So a couple months ago I finally got around to working on a project I’d had in my mind for quite some time now – custom front tweeter pods for my Hertz HT-25 tweeters. They already sounded great, but I wasn’t 100% happy with the stock dash locations due to the fact that it aimed the dash speakers (or tweeters, since I was running components) up toward the windshield. Sure, it made the sound bounce and spread towards the cabin which was by design but when it came to distinct left/right separation it wasn’t as “pinpoint accurate” as I was looking for. The solution was to figure out how to aim the tweeters towards the cabin where the sound would have a direct shot to the listeners (instead of bouncing off glass first).

Hertz HT-25’s in the OEM dash location and position.

I thought about flush mounting the tweeters into the A-pillar but that would only bring the tweeters out of the dash. They would be still be aiming towards each other, not directly towards the cabin. Also, this might be a little odd but it would bother me that I’d have dash speaker grills with no speakers underneath them. The solution I came up with was to fab up some custom tweeter pods that would elevate and aim the tweeters from the factory dash location. I already had a pair of extra dash grilles so the plan was to build custom fiberglass pods using the dash grilles as a base and the Hertz surface mounts (included with my Hertz HSK-165 6.5″ Components) to create a pod that would literally snap into place where the OEM dash grill is.

Oh, by the way: I’ve never done custom fiberglass before. Yikes!

Right… so instead of whining about it on a forum (LOL) I decided to teach myself/learn how to make my own fiberglass tweeter pods. I did the research with online tutorials, I watched countless YouTube videos and have seen 423,244,090 different ways a speaker pod is made, and then I jumped right in. To be honest I pretty much already had a good idea of the steps that were involved; a lot of the “prep/research” time was picking the right chemicals as I didn’t want to use any cheap stuff for something I knew I was going to spend some time and labor on. Here’s what the “parts” list for this project ended up looking like:

  1. 2x Hertz HT-25 tweeters (included with component system)
  2. 2x Hertz HT-25 surface mount cups (included with component system)
  3. 2x OEM Nissan Frontier dash speaker grilles ($20)
  4. Evercoat 499 Fiberglass Resin, 1-qt. ($35)
  5. Evercoat 911 Sea Glass fiberglass cloth ($16)
  6. Evercoat 425 Metal Glaze Ultra, 30-oz. ($35)
  7. Evercoat 360 Cream Hardener ($5)
  8. SEM High Build Primer, 16 oz. ($22)
  9. SEM Low Luster Clear Color Coat, 12 oz. ($16)
  10. Bottle of CA glue ($5)
  11. 3M Sanding Sponges in 60/180/220-grit ($12)
  12. 3M Pro Grade Sandpaper, 440-grit Extra-fine ($4)
  13. 3M Liquid Resin Hardener ($3)*
  14. Custom mixed SEM Color Kit paint from a painting buddy (free)
  15. Old pair of the girlfriend’s pantyhose (free, duh)
  16. Water spray bottle
  17. Some metal sanding files I already had, gloves, etc.

*only bought this because I misplaced the hardener that came with the Evercoat resin

A lot of the stuff above I already had, I mainly had to buy the resin/body filler stuff and the paints. So here we go… but first I had to make a small mod to the HT-25 tweeters. Since I knew I was going to be removing/reinstalling the tweeters numerous times during this project I went ahead and soldered in some small connectors on the tweeter leads to allow me to quickly plug and unplug them when needed:

Soldered and shrink wrapped plugs.

Next, with some guesswork (as far as positioning) I started experimenting with the angle and location of the tweeters. Using the Hertz surface mount cups, I used a simple bolt and locknut to attach them to the dash grilles. This way I could rotate the cups easily while trying to find the right angle for the tweeters. From here I temporarily stopped working on the project because I wanted to take the next few days just driving around, listening to music as I usually do, and experimenting with the direction of the tweeters.

Trying to find the right angle.
Note how I tried a few different mounting points.

A few days? Fast forward about 21 days! During the experimental period I ended up repositioning the mounting bolt 3 times, and adjusting the angle of the tweeter cups countless times, until one day I thought to myself “hey, I think that sounds pretty good” – so 3 weeks later I continued the build. The next step was to secure the mounting cups exactly at the position and angle I was happy with. This was as easy as using my hot glue gun:

Hot glue is pretty strong stuff.

I didn’t care what the glue looked like because I already knew it would be covered anyways by the fiberglass shell. To start the shell I used an old pair of pantyhose donated by the girlfriend (yes, I asked):

She doesn’t use this color anymore on airplanes.

Since my design had a concave section to it I couldn’t just stretch the hosing over the whole thing and call it a day; to get the front part to curve from the bottom of the tweeter cups, I started by sticking the hose to the outer rim of the tweeter mounting hole using CA glue:

First the tweeter ring…
…and then the perimeter.
Starting to take shape now.

…followed by stretching the hose around the base of the pod (the OEM dash grille) and also gluing the edges in place with CA glue. With this step done I had the basic shape of my tweeter pods set. Next it was time to form the solid shell of the pod, so I coated all of the panty hose (except the part where the tweeter would go) with one layer of Evercoat 499 Resin. Remember how I said I’ve never worked with resin/fiberglass before? It’s a good thing I used an old cupcake tray to mix the resin, because it took a couple tries to get the mixture of resin and hardener just right (the first batch went solid in like 30 seconds… ooops!):

So it turns out that mixing resin and hardener is a science.
First layer of resin applied.

After allowing the first layer to dry I did a second layer – but this time I laid down some fiberglass cloth to add more strength. My fiberglass cloth laying technique was super newb, but I made sure to have total coverage. After the second layer dried I put a third layer of resin on for good measure and left the pods on my workbench overnight to ensure that all of the resin was dry.

Have you done this before? Me: yeah, sure buddy.

The next day I trimmed the excess around the perimeter and took a look at my work so far. The mounting cups were secure and in position. The 3 layers of resin was enough for a strong pod. Both pods were starting to take form… however, I only did a fair job laying down the fiberglass cloth (first time, remember!). After the resin dried, the outer surfaces of the pods had a lot of bumps and stray fiberglass strands that required lots of sanding in order to get the smooth, curved shape back.

Could be better, but not that bad.

So YAY – next, here’s where the hard labor began