you can imagine the system is a typical OEM system. 7 speakers, 2 front, 2 rear, 2 dash and 1 sub. The sub is a 6" Dual voice coil open air mount. The dual voice coil was interesting as it gets both a left and right channel feed from the external amp. The amp is a 400W, 40W per channel front/rear and 30W per channel on the mid and sub (really, 30W for a Subwoofer, no wonder why its lacking in bass). Smallest thing I have ever seen so I guess I can understand the lacking bass.

The Infinity sound system also presents some interesting challenges and also some benefits that the standard, non-hybrid, does not have. One major challenge is that the external amp is fed from the head unit via digital electrical SPDIF. My initial research on finding an amp with SPDIF in was pretty much a bust. I could not find anything on the market for this. However, it really didn't matter if I wanted to intergrate the Nav system, phone and voice into my stereo since these are all separate feeds into the external amp. Oh, and how do I know all this? Because I went to Hyundai Service Website and signed up. Anyone can signup and it is a wealth of information about your Hyundai. I have to give Hyundai 4 stars for allowing anyone to have this information.

So I am going to go with speaker level inputs into the system. More to come.....

Why the Blog

I spend a lot of time researching my hobby of audio, video and home automation projects. Most of that time is spent on the web finding various resources and comparing items from multiple websites. Through this process I eventually work a design that I think functions very well give my project. I decided I should start sharing some of this. Most of my projects don't have a single source for the information I am looking for so I find a lot a long the way. Hopefully, this will be helpful for you.